The effect of vacuum packaging on physicochemical changes in rainbow trout (Oncorhynchus mykiss) during cold storage

Abstract

The aim of the study was to monitor changes in selected physical (a w water activity, pH values) and chemical (TVBN total volatile basic nitrogen, TMA-N trimethylamine nitrogen, FFA free fatty acids, PV peroxide values, TBA thiobarbituric acid value) properties in the shelf life of rainbow trout (Oncorhynchus mykiss) muscle. A total of 192 trout were examined. Control samples (96 samples) were simply packaged in contact with atmospheric oxygen, while experimental samples (96 samples) were packaged in a commercial vacuum (98%). All the samples were stored at 2 ± 2° C for 11 days. Analyses were performed on storage days 1, 2, 4, 7, 9, and 11. During the experiment, a w values increased in both types of packaging (in air: 0.982; vacuum-packaged: 0.989). At the end of storage, TVBN and TMA concentrations were at 28.88 ± 4.42 and 19.28 ± 3.00 g mg·100 -1 , respectively, in the muscle of vacuum-packaged trout; and at 30.52 ± 2.91 and 19.94 ± 2.05 mg·100 g -1 , respectively, in fish in simple packaging. The FFA content in vacuum-packaged fish initially declined before increasing to 3.67 ± 2.37% of total fat as oleic acid later in the experiment. The pattern of PV changes was inconclusive, and significant changes (P < 0.01) were observed in both types of packaging. On monitoring day 11, TBA values had increased to 7.34 ± 3.10 mg·kg -1 in vacuum-packaged fish and to 26.03 ± 8.00 mg·kg -1 in fish in simple packaging. Free fatty acids are not a good indicator of spoilage because they are converted to hydroperoxides. Vacuum packaging effectively slowed down oxidative changes in rainbow trout muscle. The peroxide content is not a suitable indicator of shelf life as peroxides are decomposed to secondary products. Total volatile basic nitrogen and thiobarbituric acid value can be recommended as suitable indicators of freshness and shelf life. Fish, modified atmosphere, shelf life, fresh water

Red beet and betaine as ingredients in diets of rainbow trout (Oncorhynchus mykiss): effects on growth performance, nutrient retention and flesh quality

“…With regard to red beet and betaine effects on flesh quality, it has been observed that the inclusion of these ingredients produced a reduction of aw compared to control diet. aw plays an important role on spoilage of fish (Ježek and Buchtová 2014). This is in agreement to the observed with the inclusion of other CHO sources, such as barley (Pinedo et al 2016).…”

Fast Protein and Metabolites (Nucleotides and Nucleosides) Liquid Chromatography Technique and Chemical Sensor for the Assessment of Fish and Meat Freshness

“…It can be observed that both curves are close in shape and correlate with the coefficient r = 0.85. The onset of the strong TVB-N increase observed on day 11 and later on correlates well with the published data [37,[49][50][51]. Moreover, the value TVB-N at day 7 in Figure 6 (the very onset of bacterial contamination according to the FAO scheme [52]) of 16 ± 2.83 mg/100g agrees very well with the average value that can be deduced from the data in [37,[49][50][51], i.e., 16.25 ± 4.2 mg/100g.…”

Effect of steaming and hot smoking treatment combination on the quality characteristics of hagfish (Myxine glutinosa)

“…Moreover,Jezek and Buchtova (2014) suggested TBARS as an indicator of oxidative changes and reported that vacuum packaging resulted in good protection against oxidation in trout muscle.The increase in TVBN value depends on the storage time during the preservation of fish and fish products. The TVBN value determined based on the content of dimethylamine, TMA, ammonia, and other protein derived compounds associated with seafood spoilage(Gokodlu, Ozden, & Erkan, 1998).…”