Journal of food science and technology(Iran)

Journal of food science and technology(Iran)

Investigation of K-value Changes and Its Correlation with Chemical Spoilage Indicators in Rainbow Trout Fillets Coated with Gelatin Containing Polysaccharide Extracted from Loquat (Eriobotrya japonica) Seed

Document Type : Original Research

Authors
mojtaba nouri 1
homa baghaei 1
Mehdi Kashani Nejad 2
Abdoreza Mohammadi-Nafchi 1
1 Department of Food Science and Technology, Da.C., Islamic Azad University, Damghan, Iran
2 Department of Food Process Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
10.48311/fsct.2026.84075.0
Abstract
Freshness and quality of fish fillets are key indicators of safety and consumer acceptance in seafood products. This study evaluated the K-value index and its correlation with other chemical spoilage indicators, including total volatile basic nitrogen (TVB-N), trimethylamine (TMA), peroxide value (PV), thiobarbituric acid reactive substances (TBA), and free fatty acids (FFA) in rainbow trout fillets during refrigerated storage. Fillets were coated with 1% gelatin containing 0.5% or 1% loquat (Eriobotrya japonica) seed polysaccharide, alongside an uncoated control, and stored at 4 ± 1 °C for 12 days. Sampling was performed on days 0, 1, 4, 7, 10, and 12, and chemical analyses were conducted to determine the indices. Results showed that fillets treated with gelatin plus 1% polysaccharide had the lowest K-values and other spoilage indicators throughout storage. Correlation analysis revealed significant positive relationships between the K-value and TVB-N, TMA, PV, TBA, and FFA (p < 0.05). These findings indicate that the K-value is a reliable indicator for assessing the quality and spoilage of coated rainbow trout fillets during refrigerated storage. Moreover, bioactive coatings containing loquat seed polysaccharide effectively improved product quality and extended shelf life.

 
Keywords
K-value
quince seed polysaccharide
edible coating
rainbow trout
correlation
spoilage

Subjects

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