Gamma radiation combined with cinnamon oil to maintain fish quality

Effect of ajwain (Trachyspermum ammi) extract and gamma irradiation on the shelf-life extension of rohu (Labeo rohita) and seer (Scomberomorus guttatus) fish steaks during chilled storage

Fishes are highly perishable, mainly stored and transported under frozen condition; however, they are mainly preferred as fresh or in chilled form for consumption because frozen storage compromises the texture quality and other sensory attributes. Shelf-life enhancement of rohu and seer fish steaks was studied using combination of ajwain extract (various concentrations) and γ-irradiation (various doses) under chilled storage (4 °C). These were analyzed periodically by microbiological, sensory, color and biochemical analyses during storage. Gas chromatography - mass spectrometry (GC-MS) analysis showed thymol as major component. High performance liquid chromatography (HPLC) analysis showed the presence of nine phenolic compounds including thymol in ajwain extract. The best result was achieved when samples were dipped in 10 % ajwain extract with 2 kGy gamma irradiation dose. An extended shelf-life of 5 and 10 days in case of rohu and seer fish steaks were attained respectively using this combination. These results were confirmed by microbial, biochemical and sensory analyses. The present study thus promises potential application of the above protocol in fishery industry for good quality of fish and commercial benefits.

Principles and applications of non-thermal technologies and alternative chemical compounds in meat and fish

Conventional methods of food preservation have demonstrated several disadvantages and limitations in the efficiency of the microbial load reduction and maintain food quality. Hence, non-thermal preservation technologies (NTPT) and alternative chemical compounds (ACC) have been considered a high promissory replacer to decontamination, increasing the shelf life and promoting low levels of physicochemical, nutritional and sensorial alterations of meat and fish products. The combination of these methods can be a potential alternative to the food industry. This review deals with the most critical aspects of the mechanisms of action under microbial, physicochemical, nutritional and sensorial parameters and the efficiency of the different NTPT (ultrasound, high pressure processing, gamma irradiation and UV-C radiation) and ACC (peracetic acid, bacteriocins, nanoparticles and essential oils) applied in meat and fish products. The NTPT and ACC present a high capacity of microorganisms inactivation, ensuring low alterations level in the matrix and high reduction of environmental impact. However, the application conditions of the different methods as exposition time, energy intensity and concentration thresholds of chemical compounds need to be specifically established and continuously improved for each matrix type to reduce to the maximum the physicochemical, nutritional and sensorial changes. In addition, the combination of the methods (hurdle concept) may be an alternative to enhance the matrix decontamination. In this way, undesirable changes in meat and fish products can be further reduced without a decrease in the efficiency of the decontamination.

Effects of cinnamaldehyde combined with ultrahigh pressure treatment on the flavor of refrigerated Paralichthys olivaceus fillets

The combined effects of cinnamaldehyde (CA) and ultrahigh pressure (UP) treatment on the flavor of olive flounder (Paralichthys olivaceus) fillets during storage at 4 °C for 20 days were investigated. Changes in total viable count, trimethylamine, ATP-related compounds, free amino acids, TCA-soluble peptides, electronic nose (E-nose) analysis and sensory quality were measured. The results indicated that CA and UP treatment, especially CA combined with UP, significantly reduced undesirable flavor compounds including inosine, hypoxanthine, TMA, and bitter amino acids, and accumulated pleasant flavor compounds such as inosine monophosphate and umami-related amino acids. In addition, the combination of CA and UP was shown to be more effective for retarding protein degradation and microbial growth than CA or UP treatment alone. In accordance with the results of E-nose analysis and sensory evaluation, CA combined with UP treatment had great potential for improving the flavor quality of refrigerated flounder fillets and extending their storage life.

The combined effects of cinnamaldehyde (CA) and ultrahigh pressure (UP) treatment on the flavor of olive flounder (Paralichthys olivaceus) fillets during storage at 4 °C for 20 days were investigated.