Physicochemical characteristics, protein hydrolysis, and textual properties of surimi during fermentation with Actinomucor elegans

Quality and flavor development of solid-state fermented surimi with Actinomucor elegans: A perspective on the impacts of carbon and nitrogen sources

The influence of four carbon and nitrogen substrates on the quality and flavor of a novel surimi-based product fermented with Actinomucor elegans (A. elegans) was investigated, with a focus on carbon and nitrogen catabolite repression. The results showed that the substrate significantly affected mycelial growth, enzyme activities, and the metabolites of A. elegans. Although glucose significantly promoted A. elegans growth by 116.69%, it decreased enzyme secretion by 69.79% for α-amylase and 59.80% for protease, most likely by triggering the carbon catabolite repression pathway. Starch, soy protein, and wheat gluten substantially affected the textural properties of the fermented surimi. Furthermore, wheat gluten significantly promoted the protease activity (102.70%) and increased protein degradation during surimi fermentation. The fishy odor of surimi was alleviated through fermentation, and a correlation between the volatile compounds and A. elegans metabolism was observed. These results explore fermentation substrates in filamentous fungi metabolism from a catabolite repression perspective.

Physiochemical Quality, Microbial Diversity, and Volatile Components of Monascus-Fermented Hairtail Surimi

In order to study the effects and mechanism of Monascus on the quality of hairtail surimi, high-throughput sequencing technology, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS), and electronic nose techniques were used to investigate the changes in the quality, microbial diversity, and volatile flavor compounds of Monascus-fermented hairtail surimi (MFHS) during fermentation. The results showed that the total volatile basic nitrogen (TVB-N) index of hairtail surimi fermented by Monascus for 0-5 h met the requirements of the national standard. Among them, the 1 h group showed the best gel quality, which detected a total of 138 volatile substances, including 20 alcohols, 7 aldehydes, 12 olefins, 4 phenols, 12 alkanes, 8 ketones, 15 esters, 6 acids, 16 benzenes, 4 ethers, and 8 amines, as well as 26 other compounds. In addition, the dominant fungal microorganisms in the fermentation process of MFHS were identified, and a Spearman correlation analysis showed that 16 fungal microorganisms were significantly correlated with the decrease in fishy odor substances in the fermented fish and that 8 fungal microorganisms were significantly correlated with the increase in aromatic substances after fermentation. In short, Monascus fermentation can eliminate and reduce the fishy odor substances in hairtail fish, increase and improve the aromatic flavor, and improve the quality of hairtail surimi gel. These findings are helpful for revealing the mechanism of the quality formation of fermented surimi and provide guidance for the screening of starter culture in the future.

Future perspectives on aptamer for application in food authentication

Food fraudulence and food contamination are major concerns, particularly among consumers with specific dietary, cultural, lifestyle, and religious requirements. Current food authentication methods have several drawbacks and limitations, necessitating the development of a simpler, more sensitive, and rapid detection approach for food screening analysis, such as an aptamer-based biosensor system. Although the use of aptamer is growing in various fields, aptamer applications for food authentication are still lacking. In this review, we discuss the limitations of existing food authentication technologies and describe the applications of aptamer in food analyses. We also project several potential targets or marker molecules to be targeted in the SELEX process. Finally, this review highlights the drawbacks of current aptamer technologies and outlines the potential route of aptamer selection and applications for successful food authentication. This review provides an overview of the use of aptamer in food research and its potential application as a molecular reporter for rapid detection in food authentication process. Developing databases to store all biochemical profiles of food and applying machine learning algorithms against the biochemical profiles are urged to accelerate the identification of more reliable biomarker molecules as aptamer targets for food authentication.

Analysis of the relationship between microorganisms and flavour development in dry-cured grass carp by high-throughput sequencing, volatile flavour analysis and metabolomics

Complex microbial community plays an important role for flavor formation in traditional dry-cured grass carp. To investigate the correlation between microorganisms and flavour development, the bacterial diversity and flavour quality of dry-cured fish at different stages of fermentation were analysed using high-throughput sequencing, volatile flavour analysis and metabolomics. Cobetia, Staphylococcus and Ralstonia were the dominant genera in dry-cured fish, with relative abundances of 37.78%, 34.46% and 3.2%, respectively. The flavour of dry-cured fish samples varied as the abundance of aldehydes, alcohols, small peptides, FAAs and carboxylic acids showed a great increase during fermentation. Moreover, there were significant correlations (P < 0.05) between specific microorganisms and volatile indicators, as well as flavour metabolites. Staphylococcus, as the dominant bacterial genus, is involved in the mechanism of flavour formation in dry-cured fish during fermentation. This information is useful for elucidating the mechanism of flavour formation in dry-cured fish.

Quality, functionality, and microbiology of fermented fish: a review

Fermentation is a traditional food preservation method and is widely used for improving food safety, shelf life, and organoleptic and nutritional attributes. Fermented fish are produced and consumed in different parts of the world and are an integral part of many food cultures. Furthermore, fermented fish are a source of interesting microbes and are an important industry in many countries. This review tries to update the types and manufacturing processes for fermented fish around the world. The emphasis is on this work related to fermented fish and their health benefits, as well as the contribution of microorganisms to their fermentation. A variety of different approaches have been used to determine and understand microbial composition and functionality. Moreover, some challenges and future research directions regarding fermented fish are also discussed in this review. Further research into fermented fish products is of crucial importance not only for the food industry but also for human health. However, extensive in vivo and toxicological studies are essential before the application of bioactive-rich fermented fish products for human health benefits.

Peptides: Production, bioactivity, functionality, and applications

Production of peptides with various effects from proteins of different sources continues to receive academic attention. Researchers of different disciplines are putting increasing efforts to produce bioactive and functional peptides from different sources such as plants, animals, and food industry by-products. The aim of this review is to introduce production methods of hydrolysates and peptides and provide a comprehensive overview of their bioactivity in terms of their effects on immune, cardiovascular, nervous, and gastrointestinal systems. Moreover, functional and antioxidant properties of hydrolysates and isolated peptides are reviewed. Finally, industrial and commercial applications of bioactive peptides including their use in nutrition and production of pharmaceuticals and nutraceuticals are discussed.