Effects of γ-aminobutyric acid on freshness and processing properties of eggs during storage

Effects supplementation of novel multi-enzyme on laying performance, egg quality, and intestinal health and digestive function of laying hens

This study investigated the effects of multi-enzyme supplementation on various aspects of laying hens, including laying performance, egg quality, intestinal health and digestive function. In total, 384 Jingfen No.6 laying hens at 65-week-age were randomly assigned to four distinct dietary treatments: a basal diet (CON), CON supplemented with 150 g/t multi-enzyme (T1), CON with 300 g/t multi-enzyme (T2), and 600 g/t multi-enzyme (T3). A significant linear (P = 0.044) and quadratic (P = 0.014) increase was observed in the laying rate, while the feed/egg ratio exhibited a linear (P = 0.001) and quadratic (P < 0.001) decrease with increasing multi-enzyme supplementation. Additionally, linear (P < 0.05) and quadratic (P < 0.05) increases were observed in yolk rate and haugh unit with increasing levels of multi-enzyme supplementation. The trypsin activity in the duodenum and crude protein digestibility showed linear (P < 0.05) and quadratic (P < 0.05) increase with the addition of multi-enzyme. Furthermore, lipase and amylase activities in the duodenum increased quadratically (P = 0.041) and linearly (P = 0.040), respectively. Both jejunal and ileal digesta viscosities showed linear (P < 0.05) and quadratic (P < 0.05) decrease with the increasing addition of multi-enzyme. Moreover, multi-enzyme supplementation significantly increased (P < 0.05) the number of goblet cells in the intestinal of the treatment groups. The mRNA expression of Occludin-1, mucin 2 (MUC-2), large neutral amino acids transporter small subunit 1 (LAT-1) in the jejunum were significantly increased (P < 0.05) in the treatment groups (T1, T2 and T3) compared to the CON group. Additionally, the mRNA expression of solute carrier family 6-member 19 (B0AT-1) and large neutral amino acids transporter small subunit 4 (LAT-4) were significantly evaluated (P < 0.05) in the T2 and T3 groups, respectively. In conclusion, multi-enzyme supplementation enhanced digestive enzyme activities and intestinal barrier function, reduced intestinal digesta viscosity, and regulated mRNA expression of intestinal amino acid and lipid transporter genes, thereby improving crude protein digestibility and positively affecting laying performance and egg quality in hens.

Strong, tough, high-release, and antibacterial nanocellulose hydrogel for refrigerated chicken preservation

Enormous amounts of food resources are annually wasted because of microbial contamination, highlighting the critical role of effective food packaging in preventing such losses. However, traditional food packaging faces several limitations, such as low mechanical strength, poor fatigue resistance, and low water retention. In this study, we aimed to prepare nanocellulose hydrogels with enhanced stretchability, fatigue resistance, high water retention, and antibacterial properties using soy hull nanocellulose (SHNC), polyvinyl alcohol (PVA), sodium alginate (SA), and tannic acid (TA) as raw materials. These hydrogels were applied in food packaging to extend the shelf life of refrigerated chicken. The structure and properties (e.g., mechanical, antibacterial, and barrier properties) of these hydrogels were characterized using different techniques. Fourier-transform infrared spectroscopy revealed the presence of hydrogen and ester bonds in the hydrogels, whereas scanning electron microscopy revealed the three-dimensional network structure of the hydrogels. Mechanical testing demonstrated that the SHNC/PVA/SA/TA-2 hydrogel exhibited excellent tensile properties (elongation = 160 %), viscoelasticity (storage modulus of 1000 Pa), and mechanical strength (compressive strength = 10 kPa; tensile strength = 0.35 MPa). Moreover, under weak acidic and alkaline conditions, the ester bonds of the hydrogel broke down with an increase in pH, improving its swelling and release properties. The SHNC/PVA/SA/TA-2 hydrogel displayed an equilibrium swelling ratio exceeding 300 %, with a release rate of >80 % for the bioactive substance TA. Notably, antibacterial testing showed that the SHNC/PVA/SA/TA-2 hydrogel effectively deactivated Staphylococcus aureus and Escherichia coli, prolonging the shelf life of refrigerated chicken to 10 d. Therefore, the SHNC/PVA/SA/TA hydrogels can be used in food packaging to extend the shelf life of refrigerated meat products. Their cost-effectiveness and simple preparation make them suitable for various applications in the food industry.

Current State of Milk, Dairy Products, Meat and Meat Products, Eggs, Fish and Fishery Products Authentication and Chemometrics

Food fraud is a matter of major concern as many foods and beverages do not follow their labelling. Because of economic interests, as well as consumers' health protection, the related topics, food adulteration, counterfeiting, substitution and inaccurate labelling, have become top issues and priorities in food safety and quality. In addition, globalized and complex food supply chains have increased rapidly and contribute to a growing problem affecting local, regional and global food systems. Animal origin food products such as milk, dairy products, meat and meat products, eggs and fish and fishery products are included in the most commonly adulterated food items. In order to prevent unfair competition and protect the rights of consumers, it is vital to detect any kind of adulteration to them. Geographical origin, production methods and farming systems, species identification, processing treatments and the detection of adulterants are among the important authenticity problems for these foods. The existence of accurate and automated analytical techniques in combination with available chemometric tools provides reliable information about adulteration and fraud. Therefore, the purpose of this review is to present the advances made through recent studies in terms of the analytical techniques and chemometric approaches that have been developed to address the authenticity issues in animal origin food products.

High-Release, Residue-Free Polysaccharide Hydrogel for Refrigerated Food Preservation

Hundreds of millions of tons of food resources are wasted annually due to microbial contamination. Effective food packaging can prevent food contamination and wastage. However, traditional food packaging has the problem of low release of bioactive substances. This study aimed to prepare a pH-responsive polysaccharide hydrogel (GDPP) by double cross-linking of ester and hydrogen bonds that could result in a high release of bioactive substances and no residual peeling. The infrared results showed the existence of ester bonds in the hydrogel, and the scanning electron microscopy results showed the porous network structure of the hydrogel. The results of texture profile analysis and self-healing tests showed that GDPP-1 has good mechanical and self-healing properties. Moreover, the ester bond of the hydrogel broke in response to the pH in the environment, improving the swelling and release properties of the hydrogel. The equilibrium swelling ratio of GDPP-1 was greater than 1000%, and the release rate of bioactive substances was more than 80%. Notably, the results of peeling experiments showed that only 0.1 N external force was needed to separate the hydrogel from the salmon, and no residue was observed on the salmon surface. The final freshness test results showed that the hydrogel effectively prolonged the shelf life of refrigerated salmon for 3-6 days. These findings indicated that hydrogels could be used in food packaging to extend the shelf life of refrigerated food. Furthermore, their advantages of low cost and simple preparation can better meet the needs of food industry applications.