نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران
2 دانشیار، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Food packaging plays a multifaceted role in maintaining quality, safety, and increasing shelf life of products. In this study, the quality of ice-coated fillets of rainbow trout (Oncorhynchus mykiss) at different initial temperatures (control: no glazing, -20, -30, -40, and -50°C) was investigated. After glazing, the samples were stored at -18°C for 6 months, and quality parameters including glaze layer thickness, moisture content, texture hardness, and chewability were evaluated at days 0, 60, 120, and 180 after the start of the experiment. The results showed that the -30°C treatment significantly (p<0.05) performed best in terms of glazing quality and increasing shelf life of the fish. At this temperature, the ice coating thickness was on average 15% greater than the -20°C treatment and 10% greater than the -40°C and -50°C treatments. The control treatment showed the highest quality loss due to the absence of a protective layer. This treatment had the highest moisture loss and chewiness, indicating the importance of the ice coating process in maintaining the quality of frozen fish. In contrast, the -20°C treatment failed to protect the quality of the fish as much as the -30°C treatment due to the formation of a thinner and more heterogeneous ice coating. On the other hand, lower temperatures (-40 and -50°C), although they increased the speed of ice coating formation, showed poorer performance in maintaining the quality and shelf life of the fish due to the formation of a thinner ice layer and reduced absorption of the glaze solution. The -30°C treatment had significantly the highest tissue hardness at all stages of storage. This result indicates that the formation of a thicker glaze layer at this temperature prevents moisture loss and tissue degradation. In the control treatment, tissue degradation occurred rapidly due to the absence of ice coating. Therefore, -30°C is suggested as the optimal temperature for glazing of salmon fillets, as this temperature significantly (p<0.05) improves glazing quality and shelf life of the product. The results showed that from the perspective of packaging functions, the ice coating process as a primary protective layer is a complement to the packaging of frozen products. Proper ice coating plays a key role in maintaining the integrity of the texture and sensory properties by creating a physical barrier against oxygen penetration, reducing oxidation and moisture of the product, and preventing surface burns caused by freezing.
کلیدواژهها [English]
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