Gravading process of Nile tilapia ( Oreochromis niloticus ) and evaluation of its biochemical and sensory changes during refrigerated storage

Abstract

Gravads were prepared from Nile tilapia (Oreochromis niloticus) and evaluated its shelf life during chilled (6°C) and iced (0°C) storage. For standardizing the gravading process, different salt:sugar combinations of gravad mix and two steaks to gravad mixture ratio (1:0.1 and 1:0.2) were selected. Gravads prepared using 1:2 salt‐sugar in the gravad mix and a ratio of 1:0.1 steaks to gravad mix was found optimum combination. Gravads prepared using the standardized combination of salt and sugar were stored at 0°C and 6°C and evaluated for its biochemical and sensorial changes. Total volatile base nitrogen (TVB‐N) increased from 10.25 mg/100 g to 29.85 and 30.66 mg/100 g on Day 41 and Day 49 for chilled and iced samples, respectively. The extend of secondary oxidation was low in both samples, registering an increase from 0.14 mg MDA/kg sample to 0.814 and 0.851 MDA/kg sample on 41st and 49th day, respectively, for chilled and iced samples. Water soluble and salt soluble nitrogen contents were reduced to 1.82 and 5.47 mg/100 g and 1.58 and 4.72 mg/100 g by the end of 41st and 49th day, respectively, for chilled and ice stored gravads. The shelf life of gravads was determined as 41 days under chilled storage and 45 days under iced storage. Practical applications Nile tilapia is widely cultured fish species in India after the Indian major carps. It is of great interest to the farmers and demand among the consumers because of its fast growth rate and good meat quality. Value addition is an effective approach to utilize this resource cost‐effectively during excessive production periods. Conversion of Nile tilapia into gravads not only increases the value but also enhances the quality and shelf life of the product. The results of the present study provide an idea of appropriate process parameters for making gravads from Nile tilapia and information on its shelf life under refrigerated storage.

Quality Improvement and Shelf-Life Extension of Iced Nile Tilapia Fillets Using Natural Garlic Extract

“…The figure shows that the initial values were 22.13 ± 1.29 and 22.82 ± 1.70 mg N/100 g of muscle for the fillets with the extract and the control, respectively. These values are similar to the 26.2 ± 1.6 mg N/100 g reported by Montoya-Camacho et al [25] and are higher than the 6.5 and 10.2 mg N/100 g for tilapia (Oreochromis niloticus) muscle described by Liu et al [34] and Pankyamma et al [54], respectively. Regarding storage time, a significant increase (p < 0.05) in TVB-N values was observed, reaching up to 34.76 ± 10.60 and 60.21 ± 10.56 mg N/100 g in the tilapia fillets with NGE and the control at day 18, respectively.…”

Evaluation of biochemical, chemical, physical and microbiological quality of tilapia (Oreochromis niloticus) muscle during storage at 0 and 5 °C

“…On the other hand, the determination of TVB-N is one of the most commonly used tests to measure the deterioration of fish products. Figure 3 illustrates an initial TVB-N value of 26.2 ± 1.6 mg N/100 g, greater than the 10.2 and 6.5 mg N/100 g described by Pankyamma et al (2020) and Liu et al (2010), respectively, for tilapia (Oreochromis niloticus) muscle.…”

The changes of phospholipid degradation in sea urchin gonads (Glyptocidaris crenularis) during cold storage at 4°C

“…Sea urchins are highly nutritious and flavorful seafoods, but complex lipid composition and susceptibility to hydrolysis and oxidation lead to short shelf life and excessive quality loss during the marketing process. [ 23,24 ] After 3 days of storage at 4°C, the total lipid content and the PL content of SUG decreased, confirming that degradation of sea urchin gonadal lipids occurs during storage, which was mainly caused by the degradation of PL in the lipids. [ 25 ] Similar results showed that TAG and polar lipid (PoL) in the lipid of mussel scallop were degraded and PL as the main component of PoL was closely related to the hydrolysis of aquatic products.…”