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Three modeling techniques namely multilayer perceptron artificial neural network (MLPANN), microbial kinetic with Levenberg-Marquardt algorithm (MKLMA) developed from microbial growth, and the response surface methodology (RSM) were used to investigate the biohydrogen (BioH2) process. The MLPANN and MKLMA were used to model the kinetics of major metabolites during the dark fermentation (DF). The MLPANN and RSM were deployed to model the electron-equivalent balance (EEB) from the cumulative data (after 24 h fermentation) during the DF. With the additional experimental results of kinetic data (20 × 10) and cumulative data (18 × 9), the uncertainties of different models were compared. A new effective strategy for modeling the complex BioH2 process during the DF is proposed: MLPANN and MKLMA are used for the investigation of kinetics of the major metabolites from the limited numbers of experimental data set, and the MLPANN and RSM are used for statistical analysis of the investigated operational parameters upon the major metabolites through EEB perspective. The proposed strategy is a useful and practical paradigm in modeling and optimizing the BioH2 production during the dark fermentation.

Peach fruit are prone to development of chilling injury during cold storage at around 0–7 °C. Nitric oxide (NO) has been proven to alleviate chilling injury, but the mechanism was still unclear. In this study, peach fruit were immersed in a NO donor (sodium nitroprusside, SNP) solution for 10 min, then stored at 0 °C. The SNP alleviated chilling injury, including decreasing the internal browning index, malondialdehyde content, electrolyte leakage, and lipoxygenase activity, and maintaining firmness. Furthermore, SNP maintenance of fruit firmness was associated with reduction of xyloglucan endotransglycosylase/hydrolase family member gene expression and decrease of cell wall hydrolase activity, especially the activities of polygalacturonase, xyloglucan endoglycosyl transferase, cellulase, and β-galactosidase. Meanwhile, SNP regulated the lipid metabolism by up-regulating the expression of genes encoding glycerol-3-phosphate acyltransferase, ketoacy-ACP synthase, phosphatidylinositol bisphosphate and long-chain acyl-CoA. Thus, the results of this study indicate that SNP alleviates chilling injury of post-harvest peach fruit by regulating cell wall and lipid metabolism.

A novel technique of CO2-assisted High Pressure Processing (CO2-HPP) was originally applied to cucumber juice at pH 5.81 and apple juice at pH 3.83. CO2-HPP was carried out with CO2 of 0.98 mmol/container assisted 600 MPa/3 min. The changes of microorganism, enzymes and quality characteristics were discussed during 15 days of storage (4 °C). Compared with HPP, CO2-HPP enhanced inactivation effect on total aerobic bacteria (TAB) in cucumber juice with 0.604 log10 CFU/mL extra reduction. During storage, CO2-HPP showed remarkable inhibition on the growth of TAB and lactobacillus in cucumber juice with 1.25 and 0.72 log10 CFU/mL lower than HPP-treated samples. Similarly, TAB and yeast and molds (Y&M) in CO2-HPP treated apple juice were 0.51 and 0.53 log10 CFU/mL lower than HPP-treated samples at the end of storage. Denaturation of polyphenol oxidase in apple juice was enhanced by CO2-HPP with only 0.5% residual activity left which contributed to stable contents of ascorbic acid and total phenol, while it was 87.0% in HPP-treated juice. However, lipoxygenase in CO2-HPP treated apple juice was 31.86% higher than that in HPP-treated samples leading to better flavor in CO2-HPP treated samples. CO2-HPP could be an alternative technique in production of high quality juice.

Roasted fish enjoys great popularity in Asia, but how roasting and subsequent digestion influence the oxidation and proteolysis of fish meat is unknown. This study aimed to investigate the effect of roasting time on lipid and protein oxidation and their evolution and consequence on proteolysis during simulated digestion of fish fillets.; Results: Several oxidation markers (thiobarbituric acid-reactive substances (TBARS), free thiols, total carbonyls and Schiff bases) were employed to assess the oxidation of fish. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay for free amino groups were used to study the proteolysis during gastrointestinal digestion. The results showed that significant lipid and protein oxidative changes occurring in roasted fish fillets were reinforced after gastric digestion and were much more intense after intestinal digestion. Throughout roasting and digestion, a close interconnection between lipid and protein was also manifested as the levels of total carbonyls and Schiff bases rose while TBARS fell. Furthermore, free amino groups decreased with prolonged roasting time, signifying that protein oxidation before digestion resulted in impaired proteolysis during digestion.; Conclusion: This study indicated that the lipid and protein oxidation of fish fillets could be dependent on time of roasting, and the oxidation continued to develop and have an impact on proteolysis during in vitro digestion. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Reducing starch digestibility can be beneficial to control the increasing of postprandial blood glucose and reduce the risk of diabetes, obesity, and other related chronic diseases. In this study, the structure, digestibility and physicochemical properties of rice flour under radio frequency (RF) treatment was investigated. The structural properties of rice flour were characterized by the X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and particle size analyzer. The results showed that RF treatment caused the aggregation of starch granules, resulting in the increase of particle size. The relative crystallinity and the short-range order of rice flour were reduced following RF treatment. In vitro digestibility results showed that the resistant starch content of indica, japonica and waxy rice flour (IRF, JRF and WRF) increased from 39.04% to 42.02%, 39.95%–45.12% and 36.26%–43.61% after RF treatment, respectively. Moreover, RF treatment reduced the peak viscosity and breakdown of IRF and JRF, whereas enhanced them in WRF. After RF treatment, the G′ and G″ of all samples increased, while the tan δ displayed an opposite trend. These results suggest that RF treatment has the potential to modify rice flour for extending its application range in food industries.

The objective of this study was to investigate the effect of ultra-high pressure treatment (0, 100, 200, 300, 400, and 500 MPa, respectively) on shucking (crayfish meat yield) and meat properties (moisture content, thermal characteristics, texture properties, protein pattern and microstructure) of red swamp crayfish (Procambarus clarkia). Comparing to the control, the crayfish meat yield increased and the moisture content decreased for the samples with the high pressure treatments, however no significant difference was observed when the pressure above 200 MPa. The denaturation enthalpy (△H) of three endothermic peaks normally found at 50 °C, 65 °C, and 80 °C were all significantly shifted to lower value (p

CO 2 -assisted high pressure processing was termed as CO 2 -HPP, and the inactivation of Escherichia coli and Staphylococcus aureus in liquid samples were treated by CO 2 -HPP in this study. When CO 2 made up 20% of the total volume, it exhibited assisted inactivation of E. coli and S. aureus in phosphate buffered saline (PBS, pH 7.0) under HPP. Twenty percent CO 2 -300 MPa/3 min induced 1.0 and 2.5 more log units reduction of E. coli and S. aureus than 300 MPa/3 min, respectively. Both mid-exponential and stationary phase cells of E. coli and S. aureus showed higher sensitivity to CO 2 -HPP than HPP. However, the two microbes showed different inactivation behavior in real food of cucumber juice (pH 6.6) and apple juice (pH 4.3), and CO 2 -HPP was more suitable for S. aureus than E. coli in the two juices. As compared with HPP, CO 2 -HPP showed more severe damage on morphology and intracellular structure of E. coli and S. aureus cells through transmission electron microscopy (TEM), scanning electron microscopy (SEM), and flow cytometer microscopy (FCM), including appearance of collapsed cells, cell disruption, and more holes on cell membrane, membrane permeability, and strength of cytoplasm aggregation, which were probably due to the penetration, explosion, and acidification of CO 2 under HPP. The CO 2 -assisted inactivation of bacteria subject to HPP has the potential application in food industry, especially for liquid food.

The objective of the present study was to investigate the effects of superchilling with modified atmosphere packaging on the physicochemical properties and shelf life of swimming crab. As the storage time increased, the rates at which the total aerobic plate count, total volatile basic nitrogen, pH, peroxide value and thiobarbituric acid-reactive substances value increase were significantly lower for the superchilling with modified atmosphere packaging (SCS + MAP) treatment compared to superchilling storage (SCS) and chilling storage (CS). With increasing storage time, the carbonyl content of the proteins increased from 1.21 nmol/mg of protein (0 day) to 2.03, 1.87, 1.66 nmol carbonyl/mg protein on the 6th day for CS, SCS and SCS + MAP, respectively. The disulfide bonds increased in a similar manner, and the total sulfhydryl content, salt extractable protein and Ca-ATPase stability decreased. Sodium dodecyl sulphate polyacrylamide gel elcetrophoresis (SDS-PAGE) and microstructure analysis also indicated that SCS + MAP could reduce the degree of protein degradation. These results suggested that superchilling with modified atmosphere packaging offers an effective approach to slowdown protein and lipid oxidation, and extends the shelf life of swimming crab. However, superchilling with high-CO2 packaging had a negative effect on the surface hydrophobicity and drip loss of swimming crab.

The effect of different cooking methods on protein and lipid oxidation of farmed sturgeon (Acipenser gueldenstaedtii) was investigated. In this study, the fish fillets were cooked using five different methods (boiling, steaming, microwaving, roasting and deep-frying), to an internal temperature of approximately 85 °C. General indexes for protein oxidation (carbonyls, free thiols and Schiff bases) and lipid oxidation were evaluated by spectrophotometric and fluorimetric methods. Side-chain modifications of amino acid residues were pinpointed by gel- and MS-based proteomic technology. The results are as follows: (1) cooking, especially roasting and frying, significantly increased the levels of carbonyls and Schiff bases and decreased the amounts of free thiols. (2) Oxidation of aromatic amino acids and extensive oxidation of lysine to carbonyl-containing compounds were characterized in all the cooked samples. (3) Indirect protein oxidation caused by interacting with lipid-derived aldehydes like malondialdehyde (MDA) and 4-hydroxynonenal (HNE) was also observed and much more pronounced in roasted and fried samples, giving a footprint of lipid–protein interaction during cooking. In summary, cooking treatment can induce protein oxidation in sturgeon fillets with a variety of modifications occurring at the protein primary structure. Molecular mapping of protein oxidation is conducive to understand the mechanism of cooking-induced protein oxidation and allows better control of the nutritional properties of protein-based products.

Electrolyzed water (EW) considered as a novel broad-spectrum and high-performance bactericide has gained immense popularity over the last few decades. It offers several advantages over other sanitizers for sanitation of both food contact and noncontact surfaces, such as safety, effective disinfection, easy operation, relatively inexpensive, and environmentally friendly. EW can be produced by electrolyzing soft tap water with sodium chloride as the chemical additive. Different producing equipment and parameters greatly influence the types and properties of EW. During production period, preparation settings are vital factors on the basic properties of EW (available chlorine concentration (ACC), pH, and oxidization reduction potential (ORP)) and then influence its inactivation efficiency, including current, water flow rate, salt/acid concentration, electrolyte and electrode, water temperature and hardness, storage environments, and so on. This chapter provides an overview of the production, properties, types of EW, as well as a section on its advantages and disadvantages.

In recent years, power ultrasound (PU) has attracted considerable interest in food science and technology due to its promising applications in food processing and preservation. It is well known to have significant effects on the rate of various processes in the food industry, and it is recognized as innovative technology for achieving the objective of sustainable “green” chemistry and industrialization. Using ultrasound, food processes can be completed in seconds or minutes with higher reproducibility, lower processing costs, easier operation, higher product purity, elimination of post-treatment of waste water, and lower energy requirements than traditional processes. Several processes such as extraction, degradation, sterilization, and enzyme modification have been applied efficiently in the food industry. Food processes performed under ultrasound treatment will be affected by cavitation phenomena and mass transfer processes. This chapter presents the current knowledge on the applications of ultrasound in food processing.

Roasted fish enjoys great popularity in Asia, but how roasting and subsequent digestion influence the oxidation and proteolysis of fish meat is unknown. This study aimed to investigate the effect of roasting time on lipid and protein oxidation and their evolution and consequence on proteolysis during simulated digestion of fish fillets.Several oxidation markers (thiobarbituric acid-reactive substances (TBARS), free thiols, total carbonyls and Schiff bases) were employed to assess the oxidation of fish. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay for free amino groups were used to study the proteolysis during gastrointestinal digestion. The results showed that significant lipid and protein oxidative changes occurring in roasted fish fillets were reinforced after gastric digestion and were much more intense after intestinal digestion. Throughout roasting and digestion, a close interconnection between lipid and protein was also manifested as the levels of total carbonyls and Schiff bases rose while TBARS fell. Furthermore, free amino groups decreased with prolonged roasting time, signifying that protein oxidation before digestion resulted in impaired proteolysis during digestion.This study indicated that the lipid and protein oxidation of fish fillets could be dependent on time of roasting, and the oxidation continued to develop and have an impact on proteolysis during in vitro digestion. © 2018 Society of Chemical Industry.

Freshly harvested bamboo (Phyllostachys violascens) shoots were stored for 35 days under various hypobaric conditions (101, 75, 50 and 25 kPa) at 2 ± 1 °C to investigate the effects of hypobaric storage on flesh lignifications. It was found that hypobaric storage at 50 kPa was most effective in preventing the increase in shoots firmness and allied accumulations of lignin and cellulose. Furthermore, the hypobaric storage at 50 kPa inhibited the ethylene production, reduced the rate of O 2 · − production and the accumulation of malondialdehyde (MDA) and H 2 O 2 , and maintained significantly higher activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), but restrained the activities of phenylalanine ammonia-lyase (PAL) and peroxidase (POD). These data indicate that the delay in flesh lignification of bamboo shoots by hypobaric storage was due to maintenance of higher antioxidant enzymes activities and reduced ethylene production, leading to less ROS accumulation and better cell-membrane integrity.

The effects of high pressure processing (HPP) on the activity of soluble acid invertase (SAI) in mango pulp, crude extract, purified SAI and purified SAI in model systems (pectin, bovine serum albumin (BSA), sugars and pH 3–7) were investigated. The activity of SAI in mango pulp was increased after HPP, and that in crude extract stayed unchanged. The activity of purified SAI was decreased after HPP at 45 and 50 °C. Pectin exhibited a concentration-dependent protection for purified SAI against HPP at 50 °C/600 MPa for 30 min. Pectin that had an esterification degree (DE) of 85% exhibited a greater protection than pectin that had a DE of 20–34%. BSA, acidic pH (3–6) and sucrose also exhibited protection for purified SAI against HPP. HPP at 50 °C/600 MPa for 30 min disrupted the secondary structure and tertiary structure of purified SAI, but no aggregation of purified SAI was observed after HPP.