•Stable β-carotene nanoemulsion was prepared by OSA modified starch.•The addition of calcium promoted digestion of lipid.•Calcium suppressed bioaccessibility of β-carotene in OSA nanoemulsions.•Calcium decreased the lipolytic products and bile salts in micelle phase.•The mechanism of calcium impact on the bioaccessibility of β-carotene was proposed.The aim of this study was to investigate the influence of calcium on and its mechanism in the digestion and bioaccessibility of β-carotene in nanoemulsions stabilized by modified starch, using an in vitro digestion model. Higher concentrations of calcium ions resulted in more irregular aggregates, a greater rate and extent of lipid digestion but a lower bioaccessibility of β-carotene. The major components of the mixed micelles were analyzed to explain the relationship between lipolysis and bioaccessibility. The lipolytic products and bile salts in the mixed micelles decreased with an increase in the calcium concentration because of the formation of calcium soaps and calcium–bile acid complexes. A correlation analysis showed that the bioaccessibility of β-carotene had a highly statistically significant positive linear correlation with both lipolytic products (r = 0.943) and bile salts (r = 0.896) in mixed micelles with calcium. These results illustrated that the lipolytic products and the bile salts in the micelles were the critical factors contributing to the bioaccessibility of β-carotene. This study could help in an understanding of the function of calcium in the digestion of delivery systems and the bioaccessibility of encapsulated lipophilic functional ingredients.Download high-res image (183KB)Download full-size image

•KO loaded CSNPs were prepared using emulsion-electrostatic interaction method.•KO loaded CSNPs were irregular in shape with average diameter of <130 nm.•CSNPs successfully entrap KO as evident by FTIR.•KO loaded CSNPs prevented formation of hydroperoxides at elevated temperature.Encapsulation of krill oil (KO), a rich source of eicosapentanoic (EPA) and docosahexanoic acid (DHA) was carried out in chitosan-TPP (tripolyphosphate) nanoparticles using a newly developed two-step process (i.e, formation of emulsion and later electrostatic interaction of chitosan with TPP). The encapsulation of KO in chitosan nanoparticles (CSNPs) was confirmed by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA) techniques. Loading capacity (LC) and encapsulation efficiency (EE) of the obtained particles were about 9–25 and 33–59% respectively, when the initial KO content was in the ratio of 0.25–1.25 g/g of Chitosan. Bulk KO showed less protection to oxidation and showed more formation of hydroperoxides during first week as noted by FTIR. However, KO loaded CSNPs showed better prevention of KO towards oxidation with less hydroperoxide formation even after two weeks of storage at elevated temperature (45 °C). The obtained KO-loaded CSNPs were irregular in shape with an average particle diameter of <130 nm as observed by SEM. The results obtained confirmed the suitability of the emulsion and later electrostatic interaction of CS with TPP for the formation of KO loaded CSNPs with greater EE & LC, which will enhance their usage in the Food and Pharmaceutical industries.Download high-res image (200KB)Download full-size image

•TGase's effect on mechanical properties was related to glycerol contents.•Cross-linking was inhibited by glycerol, resulting in increase of water solubility.•Both glycerol and TGase affected triple-helix formation and thus film strength.•TGase increased single α-helix but decreased disordered coil of gelatin.•TGase-modification enhanced the smoothness and compactness of films.Gelatin films plasticized with different glycerol contents (0–40%) were cross-linked using transglutaminase (TGase). Unmodified films were prepared as controls. Cross-linking degree of the films decreased linearly with increasing glycerol content, resulting in an increase in water solubility. Glycerol increased the mobility and free volume of the gelatin film matrix as observed by differential scanning calorimetry, thus increasing the moisture content and thickness. Tensile strength and Young's modulus had a negative linear correlation with glycerol content, with no significant differences between TGase-modified and unmodified films (p > 0.05). However, TGase-modified films showed a 294% and 187% relative increase in elongation at break and toughness, respectively, in comparison with controls at 30% glycerol content (p < 0.05). X-ray diffraction and circular dichroism spectroscopy both showed a linear decrease in triple-helix content as glycerol content increased, and TGase-modified films had lower triple-helix contents. Also, the second derivative of FTIR spectra showed that TGase-modified films had increased single α-helix structures, but decreased disordered coil structures. In addition, SEM results indicated that TGase-modified films had more smooth and compact microstructures, especially at high glycerol contents (30–40%).Download high-res image (168KB)Download full-size image

•OSA starch type and eugenol both influence the characteristics of FSO emulsions.•PG1 stabilized FSO-EUG emulsions showed better physical and oxidative stability.•Eugenol served as antioxidant.•PG1 formed a thick protective layer at interface as compared to PG2.Flax seed oil (FSO) is rich in α-linolenic acid (ALA) and its application as a functional ingredient in oil-in-water systems is limited due to its high vulnerability towards oxidation. To overcome this, flax seed oil nanoemulsions were formulated using eugenol (EUG) as a natural antioxidant and two modified starches (Purity Gum Ultra and Purity Gum 2000) as emulsifier. The effect of eugenol addition and emulsifier type on the size, charge, rheological properties and oxidative stability of nanoemulsions stored under different temperatures (4, 25 and 40 °C) for 4 weeks was investigated. Nanoemulsions containing eugenol, stabilized by Purity Gum Ultra, showed better physical and oxidative stability during storage as compared to Purity Gum 2000 stabilized emulsions. Results revealed higher % retention of ALA (66.34%) and EUG (63.20%) in Purity Gum Ultra stabilized emulsions containing FSO + EUG stored for 4 weeks at 40 °C as compared to Purity Gum 2000 stabilized emulsions containing FSO + EUG. This was attributed to the role of eugenol as antioxidant as well as the formation of a thick protective layer at interface by Purity Gum Ultra due to its higher molecular weight and density.Download high-res image (355KB)Download full-size image

•β-Carotene and α-tocopherol were co-encapsulated using LCT and MCT as carrier oils.•Behavior of lipophilic antioxidants were different in emulsions and bulk oils.•Incorporation of eugenol improved oxidative stability of emulsions during storage.•Carrier oils and emulsifiers both influenced on oxidative stability of emulsions.•Purity Gum Ultra provided higher stability to the encapsulated bioactives.β-Carotene (precursor of vitamin A) and α-tocopherol (VE) are essential fat soluble vitamins (FSV) required for better body functioning and deficiencies of these vitamins are linked to many chronic diseases. Encapsulation of FSV into nanoemulsion-based delivery systems improves their aqueous solubility, oxidative stability and bioavailability. In this study, β-carotene (BC) and VE were co-encapsulated using flax seed oil (FSO) or medium chain triglycerides (MCT) as carrier oils and octenyl succinic anhydride modified starch (Purity Gum Ultra, PGU) or Tween-80 (TW) as emulsifiers. Nanoemulsions and bulk carrier oils containing bioactives were stored for 4 weeks to assess the effect of storage temperature on physicochemical properties. Oxidation behavior of bioactives was different in emulsions compared to bulk oil systems. The degradation of FSV was higher at elevated temperature, which was more profound for BC. VE worked as antioxidant for the protection of BC in MCT-based emulsions but it did not protect BC degradation in FSO-based emulsions. However, incorporation of eugenol (EU) improved the oxidative stability as well as retention of FSV in all emulsions. Nanoemulsions containing FSV and EU stabilized by PGU showed overall higher retention of BC (≈42%) and VE (≈90%) after 4 weeks of storage at 40 °C as compared to TW. The higher stability of PGU was due to its ability to form a thicker protective layer around oil droplets. This research provides useful information regarding the simultaneous encapsulation of lipophilic bioactives for the development of functional foods and beverages.Download high-res image (229KB)Download full-size image

•The major functions of Microcrystalline cellulose in food products as organoleptic enhancer are summarized.•The food industry is the second biggest user of MCC after the pharmaceutical sector.•MCC has nutraceutical functions and impact positively on the gastrointestinal physiology as well weight management.•MCC is a good candidate for emulsion stabilization and fat replacer in many food systems.•The physicochemical properties and functions of MCC are influenced by the its source and preparation methods.Microcrystalline cellulose (MCC) is among the most commonly used cellulose derivatives in the food industry. In order assess the recent advances of MCC in food product development and its associated nutraceutical implications, google scholar and database of journals subscribed by Jiangnan university, China were used to source literature. Recently published research articles that reported physicochemical properties of MCC for food application or potential application in food and nutraceutical functions were reviewed and major findings outlined. The selected literature reviewed demonstrated that the material has been extensively explored as a functional ingredient in food including meat products, emulsions, beverages, dairy products, bakery, confectionary and filling. The carbohydrate polymer also has many promising applications in functional and nutraceutical food industries. Though widely used as control for many dietary fiber investigations, MCC has been shown to provide positive effects on gastrointestinal physiology, and hypolipidemic effects, influencing the expression of enzymes involved in lipid metabolism. These techno-functional and nutraceutical properties of MCC are influenced by the physicochemical of the material, which are defined by the raw material source and processing conditions. Apart from these functional properties, this review also highlighted limitations and gaps regarding the application of material in food and nutritional realms. Functional, Nutritional and health claims of MCC.Download high-res image (124KB)Download full-size image

•FSO, BC and EU were co-encapsulated using two different OSA-MS as wall material.•Microcapsules of OSA-MS-1 showed better physicochemical properties during storage.•Incorporation of EU improved the oxidative stability.•Maximum retention of BC (71%), EU (84%) and ALA (92%) were obtained during storage.•OSA-MS-1 was found better over OSA-MS-2 due to its lower Mw and density.Food industry is concentrating on development of novel functional foods fortified/enriched with lipophilic bioactives to improve health and well-being of consumers. β-carotene (BC) and eugenol (EU) co-encapsulated flax seed oil (FSO) emulsions stabilized by octenyl succinic anhydride modified starches (OSA-MS) were spray dried to powders after the emulsification process. Microcapsules showed good dissolution behavior, high (≈90%) microencapsulation efficiency and semi-spherical morphology observed by scanning electron microscopy. A 28 days storage test at 40 °C was carried out to evaluate the effect on physicochemical properties of microcapsules. Microcapsules encapsulated by lower Mw OSA-MS-1 presented higher oxidative stability, lower moisture contents and water activity during storage compared to high Mw OSA-MS-2. Incorporation of EU played its antioxidant role and further improved the oxidative stability as well as retention of core materials. Microcapsules of OSA-MS-1 containing FSO + BC + EU exhibited the maximum retention of BC (71%), EU (84%) and α-linolenic acid (92%). This study indicated a positive role of EU as antioxidant and low Mw OSA-starch as wall material for the encapsulation of lipophilic bioactives that could be used for the development of functional foods and beverages.Download high-res image (280KB)Download full-size image

•TP/TP-CSNs affected the properties of gelatin solutions and films in different ways.•TP did not enhance the gel strength but led to an increase in film tensile strength.•TP-CSNs enhanced the film tensile strength but decreased the gel strength.•Influences of TP/TP-CSNs on solutions and films depended on the Bloom values.Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and TP-loaded chitosan nanoparticles (TP-CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Gelatins with higher Bloom values had more α- and β-chains as well as more triple-helix structures. Gelatin film-forming solutions and films with higher Bloom values showed superior physical and mechanical properties. TP significantly decreased the surface tension, but increased the viscosity of film-forming solutions. TP-CSNs showed relatively insignificant effects on the surface tension and viscosity of solutions. Incorporation of TP resulted in a dramatic increase in tensile strength of films (P < 0.05), whereas the gel strength of gels had negligible increases (P > 0.05) in value. The addition of TP-CSNs led to significant enhancements in tensile strength and stiffness of films, especially for the 100 Bloom value sample (P < 0.05). In comparison, the gel strength of gels was significantly decreased (P < 0.05) for all Bloom values. Both TP and TP-CSNs enhanced the extensibility and toughness of the 225 Bloom value gelatin film due to the presence of high triple-helix content. SEM results showed that the presence of TP led to more compact microstructures of gelatin gels and films. In addition, the TP-CSNs were uniformly distributed within the three-dimensional network matrix of gels and within the cross-section matrix of films, without obvious aggregation.Download high-res image (215KB)Download full-size image

•Gelatin films containing TP-loaded CSNs with different EEs were prepared.•CSNs enhanced the compactness of films and restricted gelatin chain relaxation.•TP release in 50% ethanol fatty food simulant was much faster than 95% ethanol.•TP release was controlled by EE (0% > 51.3% > 83.3% > 96.9%) at both food simulants.•Films were intact when exposed to 95% ethanol but not for 50% ethanol.Chitosan nanoparticles with different encapsulation efficiencies were incorporated to obtain gelatin films with controlled-release properties. Nanoparticles tended to aggregate as encapsulation efficiency increased, due to the increase in surface tension of film-forming solutions. The addition of nanoparticles increased the compactness and isotherm hysteresis of films, whereas decreased the moisture diffusion. Tea polyphenol released faster and greater from films in 50% ethanol (4 °C) than in 95% ethanol (25 °C) fatty food stimulant due to the swelling by water. However, controlled-release showed in both simulants, where free tea polyphenol had the largest release followed by 51.3%, 83.3% and 96.9% encapsulation efficiency. The diffusion coefficient in 50% ethanol was 2 orders of magnitude higher than that 95% ethanol (10−13 and 10−11 cm2/s, respectively). Films maintained their structures in 95% ethanol after 240 h but not in 50% ethanol. These results might open up new designs in long-term protection for fatty foods.Download high-res image (215KB)Download full-size image

•Food grade clove oil (CO) nanoemulsion of 150 nm size with purity gum ultra (PGU) was prepared.•PGU nanoemulsion showed strong antimicrobial activity against Gram positive bacterial strains.•Bactericidal mechanism was not associated with the charge of surfactant.Clove oil (CO) anionic nanoemulsions were prepared with varying ratios of CO to canola oil (CA), emulsified and stabilized with purity gum ultra (PGU), a newly developed succinylated waxy maize starch. Interfacial tension measurements showed that CO acted as a co-surfactant and there was a gradual decrease in interfacial tension which favored the formation of small droplet sizes on homogenization until a critical limit (5:5% v/v CO:CA) was reached. Antimicrobial activity of the negatively charged CO nanoemulsion was determined against Gram positive GPB (Listeria monocytogenes and Staphylococcus aureus) and Gram negative GNB (Escherichia coli) bacterial strains using minimum inhibitory concentration (MIC) and a time kill dynamic method. Negatively charged PGU emulsified CO nanoemulsion showed prolonged antibacterial activities against Gram positive bacterial strains. We concluded that negatively charged CO nanoemulsion droplets self-assemble with GPB cell membrane, and facilitated interaction with cellular components of bacteria. Moreover, no electrostatic interaction existed between negatively charged droplets and the GPB membrane.

•Oxidative stability of EGCG incorporated into ICs and CSNs were both investigated.•EGCG-ICs and related CSNs were physically unstable at higher pH and temperature.•Antioxidant activities of CSNs decreased more compared to EGCG-ICs and free EGCG.•Extreme entrapment of EGCG in aggregated CSNs inhibited the antioxidant activities.•Nanostructure of CSNs was lost but the activity of encapsulated EGCG may remain.The oxidative stability of (−)-epigallocatechin-3-gallate (EGCG) incorporated as inclusion complexes (ICs) in sulfobutylether-β-cyclodextrin sodium (SBE-β-CD) and then ionotropically crosslinked with chitosan hydrochloride (CSH) into nanoparticles were investigated. EGCG-loaded CSH-SBE-β-CD nanoparticles (CSNs) were physically unstable at higher pH and temperature. The particle size of CSNs was unchanged in the pH range of 3–5, but the microenvironment of EGCG-IC appeared to be intact until the pH increased to 6.5 by fluorescence spectroscopy. The physical structure of EGCG-ICs was also affected during storage in addition to CSNs, which was further affected as temperature increased from 25 to 55 °C. The decrease in antioxidant activities of EGCG-ICs and free EGCG with increasing pH, storage time and temperature were modest compared to the prominent decreases in antioxidant activities of EGCG-loaded CSNs. The extreme entrapment of EGCG-ICs and/or free EGCG in the aggregated CSNs restricted the release of EGCG, thus inhibiting the antioxidant activities.Possible changes of EGCG-loaded CSNs and EGCG-ICs after altering the pH value or temperature of nanoparticle suspensions.

In order to improve the chemical stability and antioxidant activity of (−)-epigallocatechin gallate (EGCG) in the gastrointestinal tract, niosomes composed of Tween-60 and cholesterol were developed to encapsulate EGCG in this investigation. EGCG loaded niosomes with encapsulation efficiency around 76% exhibited a small Z-average diameter about 60 nm. Compared to free EGCG, the EGCG remaining in dialysis tubes was significantly improved for niosomes at pH 2 and 7.4. Meanwhile, the residual EGCG for niosomes increased from 3% to 49% after 2 h incubation in simulated intestinal fluid (SIF). Pancreatin was found to impact the stability of niosomes in SIF mainly. Furthermore, the results from ferric reducing antioxidant power and cellular antioxidant activity tests indicated that EGCG loaded niosomes exhibited stronger antioxidant ability than free EGCG during intestinal digestion. Thus, we can infer that niosomal encapsulation might be a promising approach to improve the oral bioavailability of EGCG in the body.Keywords: (−)-epigallocatechin gallate (EGCG); cellular antioxidant activity (CAA); digestive stability; niosomes;

The objective of this study was to investigate the effects of supplementation of tea polyphenols (TP) in dry dog food on the palatability of dry dog food, serum oxidative stress biomarkers, and fecal pathogenic bacteria in adult dogs. Four different concentrations of TP (0.25%, 0.50%, 0.75% and 1.0%) were added to the basal dog food before or after extrusion. The TP retention rate before extrusion was more than 80% and significantly higher than that after extrusion (<60%). First-choice ratios of palatability were 72%, 68% and 70% for TP concentrations of 0.50%, 0.75% and 1.0%, respectively, resulting in significant increases compared to the palatability for the control of 28%, 32% and 30%. The intake ratio (one-pan test) and consumption ratio (two-pan test) of the 0.50% TP experimental dog food were 73% and 74%, respectively, significantly higher than the other three TP supplemented foods. The serum total antioxidant capacity, superoxide dismutase activities and glutathione peroxidase activities determined in the dogs' food of 0.50% TP group increased by 19.30%, 7.72% and 4.64%, as compared to the control group after 12 weeks, respectively. The serum malondialdehyde concentration was reduced by 15.05%. The fecal aerobic plate count and Coliform bacteria MPN (most probable number) of 0.50% TP group decreased by 2logs and 1log, respectively, compared with the control group after 12 weeks. The findings of this study have demonstrated that a concentration of 0.50% TP added to the dry dog food can significantly increase the palatability, antioxidant capacity and antibacterial activity of dry dog food in the canine model.

In this study, the effect of gallic acid on mechanical and water barrier properties of zein-oleic acid 0–4 % composite films was investigated. Molecular weight distribution analysis was carried out to confirm gallic acid induced cross linking through change in molecular weight in fraction containing zein proteins. Results revealed that gallic acid treatment increased tensile strength from 17.9 MPa to 26.0 MPa, decreased water vapour permeability from 0.60 (g mm m−2 h−1 kPa−1) to 0.41 (g mm m−2 h−1 kPa−1), increased solubility from 6.3 % to 10.2 % and marginally increased elongation at break from 3.7 % to 4.2 % in zein films only. However, gallic acid treatment in zein-oleic composite films did not significantly influence mechanical and water barrier properties and in most instances irrespective of oleic acid concentration, the properties were negatively affected. Results from scanning electron microscopy showed that both gallic acid treated and untreated zein films and composite films containing 3 % oleic acid had a compact and homogeneous structure while those containing 4 % oleic acid had inhomogeneous structure. The findings have demonstrated that gallic acid treatment can significantly improve mechanical and water barrier properties especially in zein films only as opposed to when used in composite films using zein and oleic acid.

This review introduces recent changes regarding measurement of preferences brought about by the discovery of false preferences that occur with paired preference testing. Testing protocols are examined critically. False preferences result from a response bias elicited by factors distinct from sensory properties of products being tested that can distort results. Statistical approaches to circumventing this problem are examined. Alternative methods are being developed to eliminate false preferences based on understanding information processing in the brain. This has led to development of disruptive experimental preference testing protocols based on hypothesized use of processing subroutines in the brain to protect the central processing system from overload. These disruptive protocols suppress response bias. Paired preference testing is designed to predict consumer behavior. A paucity of studies addressing whether they do is put into perspective.

•Nanoencapsulation of Vitamin E using OSA modified starches.•Characterization of OSA modified starches as good emulsifiers and wall materials.•The high DS, low Mw and low interfacial tension enhanced emulsification properties.•The OP and WVP enhanced the film forming properties of OSA modified starches.•50% retention was obtained in MS-A and MS-B after 60 days storage at 4–35 °C.Spray drying technique was used to fabricate Vitamin E loaded nanocapsules using Octenyl Succinic Anhydride (OSA) modified starches as emulsifiers and wall materials. Several physicochemical properties of modified starches that are expected to influence emulsification capacity, retention and storage stability of Vitamin E in nanocapsules were investigated. High Degree of Substitution (DS), low Molecular Weight (Mw) and low interfacial tension improved emulsification properties while Oxygen Permeability (OP) and Water Vapor Permeability (WVP) affected the film forming properties. The degradation profile of Vitamin E fitted well with the Weibull model. Nanocapsules from OSA modified starches MS-A and MS-B retained around 50% of Vitamin E after a period of 60 days at 4–35 °C. Reduced retention and short half-life (35 days) in nanocapsules fabricated using MS-C at 35 °C were attributed to autoxidation reaction occurred due to poor film forming capacity. These results indicated that low molecular weights OSA modified starches were effective at forming stable Vitamin E nanocapsules that could be used in drug and beverage applications.

•RBIDF-2.0 showed the highest lipase adsorption with greater specific surface area.•RBIDF physicochemical properties were dependent on the level of acid treatment.•Adsorbed and unabsorbed PL activity was independent of its quantity.•Moderate modification of RBIDF had the greatest inhibitory effect on PL.•PL and RBIDF interaction was hydrophobic, electrostatic and is spontaneous and exothermic.A cellulosic rice bran insoluble dietary fibre (RBIDF) with different structures and physicochemical properties is shown to inhibit the activity of pancreatic lipase (PL) at different levels. The adsorption rate and saturation level to PL were greatest for RBIDF-2.0 (modified with 2.0% H2SO4 + 1.25% KOH), which had the highest specific surface area and oil holding capacity. The conformational deformation of unbound PL in the supernatant of PL-RBIDF confirmed by circular dichroism (CD) suggested that not only bound but also unbound PL activities were altered. Free energy calculations using data from fluorescence spectroscopy revealed that binding of PL to fibre depends primarily on electrostatic interactions, and the binding process is spontaneous and exothermic. This study indicates that dietary intake of cellulosic fractions of rice bran may be useful in reducing the bioavailability of dietary fat by altering the conformation and activity of PL that might be useful to control obesity.

Recently there has been an increased interest towards the biological activities of essential oils (EOs). However, EOs are unstable and susceptible to degradation when exposed to environmental stresses like oxygen, temperature, and light. Therefore, attempts have been made to preserve them through encapsulation in various colloidal systems such as microcapsules, nanospheres, nanoemulsions, liposomes, and molecular inclusion complexes. This review focuses on various techniques used for the encapsulation of EOs, potential applications in food, and their behaviours/trends after encapsulation. The encapsulation efficiency, particle size, and physical stability of EOs encapsulated in colloidal systems is dependent on the kind of technique and the type and concentration/ratio of emulsifier/wall material used. Moreover, the benefits associated after encapsulation, namely bioavailability, controlled release, and protection of EOs against environmental stresses are discussed. The applications of encapsulated EOs are also summarized in this review. Encapsulated EOs are promising agents that can be used to increase the anti-microbial, antifungal, antiviral, and pesticidal activities of EOs in real food systems, to study their action mechanism, and to provide nonlethal therapeutic agents to treat several diseases.

Influences of solution pH on the properties of pullulan–chitosan blended (Pul–Chi) films and the rheological properties of film-forming solutions were investigated. The extended conformation of chitosan in a pH 4.0 solution increased the intermolecular interactions with pullulan compared to the more compact coiled form, resulting in higher tensile strength and barrier properties of the Pul–Chi film and higher viscosity of the film-forming solution. The water solubility (Ws) of the Pul–Chi film decreased to 35% above pH 4.0. Water content, thickness and percentage elongation (E%) all decreased with decreasing pH. Fourier Transform infrared spectroscopy (FTIR) analysis suggested that the formation of –NH3+ and intermolecular hydrogen bonds increased the amide II bending mode. At pH values below 4.0, shielding of the protonated amine groups caused a decrease in bending frequency. An X-ray diffraction (XRD) peak for crystallite chitosan was not observed in Pul–Chi films. The properties of Pul–Chi films depended on the conformation changes of chitosan molecules and can be controlled by pH.

The structural modifications of insoluble rice bran fiber (IRBF) by sequential regimes of sulphuric acid (H2SO4) and their effects on the physicochemical attributes were studied. The increment of H2SO4 concentration resulted in decreased water holding capacity that ultimately enhanced the oil binding capacity due to the partial removal of starch, protein and hemicelluloses. The starch and hemicelluloses were hydrolyzed exponentially by sequential increments of H2SO4 while protein was mainly dissolved by KOH for all samples. Moreover, higher H2SO4 concentration improved the porosity and crystallinity that led to higher thermal stability of the fiber as evident from XRD and TGA analysis. Furthermore, decreased monosaccharide linkages and increases of porosity with H2SO4 regimes were confirmed by FT-IR and SEM. The change in composition and microstructure of insoluble rice bran fiber (IRBF) induced significant physicochemical changes that might be suitable for their application in the food industry as an anti-diabetic and cholesterol lowering functional ingredient.

Beta-lactoglobulin (BLG)–catechin conjugates were prepared by a free radical method and investigated with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), electrospray ionization–mass spectrometry (ESI-MS), and far-UV circular dichroism (CD). Covalent binding between BLG and catechin were confirmed with SDS-PAGE and ESI-MS. About 93% of beta-lactoglobulin was conjugated with catechin or catecin fragments according to the gel intensity analysis software. Far-UV CD results showed that the content of β-sheet decreased with a corresponding increase in unordered structures after grafting. Both nanoemulsions with mean particle size between 160 and 170 nm were prepared. Both the rate of particle growth and the total beta-carotene (BC) loss at 50 °C were significantly greater than at 4 and 25 °C. The retention rates of BC in nanoemulsions were 27.8% and 48.6% for BLG and BLG–catechin conjugates, respectively, after 30 days of storage at 50 °C. The BC retention encapsulated in nanoemulsion was significantly improved using BLG–catechin conjugates, compared with BLG alone. The increase of BC retention in nanoemulsions encapsulated with BLG–catechin conjugates was due to the significant improvement of antioxidative properties (reducing power, free radical scavenging activity, and hydroxyl radical scavenging activity) of BLG after covalent binding with catechin. The results indicated that the proteins modified with polyphenols can be widely used in a labile bioactive compounds encapsulation delivery system.

Gelatin films incorporated with chitosan nanoparticles in various free/encapsulated tea polyphenol (TP) ratios were prepared in order to investigate the influence of different ratios on the physicochemical and antioxidant properties of films. The TP-containing nanoparticles were prepared by cross-linking chitosan hydrochloride (CSH) with sulfobutyl ether-β-cyclodextrin sodium (SBE-β-CD) at three different encapsulation efficiencies (EE; ∼50%, ∼80%, and ∼100%) of TP. The stability of TP-loaded nanoparticles was maintained during the film drying process from the analysis of free TP content in the redissolved film solutions. Composite films showed no significant difference in visual aspects, while the light transmittance (250–550 nm) was decreased with incorporation of TP. Nanoparticles appeared to be homogeneously dispersed within the film matrix by microstructure analysis (SEM and AFM). TP-loaded films had ferric reducing and DPPH radical scavenging power that corresponded to the EEs. Sunflower oil packaged in bags made of gelatin films embedded with nanoparticles of 80% EE showed the best oxidation inhibitory effect, followed by 100% EE, 50% EE, and free TP, over 6 weeks of storage. However, when the gelatin film was placed over the headspace and was not in contact with the oil, the free TP showed the best effect. The results indicate that sustained release of TP in the contacting surface can ensure the protective effects, which vary with free/encapsulated mass ratios, thus improving antioxidant activities instead of increasing the dosage.

Four different WPI saccharide conjugates were successfully prepared to test whether glycation could inhibit WPI precipitation induced by trichloroacetic acid (TCA). Conjugates molecular weights after glycation were analyzed with SDS-PAGE. No significant secondary structure change due to glycation was detected. Glycation decreased the apparent denaturation enthalpy (ΔH) and increased denaturation temperature (Td). The TCA-induced WPI precipitation profiles were shown to be U-shaped. The attachment of maltodextrin and dextran increases WPI solubility against TCA-induced precipitation. However, similar effects were not observed when WPI was glycated with monosaccharide (mannose) and disaccharide (maltose), even though the degrees of glycation were significantly higher, compared to WPI-maltodextrin or WPI-dextran conjugates. The effects against precipitation depended on the molecular weight of saccharides, while the effects of the degrees of glycation were not pronounced. Steric hindrance may be the reason to inhibit TCA-induced protein precipitation after glycation. The information of this study provided may extend our knowledge about TCA-induced protein precipitation mechanism.

•Emulsion phase inversion method was used to fabricate Vitamin E nanoemulsions.•Nanoemulsions were physically stable to heat, pH, salt and long term storage.•There was significant Vitamin E degradation to heat shock and long-term storage.•The Vitamin E retention was increased when nanoemulsions were stored in the dark.•Physical tests may not be enough to assess stability of Vitamin E delivery systems.Physicochemical stability and thermal degradation of vitamin E (VE) in nanoemulsions fabricated by low energy emulsification method known as Emulsion Phase Inversion: catastrophic phase inversion (EPI) with different carrier oils (short-chain, medium-chain and long-chain triglycerides) and Tween 80 were investigated. Although nanoemulsions made with VE and the 3 carrier oils showed physical stability to heat shock (30–90 °C, 30 min), ionic strength (0–500 mM), pH (2.0–8.5) and long term storage (60 days, under light and darkness, 4, 25 and 40 °C), there was significant VE degradation in heat processed and long-term storage samples. The VE degradation in long-term storage fitted well with Weibull model, while heat degradation followed the first order kinetics, with medium-chain triglyceride (MCT) based nanoemulsions held at 90 °C showing the greatest degradation rate (k = 0.1526 × 10−3 min−1) and lowest half-life of 4.54 min. The lack of droplets aggregation or coalescence was associated with absence of electrostatic screening and ion-binding effects. The nanoemulsions stored at 4 °C were more stable than those at 40 °C. The short-chain triglyceride (SCT) based nanoemulsions did not physically withstand the high temperatures (>25 °C) while long-chain triglyceride (LCT) showed good retention in all studied conditions. The VE retention was increased when nanoemulsions were stored in the dark. This study might be helpful to food and pharmaceutical industries in choosing better processing and storage conditions of VE delivery systems.

Flow cytometry exactly discriminated three subpopulations, i.e., viable, damage and sublethal cells of L. monocytogenes, S. aureus and E. coli when treated at their MIC values. Purity gum ultra (PGU) a large molecule surfactant-based CO nanoemulsion exerted significant impact on cellular subpopulations of L. monocytogenes and S. aureus, with more membrane-damaged cells. On the other hand, when compared with bulk CO the results showed minimum membrane damage and more viable cells, whereas PGU CO nanoemulsion showed minimum effect on cellular subpopulation and represented more viable than damaged cells in case of E. coli. Similarly, Tween 80 a small molecule surfactant-based CO nanoemulsion showed limited overall activity against three tested microorganisms with more viable cells. We conclude that it was due to sequestration of CO constituents in interfaces, less availability in aqueous phase and finally inhibit bactericidal activity. Moreover, both CO and CO nanoemulsions showed membrane damage as primary inactivation mechanism of tested bacterial cells.

•Chitosan–tripolyphosphate nanoparticles were prepared through ionic-crosslinking.•Control of particle size by selecting appropriate conditions.•Influence of initial pH and salinity of chitosan solution on nanoparticles formation.•Separation of aggregates from nanoparticles by centrifugation.•Ultra-sonication reduced particle size but caused fragmentation on their structure.Chitosan–tripolyphosphate nanoparticles have been extensively studied during the last decade because of their numerous applications. In this study, we describe conditions to optimize chitosan nanoparticles as potential nano-fillers in edible films. The ionic cross-linking between the cationic amino groups on the chitosan (CS) chain and the anionic phosphate groups of sodium tripolyphosphate (TPP) was verified via FTIR. Particle size, polydispersity index (PDI) and surface ζ-potential were controlled by chitosan's Mw and concentration, CS:TPP mass ratio, and external conditions such as pH and salinity of the initial chitosan solution. Post-processing methods such as centrifugation and ultra-sonication were used to further control particle size. We show that particle size can be controlled by selecting appropriate conditions. Particles with sizes below 120 nm were produced at different CS:TPP mass ratios depending on the CS concentration. Dilute NaCl was the optimal solution ionic composition that decreased the size by 25% and also resulted in a narrow particle size distribution. We show using UV–vis spectrophotometry that particles of different size, separated by centrifugation had different phosphorus content. Ultra-sonication can be used to reduce the size by 50% but long time caused fragmentation of the nanoparticles. Transmission electron microscopy (TEM) revealed the differences in the morphology of chitosan nanoparticles under various fabrication conditions.

•The exogenous fibers (HP and SP) were added to the reconstituted tobacco sheet (RTS).•The effects of HP and SP on the generation of carbonyl compounds were studied.•HP-RTS and SP-RTS generated higher amounts of carbonyl compounds.•Xylose was the relatively prevalent monosaccharide for HP and SP.•Xylose increased the generation of carbonyl compounds.In recent years, many efforts have been devoted to assessing the influence of saccharides on the toxicity of cigarette mainstream smoke. The primary goal of this paper was to investigate the influence of exogenous saccharides of hemp pulp (HP) and softwood pulp (SP) on the generation of carbonyl compounds (i.e., formaldehyde, acetaldehyde, acetone, acrolein, propanal, butenal, 2-butanone and butyraldehyde) in comparison with tobacco pulp (TP). The yields of carbonyl compounds in cigarette mainstream smoke of three reconstituted tobacco sheets (RTS) (TP-RTS, HP-RTS and SP-RTS) were studied under ISO standard smoking conditions. Thermogravimetric (TG) analysis and isothermal oxidative pyrolysis experiment in combination with high performance liquid chromatography (IOPy-HPLC) have been employed to indirectly investigate the influence of exogenous fiber on the generation of carbonyl compounds. The compositions of three fibers were analyzed by Ion chromatography (IC) and the monosaccharide was studied by IOPy-HPLC. Cigarette smoking results illustrated that, compared with TP-RTS, HP-RTS and SP-RTS generated significantly higher amounts of carbonyl compounds in cigarette mainstream smoke. TG results showed that the differences of thermal behavior between three RTS were mainly caused by the differences of three fibers. IOPy-HPLC results demonstrated that xylose (17.47 mg g−1) generated significantly higher amount of carbonyl compounds than fructose (15.22 mg g−1) and mannose (15.54 mg g−1), and particularly than glucose (14.27 mg g−1). Due to higher contents of xylose and lower contents of glucose, the exogenous fibers of HP and SP indeed generated higher amounts of carbonyl compounds than TP.

•Citric acid-heat treatment (CAH) can effectively increase the RS content in normal maize starch.•Amylopectin is more preferable to be hydrolyzed than amylose during CAH.•CAH would generate highly compacted chain structure.•CAH would change the crystalline pattern and decrease the crystalline region.The objective of this study was to analyze the influence of thermal-acid treatment on the formation of resistant starch (RS). The maximum RS content in citric acid-heat treated starches (CAHT) reached 36.55%, which was 7 times higher of that in native starch. According to HPSEC–MALLS–RI analysis, amylopectin was more susceptible to hydrolysis than amylose during citric acid-heat treatment (CAH). X-ray measurement revealed that even though the starch crystalline pattern was changed from A-type to a more resistant B-type after CAH, the fraction of crystalline region decreased from 21.16% to 8.37%. The hydroxyls on the starch chains were substituted by the citric acid anhydrides during CAH according to FT-IR analysis, which led to the formation of ester bond cross-linking structures in starch granules, and it could be the main contribution to the increase of RS content in CAHT samples.

•Free standing edible films were produced from tara gum by the casting method.•The influence of polyols as plasticizers on the properties of the films was investigated.•Thermomechanical, physicochemical and barrier properties were determined.•Incorporation of glycerol improved the thermomechanical properties.•Incorporation of sorbitol presented the best barrier properties.The aim of this study was to evaluate tara gum as edible film material as well as the influence of polyols as plasticizers on the properties of the films. Thermomechanical, physicochemical and barrier properties were determined as a function of plasticizer type and concentration. Glycerol, sorbitol and PEG 400 were used in the range of 0.075–0.3 g/tara g. Glycerol was the best plasticizer in terms of mechanical properties with the highest elongation (16–44%) and resistance (45–90 MPa). Sorbitol presented the best barrier properties with the lowest hydrophilicity and water vapour permeability (0.24–0.34 g mm m−2 h−1 kPa−1). Fourier transform infrared (FTIR) spectroscopy showed no significant effect on the structure of the polysaccharide. Dynamic mechanical analysis (DMA) revealed that incorporation of plasticizers increased the mobility of the polymer chains and reduced the glass transition and melting temperature by 30 and 100 °C respectively.

Undesirable aggregation of nanoparticles stabilized by proteins may occur at the protein’s isoelectric point when the particle has zero net charge. Stability against aggregation of nanoparticles may be improved by reacting free amino groups with reducing sugars by the Maillard reaction. β-Lactoglobulin (BLG)–dextran conjugates were characterized by SDS-PAGE and CD. Nanoparticles (60–70 nm diameter) of β-carotene (BC) encapsulated by BLG or BLG–dextran were prepared by the homogenization–evaporation method. Both BLG and BLG–dextran nanoparticles appeared to be spherically shaped and uniformly dispersed by TEM. The stability and release of BC from the nanoparticles under simulated gastrointestinal conditions were evaluated. Dextran conjugation prevented the flocculation or aggregation of BLG–dextran particles at pH ∼4–5 compared to very large sized aggregates of BLG nanoparticles. The released contents of BC from BLG and BLG–dextran nanoparticles under acidic gastric conditions were 6.2 ± 0.9 and 5.4 ± 0.3%, respectively. The release of BC from BLG–dextran nanoparticles by trypsin digestion was 51.8 ± 4.3% of total encapsulated BC, and that from BLG nanoparticles was 60.9 ± 2.9%. Neither BLG–BC nanoparticles nor the Maillard-reacted BLG–dextran conjugates were cytotoxic to Caco-2 cells, even at 10 mg/mL. The apparent permeability coefficient (Papp) of Caco-2 cells to BC was improved by nanoencapsulation, compared to free BC suspension. The results indicate that BC-encapsulated β-lactoglobulin–dextran-conjugated nanoparticles are more stable to aggregation under gastric pH conditions with good release and permeability properties.

With a homogenization–evaporation method, β-carotene (BC) loaded nanoparticles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cellular uptake by Caco-2 cells. The particle diameters of the BC loaded nanoparticles with 0.75% SC or 1.0% WPI emulsifiers were 75 and 90 nm, respectively. Mean particle diameters of three BC loaded nanoparticle nanoemulsions increased less than 10% at 4 °C while they increased more at 25 °C (10–76%) during 30 days of storage. The oxidative stability of BC loaded nanoparticles encapsulated by proteins decreased in the following order: SC > WPI > SPI. The retention rates of BC in nanoparticles were 63.5%, 60.5%, and 41.8% for SC, WPI, and SPI, respectively, after 30 days of storage at 25 °C. The BC’s chemical stability was improved by increasing the concentration of protein. Both the rate of particle growth and the total BC loss at 25 °C were larger than at 4 °C. The color of BC loaded nanoparticles decreased with increasing storage in the dark without oxygen, similar to the decrease in BC content of nanoparticles at 4 and 25 °C. Almost no cytotoxicity due to BC loaded nanoparticles cellular uptake was observed, especially when diluted 10 times or more. The uptake of BC was significantly improved through nanoparticle delivery systems by 2.6-, 3.4-, and 1.7-fold increase, respectively, for SC, WPI, and SPI, as compared to the free BC. The results of this study indicate that protein stabilized, BC loaded nanoparticles can improve stability and uptake of BC.

The effects of alkalization treatments on color, colorimetric fractions, total polyphenol content, and anthocyanin content of cocoa powder were investigated. A darker color and a lower total polyphenol content were obtained for cocoa powder alkalized using a K2CO3 solution than with an NaOH solution. A high temperature and basic pH conditions favored formation of dark components during alkalization due to sugar degradation, Maillard reactions, and anthocyanin polymerizing. The anthocyanin content decreased with an increasing alkali concentration, suggesting that more anthocyanins were transformed into brown polymers in darker cocoa powder. Cocoa powder with a heavy degree of alkalization had the lowest ratio of monomer anthocyanins to yellow/brown polymer content. OD460/OD525 values for alkalized samples were higher than for non-alkalized samples. Cocoa powder presented a better color quality after alkalization treatment.

The influences of various factors on the formation of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) were investigated in a solid-state Maillard reaction system. Thermogravimetric analysis (TG) and differential scanning calorimetry analysis (DSC) showed that the solid-state Maillard reaction mainly occurred at around 150 °C. The DDMP formation from reducing sugars (glucose or fructose) and several selected amino acids (l-proline, l-alanine, l-asparagine, l-threonine, l-tyrosine and l-lysine) was compared. Proline was found to have special activity in DDMP formation when reacted with glucose because of its special catalytic action. The influences of reactant ratios, oxygen, reaction temperature and reaction time on DDMP formation from the reaction of proline with glucose were studied. Reactant molar ratios of glucose to proline played important impact on DDMP formation, and the formation of DDMP was improved when the ratio was higher than 1:1 and achieved the highest level at 2:1. Oxygen had no obvious effects on DDMP formation. The effects of reaction time and temperature were investigated together and revealed the information on the highest yield and minimum temperature for DDMP formation. Furthermore, the kinetics of DDMP formation was studied, and DDMP formation in the initial stage was shown to follow an apparent first-order reaction with an activation energy of 68.8 kJ/mol.

Waxy rice starch was impregnated with xanthan and heat-treated in a dry state. The effects on the pasting and rheological properties of the treated starch–xanthan mixture were evaluated. Swelling of the granule was restricted, and a continuous rise of the viscosity during pasting was provided for the treated sample. After pasting, the gel forming ability of the treated starch was strengthened, as both storage and loss modulus increased and tan δ decreased. The paste also owned the highest zero order Newtonian viscosity and yield stress. An increase in starch particle size of the dry heated starch–xanthan mixture suggested a cross linking of the starch granules by the xanthan polymers. An increase of crystallinity was observed for the starch after dry heat treatment, but with the addition of xanthan the amorphous region of the granule became more resistant to dry-heating. The melting enthalpy was found to be correlated with the crystallinity.

Oil-in-water nanoemulsions stabilized by food-grade biopolymer emulsifiers (modified starches) were fabricated using high-pressure homogenization in an effort to improve the stability and bioaccessibility of β-carotene. Physicochemical and biological properties of β-carotene nanoemulsions were investigated considering the particle size, β-carotene retention, and in vitro digestion. During 30 days of storage at different conditions, the mean diameters of the emulsion systems were increased by 30–85%. The retention of β-carotene in nanoemulsions was significantly higher compared to that of the β-carotene dispersed in bulk oil. After in vitro digestion, the bioaccessibility of β-carotene was increased from 3.1% to 35.6% through nanoencapsulation. The results also indicated that modified starch with high dispersed molecular density led to a higher retention but lower bioaccessibility of β-carotene in nanoemulsions. This could be due to the thick and dense interfacial layer around the oil droplets. This result provides useful information for developing protection and delivery systems for carotenoids.

Fragrance encapsulated in small particles of <20 μm diameter is preferred for use in textiles. This study demonstrated that the proper combination of surfactants could produce small and heat-stable emulsion droplets with chitosan that could be spray-dried to produce microcapsules. The microcapsules were able to be deposited onto cotton using water or detergents. It was found that stable emulsion was obtained when Tween 40 and Span 20 were used as compound emulsifiers with the ratio of 4:1 (w/w). The optimum conditions were 1% (w/w) chitosan in acetic acid with the compound emulsifiers of 3–7% (w/w) in the oil, and the inlet temperature for spray-drying was 150 °C. The encapsulation efficiency for orange oil was >90% with a 1:2 (w/w) ratio of oil to chitosan. Microcapsules had a mean diameter of <20 μm and regular particle morphology. The orange oil in the microcapsules was well retained in cotton fabrics after washing in normal detergent solution. The process and products are low in cost, nontoxic, biocompatible, and biodegradable.

A method suitable for routine analysis was developed and validated for the major aroma compounds in cigarette smoke condensates (CSC). The samples were prepared with direct solvent extraction (DSE) and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) coupled to time-of-flight mass spectrometry (TOFMS). The 37 interested compounds were identified and quantified by means of internal calibration curves. The limit of detection was 0.015–0.84 μg mL−1, the relative standard deviation for most compounds was less than 10% and the recovery for most compounds was between 85–120%. Compared with simultaneous distillation extraction, DSE provided more reliable quantitative results, simpler sample preparation procedure, and was shown to be more suitable for CSC sample preparation. The unknown peaks of DSE were quickly screened and identified by GC × GC-TOFMS mass spectra match factors, structured chromatography and approximate first dimension linear retention index. One hundred and thirty four compounds were tentatively identified and semi-quantified and the repeatability of the results was also satisfactory. The results indicate that GC × GC-TOFMS combined with DSE are suitable for fast and comprehensive quantitative analysis of the aroma compounds in CSC.

Konjac glucomannan (KG, neutral), carboxymethylcellulose (CMC, negatively charged), and chitosan (positively charged) were added to cornstarch dispersions to study the effect of polysaccharide–starch interactions on starch gelatinization properties. Pasting and retrogradation properties were measured with a rheometer and DSC. Swelling properties of the starch granules were determined by solubility index, swelling power, and particle size distribution. Depending on the nature of the different polysaccharides, viscosities of cornstarch dispersions were affected differently. The particle size distributions were not influenced by the addition of any of the polysaccharides. Swelling results showed that the KG and CMC molecules interacted with the released or partly released amylose in the cornstarch dispersions. This was correlated with the short-term retrogradation of the starch pastes being retarded by the additions of KG and CMC. However, the chitosan molecules appeared not to associate with the amylose, so the retrogradation of the chitosan–cornstarch dispersions was not retarded.

The mixture of peppermint oil (PO) with medium-chain triacylglycerol was emulsified in water and stabilized with a food-grade biopolymer, modified starch, to form PO nanoemulsions. The effects of emulsifying conditions including homogenization pressure, the number of processing cycles, and oil loading on the mean diameters and viscosities of nanoemulsions were characterized by dynamic light scattering, optical microscopy, and rheological measurements. The formulated PO nanoemulsions with mean diameters normally <200 nm showed high stability over at least 30 days of storage time. Their antimicrobial properties related to those of PO have also been evaluated by two assays, the minimum inhibitory concentration (MIC) and time-kill dynamic processes, against two Gram-positive bacterial strains of Listeria monocytogenes Scott A and Staphylococcus aureus ATCC 25923. Compared with bulk PO, the PO nanoemulsions showed prolonged antibacterial activities. The results suggest that the nanoemulsion technology can provide novel applications of essential oils in extending the shelf life of aqueous food products.

Differentiation of tobacco leaves in different plant stalk positions in China was achieved based on basic chemical compounds and neutral volatiles by principal component analysis (PCA). The continuous flow analysis method was used to determine the quantity of the basic chemical compounds (sugars, total nitrogen and nicotine) of 30 samples. The neutral volatiles of tobaccos were analyzed by GC–MS. It was found that the disparity in basic chemical components was not enough to assess the different quality of tobacco leaves. PCA was used to reveal the differences among these three species based on neutral volatile compounds. Tobacco leaves in different positions were differentiated according to the results of PCA. Four principal components were extracted and altogether accounted for exceeding 80 % of the total variances. The first principal component explained 48.1 % of the total variation and was mainly defined by solanone, megastigmatrienone, 5-methylfurfural, furfuralcohol, phenylethylalcohol and benzylalcohol. The second principal component explained 18.1 % of the total variation and was mainly defined by β-ionone and farnesylacetone. The plots of sample loadings showed that a good differentiation on the basis of concentrations of neutral volatiles was achieved. These results demonstrated that neutral volatiles can be used as the useful variables to characterize the tobacco leaves in different positions.

Partial least squares regression modeling (PLSR) was used to elucidate the relationship and predictability among the chemical parameters, the GC–MS data and electronic nose responses for controlled oxidation of tallow. Models for predicting chemical parameters changes during controlled oxidation from electronic nose data were estimated by projection of test samples onto calibration models based on PLSR. The results showed that peroxide value (PV) and p-anisidine value (p-AV) were significantly well predicted by the electronic nose responses, whereas acid value (AV) was found fairly well predicted only for mildly oxidized tallow. Overall this study gave evidence of the electronic nose system to be a relevant device for future at- or on-line implementation in oxidation control of tallow for preparing fat flavour.

The glycation of rice proteins with reducing sugars was investigated in an attempt to improve their solubility and functionality. Rice proteins isolated from a Chinese milled medium-grain rice were glycated with glucose, lactose, maltodextrin, or dextran in 2% aqueous dispersions. The sugar that provided the most improvement of the solubility, emulsification activity (EA) and emulsification stability (ES) of the Maillard reaction products was glucose. The optimum reaction conditions were at pH 11, 100 °C, and reaction time 15 min, which increased the solubility, EA and ES of rice protein from 20%, 0.46 and 11.1 to 92%, 0.64 and 18.2, respectively. Extending the reaction time beyond 15 min continued the development of latter-stage Maillard browning products without improvements in the functional properties of the Maillard reaction products. SEC–HPLC analysis with light scattering detection showed a decrease of the weight-averaged molecular weight from 500 to 100 K during the initial 15 min.

Preparation and characterisation of microemulsions (ME) with mint oil (MO) as the oil phase were conducted to find a system which could provide a controlled, sustained, and prolonged delivery of MO. The influence of surfactant type and processing parameters on the formation of MO-ME’s was studied by comparing the areas of the monophase ME regions in pseudoternary phase diagrams. A 1:1 mixture of the surfactants, AOT and CrEL, was found to be the most effective, and it produced a ME monophase area of about 70%. The monophase regions were analysed by conductivity measurements; the results suggested that O/W regions within the ME phases were formed when the water content was higher than 60–65%. As tested with dynamic light scattering (DLS) and head space (HS) GC analysis, the particle size of O/W ME, with 60% water and AOT/CrEL = 1:1 as surfactants, was 20.0 nm and the encapsulation efficiency was 78.4%. The results indicated that a ME of MO/AOT and CrEL/ethanol/water, may be a promising dispersion for the protection of MO in food products.

Starch modified by combination with sodium carboxymethylcellulose (CMC) has been reported to have improved film properties. In this study, rice starches with different amylose content were heat-treated in a dry state after being impregnated with low or medium-viscosity CMC. Noticeable change was found in pasting properties of the starches after dry heat treatment with CMC. It indicated that crosslinkage occurred between the starch and CMC. The waxy starch showed significant change in viscosity throughout pasting after dry heating with CMC, suggesting that the ester bonds were mostly formed between the hydroxyl groups in amylopectin branches of rice starch and carboxylate acid groups of CMC. Particle size also increased after heat treatment with CMC. The modified starch-based films showed improvement in the tensile strength. Both water vapor and oxygen permeability reduced for the modified starch-based films. Dynamic mechanical analysis (DMA) study showed that the values of G′ of modified starch-based film were higher than those of native starch-based film over the temperature range −40 to 60 °C. The heating process with CMC could be used as a modification method for starch and provide desirable properties of starch-based films.

•Effect of stirring speed on mechanical and water barrier properties investigated.•Mechanical and water barrier properties affected by stirring speed.•Higher TS at 12,000 rpm, 16,000 rpm and 18,000 rpm stirring speeds.•Lower WVP at stirring speeds of 10,000 rpm, 12,000 rpm and 16,000 rpm.•Homogeneous microstructure in low speed homogenized films.In this study, the effect of different homogenization stirring speeds (10,000 rpm, 12,000 rpm, 14,000 rpm, 16,000 rpm, 18,000 rpm and 20,000 rpm) on mechanical and water barrier properties of gallic acid treated zein-oleic acid composite films was investigated. In addition, the effect of low and high homogenization speed on film microstructure with respect to speeds at 10,000 rpm and 20,000 rpm was also investigated. Results showed that homogenization stirring speed significantly (p < 0.05) and diversely affected the mechanical and water barrier properties of the films. A higher tensile strength (TS) of 33.4 MPa was registered in gallic acid treated zein-oleic acid composite containing 2% oleic acid homogenized at 12,000 rpm while the lowest tensile strength of 10.9 MPa was registered in gallic acid treated zein-oleic acid composite containing 2% homogenized at 10,000 rpm. Overall, higher tensile strength values irrespective of film type were observed at homogenization stirring speeds of 12,000 rpm, 16,000 rpm and 18,000 rpm. Lower water vapour permeability values (WVP) were obtained at homogenization stirring speeds of 10,000 rpm, 12, 000 rpm and 16,000 rpm with the lowest value of 0.23 (g mm m−2 h−1 kPa−1) registered in gallic acid treated sample homogenized at 10,000 rpm. Results further revealed that WVP increased with increasing homogenization stirring speed especially in gallic acid treated zein films suggesting that the film matrix was being weakened as homogenization became more intense. Films produced by low homogenization speeds were characterized by smooth and homogeneous film microstructures as opposed to heterogeneous and coarse microstructures exhibited by films produced using high homogenization speeds.

A method suitable for routine analysis was developed and validated for the major aroma compounds in cigarette smoke condensates (CSC). The samples were prepared with direct solvent extraction (DSE) and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) coupled to time-of-flight mass spectrometry (TOFMS). The 37 interested compounds were identified and quantified by means of internal calibration curves. The limit of detection was 0.015–0.84 μg mL−1, the relative standard deviation for most compounds was less than 10% and the recovery for most compounds was between 85–120%. Compared with simultaneous distillation extraction, DSE provided more reliable quantitative results, simpler sample preparation procedure, and was shown to be more suitable for CSC sample preparation. The unknown peaks of DSE were quickly screened and identified by GC × GC-TOFMS mass spectra match factors, structured chromatography and approximate first dimension linear retention index. One hundred and thirty four compounds were tentatively identified and semi-quantified and the repeatability of the results was also satisfactory. The results indicate that GC × GC-TOFMS combined with DSE are suitable for fast and comprehensive quantitative analysis of the aroma compounds in CSC.