Co-reporter:Longteng Zhang, Qian Li, Jian Lyu, Chunli Kong, Sijia Song, Yongkang Luo
Food Chemistry 2017 Volume 216() pp:130-137
Publication Date(Web):1 February 2017
DOI:10.1016/j.foodchem.2016.08.004
•Effects of stunning methods on stress and quality were measured.•Stunning methods significantly affect the rate of ATP degradation.•Stunning methods strongly corresponded to stress conditions.•Fish stunned by percussion and ice/water slurry resulted in better flesh quality than gill cut.This study aimed to evaluate different stunning methods [percussion (T1), immersion in ice/water slurry (T2), and gill cut (T3)] on quality and stress conditions of silver carp (Hypophthalmichthys molitrix) fillets stored at 4 °C in 72 h postmortem. Rigor index (RI%), behavioral analysis, levels of lactic acid and muscle glycogen were measured for stress level evaluation. Meanwhile, sensory assessment, texture properties, cooking loss, adenosine triphosphate (ATP) related compounds, adenosine monophosphate deaminase (ADA) activity, and acid phosphatase (ACP) activity were analyzed. The least stress condition, significantly (P < 0.05) higher initial glycogen content was observed in T1. Ice/water stunning reduced the rate of ATP degradation, reflected in the lowest K value during 72 h. Aversive behaviors, significantly (P < 0.05) higher cooking loss, hypoxanthine riboside (HxR) content, and lower sensory score were observed in T3. The results indicated that gill cut in aquatic processing industry should be avoided for inferior quality and aversive reactions during stunning.
Co-reporter:Dapeng Li, Shiliang Jia, Longteng Zhang, Qingzheng Li, Jinfeng Pan, Beiwei Zhu, Witoon Prinyawiwatkul, Yongkang Luo
Innovative Food Science & Emerging Technologies 2017 Volume 42(Volume 42) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.ifset.2017.06.005
•Thawing time of frozen common carp were significantly decreased by HVEF.•HVEF reduced water loss of thawed common carp.•HVEF decreased the level of microorganisms.•HVEF significantly delayed ATP degradation.In recent years, high voltage electrostatic field (HVEF) technology has been demonstrated to be a viable alternative to high-temperature treatments in processing for inhibiting microbial growth and maintaining post-thawing quality of foods. In this study, common carp (Cyprinus carpio) meat cubes were treated with HVEF, and compared to air-thawed and running tap water-thawed controls to investigate how HVEF affects common carp meat quality after thawing and low-temperature storage (4 °C). The results showed that thawing under − 6, − 12 kV HVEF and running tap water significantly decreased the thawing time by 30, 50 and 45 min, respectively, compared to air thawing control. In addition, − 12 kV HVEF treatment also reduced the moisture loss, which the initial drip loss of it was lower by 2.95% than CK. The initial total viable counts, Aeromonas, Pseudomonas, and lactic acid bacteria were 3.58, 3.15 2.88 and 3.25 log CFU/g in CK after thawing, respectively, which were higher than that in the cube thawed by − 12 kV HVEF (3.11, 2.93 2.71 and 2.91 log CFU/g). Additionally, − 12 kV HVEF treatment enhanced adenosine monophosphate deaminase (AMP-deaminase) activity, reduced acid phosphatase (ACP) activity and delayed the degradation of inosine monophosphate (IMP) to hypoxanthine (Hx). These results suggested that HVEF treatment could be useful in the thawing and storage of frozen common carp fish.Industrial relevanceThe study investigated the effects of high voltage electrostatic field (HVEF) thawing on the water-holding capacity, adenosine triphosphate degradation and microbial community changes of frozen common carp (Cyprinus carpio) cubes when stored at 4 °C. HVEF under − 12 kV was found to have positive influence on reducing the thawing time, maintaining water-holding capacity, decreasing the level of microbe, and delaying adenosine triphosphate (ATP) degradation. A potential application for HVEF in the thawing and storage of frozen aquatic product was highlighted in food industry.
Co-reporter:Dapeng Li, Shiliang Jia, Longteng Zhang, Zhiying Wang, Jinfeng Pan, Beiwei Zhu, Yongkang Luo
Journal of Food Engineering 2017 Volume 212(Volume 212) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.jfoodeng.2017.06.003
•HVEF thawing delayed the ATP degradation in lightly salted common carp in 4 °C storage.•HVEF enhanced AMPD activity and lowered ACP activity of the common carp.•HVEF treatment reduced the level of microbes in the carps significantly.As a novel technology, high voltage electrostatic field (HVEF) technology has been demonstrated to be a viable alternative to high-temperature treatments in food processing due to its ability to lower energy consumption, reduce thawing time, and maintain the post-thawing quality of several foods. We investigated the effect of HVEF thawing on microbial communities, degradation of adenosine triphosphate (ATP), and water loss of lightly-salted, frozen common carp (Cyprinus carpio) cubes stored at 4 °C compared to air-thawed or thawing by running tap water. Thawing time was shortened significantly under HVEF and running tap water compared to the control of thawing by air. Moreover, −12 kV HVEF treatment also reduced moisture loss, lowered the total viable counts, Pseudomonas, and lactic acid bacteria significantly after thawing, and lowered counts of Aeromonas, Pseudomonas, and halophilic bacteria by 0.5–1 log CFU/g in thawed fish cubes after 8 days refrigeration storage. Additionally, the activity of adenosine monophosphate deaminase (AMPD) was enhanced, but the activity of acid phosphatase (ACP) was decreased under −12 kV HVEF treatment. This resulted in delaying the degradation of inosine monophosphate (IMP) to hypoxanthine (Hx). These results suggested that HVEF treatment could be useful in the thawing and storage of frozen, lightly-salted fish.
Co-reporter:Chi Zhang, Yuqi Zhang, Zhiying Wang, Shangwu Chen, Yongkang Luo
Journal of Functional Foods 2017 Volume 35(Volume 35) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.jff.2017.05.032
•Pepsin hydrolysates of Hypophthalmichthys nobilis muscle protein displayed multiple bioactivities.•Novel peptides with good antioxidant, DPP-IV and ACE inhibitory activity were identified.•Peptides were predicted to be non-toxic and some were non-allergenic in silico.We investigated bioactive peptides obtained from muscle protein hydrolysate of bighead carp by evaluating in vitro dipeptidyl peptidase IV (DPP-IV) and angiotensin-converting enzyme (ACE) inhibitory capacities and antioxidant activity. Peptide sequences were identified from pepsin hydrolysates. Met-Lys-Ala-Val-Cys-Phe-Ser-Leu was one of the most effective sequences with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (EC50 = 4.58 ± 0.15 μM) and relatively high ACE inhibitory capacity (IC50 = 3.68 ± 0.13 μM). Tyr-Asn-Leu-Lys-Glu-Arg-Tyr-Ala-Ala-Trp (IC50 = 1.35 ± 0.23 μM) and Tyr-Asn-Arg-Leu-Pro-Glu-Leu (IC50 = 3.42 ± 0.39 μM) exhibited the most potent ACE inhibitory activity. Ile-Ala-Asp-His-Phe-Leu showed the highest DPP-IV inhibitory activity with an IC50 value of 610.1 ± 82.6 μM. All selected peptides were non-toxic, and most were non-allergenic according to in silico predictions. These results indicate the promising potential of bighead carp muscle hydrolysates as functional additives in foods and pharmaceuticals.
Co-reporter:Qian Li, Longteng Zhang, Han Lu, Sijia Song, Yongkang Luo
LWT - Food Science and Technology 2017 Volume 78(Volume 78) pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.lwt.2016.12.035
•Postmortem changes in white and dark muscles of carp were investigated.•Dark muscle had a lower content of IMP and a higher K value.•Activities of ADA, ACP, cathepsins B and B + L were higher in dark muscle.Postmortem changes in white muscle and dark muscle of common carp (Cyprinus carpio) during 72 h at 4 °C were evaluated by determining ATP-related compounds, AMP-deaminase (ADA) activity, acid phosphatase (ACP) activity, pH, texture properties, contents and SDS-PAGE patterns of myofibrillar and sarcoplasmic proteins, as well as activity of cathepsins B and B + L. The results showed that white muscle had a significantly (P < 0.05) higher pH and inosine monophosphate (IMP) concentration but a lower hardness after slaughter. Higher activity of ADA and ACP in dark muscle coincided with its higher K value. The SDS-PAGE patterns showed that white muscle contained more protein bands for myofibrillar and sarcoplasmic proteins, while dark muscle had more bands with low molecular weights for sarcoplasmic protein. Cathepsins B and B + L showed higher activity in dark muscle than in white muscle, especially at the later period of storage. Higher activity of endogenous enzymes in dark muscle might contribute to its faster quality loss.
Co-reporter:Zhan Huang, Xiaochang Liu, Shiliang Jia, Yongkang Luo
Food Control 2017 Volume 82(Volume 82) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.foodcont.2017.07.017
•The antimicrobial activity of 11 essential oils was examined.•A stable cinnamon bark oil-in-water emulsion was prepared.•Pseudomonas followed by Aeromonas were dominant in spoiled grass carp fillets.•Cinnamon bark oil inhibited the growth of Aeromonas and Shewanella in grass carp.•Cinnamon bark oil treatment prolonged the shelf-life of grass carp.In this study, 11 essential oils were initially screened for antimicrobial activity against Aeromonas veronii, Acinetobacter johnsonii, Shewanella putrefaciens, and Pseudomonas jessenii. Cinnamon bark oil exhibited the highest antimicrobial activity and was used as a natural preservative in grass carp fillets stored at 4 ± 1 °C. Sensory assessment, total volatile basic nitrogen (TVB-N), color, biogenic amines, adenosine triphosphate (ATP)-related compounds, K-value, and presence of microbiota were analyzed during storage. Cinnamon bark oil treatment was found to be effective in enhancing organoleptic quality, inhibiting microbial growth, and delaying the increase of TVB-N, putrescine, cadaverine and K-value. Based on sensory analysis, shelf-life of grass carp fillets was 8 days for the control and 12 days for the treatment group. According to high-throughput sequencing, Aeromonas and Pseudomonas were the predominant microbiota in fresh grass carp. As storage time progressed, the microbial composition of both control and treatment samples became less diverse. Pseudomonas followed by Aeromonas were dominant in spoiled control samples. However, there were significant differences in microbial composition between control and treatment samples at the end of storage. Cinnamon bark oil treatment inhibited the growth of Aeromonas and Shewanella, and Pseudomonas was the only predominant microbiota found in spoiled treatment samples.
Co-reporter:Na Qin, Longteng Zhang, Jingbin Zhang, Sijia Song, Zhiying Wang, Joe M. Regenstein, Yongkang Luo
Journal of Food Engineering 2017 Volume 215(Volume 215) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.jfoodeng.2017.07.011
•Salted samples showed higher T21 while the T21 of heated flesh was lowered.•Curing treatment improved microbial and sensory quality of super-chilled grass carp.•Pearson's regression analysis supports that LF-NMR can monitor unsalted fish quality.Low Field Nuclear Magnetic Resonance (LF-NMR) was used to evaluate the water mobility in grass carp during super-chilled storage. Grass carps were analyzed for inosine monophosphate (IMP), total viable counts, cooking loss, drip loss, biogenic amines, and sensory. Pearson's regression analysis between LF-NMR parameters and quality indicators was done to assess the feasibility of using LF-NMR to predict fish quality. Three water populations, T2b (<10 ms), T21 (20 ms–80 ms), and T22 (>100 ms), were measured. The major component T21, immobilized water, shifted to longer relaxation time with added salt and sugar due to the swelling of myofibers (P < 0.05). T21 of cooked (85 °C) flesh was lowered, indicating that immobilized water mobility decreased during heating. Curing treatments predominately accelerated IMP formation, inhibited bacterial growth, retarded cooking loss, and improved the overall sensory quality. The study also showed that the LF-NMR was capable of monitoring unsalted fish deterioration.
Co-reporter:Dapeng Li, Na Qin, Longteng Zhang, Jian Lv, Qingzheng Li, Yongkang Luo
Food Chemistry 2016 Volume 211() pp:812-818
Publication Date(Web):15 November 2016
DOI:10.1016/j.foodchem.2016.05.120
•Investigation of the effect of 6 kinds of metal ions on ATP degradation in fillets.•Effects of metal ions on AMP-deaminase and ACP was different.•Metal ions impacts ATP degration by affecting enzyme activities.•Zn2+ is an ideal metal ion to keep the flavor of the fish for a long time.The impact of different concentrations of Na+, K+, Ca2+, Mg2+, Fe2+, and Zn2+ on the degradation of adenosine triphosphate (ATP) and the influence of these ions on the activity of adenosine monophosphate deaminase (AMP-deaminase) and acid phosphatase (ACP) in common carp fillets (in vivo) during 4 °C storage was examined. The content of ATP, inosine monophosphate (IMP), and hypoxanthine (Hx), and the activity of AMP-deaminase and ACP were determined. Results indicated that the effects of different concentrations of six kinds of metal ions on AMP-deaminase and ACP were not the same. Na+, K+, Fe2+, and Zn2+ enhanced AMP-deaminase activity, which led to the rapid degradation of ATP and to the generation of a large quantity of IMP within a short time. Ca2+ and Mg2+ delayed the change in AMP-deaminase and ACP activity in carp and caused a further delay in the degradation of ATP. Fe2+ and Zn2+ inhibited ACP activity, which reduced the decomposition of IMP and the formation of Hx.
Co-reporter:Chunli Kong, Huiyi Wang, Dapeng Li, Yuemei Zhang, Jinfeng Pan, Beiwei Zhu, Yongkang Luo
Food Chemistry 2016 Volume 201() pp:327-333
Publication Date(Web):15 June 2016
DOI:10.1016/j.foodchem.2016.01.088
•Quality of frozen brined carp fillets were evaluated systematically.•RBF neural networks were utilized first in frozen brined carp fillets.•Relative errors of RBF neural networks in prediction were all within ±5%.To investigate and predict quality of 2% brined common carp (Cyprinus carpio) fillets during frozen storage, free fatty acids (FFA), salt extractable protein (SEP), total sulfhydryl (SH) content, and Ca2+-ATPase activity were determined at 261 K, 253 K, and 245 K, respectively. There was a dramatic increase (P < 0.05) in FFA and a sharp decrease (P < 0.05) in SH at 261 K during the first 3 weeks. SEP decreased to 67.31% after 17 weeks at 245 K, whereas it took about 7 weeks and 13 weeks to decrease to the same extent at 261 K and 253 K, respectively. Ca2+-ATPase activity kept decreasing to 18.28% after 7 weeks at 261 K. Furthermore, radial basis function neural networks (RBFNNs) were developed to predict quality (FFA, SEP, SH, and Ca2+-ATPase activity) of brined carp fillets during frozen storage with relative errors all within ±5%. Thus, RBFNN is a promising method to predict quality of carp fillets during storage at 245–261 K.
Co-reporter:Zheng Li, Juan You, Yongkang Luo, and Jianping Wu
Journal of Agricultural and Food Chemistry 2014 Volume 62(Issue 26) pp:6212-6218
Publication Date(Web):May 27, 2014
DOI:10.1021/jf500817f
The prevalence of fish allergy is rapidly increasing because of a growing fish consumption driven mainly by a positive image of the fish and health relationship. The purpose of this study was to characterize parvalbumin isotypes from grass carp (Ctenopharyngodon idella), one of the most frequently consumed freshwater fish in China. Three parvalbumin isotypes were purified using consecutive gel filtration and reverse-phase chromatography and denoted as PVI, PVII, and PVIII. The molecular weights of the isotypes were determined to be 11.968, 11.430, and 11.512 kDa, respectively. PVI showed 74% matched amino acids sequence with PV isotype 4a from Danio rerio, while PVII and PVIII showed 46% matched amino acids sequence with PV isotypes from Hypophthalmichthys molitrix. PVII is the dominant allergen, but it was liable to gastrointestinal enzymes as PVIII; however, PVI was resistant to pepsin digestion. A further study is to characterize the epitopes of PVII, the dominant allergen.
Co-reporter:Juan You;Huixing Shen
Journal of Food Biochemistry 2013 Volume 37( Issue 5) pp:604-610
Publication Date(Web):
DOI:10.1111/jfbc.12012
Abstract
The effect of heat treatment at different temperatures ranging from 30 to 80C on the physicochemical properties of water-soluble proteins from silver carp (Hypophthalmichthys molitrix) was investigated. Silver carp water-soluble proteins would suffer huge denaturation and aggregation from 40 to 55C. Both solubility and total sulfhydryl groups remained constant below 40C and sharply decreased from 50 to 55C. Surface hydrophobicity started to increase at 40C and reached maximum at 70C. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis of heated water-soluble proteins showed that the molecular weights of the main proteins ranged from 30 to 97 kDa. Most of silver carp water-soluble proteins precipitated at 55C. Lyophilization could increase surface hydrophobicity of water-soluble proteins, but decrease its solubility and sulfhydryl groups.
Practical Applications
The results indicate that the physiochemical properties of silver carp water-soluble proteins were greatly affected by processing and it would be a beneficial ingredient for functional food and pharmaceuticals at proper food processing conditions.
Co-reporter:Yulong Bao;Yuemei Zhang;Yangfan Shen
Food Science and Biotechnology 2013 Volume 22( Issue 5) pp:1-5
Publication Date(Web):2013 October
DOI:10.1007/s10068-013-0217-3
To study the quality changes of blunt-snout bream (Megalobrama amblycephala) stored at chilled temperature (0–9°C), a global stability index (GSI) method was developed. Sensory score, total aerobic counts (TAC), total volatile basic nitrogen (TVB-N), and K value (as a percentage of the ratio between HxR (hypoxanthine riboside)+Hx (hypoxanthine) to the total ATP (adenosine triphosphate) and its degradation products) were determined to form a GSI value, and a predictive model of GSI was established by combining zero order kinetics with the Arrhenius equation. The results showed that the goodness of fit remained a high level (R2>0.97), the activation energy (EA) and the corresponding pre-exponential factor (k0) were 83.49 kJ/mol and 4.78×1014 respectively. Relative errors between experimental GSI values and predicted GSI values were all within ±15% before the 15th day. Therefore, the model could effectively predict the quality deterioration of blunt-snout bream during chilled storage.
Co-reporter:Hui Hong, Yongkang Luo, Zhongyun Zhou, Huixing Shen
Food Chemistry 2012 Volume 133(Issue 1) pp:102-107
Publication Date(Web):1 July 2012
DOI:10.1016/j.foodchem.2012.01.002
The effect of low concentration of salt and sucrose on the quality of bighead carp (Aristichthys nobilis) fillets was evaluated over a 16-day storage at refrigerated temperature (4 °C). Fish samples were brined with 1.1% salt (T1) and 1.1% salt + 0.9% sucrose (T2). The control and the treated fish samples were analysed periodically for physicochemical (pH, total volatile base nitrogen (TVB-N), water loss, electrical conductivity (EC), color), microbial (total viable counts) and sensory characteristics. No significant differences were observed between T1 and T2 for sensory score and EC (p > 0.05). Brining treatments predominantly decreased chemical changes, reflected in TVB-N and pH, retarded water loss and discoloration, inhibited bacterial growth and increased the overall sensory quality of fish, compared to untreated fillets. The results indicated that brining treatments improved the quality and safety of bighead carp fillet, which can be exploited by fish processors.Highlights► Effects of low salt and sucrose on the quality of bighead carp fillet were investigated. ► Brining treatments prolonged the shelf life of bighead carp fillet. ► Low salt and sucrose provide good taste to freshwater fish fillet. ► Low salt and sucrose brining is a safe method for preservation of prepared fish.
Co-reporter:JINFENG PAN;HUIXING SHEN;JUAN YOU
Journal of Food Biochemistry 2011 Volume 35( Issue 3) pp:939-952
Publication Date(Web):
DOI:10.1111/j.1745-4514.2010.00431.x
ABSTRACT
Turbidity, lightness, viscosity and Ca2+-adenosine triphosphat ase activity of silver carp myofibrillar protein during heat treatment were investigated. Differential scanning calorimetry (DSC) method was taken to analyze the thermal properties of myofibrillar protein. Turbidity increased as temperature rose, and three peaks of change rate were observed at 48, 64 and 69C; lightness decreased gradually and peaks appeared at 48 and 60C; viscosity declined from 18 to 41C and reached the lowest value at 41C; Ca2+-ATPase activity decreased over range 20 to 31C and 35 to 45C and reduced to zero at 45C, with a slight increase from 31 to 35C; two endothermic peaks exhibited at 48.88 and 70.25C in DSC thermograms.
PRACTICAL APPLICATIONS
Silver carp is one of the main freshwater fish species in China and has been widely used as a raw material for many fish products. Heating plays a great role in lowering quantity of microbe and exerts great influences on organoleptic attributes of products. Research on changes in physicochemical properties of myofibrillar protein during heat treatment can help to understand the thermal denaturation of it and provide practical information for silver carp muscle processing, so as to promote the utilization of huge mount of freshwater fish resources in China.
Co-reporter:QIAN SUN;HUIXING SHEN;XIN HU
Journal of Food Biochemistry 2011 Volume 35( Issue 1) pp:44-61
Publication Date(Web):
DOI:10.1111/j.1745-4514.2010.00365.x
ABSTRACT
The effects of pepsin-assisted hydrolysis conditions on the antioxidant activity (AA) of porcine hemoglobin hydrolysate (PHH) were investigated in this study. Effects of temperature, pH and enzyme to substrate ratio on the AA were evaluated and compared using response surface methodology. Temperature and pH were the major factors affecting the AA. Enzyme to substrate ratio influenced AA to a lesser extent. The model for the AA of PHH was established and it showed a good fit with the experimental data. The PHH (1 mg/mL) showed the strongest AA (65.43%) at 40.4C, pH 1.6, enzyme to substrate ratio = 1.6% (w/w). The degree of hydrolysis (DH) and AA of pepsin-assisted hydrolyzed PHH were significant higher (P < 0.05) than chemical hydrolyzed PHH whatever the hydrolysis time. There was no correlation between DH and AA.
PRACTICAL APPLICATIONS
Blood protein is a by-product of the meat industry with high nutritional and functional value but high pollution power. The proportion of hemoglobin in blood protein is 60–70%. Enzymatic hydrolysis of food proteins generally results in profound changes in the bioactivities of proteins treated. The porcine hemoglobin hydrolysate prepared with pepsin at the optimal hydrolysis conditions was a potent natural free radical scavenger, which would be expected to protect against oxidative damage in living systems and might be potential anti-oxidant for application in food, cosmetic and medicine industries.
Co-reporter:Xiaochang Liu, Yuemei Zhang, Dapeng Li, Yongkang Luo
Food Microbiology (April 2017) Volume 62() pp:106-111
Publication Date(Web):1 April 2017
DOI:10.1016/j.fm.2016.10.007
•Microbiota of lightly salted freshwater fish fillets were conducted.•Light salting dramatically inhibited the growth of Aeromonas.•Aeromonas was dominant in spoiled unsalted bighead carp fillets.•Pseudomonas was dominant in spoiled salted bighead carp fillets.The microbiota of unsalted and salted (dry-cured with 2% salt) bighead carp (Aristichthys nobilis) fillets during storage at 4 °C were identified by 16S rRNA gene analysis. Eleven genera were present in the initial microbiota of bighead carp fillets, where Acinetobacter, Aeromonas and Kocuria were the dominant bacteria. As storage time progressed, the microbial composition of both unsalted and salted fillets became less diverse. Additionally, differences in microbiota were observed between these two treatments. For unsalted bighead carp fillets, Aeromonas became the dominant genus at the end of storage and Pseudomonas was found less commonly. For salted fillets, Pseudomonas was the only bacteria identified at the end of storage.
Co-reporter:Yuemei Zhang, Dongping Li, Jian Lv, Qingzheng Li, Chunli Kong, Yongkang Luo
International Journal of Food Microbiology (16 May 2017) Volume 249() pp:1-8
Publication Date(Web):16 May 2017
DOI:10.1016/j.ijfoodmicro.2016.10.008
•High-throughput sequencing was used to assay bacterial diversity in carp samples•Macrococcus and Aeromonas dominated the bacterial flora of fresh carp•Aeromonas followed by Lactococcus were predominant in spoiled vacuum-packed carp•Cinnamon essential oil inhibited Aeromonas in vacuum-packed carp during storage•Cinnamon essential oil treatment extended shelf-life of vacuum-packed carpThe present study investigated the effect of cinnamon essential oil on the quality of vacuum-packaged common carp (Cyprinus carpio) fillets stored at 4 ± 1 °C in terms of sensory scores, physicochemical characteristics (total volatile basic nitrogen (TVB-N), biogenic amines, and color), and presence of spoilage microbiota. A total of 290,753 bacterial sequences and 162 different genera belonging to 14 phyla were observed by a high-throughput sequencing technique targeting the V3–V4 region of 16S rDNA, which showed a more comprehensive estimate of microbial diversity in carp samples compared with microbial enumeration. Before storage, Macrococcus and Aeromonas were the prevalent populations in the control samples, but cinnamon essential oil decreased the relative abundance of Macrococcus in the treated samples. Variability in the predominant microbiota in different samples during chilled storage was observed. Aeromonas followed by Lactococcus were the major contaminants in the spoiled control samples. Microbial enumeration also observed relatively higher counts of Aeromonas than other spoilage microorganisms. Compared with the control samples, cinnamon essential oil inhibited the growth of Aeromonas and Lactococcus were the predominant components in the treated samples on day 10; plate counts also revealed a relatively high level of lactic acid bacteria during refrigerated storage. However, there were no significant differences (P > 0.05) in the composition of dominant microbiota between these two treatments at the end of the shelf-life. Furthermore, cinnamon essential oil treatment was more effective in inhibiting the increase of TVB-N and the accumulation of biogenic amines (especially for putrescine and cadaverine levels). Based primarily on sensory analysis, the use of cinnamon essential oil extended the shelf-life of vacuum-packaged common carp fillets by about 2 days.
Co-reporter:Han Lu, Longteng Zhang, Qingzheng Li, Yongkang Luo
Food Chemistry (15 May 2017) Volume 223() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.foodchem.2016.11.143
•A certain range in contents of disulfide crosslinks promotes gel hardness.•Mild protein oxidation (−20 °C for 7 weeks or 0.1 mM H2O2) promoted gel properties.•Freezing bighead carp for a certain period was a good source of gel products.We wanted to clarify whether gel properties can be affected by in vivo or in vitro myofibrillar protein oxidation and, thus, to provide relevant information and a scientific foundation for the processing of gel products. To accomplish this, we measured the changes in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), total disulfide (SS) content, surface hydrophobicity (So-ANS), carbonyl content, and gel texture and water-holding capacity (WHC) of isolated myofibrillar protein from bighead carp fillets during frozen storage and under different H2O2 concentrations, which were used to represent in vivo and in vitro conditions, respectively. The results indicated that a certain range in content of disulfide crosslinks (0.91 mol/105 g protein) would promote gel hardness. Mild protein oxidation caused by a certain degree of frozen storage and hydroxyl radicals can promote gel texture and WHC. Based on those results, freezing bighead carp for a certain period can be used to produce gel products.
Co-reporter:Sichao Zhu, Zhongyun Zhou, Ligeng Feng, Yongkang Luo
Food Bioscience (1 March 2015) Volume 9() pp:75-79
Publication Date(Web):1 March 2015
DOI:10.1016/j.fbio.2014.12.003
In order to estimate the physicochemical changes of songpu mirror carp (Cyprinus carpio) during 72 h postmortem storage in ice, the concentration of ATP and related compounds, texture parameters, pH value, color parameters and water holding capacity (WHC) were studied. The inosine monophosphate (IMP) concentration in songpu mirror carp increased to top at 36 h while the pH reached the lowest value at 8 h after slaughter. Adenosine triphosphate (ATP) concentration, texture parameters (hardness, adhensiveness, springiness cohesiveness, gumminess, chewiness and resilience) and WHC all reached the extreme values within 2 h during postmortem storage. K value increased from 1.41% to 7.50% during the whole storage. Both a⁎ and b⁎ values showed no significant change after 8 h. The ice-stored songpu mirror carp has obtained better characteristics for processing and consuming at 2–4 h after slaughter.
Co-reporter:Dapeng Li, Longteng Zhang, Sijia Song, Zhiying Wang, Chunli Kong, Yongkang Luo
Food Chemistry (1 June 2017) Volume 224() pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.foodchem.2016.12.056
•AMPD was derived from the carp itself, and less related to the microbe.•ACP was derived from the carp in the first 2 days’ storage.•ACP was derived from both fish and spoilage bacteria in middle and later stages of storage.•Degradation of ATP to IMP was less related to the microorganism.•Transformation of HxR to Hx was quite related with spoilage bacteria.Biochemical and microbial changes after harvest strongly affect the final quality and shelf life of fish and fish products. In this study, the role of microbes in the degradation of adenosine triphosphate (ATP), and the origin of adenosine monophosphate deaminase (AMPD) and acid phosphatase (ACP) in common carp fillets during different stages of chilled storage (at 4 °C) were investigated. The content of ATP, ADP, AMP, IMP, HxR, and Hx, the activity of AMPD and ACP, and the total count of viable, Aeromonas, Pseudomonas, H2S-producing bacteria, and lactic acid bacteria were examined. Results indicated that the population of microbial communities in control samples increased with storage time, and Pseudomonas peaked on the 10th day of storage. Changes in AMPD activity were less related to the abundance of microbes during the entire storage period. However, ACP was derived from both fish muscle and microbial secretion during the middle and late stages of storage. Degradation of ATP to IMP was not affected by spoilage bacteria, but the hydrolysis of IMP, and the transformation of HxR to Hx was affected considerably by the spoilage bacteria.
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