Research Information System
vol.1, no.1, pp.10-16, 2026 (Peer-Reviewed Journal)
Rainbow trout (Oncorhynchus mykiss) is a commercially important aquaculture species widely produced and consumed in Türkiye and exported to international markets; however, due to its high water activity and rich nutrient composition, it is highly susceptible to microbial spoilage. Maintaining product quality throughout the cold chain from production to consumption is therefore critical for preventing food waste and reducing economic losses. This study aimed to determine the effectiveness of natural additives in delaying microbial growth in rainbow trout fillets during refrigerated storage. In this study, trout fillets were treated with solutions containing shalgam juice, red wine, soy sauce, pomegranate molasses, ginger, wasabi, or turmeric. Liquid additives were prepared at a 1:2 (additive:water) ratio, while solid additives were prepared at a concentration of 4%. Fish samples were individually immersed in these solutions (fish:solution = 1:2) for 20 min and subsequently stored under refrigerated conditions (4 ± 1 °C). Throughout storage, mesophilic aerobic bacterial counts in the control group were significantly higher than those in all treated groups (p < 0.05). Among the applied treatments, soy sauce was the most effective in suppressing mesophilic and psychrotrophic aerobic bacterial growth, particularly at the advanced stages of storage, followed by wasabi (p < 0.05). On the fourth day of refrigerated storage, psychrotrophic aerobic bacterial counts exceeded 6 log CFU/g in all other groups, whereas this increase was significantly limited in samples treated with soy sauce and wasabi (p < 0.05). These findings demonstrate that the use of natural additives, particularly soy sauce and wasabi, can improve the microbial quality of rainbow trout fillets, thereby contributing to the maintenance of product safety and quality throughout the cold chain and offering significant potential for reducing food waste and economic losses.