preparation-of-high-quality-fermented-fish-product

Preparation of High-Quality Fermented Fish Product

This protocol provides a method for preparation of industrialized fermented fish product with sturgeon (Aquilaria sinensis) meat product. The procedures ...

establishing-silicosis-rat-model-via-exposure-whole-body-to

Establishing a Silicosis Rat Model via Exposure of Whole-Body to Respirable Silica

The major cause of silicosis is the inhalation of silica in the occupational environment. Despite some anatomical and physiological differences, rodent ...

Jiangnan University

North China University of Science and Technology

The aim of this study was to investigate endogenous proteolytic activities in a cod product and their impact on muscle proteins and textural properties during fermentation and storage. The result of specific proteolytic activities showed that cathepsins, especially cathepsin B, had the highest activities during fermentation and storage. SDS-PAGE indicated more degradation of myofibrillar proteins by cathepsin L than other proteases and that the hydrolysis by cathepsins was pronounced in the last stage of fermentation. Texture analysis showed that cathepsins had a negative impact on gel strength and this impact increased in the last stage of fermentation. However the product still had a firm texture. During storage (4 °C) for one week, no significant changes were seen in the gel strength. In conclusion, cathepsins had more impact on muscle proteins and textural properties than other proteases during fermentation but had little impact on gel strength during storage at 4 °C.

Endogenous proteolytic enzymes--a study of their impact on cod (Gadus morhua) muscle proteins and textural properties in a fermented product.

The study was aimed to investigate different roles of endogenous and Lactobacillus plantarum proteases during fast fermentation of silver carp. The results show that endogenous proteases could degrade both sarcoplasmic and myofibrillar proteins. In contrast, L. plantarum had low proteinase activities and could only hydrolyze sarcoplasmic peptides. This indicates that gel properties could be mainly affected by endogenous proteolysis while microbial proteolysis contributed to the production of smaller peptides and free amino acids which may be related to flavor and taste. Texture and free amino acid analyses verified these hypotheses. It shows that endogenous lysosomal proteases were the major contributors for the decrease of gel strength while L. plantarum proteolytic activities could lead to the increase of aspartic acid, glutamic acid, and alanine, which may result in umami and sweet taste; and also lead to a rise in some amino acids which were volatile compounds precursors. 

A comparison of endogenous and microbial proteolytic activities during fast fermentation of silver carp inoculated with Lactobacillus plantarum.

The aim of the present study was to compare the different effects of berberine (Ber) and Coptischinensis extract (CCE) on a rat model of type 2 diabetes mellitus (T2DM), and the islet Rin‑5f cell line was used to examine the differences between Ber and CCE and the underlying mechanisms. CCE was extracted and purified prior to analysis. Male Sprague‑Dawley rats were provided with a high‑fat diet to induce insulin resistance prior to injecting with streptozotocinto establish the T2DM model, the T2DM rats were treated with Ber and CCE, and blood samples and pancreatic tissues were obtained and compared to examine T2DM metabolic syndromes among the groups of rats, which included healthy rats, model rats, and model rats treated with Ber and CCE at different doses between 0 and 8 weeks. The protective effects of Ber and CCE on the Rin‑5f islet cell line were also evaluated. The effects on Rin‑5f cell proliferation and cell cycle, glucose‑stimulated insulin release test (GSIS), the anti‑apoptotic effects caused by fat induction, and protein expression levels of poly ADP‑ribose polymerase (PARP‑1) were evaluated. The results showed that the content of the prepared CCE was 96.07% for five alkaloids. When it was used for treatment of the T2DM rats, compared with Ber, metformin and rosiglitazone, the fasting blood glucose, glucosylated serum protein (GSP) and glucose infusion rate indicesin the fasting rats were ameliorated, compared with those in the T2MD rats, with no significant differences between treatment with Ber or CCE and metformin or rosiglitazone. The indices of mean optical density and fasting β‑cell function index (FBCI) were different following treatment with Ber and CCE, compared with those in the model rats, which may have stimulated the pancreatic secretion of insulin. When Ber and CCE were used to examine the protective effects on Rin‑5F cells, it was found that the Rin‑5f cell GSIS, cell cycle, lipotoxic islet cell proliferation and protein expression of PARP‑1 were altered and improved, which may have protected pancreatic islet β‑cells by improving islet β‑cell proliferation and the protein expression of PARP‑1. CCE and Ber exerted similar effects when used for the treatment of T2MD rats, and may have stimulated the pancreatic secretion of insulin through the protective effect on islet β‑cells via improving islet β‑cell proliferation and the protein expression of PARP‑1.

Protective role of berberine and Coptischinensis extract on T2MD rats and associated islet Rin‑5f cells.

This study investigated the effects of chitosan-based coatings on flavor retention of refrigerated grass carp fillets by using various indicators: free amino acids (FAA), nucleotides, trimethylamine (TMA), volatile profile, sensory quality, and electronic nose analysis. The results indicated that chitosan-based coatings contributed to the significant reduction of off-flavor compounds, such as TMA, hypoxanthine (Hx) and histidine, and accumulation of inosine monophosphate (IMP) and umami-associated FAA. GC-MS analysis showed 23 volatile organic compounds, including many C-C aldehydes and alcohols in the fresh fillets. The coating treatments, especially chitosan-clove bud essential oil composite coatings, sharply reduced the relative content of off-odor volatiles, such as hexanal, octanal and 1-octen-3-ol. According to the results of the sensory evaluation and electronic nose analyses, chitosan coating combined with glycerol monolaurate and clove bud essential oil was a promising method to improve the edibility of grass carp fillets by maintaining flavor quality during refrigerated storage.

The effects of edible chitosan-based coatings on flavor quality of raw grass carp (Ctenopharyngodon idellus) fillets during refrigerated storage.

The study evaluated the inhibitory effects of chitosan-based coatings on endogenous enzyme activities, proteolytic degradation and texture softening of grass carp (Ctenopharyngodon idellus) fillets stored at 4 °C for 15 days. In general, the inhibitory effects of chitosan coating were worse than that of chitosan composite coatings, which significantly inhibited cathepsin B, B + L and calpain activities of fillets, with the most reductions of 58%, 65% and 41%, respectively when compared to the corresponding values of control fillets. Besides, the treatments also retarded the proteolytic degradation through quantifiable indicators including salt-soluble proteins (SSP), TCA-soluble peptides and SDS-PAGE pattern. After storage of 15 days, the shear forces of coated fillets were 28-53% higher than that of control samples. These results indicated that chitosan composite coating combined with glycerol monolaurate and clove essential oil improved the quality of refrigerated grass carp fillets by alleviating endogenous enzyme induced proteolysis and softening.

Inhibitory effects of chitosan-based coatings on endogenous enzyme activities, proteolytic degradation and texture softening of grass carp (Ctenopharyngodon idellus) fillets stored at 4 °C.

The main goal of this study was to investigate the dynamics, diversity and succession of microbial community present during the preparation of Suan yu (fermented fish), with and without starter cultures by high-throughput sequencing of 16S rRNA and ITS1 genes. Firmicutes and Ascomycota were the predominant phyla of bacteria and fungi, respectively, in all samples. At the genus level, Lactobacillus, Macrococcus and Staphylococcus were the predominating bacteria throughout the fermentation process, regardless of the inclusion of starter cultures. Saccharomyces was the predominating fungal genus in the early-fermentation stage of samples that inoculated starter cultures (MS), while the final product was dominated by Candida and Wickerhamomyces. Compared with naturally-fermented samples (NS; no starter cultures), Lactococcus, Leuconostoc, Enterococcus, Vibrio, Fusicolla and Torulaspora were inhibited and Aureobasidium emerged in samples inoculated with starter cultures (P < .05). Unweighted pair-group and principal component analyses of bacterial and fungal compositions revealed that microbiota structures differed between NS and MS samples. Redundancy analysis indicated that water content and pH might be important factors influencing the dominant bacterial and fungal community. Results indicated that microbial community were dynamic during fermentation process and the inoculation of mixed starter culture inhibited the growth of many organisms associated with food spoilage and contributed to the improvement of the quality of Suan yu products.

Dynamics and diversity of microbial community succession during fermentation of Suan yu, a Chinese traditional fermented fish, determined by high throughput sequencing.

Phospholipid molecular species composition of Chinese traditional low-salt fermented fish (Suan yu) inoculated with different starter cultures was investigated. Fifty-six molecular species of phospholipid including 20 species of phosphatidylcholine (PC), 15 species of phosphatidylethanolamine (PE), 6 species of phosphatidylserine (PS), 9 species of lysophosphatidylcholine (LPC), and 6 species of lysophosphatidylethanolamine (LPE) were identified using ultra-performance liquid chromatography with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). PC (C16:0-C18:1), PE (C16:0-C22:6), PS (C15:0-C22:6), LPC (C22:6) and LPE (C22:5) were the predominant species. Bioactive polyene phospholipids mainly existed in PE. Furthermore, starter cultures exhibited different influence on phospholipid molecular species. Compared to naturally fermented Suan yu, more molecular species of PE and PS as well as polyene phospholipids were detected in the samples inoculated with Saccharomyces cerevisiae 31 and mixed starter cultures.

Phospholipid molecular species composition of Chinese traditional low-salt fermented fish inoculated with different starter cultures.

Obscure pufferfish (Takifugu obscurus) softening during frozen storage remains to be solved. This study was therefore aimed to provide explanations by differentiate the roles of three potential factors in fish softening. The influences of ice crystal, endogenous proteolytic activities, and oxidization were distinguished by treatment of fish fillets with liquid nitrogen, iodoacetic acid, and tea polyphenol with ascorbic acid, respectively. This distinguishing method was verified to be effective by investigation in ice crystal microstructure, endogenous proteolytic activities and lipid and protein oxidation. In comparison of three factors, it showed that the shear force of fish fillets with smaller ice crystals was about 15.5% and 13.7% higher than those with the inhibition of endogenous proteolytic activities and oxidation respectively, indicating the dominant role of ice crystal in frozen fish softening. Besides, quality decline of frozen fish was initially fast and then slowed down during the storage.

Differential roles of ice crystal, endogenous proteolytic activities and oxidation in softening of obscure pufferfish (Takifugu obscurus) fillets during frozen storage.

BRAF V600E is the most common mutation identified in thyroid cancers. However, the relationship between BRAF V600E and metabolic reprogramming in thyroid cancer is unclear. Here, we investigate the mechanism of metabolic reprogramming in BRAF V600E thyroid cancer by constructing BRAF V600E-overexpressing and BRAF-knockdown thyroid cell lines for use in mitochondrial respiration and glycolysis experiments. Western blot and RT-qPCR were performed to measure the level of metabolism-related proteins, and various approaches were used to investigate transcriptional regulation. In thyroid cancer cells, the overexpression of BRAF V600E inhibited OXPHOS gene expression and mitochondrial respiration but enhanced aerobic glycolysis. Clinical thyroid cancer samples carrying the BRAF V600E mutation had suppressed levels of PGC-1β but increased expression of HIF1α. Our results show that BRAF V600E reduced mitochondrial respiration by decreasing the expression of PGC-1β. In addition, HIF1α, which is a target of BRAF V600E, was found to regulate the expression of PGC-1β via MYC. Furthermore, glycolysis-related enzymes, such as LDHA and PKM2, were upregulated in BRAF V600E mutant thyroid cancer specimens, thereby promoting glycolysis. MEK1/2 inhibitor treatment enhanced the specific dependence of BRAF V600E mutant thyroid cancer on mitochondrial respiration. These results indicate that in thyroid cancer, the BRAF V600E mutation alters the HIF1α-MYC-PGC-1β axis, causing mitochondrial respiration to be inhibited and aerobic glycolysis to be enhanced.

Mitochondrial metabolism is inhibited by the HIF1α-MYC-PGC-1β axis in BRAF V600E thyroid cancer.

Fishery products are delicious, nutritional and healthy foods, and their popularity in today's market is growing. With the changes in consumer consumption expectations as well as the development of reliable cold-chains, fresh preprocessed fishery products such as fillets are more popular with consumers and producers because of their convenience for processing and cooking. However, fishery products after being removed from water have a short shelf life due to their intrinsic characteristics. Therefore, developing effective preservation technology to extend postmortem shelf life of fishery products has been an on-going area of study. This review summarizes the patterns of quality deterioration and external factors that affect postmortem quality of fishery products, and then updates the recent advances with preservation methods for fishery products including superchilling, modified atmosphere packaging, active packaging, edible coatings, irradiation and high hydrostatic pressure. Moreover, the advantages and disadvantages of each technology are discussed, and future trends for improving the preservation of fishery products are also discussed.

ArticleTotal : 2	Year
Publication title Cited by 4	2019
Publication title Cited by 2	2022

Article	Year
Endogenous proteolytic enzymes--a study of their impact on cod (Gadus morhua) muscle proteins and textural properties in a fermented product. Food chemistry\| PubMed ID: 25442591	2015
A comparison of endogenous and microbial proteolytic activities during fast fermentation of silver carp inoculated with Lactobacillus plantarum. Food chemistry\| PubMed ID: 27080883	2016
Protective role of berberine and Coptischinensis extract on T2MD rats and associated islet Rin‑5f cells. Molecular medicine reports\| PubMed ID: 28901416	2017
The effects of edible chitosan-based coatings on flavor quality of raw grass carp (Ctenopharyngodon idellus) fillets during refrigerated storage. Food chemistry\| PubMed ID: 29037708	2018
Inhibitory effects of chitosan-based coatings on endogenous enzyme activities, proteolytic degradation and texture softening of grass carp (Ctenopharyngodon idellus) fillets stored at 4 °C. Food chemistry\| PubMed ID: 29751895	2018
Dynamics and diversity of microbial community succession during fermentation of Suan yu, a Chinese traditional fermented fish, determined by high throughput sequencing. Food research international (Ottawa, Ont.)\| PubMed ID: 30007719	2018
Phospholipid molecular species composition of Chinese traditional low-salt fermented fish inoculated with different starter cultures. Food research international (Ottawa, Ont.)\| PubMed ID: 30007741	2018
Differential roles of ice crystal, endogenous proteolytic activities and oxidation in softening of obscure pufferfish (Takifugu obscurus) fillets during frozen storage. Food chemistry\| PubMed ID: 30583396	2019
Mitochondrial metabolism is inhibited by the HIF1α-MYC-PGC-1β axis in BRAF V600E thyroid cancer. The FEBS journal\| PubMed ID: 30768848	2019
Recent advances in quality retention of non-frozen fish and fishery products: A review. Critical reviews in food science and nutrition\| PubMed ID: 30924360	2019

Fang Yang

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