Effect of electron beam irradiation on the biochemical, microbiological and sensory quality of Litopenaeus vannamei during chilled storage.

The effects of electron beam irradiation (0, 2.5, 5.0, 7.5 and 10 kGy) on the quality characteristics of vacuum packed headless vannamei stored under chilled condition (2 °C) was assessed. The total volatile base nitrogen, non protein nitrogen content, peroxide value and thiobarbituric acid reactive substances showed an increasing trend during storage. Texture analysis indicated that shrimp irradiated at above 2.5 kGy dose had a lower hardness than control. L* value showed a decreased trend during storage (51.87-13.89). Moreover, b* and a* value showed a gradual increase during storage. The total viable count was lower in the irradiated sample than control. A similar trend also observed for psychrophilic, pseudomonas and H2S former count. There is a significant (p < 0.05) reduction in Brochothrix thermosphacta and lactobacillus count in the irradiated sample. Based on the microbial and sensory analysis control had a shelf life up to 12th day. However, electron beam irradiated sample had extended shelf life of 15-23 days with respect to dose level.

Tuna red meat hydrolysate as core and wall polymer for fish oil encapsulation: a comparative analysis.

Microencapsulation by spray drying is a well-accepted technique for fish oil stabilization. However, severe operational conditions during atomisation destabilise the emulsion, leading to capsule collapse and induction of auto-oxidation. Hence, use of food grade cross-linkers to strengthen the wall material and antioxidants to prevent lipid oxidation has been suggested. A promising option in this line is the use of bioactive peptides, which ensure oxidative stability through structural and chemical stabilisation. Present study attempted to compare the efficacy of yellowfin tuna red meat hydrolysate in protecting the core sardine oil, when used as wall and core polymer during encapsulation. Encapsulates were characterised based on morphological and physical parameters, as well as by in vitro digestibility studies. Their storage stability was also compared under accelerated (60 °C), chilled (4 °C) and ambient conditions (28 °C). Tuna protein hydrolysate exhibited significantly higher protective efficacy when used as core polymer rather than in the wall matrix of encapsulates.