Depuration of live oysters to reduce Vibrio parahaemolyticus and Vibrio vulnificus: A review of ecology and processing parameters.

Consumption of raw oysters, whether wild-caught or aquacultured, may increase health risks for humans. Vibrio vulnificus and Vibrio parahaemolyticus are two potentially pathogenic bacteria that can be concentrated in oysters during filter feeding. As Vibrio abundance increases in coastal waters worldwide, ingesting raw oysters contaminated with V. vulnificus and V. parahaemolyticus can possibly result in human illness and death in susceptible individuals. Depuration is a postharvest processing method that maintains oyster viability while they filter clean salt water that either continuously flows through a holding tank or is recirculated and replenished periodically. This process can reduce endogenous bacteria, including coliforms, thus providing a safer, live oyster product for human consumption; however, depuration of Vibrios has presented challenges. When considering the difficulty of removing endogenous Vibrios in oysters, a more standardized framework of effective depuration parameters is needed. Understanding Vibrio ecology and its relation to certain depuration parameters could help optimize the process for the reduction of Vibrio. In the past, researchers have manipulated key depuration parameters like depuration processing time, water salinity, water temperature, and water flow rate and explored the use of processing additives to enhance disinfection in oysters. In summation, depuration processing from 4 to 6 days, low temperature, high salinity, and flowing water effectively reduced V. vulnificus and V. parahaemolyticus in live oysters. This review aims to emphasize trends among the results of these past works and provide suggestions for future oyster depuration studies.

A pectin-gelatin gel containing oral rehydration solution and the release of sodium chloride under simulated gastric conditions.

Both gelatin and pectin have the ability to trap salt and facilitate its release under simulated gastric conditions. The objective of this study was to develop a pectin-gelatin gel fortified with oral rehydration solution/s (ORS) that can maintain a more rigid structure to limit salt mobility (potentially less salty taste), yet allow rapid release in simulated gastric conditions. Two gels containing both pectin and gelatin were developed: (1) low salt (LS) containing 2.6 g/L salt and 13.5 g/L sugar and (2) high salt (HS) containing 5.2 g/L salt and 27.0 g/L sugar. The ORS-fortified gels were compared with commercially available gelatin gels and a control pectin-gelatin gel without added salt or sugar. A stronger gel network (higher G') and higher viscosity was noted for HS compared to other samples. HS had slower salt release (80.70 ±â€¯1.92%) than LS (95.95 ±â€¯3.82%) at 1 min in simulated gastric conditions. After 120 min, HS showed up to 99.38 ±â€¯1.08% release of salt, while LS had 95.95 ±â€¯3.82% release. HS had a favorable textural profile, having values more similar to the ready-to-eat commercial cup gel than did the LS formulation. The HS formulation resulted in a stable structure for ORS delivery and beneficial release properties.

Delivery of alpha-tocopherol through soluble dietary fibre-based nanofibres for improving the life span of Caenorhabditis elegans.

The effect of alpha-tocopherol (α-TOC) delivered by soluble dietary fibre-based nanofibres (α-TOC-SDNF) on the life span of nematode Caenorhabditis elegans N2 (wild type) and TK22 (mev-1 mutants) with and without heat shock was investigated. Without heat shock, the wild-type and mev-1 mutants maintained in the 100 µg/mL of α-TOC-SDNF had longer life spans than their respective blank control groups. With heat shock, the wild-type N2 in the 200 µg/mL of α-TOC-SDNF had a survival rate of 5% at day 49, while no nematodes survived in the blank control group. An increased pharyngeal pumping rate was observed in the α-TOC-SDNF treated mev-1 mutants worms compared to the blank control group. Encapsulating α-TOC in SDNF yielded protective effects and the life span and pumping rate of C. elegans was increased with α-TOC delivered by SDNF.

Application of Edible Films Containing Oregano (Origanum vulgare) Essential Oil on Queso Blanco Cheese Prepared with Flaxseed (Linum usitatissimum) Oil.

Fortification of queso blanco (QB) with flaxseed oil (FO) containing omega-3 polyunsaturated fatty acids may provide a functional food with health benefits such as improved cell, brain, and retina functionality, and protection against cardiovascular and immune-inflammatory diseases. However, QB experiences a short shelf life because of the early development of yeasts and molds and addition of FO may increase susceptibility to lipid oxidation. Oregano essential oil (OEO) is known for its antimicrobial and antioxidant properties, but due to its intense flavor compounds it may not be suitable for direct incorporation into QB. Thus, incorporation of OEO into an edible film prepared with whey protein isolate (WPI) may improve the shelf life of QB. Scanning electron microscopy (SEM) micrographs revealed that FO was successfully retained by the cheese after homogenization. The thiobarbituric-acid-reactive-substances (TBARS) and yeast and mold counts (YMC) of the wrapped cheeses were analyzed during 60 d of refrigerated storage. The oxidation rate increased significantly for nonwrapped QB containing FO (QBFO) during storage, however wrapping with WPI edible films containing OEO (WOF) significantly limited lipid oxidation and prevented growth of yeasts and molds. This study demonstrated the antioxidant and antimicrobial properties of WOF for preservation of QBFO during refrigerated storage.