•Curcumin-loaded octenylsuccinated corn dextrin micelles were spray-dried.•Spray-dried micelles appeared like unaerated balls.•Maltodextrin favored curcumin retention in spray-drying process.•Maltodextrin highly improved curcumin stability in redissolved micelle.•Curcumin in redissolved micelle was more resistant to freeze–thaw and acid than heat.Self-assembled micelles of octenylsuccinated corn dextrin (OSCD) could be used as a vehicle to disperse curcumin in water, but the resultant solution is inconvenient for storage and transportation. To overcome these shortcomings, curcumin-loaded OSCD micelles were spray-dried with or without maltodextrin (MD). The physico-chemical properties of dried micelles and the stability of their redissolved solutions against thermal, freeze–thaw and acid treatments were investigated. Spray-dried micelles appeared like unaerated balls, and their density, fluidity and curcumin retention increased with the addition of MD. DSC and XRD revealed the amorphous form of curcumin in dried micelles. In terms of curcumin retention, redissolved micelles presented better stability against freeze–thaw and acid treatments than thermal treatment. More importantly, MD highly stabilized the redissolved micelles against freeze–thaw-, acid- and thermal-treatment under 50–70 °C. The present study paves the way for industrial applications of curcumin-loaded OSCD.

•Addition of oat β-glucan affected the hydration and rheological properties of dough.•Addition of oat β-glucan increased the water mobility in the composite dough.•Oat β-glucan induced the deterioration of gluten network in the composite dough.•Oat β-glucan reduced the gas retention capacity of the fermented composite dough.The objective of this study was to evaluate the effects of the incorporation of oat β-glucan (OβG) on the hydration, rheological and fermentation properties of wheat flour dough. Wheat flour was substituted with OβG at levels varying from 1 g/100 g–5 g/100 g. The addition of OβG significantly increased water absorption and dough development time. The dilution effect of OβG, competing for water and interaction between OβG and gluten proteins, deteriorated the gluten network structure and reduced the stability of dough. Rheological evaluation revealed an increasing tendency to solid-like behavior with increasing addition of OβG. Regarding dough fermentation properties, OβG had no effect on yeast activity but reduced the gas retention capacity of dough. Our findings indicate that OβG is a key component that determines the properties of dough, and excess OβG exhibited poorer processing characteristics compared with control.

•Oat β-glucan was darker than wheat flour in terms of lightness and white index.•Oat β-glucan addition increased water absorption of wheat flour in dough formation.•Wheat flour with oat β-glucan is more resistant to gelatinization and retrogradation.•Oat β-glucan addition facilitated the flowability of wheat flour.•Oat β-glucan addition did not change water vapor adsorption of wheat flour at 20 °C.The objective of this study was to evaluate the effects of oat β-glucan (OβG) incorporation on the gelatinization, flowability and moisture sorption of wheat flour. OβG was incorporated at levels varying from 1 to 5 g/100 g on wheat flour basis. The blends with OβG incorporation beyond 3 g/100 g were darker than wheat flour, which caused by the lower lightness (88.6) and white index (85.8) but higher redness (1.16) of OβG versus wheat flour. The blend with 5 g/100 g OβG was more resistant in gelatinization and retrogradation but more liable to flow than wheat flour indicated by the increased pasting temperature, decreased past viscosity, setback, and angles of repose and slide. In lower water activity (aw) scope (< 0.6), OβG powder presented inferior moisture adsorption than wheat flour, while opposite situation happened in higher aw scope (> 0.6). The moisture adsorption curves of wheat flour and the blends were highly resembled throughout aw scope of 0.11 to 0.85. To guarantee the product safety during storage at 20 °C, the moisture content of wheat flour, OβG and the blends must be < 12.6 g/100 g.Download high-res image (87KB)Download full-size image

Farinograph tests are used to predict the functional properties and quality of wheat flour. However, these tests are time-consuming and labor-intensive. Conventional rapid determination methods based on near-infrared (NIR) spectra showed a limited ability to predict farinograph parameters. The potential of combining NIR and mid-infrared (MIR) spectral regions to predict wheat flour farinograph quality properties (water absorption, dough development time, dough stability, and degree of softening) was investigated. Partial least squares models based on NIR, MIR and fused spectra were calibrated and compared. Two data fusion strategies (low- and mid-level) have been applied to take advantage of the synergistic effect of information obtained from MIR and NIR. Low-level data fusion models showed inferior performance compared to the corresponding MIR and NIR models, whereas mid-level data fusion models combined with a forward interval variable selection algorithm were validated to show good performance. Fusion of the previously selected variables from MIR and NIR spectra improved the prediction accuracy of farinograph parameters, which indicates the superiority of the forward interval variable selection algorithm that will be helpful for the cereal and baking industries.

•Micellar entrapment method for curcumin.•Curcumin was solubilized with octenylsuccinated corn dextrin micelle up to 4.44 μg/mL.•Solubilization of curcumin in the micelles was dependent on IP, DS and MW.•Curcumin solubilized in the micelles was in an amorphous state.•The lyophilized curcumin-loaded micelles are easily reconstituted with water.Hydrophobized polysaccharides are promising substrates for the micellar entrapment of lipophilic food ingredients. In this study, we investigated the solubilization of curcumin with octenylsuccinated corn dextrin micelles. A Box-Behnken design was used to determine the dependence of the apparent solubility of curcumin on the operation parameter (the stirrer input power, IP) and the structural parameters (molecular weight, Mw, and degree of substitution, DS) of octenylsuccinated corn dextrin micelles. Additionally, the properties of curcumin-loaded octenylsuccinated corn dextrin micelles were characterized. The maximal apparent solubility of curcumin (4.44 μg/mL) encountered with an intermediate IP (4.0 W), Mw (10.4 × 104 Da) and DS (0.0302). The curcumin-loaded octenylsuccinated corn dextrin micelles were spherical in shape with a mean diameter of 247 nm. Lyophilization and reconstitution showed insignificant effect on polydispersity index and ζ-potential of the curcumin-loaded micelles (p > 0.05). Curcumin entrapped in octenylsuccinated corn dextrin micelles was in an amorphous state, as revealed by Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. The results suggested that octenylsuccinated corn dextrin micelles displayed encouraging capacities as a nano-carrier for solubility enhancement of curcumin.

•A novel method for preparing corn starch ferulates.•Reaction parameters were optimized by response surface methodology.•Corn starch ferulates were found to exhibit the DPPH radical scavenging effects.•The DS value of the products has a positive impact on the antioxidant activity.This work presents novel synthesis processes and properties of corn starch ferulates. First, N,N′-carbonyldiimidazole, a green activating reagent, was used to transform ferulic acid into ferulate-imidazolide. The ferulate-imidazolide was then further reacted with corn starch to produce corn starch ferulates. The grafting reaction of ferulic acid onto corn starch was confirmed by FT-IR and 1H NMR. The degree of substitution (DS), relating products and reaction parameters, depended on the molar ratio of the anhydroglucose unit to ferulic acid (nAGU/FA), the temperature of the reaction, and the time that elapsed. The dependence of the degree of substitution was optimized by response surface methodology. Results implied the greatest DS (0.389) was obtained under the conditions of nAGU/FA 1:3.6, 90 °C and 7.12 h. The morphological, crystalline, and in vitro antioxidant properties were evaluated. The DPPH radical scavenging activity, reducing power, and ferric reducing power of the corn starch ferulates showed potential for antioxidant properties.

•Carboxymethyl sweetpotato starch (CMSS) is esterified by quercetin.•Esterification with quercetin improves the thermal stability of CMSS.•Antioxidant capacity conferred on CMSS by quercetin esterification increases with DS.•Significant but limited changes occur in CMSS digestibility by quercetin modification.Quercetin is grafted to carboxymethyl sweetpotato starch (CMSS) by esterification. Upon esterification, the water solubility of CMSS decreases and the CMSS-quercetin conjugates (CMSS-Q) are yellowish. FT-IR and 1H NMR indicated the covalent attachment of quercetin to CMSS. Thermogravimetry revealed the superior thermal stability of CMSS-Q over CMSS and native sweetpotato starch (NSS). The in vitro digestibility assays showed that CMSS is highly resistant to digestion while the quercetin graft with degree of substitution (DS) above 0.074 slightly increased its digestibility. The quercetin graft imparted CMSS with strong antioxidant activity and enhanced its thermal stability, which increased with quercetin DS. In vitro cyotoxicity assessment revealed that CMSS-Q is as safe as CMSS and NSS. This study showed that CMSS-Q is a novel antioxidant-resistant starch in RS4 form.

An amphiphilic fatty acid oat β-glucan ester (FAOGE) was first synthesized, and its structure–curcumin loading capacity (CLC) relationship was investigated. The DS of product increased with the addition of acyl imidazole, decreased with Mw of β-glucan, and did not relate to the acyl chain length. Characterizations by FT-IR and 1H NMR evidenced the presence of ester groups in FAOGE and confirmed its successful synthesis. The aqueous self-aggregation behavior of FAOGE was revealed by transmission electron microcopy and dynamic light scattering. With the aid of response surface methodology, a quadratic polynomial equation was obtained to quantitatively describe the structure–CLC relationship of FAOGE by using Mw of β-glucan, acyl chain length, and DS as variables. The CLC increased with Mw of β-glucan and acyl chain length but maximized at a medium DS. The maximum CLC value was obtained as 4.05 μg/mg. Hence, FAOGE is a potential candidate in solubilizing and delivering hydrophobic food ingredients.

The effects of mechanical and jet grindings on the proximate composition, phenolics, and antioxidant capacity of insoluble antioxidant dietary fiber powder from citrus pomace (IADFP-CP) were investigated in comparison with ordinary grinding. IADFP-CP from jet grinding showed higher levels of crude fat, total sugar, and free phenolics and lower levels of crude protein and bound phenolics than that from ordinary grinding. Totally, 14 phenolics (9 free, 1 bound, and 4 free/bound) in IADFP-CP were identified by RP-HPLC-DAD/ESI-Q-TOF-MS/MS. Hesperidin accounted for >57% of total phenolics in IADFP-CP. Among IADFP-CPs, the jet-ground presented the highest free phenolics but the lowest bound phenolics. The IADFP-CP from jet grinding presented the highest antioxidant capacity of free phenolics (by DPPH and FRAP assays), followed by the ones from mechanical and then ordinary grinding. The present study suggests that jet grinding could improve the extraction of phenolic compounds from IADFP-CP and increase the antioxidant capacities of free phenolics and the resultant powder.

The dependence of the curcumin loading capacity (CLC) of octenylsuccinate oat β-glucan (OSG) micelles on the structural parameters (degree of substitution, DS; molecular weight, Mw) of OSG was unknown and explored in this study. Meanwhile, the curcumin-loaded OSG micelle (COM) was first characterized. The results from response surface methodology revealed that the linear effects of Mw and stirrer input power, as well as the quadratic effect of DS, were significant (p < 0.05). The maximum CLC value of the OSG micelle was obtained as 4.21 μg/mg. Dynamic light scattering showed that the average size and ζ potential of the COM were 308 nm and −10.8 mV, respectively. Transmission electron microscopy and atomic force microscopy evidenced that the COM was elliptical in shape. Fourier transform infrared spectroscopy, differential scanning calorimeltry, and X-ray diffraction revealed that curcumin was loaded in OSG micelles in an amorphous form by interacting with OSG molecules.

Thermal and storage stabilities of red radish anthocyanins (RRAs) in various juice beverages (apple, grape, peach, pear, pomegranate and lemon) were studied over temperature range 70–90 °C and 4–25 °C. RRAs degradation in all juice beverages followed first-order reaction kinetics. RRAs showed a much faster degradation rate during storage at room temperature (t1/2 value ≤84.0 days) than did in refrigerated temperature (t1/2 ≥value 130.9 days). The rate constant (k), Ea and Q10 values for RRAs in juice beverages varied from 1.33 to 0.33, 47.94 to 14.77 kJ mol−1 and 1.16 to 1.89 at 70–90 °C. During heating, RRAs in peach and pomegranate showed higher stability than others at these temperatures. There was a positive correlation (R2 > 0.9128) between ascorbic acid content of juice beverages (8–36 mg/100 mg) and stability of RRAs at 70–90 °C. It was found that RRAs in apple and pear juice beverage were more stable than in other juice beverages.

The influence of geographical origin (Lvliang, Baotou, Gulang, and Jilin) on the physicochemical properties of proso millet (Panicum miliaceum L.) starches from China, and starch chemical compositions were studied. Scanning electron microscopy showed that starch granules from millet starches were polygonal and spherical with smooth surfaces with sizes ranging from 2.5 to 12 μm. X-ray diffraction showed that millet starches were typical of A-type starch granules with a mean crystallinity of 35.81%. The transition temperatures (To, Tp, and Tc) and enthalpy of gelatinization (ΔH) of Lvliang, Baotou, Gulang, and Jilin proso millet starches were 66.81 to 70.01°C, 72.79 to 76.55°C, 78.30 to 82.44°C, and 10.4 to 14.46 J/g, respectively. Significant differences (p<0.05) were observed for the amylose content, granule size, peak temperature, gelatinization enthalpy, and peak viscosity temperature among the millet starches. Millet starches may have potential applications in production of puffed starch food products and other food items.

Storage (4°C and 25°C, 28 days) and thermal (70°C–90°C, 6 h) stabilities of purple sweet potato anthocyanins (PSPAs) with varying concentrations of ascorbic acid (AA) were investigated in a model soft drink medium. For storage stability, the model drink was sterilized at 85°C for 15 min prior to storage. Zero-order kinetics and first-order kinetics were fitted for storage degradation at 4°C and 25°C, respectively. However, all data for thermal degradation fitted first-order kinetics. The temperature dependence on degradation was modeled after the Arrhenius equation. Storage degradation of PSPAs was increased by the presence of AA (40–360 mg/L). Retarded thermal degradation was be achieved by adding 120 mg/L of AA, while accelerated thermal degradation resulted from 360 mg/L of AA. Heat treatment did not markedly change the DPPH radical-scavenging activity of PSPAs.

Amphiphilic oat β-glucan derivatives carrying octenylsuccinic groups as hydrophobic moieties have been synthesized. Materials with a different degree of substitution (DS) and weight-average molecular weight (Mw) for oat β-glucan were prepared and characterized using elemental analysis, infrared (IR) spectroscopy, and high performance size exclusion chromatography (HPSEC). Dynamic light scattering (DLS), fluorescence spectroscopy, and transmission electron microscopy (TEM) revealed that octenylsuccinate oat β-glucan (OSG) can self-assemble into spherical micelles in water with an average size ranging from 175 to 600 nm. OSG micelles were negatively charged as indicated by ζ-potential measurement. The critical micelle concentration (CMC) of OSGs varied from 0.206 to 0.039 mg/mL, depending on the DS and Mw of the oat β-glucan. It was found that the presence of OSG micelles in aqueous solution could significantly enhance the solubility of curcumin by 880 fold. Thus, OSG might have great potential in applications as hydrophobic nutrient delivery carriers.Keywords: curcumin; octenylsuccinate oat β-glucan; self-assembly;

The interaction between ε-polylysine (ε-PL) and anionic polysaccharides has gained considerable attention recently because of its scientific impact on the stability and appearance of liquid food systems. The purpose of this study was to characterize the interactions between ε-PL and carboxymethyl sweet potato starch (CSS) using isothermal titration calorimetry (ITC), electrical charge, and turbidity measurements. The results showed that the interaction between ε-PL and CSS was electrostatic and mainly dependent on the molar ratio of amino groups in ε-PL to carboxyl groups in CSS. Additionally, the interaction between ε-PL and CSS was also associated with pH, degree of substitution (DS) of CSS, and ionic strength of the system. For the interaction of ε-PL with high DS (>0.235) CSS, three states of the ε-PL/CSS mixture were observed as transparent, turbid, and precipitated with a successive increase in amino/carboxyl molar ratio. Distinguishingly, a transparent mixture could be obtained for CSS with low DS (0.114) at a sufficiently high amino/carboxyl molar ratio. The present study provided basic guidance in designing liquid food systems containing both ε-PL and CSS.

Ray florets (Rf) and disc florets (Df) are agricultural byproducts of sunflower seeds. Their nutrition-related compounds were determined. The dietary fiber contents in Rf and Df were 42.90 mg/100 g and 58.97 mg/100 g. In both florets, palmitic, linoleic, and linolenic acids were identified as the three most abundant fatty acids, and the saturated ones constitute approximately two-thirds (w/w) of the total fatty acids. Lysine was the limiting amino acid in both florets by World Health Organization standards. Sixteen phenolic compounds, nine free and eight bound, mainly depsides, were identified in florets by RP-HPLC-DAD/ESI-TOF-MS. The free and bound phenolic compounds in Df were higher than in Rf. 1,5-di-O-caffeoylquinic acid was the predominant free phenolic compound in both florets. The present study revealed that the florets of sunflower are rich sources of dietary fiber, Fe, and phenols.

Few data were available on the interactions between polyphenols and polysaccharides. The effects of the chemical structure of polyphenols on their interactions with oat β-glucan were analyzed. Ultrafiltration was applied to determine the adsorption capacities of polyphenols into oat β-glucan. Hydroxylation favored the adsorption of flavonoids with three or fewer hydroxyl groups but deteriorated those with four or more hydroxyl groups. Among flavonoid isomers, the adsorption capacities increased in the order flavonol > flvaone > flavanone > isoflavone. Glycosylation exerted complicated influences on the adsorption capacities of flavonoids into oat β-glucan. In most cases, methylation and methoxylation of phenolic acids lowered their adsorption capacities into oat β-glucan. Esterification of gallic acid weakened its adsorption capacity into oat β-glucan, whereas o-coumaric acid presented higher adsorption capacity into oat β-glucan than p- and m-coumaric acids. Galloylation improved the adsorption capacities of catechins into oat β-glucan.

Carboxymethyl potato starch was synthesised with the aid of microwave. Optimal degree of substitution (DS) of 0.32 was obtained at 45 °C in 25 min using aqueous ethanol media with water/solvent of 0.15 at 200 W. The molar ratio of sodium hydroxide and monochloroacetic acid to anhydroglucose unit for optimal DS were 2.5 and 1.0, respectively. FT-IR spectrometry revealed the carboxymethyl starch to show new bands at ν = 1614 cm−1 and ν = 1429 cm−1. Wide angle X-ray diffractometry and DSC revealed a remarkable reduction in starch crystallinity after carboxymethylation, which was consistent with destroyed surface observed in SEM. The digestibility of carboxymethyl starch (CMS) was lower than that of native starch. With similar DS, there was no difference in digestibility of carboxymethyl starch prepared with and without microwave. As DS increased from 0.05 to 0.32, the amount of resistant starch in microwave-assisted carboxymethyl starch was elevated from 14.6% to 20.0%, which was much higher than that of native starch (10.8%).Highlights► Microwave radiation could effectively accelerate carboxymethylation of potato starch. ► Carboxymethyl starch gave a higher content of RS than native starch. ► Carboxymethyl starch paste had a more stable behave than native starch paste.

Polyphenol–polysaccharide interaction attracted much attention due to its crucial impact on the functional and sensory quality of foods. Monomers of tea polyphenols (TP) were selectively adsorbed by oat β-glucan and (−)-epigallocatechin gallate (EGCG) was the mostly adsorbed one in terms of adsorption capacity (qe) and efficiency (Ee) determined by equilibrium dialysis. Contrast to Langmuir, Freundlich and Redlich-Peterson models, Toth model fit best to the adsorption isotherm of EGCG. The adsorbing variables were optimised using response surface methodology. Linear variables of pH and temperature (T), interactive terms of EGCG concentration (CEGCG)/buffer concentration (CPBS) and pH/T   and all quadratic variables of CEGCG2, pH2, CPBS2 and T2 made significant senses on qe. The highest qe could be achieved with the following conditions: CEGCG 0.7 mg/mL, pH 5.80, CPBS 0.10 M and T 50 °C. The consistency of the experimental (321.5 μg/mg) and predicted (333.3 μg/mg) values in qe confirmed the adequacy of the response surface equations. The bonds which governed the interaction between EGCG and oat β-glucan was hydrogen bond.Highlights► (−)-Epigallocatechin gallate was the mostly adsorbed monomer of TP onto oat β-glucan. ► Toth model fit best to the adsorption isotherm of EGCG onto oat β-glucan. ► The highest adsorption capacity for EGCG onto oat β-glucan was 321.5 μg/mg.

The degree of substitution (DS) markedly affects the properties of carboxymethyl starch (CMS). The conventional methods for the DS determination are time-consuming and not environment friendly. Fourier transform mid-infrared (FT-MIR) spectroscopy coupled with partial least squares (PLS) regression is applied to determine the DS of CMS in the present study. Calibration models with direct titration as the reference method were optimised by cross validation. A PLS regression model with a coefficient of determination (R2) of 0.9593 and root-mean-square error of cross validation (RMSECV) of 0.0141 was obtained in the spectral range from 500 to 4000 cm−1. The prediction set gave a coefficient of determination (R2) and root-mean-square error of prediction (RMSEP) of 0.9368 and 0.0228, respectively. The results obtained in this study indicate that FT-MIR spectroscopy can be used as an easy, rapid, and novel tool to quantitatively predict the DS of CMS.Highlights► Partial least square is qualified to extract spectral feature of carboxymethyl starch. ► MIR is effective in determination of degree of substitution of carboxymethyl starch. ► MIR is rapid and environment friendly compared to conventional methods.

Information on interactions between oat β-glucan and tea polyphenols (TP) is not available in the published literatures. Equilibrium dialysis was applied to determine the adsorption of TP into β-glucan, and response surface methodology (RSM) was employed to optimize the absorbing variables (pH, temperature, and phosphate buffered saline (PBS) buffer concentration). The equilibrium data at constant temperature were fitted with the Langmuir, Freundlich, and Redlich-Peterson models. The results showed that the Freundlich model was the best method to describe the experimental data. Parabolic curves were obtained for pH and temperature. In terms of adsorption capacity, factors including temperature, pH/temperature, and buffer concentration/temperature had the greatest influence on the response. The highest adsorption capacity of TP into β-glucan was 134.55 μg mg−1 at the following optimized conditions: pH 5.56, PBS buffer concentration 0.13 M, and temperature 40 °C. No significant differences (p > 0.05) between the experimental and predicted values confirmed the adequacy of the response surface equations.

Few data are available about the effects of complexation of polyphenols with polysaccharide on their bioavailability. The complex of tea polyphenols (TP) with oat β-glucan was characterized by ultraviolet–visible spectrometry, Fourier transform infrared spectrometry, differential scanning calorimetry, atomic force microscopy, and solid-state 13C NMR spectroscopy. The results indicated that the bonds which governed the interaction between TP and oat β-glucan were strong hydrogen bonds. The in vitro antioxidant activity of TP, β-glucan, their complex, and physical mixture was assessed using four systems, namely, DPPH•, OH•, and O2•– scavenging activities and reducing power. The complexation and blending of TP and β-glucan exhibited different impacts on the index of in vitro and in vivo antioxidant capacities. In the concentration range of 0.5–2.5 mg mL–1, the complex had highest O2•– scavenging activity, whereas the highest OH• scavenging activity was found with the physical mixture. For antioxidant testing in vivo, there was no significant difference between the complex and the physical mixture in terms of glutathione peroxidase activity and levels of malondialdehyde and total antioxidant capacity in serums. However, the complex exhibited much higher activities of superoxide dismutase and glutathione peroxidase in livers than the physical mixture. The present study provided a deeper understanding of the influence of molecular interaction between TP and oat β-glucan on their antioxidant activities.

κ-Carrageenan was explored to improve genistein solubility by matrix retention. The corresponding maximum value in the efficiency of retention (Re) (50.48 mg/100 mg) was achieved when variables were set as: pH 4.76, temperature 52.12 °C and genistein concentration 0.27 mg/mL. The coefficient of determination (R2) of the response surface regression model presented in this study was 0.9848. The evidences from XRD, DSC and FT-IR attested the amorphous form of genistein in hydrogel matrix. Importantly, the solubility of genistein in hydrogel amorphous form (16.84–34.42 μg/mL) was much higher than that of its free crystalline form (1.89–6.09 μg/mL) over 30–90 °C.

Feruloyl amylopectin (FAP) was synthesized by the N,N′-carbonyldiimidazole (CDI) activation method, and the enzymatically cross-linked feruloyl amylopectin (CL-FAP) was prepared via catalysis of horseradish peroxidase (HRP) with the presence of hydrogen peroxide (H2O2). RP-HPLC-DAD/ESI-TOF-MS measured ferulic acid and its derivatives in FAP and CL-FAP. FAP was primarily composed of two ferulate monomers, while CL-FAP was composed of two ferulate monomers and two ferulate dehydrodimers. The ester formation in the feruloyl group was confirmed by the presence of carbonyl and aromatic CC signal near 1725 (1723) and 1510 cm−1 in the FT-IR spectra. X-ray diffraction studies showed that the two modified amylopectins lost the ordered A-type crystalline structure, characteristic of maize amylopectin. The encapsulation capacity of curcumin (ECC) in 1 mg/mL CL-FAP microemulsion was measured at 88.13 μg/mg by HPLC.

The purified Gastrodia elata Blume polysaccharide (PGEB-3H), was found to be a glucan with a molecular weight of 28.8 kDa and specific rotation of +206.3 (ca.0.003, H2O). The structural characterics of PGEB was investigated by chemical methods (partial hydrolysis with acid, methylation reaction, periodate oxidation, and Smith degradation) and instrument analysis (IR and NMR). PGEB-3H was mainly composed by glucose, and had a (1→4)-α-D-glucan main chain occasionally branched with α-1,6 glycosidic linkage. PGEB-3H exhibited potential lipid-lowering effects in hyperlipidemia rats.^p

•Bamboo shoot shell (BSS) lignin is an activator to α-amylase.•α-Amylase was immobilized on BSS lignin via adsorption.•Immobilization enhanced α-amylase catalytic activity and storage stability.•Immobilization did not change α-amylase working temperature and pH.•Immobilized enzyme owned good reusability.This study examined the feasibility of α-amylase activation and immobilization, using lignin from bamboo shoot shells (BSS). Our results demonstrated that BSS lignin is an excellent α-amylase activator and it elevated α-amylase activity more than two-fold at a concentration of 5 mg/ml. For immobilization of α-amylase via adsorption, BSS lignin was incubated in an α-amylase solution (5 mg/ml) for 20 min, and the maximum specific activity, amount of loaded protein and activity recovery were 92.4 U/mg, 19.0 mg/g and 111%, respectively. In contrast to its free counterpart, immobilized α-amylase improved the catalytic efficiency and storage stability, under comparable working conditions (temperature and pH). Regarding its convenient usage, immobilized enzyme can be suspended in advance, but a suspension incubated at 60 °C should be used within 30 min. The residual activity after 14 re-uses remained at a reasonable level (53.2%). In conclusion, this study reveals a novel support for enzyme immobilization.