Effect of cold plasma on maintaining the quality of chub mackerel (Scomber japonicus): biochemical and sensory attributes.

BACKGROUND: Atmospheric cold plasma (ACP) has emerged as a potential alternative to traditional methods for non-thermal food decontamination. However, few data are available about ACP treatment for seafood. In this study, dielectric barrier discharge (DBD) was applied to generate CP, and the aim of the study was to investigate the effectiveness of DBD-ACP on improving the quality of chub mackerel on the basis of chemical, microbial and sensory characteristics. RESULTS: The effect of DBD-ACP on the quality of chub mackerel (Scomber japonicus) during storage was examined. Results revealed that the optimal voltage level and exposure time of this treatment were 60 kV and 60 s respectively, and such conditions exhibited excellent inactivation efficacy and weak influence on proximate chemical compositions. Variations in total viable count (TVC), sensory scores and total volatile basic nitrogen (TVB-N) indicated that ACP treatment extended the shelf life of chub mackerel to 14 days, whereas samples without this treatment exceeded the limits of the three parameters after 6 days. The slow development rates of peroxide value (PV) and thiobarbituric acid (TBA) value implied that lipid oxidation was also effectively retarded by ACP exposure. Scanning electron microscopy confirmed that CP could effectively delay the degradation of myofibrillar proteins and enhance the stability of tissue structures. CONCLUSION: The excellent antimicrobial efficacy of ACP treatment makes it a potential and promising alternative to other seafood preservation technology. This is the first report on the application of ACP to seafood, which is essential to perishable food storage. © 2018 Society of Chemical Industry.

Carcass Characteristics and Meat Quality of Wild-Living Mallard (Anas platyrhynchos L.) Originating from Croatia.

The aim of this study was to determine the effects of sex and hunting location on carcass characteristics and meat quality of wild-living mallard (Anas platyrhynchos) from Croatia. Twenty-eight mallards (14 ♂; 14 ♀) were hunted at two hunting locations (HL I = 8 ♂, 8 ♀; HL II = 6 ♂, 6 ♀) in the Croatian lowlands. The carcasses were eviscerated, dressed, and dissected, and the individual internal organs and carcass parts were weighed. The breast muscle (m. pectoralis major) was sampled and used to determine color, pH, drip loss, cooking loss, shear force, and proximate chemical and fatty acid composition. Sex and HL had a significant effect on the majority of carcass characteristics analyzed, but they had no effect on the physical meat parameters. The protein and ash content of mallard meat was significantly higher in HL II (23.16% vs. 22.67%; 1.45% vs. 1.36%, respectively) and the moisture content in females (72.40% vs. 71.59%). HL had a significant effect on SFA (II 33.96% vs. I 29.91%), PUFA n-3 (II 3.55% vs. I 2.69%), PUFA/SFA and n-6/n-3 ratios, and all lipid indices. Females had a significantly higher C22:6n-3 content, a higher PI index and a lower n-6/n-3 ratio. The data presented in this study contribute to a better understanding of game-bird meat quality originating from different regions.

Mannan Oligosaccharide Enhanced the Growth Rate, Digestive Enzyme Activity, Carcass Composition, and Blood Chemistry of Thinlip Grey Mullet (Liza ramada).

Mannan oligosaccharide (MOS) is prebiotic with high functionality in aquaculture. The current study investigated the potential roles of MOS on the growth performance, digestive enzyme activity, carcass composition, and blood chemistry of Thinlip grey mullet (Liza ramada). Four tested diets with 34.49% crude protein and 6.29% of total lipids were prepared and fortified with 0, 0.5, 1, and 2% MOS. Fish of initial weight = 5.14 ± 0.11 g/fish were distributed in 12 hapas (0.5 × 0.5 × 1 m) at 15 fish per hapa (triplicates) and fed the test diets to the satiation level two times a day (08:00 and 15:00) for eight weeks. At the end of the trial, all fish were weighed individually for growth performance calculation. Blood was collected to check blood chemistry traits, and intestines were dissected for digestive enzyme analysis. Fish treated with MOS had marked enhancement in the final body weight, feed conversion ratio, protein gain, and protein retention regardless of inclusion dose (p < 0.05). The weight gain, specific growth rate, and protein efficiency ratio were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). Insignificant influences of MOS were seen on the chemical composition of carcass components (moisture, crude protein, total lipids, and ash) (p > 0.05). Fish treated with MOS at 0.5 and 1% had marked enhancement in the amylase, lipase, and protease activities regardless of inclusion dose (p < 0.05). The blood total protein and albumin levels were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). The blood globulin was significantly enhanced in fish fed 1% MOS than fish treated with 0, 0.5, and 2% of MOS (p < 0.05). The blood lysozyme activity was meaningfully enhanced by including MOS at 1%, followed by fish treated with 0.5 and 2%, while the lowest values were in the control group (p < 0.05). Phagocytic activity and phagocytic index were markedly improved in fish treated with 1 and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Superoxide dismutase and glutathione peroxidase were markedly improved in fish treated with 1, and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Dietary MOS (0.5, 1, and 2%) meaningfully enhanced catalase activity while decreased the malondialdehyde concentration (p < 0.05). In summary, dietary MOS is required at 0.5-1% for enhancing the growth rate, feed efficiency, digestive enzyme activity, blood chemistry, and antioxidative capacity of grey mullet.

Quality and Consumer Acceptance of Meat from Rabbits Fed Diets in Which Soybean Oil is Replaced with Black Soldier Fly and Yellow Mealworm Fats.

This trial investigated the effect of the dietary inclusion of Hermetia illucens (H) and Tenebrio molitor (T) fats as alternative lipid sources for growing rabbits, and assessed the carcass characteristics; proximate composition; lipid peroxidation, and fatty acid profile of the meat, as well as consumer acceptance. At weaning, 200 crossbred rabbits (1051 ± 138 g initial body weight) were allotted to five isolipidic (4% dry matter (DM)) dietary treatments: a control diet (C) containing 1.5% of soybean oil, and four experimental diets in which soybean oil was partially (50%) or totally (100%) substituted by H (H50 and H100) or T (T50 and T100) fats. The carcass characteristics, the meat quality traits, and the consumer acceptance of the cooked meat were not affected. The fat content of Longissimus thoracis et lumborum muscle of the rabbits was 1.1% on average. In the case of rabbit fed the H diets (average of diets H50 and H100), the same muscles revealed a higher saturated fatty acid proportion (47.1% vs. 39.7% and 40.8%, respectively) and a lower polyunsaturated fatty acid proportion than the rabbits fed the C and T diets (average of diets T50 and T100) (26.5% vs. 31.7% and 29.7%) (p < 0.001). The meat of the rabbits fed the diets containing insect fat (average for H and T diets) was less susceptible to oxidation (0.24 vs. 0.39 mg malondialdehyde/kg meat in the C group; p < 0.01).