Search

Effect of coating with curry leaf and clove essential oils (EO) on oxidative and textural stability of sutchi catfish fillets were evaluated during chilled storage. The changes in parameters associated with textural and lipid degradation was also evaluated to ascertain the interactive effect of polyphenols with muscle proteins. Further, the results were compared against vacuum and conventional polyethylene packaging practices. Prior to coating, the properties of antioxidants were evaluated in vitro based on total phenolic and flavonoid contents, 2, 2-diphenyl-1- picrylhydrazyl radical scavenging activity, inhibition of linoleic acid peroxidation, iron reducing power, and metal chelating ability. Coating with clove bud EO was found to be more effective in protecting the textural quality and retarding lipid oxidation of the fillets during chilled storage. Curry leaf EO was found to have only moderate effect., Practical Applications: In addition to the well-studied antibacterial and antioxidant properties, plant polyphenols have become an intense focus of research for their ability to cross-link proteins that widens their applications for textural and functional modification of food and beverages. Currently, a number of carcinogenic chemicals such as ammonia and formalin are hazardously used to prevent texture deterioration in chilled fish associated with post-rigor changes and microbial reactions. This study evaluates the efficacy of polyphenols present in culinary herbs such as clove bud and curry leaf EO, in stabilising the texture of fish meat during chilled storage. From the results, it could be inferred that both the EO at 0.25% level mediated protein cross-linking/complexation and maintained textural integrity during chilled storage apart from exhibiting antioxidant activities., (© 2016 Wiley Periodicals, Inc.)

Despite the potential of LC with tandem MS (MS/MS) in improving sensitivity and selectivity, analytical methods are scarce for the determination of protein-bound and phosphorylated forms of B vitamins in food. This prompted us to develop a method for LC-MS/MS determination of naturally occurring nicotinamide, nicotinic acid, thiamine, pyridoxine, riboflavin, pantothenic acid, biotin, folic acid, and cyanocobalamin in fish. Baseline separation of the vitamins was achieved in a hydrophilic interaction LC condition. An ultrasonication-assisted enzymatic extraction protocol for sample preparation was optimized and validated. The time required for extraction was significantly reduced (to 4 h), while maintaining good extraction efficiency. Acetonitrile content (80%, v/v) in the prepared sample was found to be optimum for excellent peak shape and sensitivity. The dynamic linear range of the vitamins ranged from 2.5 to 500 ng/g, and the regression coefficient values were greater than 0.99. LOQ values ranged from 0.4 to 50 ng/g for the different vitamins. The spike recovery values at 50 and 100 ng/g ranged from 87.5 to 97.5%. The intra- and interday precision values were satisfactory. Accuracy of the developed method was determined by analysis of a Certified Reference Material. The method could also be used for unambiguous determination of the natural content of the target vitamins in fish.

The effect of reduced oxygen atmosphere and sodium acetate treatment on the microbial quality of seer fish (Scomberomorus commerson) steaks was determined during chilled storage (1-2 degrees C). The O2 absorber reduced the oxygen content in the pack to less than 0.01% corresponding to 99.96% reduction within 24 h. The use of O2 absorber with sodium acetate dip treatment (2% w/v) extended the sensory shelf life up to 25 days compared to only 12 days for control air packs and 20 days for untreated samples with O2 absorber. A prominent lag phase was observed for many bacterium studied, particularly for the sodium acetate treated samples with O2 absorber. On the day of sensory rejection, both the total mesophilic and psychrotrophic counts reached 7.7-8.1 and 7.1-7.9 log cfu/g, respectively. The sodium acetate treatment and reduced O2 atmosphere affected the type of major spoilers. In air packed samples, H2S-producers predominated followed by Brochothrix thermosphacta, Pseudomonas spp., where as in the untreated samples with O2 absorber, H2S-producers predominated the microbial flora followed by Lactobacillus spp. For treated samples with O2 absorber, B. thermosphacta formed the major micro-flora followed by Lactobacillus spp. The use of O2 absorber inhibited the growth of Pseudomonas spp., and total Enterobacteriaceae., (2010 Elsevier Ltd. All rights reserved.)

The present study aims to find the effect of freezing methods on the quality of mackerel (Rastrelliger kanagurta) in commercial plate and air blast freezers during freezing and subsequent frozen storage (-18 degrees C). Total time for freezing was significantly different (P < 0.05) between the plate and air blast freezers (90 and 220 min, respectively). This difference in the freezing time could be attributed to the varied quality of the 2 samples. Upon freezing, the moisture content decreased in air blast frozen samples compared to plate freezer where protein content decreased in both the samples. Upon freezing and during frozen storage, lipid oxidation products (peroxide value, thiobarbutiric acid value, and free fatty acid value) and volatile bases (total volatile base nitrogen and trimethyl amine nitrogen) showed an increasing trend in both the samples with values slightly higher in air blast frozen samples compared to plate frozen samples. The total plate counts showed a significantly (P < 0.05) decreasing trend in both the samples. K value did not show any significant (P < 0.05) difference between the samples where as the histamine formation was significantly (P < 0.05) increased in air blast frozen samples compared to plate frozen samples. The taste and overall acceptability was significantly different (P < 0.05) in plate frozen samples compared to air blast frozen samples on 3rd month. Both samples were in acceptable condition up to 3 mo but the plate frozen samples quality was slightly better than the air blast frozen samples.