Effect of sea cucumber (Holothuria leucospilota) extract on the quality of (Otolithes rubber) fillet during refrigerated storage

Many studies have shown that marine resources contain bioactive compounds that can be used as food preservatives in the food industry. Hence in our research, Methanolic extracts of marine cucumber Holothuria leucospilota were extracted and fillets fish stored in the refrigerator were treated with, in different concentrations (0.5, 1 and 2%), in order to evaluate the chemical quality of fillets. The fillets were kept in the refrigerator for 16 days and chemical tests including volatile bases nitrogen (TVB-N), thiobarbitoric acid (TBA) and pH test were done every 4 days. The results showed that the amount of volatile bases nitrogen (TVB-N) in treated samples with extract in 1 and 2% concentration did not exceed the acceptable level until the last day, while the amount of this index in the control samples until the 8th day and the treated samples with 0.5% concentration of the extract, was acceptable until the 12th day. Thiobarbitoric acid (TBA) was acceptable in all treatments, except in treatment with 2% concentration until 8th day, though the treated samples with an extract of 2% concentration in the last day of storage were more than expectation. The pH index was lower in the samples treated with sea cucumber extract throughout the storage period than the control samples. Based on the results obtained in this study, it can be concluded that cucumber extract can be used as a natural preservative for fish fillets during the short-term storage period in a refrigerator condition and up to 2% concentration is suggested for this procedure.