Avaliação do frescor do olho-de- cão (Priacanthus arenatus) eviscerado durante a estocagem em gelo pelo Método do Índice de Qualidade

Abstract

The Atlantic bigeye (Priacanthus arenatus) is a marine fish deep red color, high culinary value, sold fresh and found all along the Brazilian coast. This research aimed to develop a quality protocol according to the Quality Index Method (QIM) to bigeye, gutted stored on ice (0 ± 1 °C) and accompanied by chemical, physical and bacteriological loss of freshness during storage. We collected lots of third bigeye in the region of Grumari, RJ. Once captured were eviscerated, washed transported to Embrapa Food (Guaratiba, RJ), they were packed in ice during the period of 21 days. The composition analysis performed showed significant differences after the storage period, allowing the species classified as high protein and medium fat content. The analyzes of total count of psychrotrophic and mesophilic bacteria, the sensory evaluation, pH and total volatile bases (BVT) were performed in the following ranges 0, 2, 4, 7, 9, 11, 14, 16, 18, 21 days while the color and texture analysis instruments were performed on days 0, 4, 9, 14, 18, 21. The QIM scheme developed was composed of four major quality criteria divided into twelve attributes, adding 24 demerit points, called the Quality Index (QI). Showed high linear correlation (R2 = 0.9559) with time of storage (IQ = 1.9071 + 1.203 x days in ice). All sensory attributes were highly correlated in the PCA analyzes, which marked 95.81% of the total information given by 24 demerit points QIM scheme. The bacteriological analyzes were not decisive in determining the moment of rejection, and their values ranged from <1 log CFU / g to 4.7 log CFU / g for mesophilic and 6.8 log CFU / g for psychrotrophic. The pH varied from 5.76 to 6.6 and the limit (6.5) was achieved after 9 days of ice. The BVT content ranged from 8.82 mg to 17.64 mg N/100g N/100g. A decrease in the strength of the fillets, ranging from 1.37 (N), 0.96 (N), and the strength of the whole fish 13.48 (N), 3.39 (N) shown to be a good indicator of the tendency muscle deterioration with time. The color instrumentally evaluated showed significant differences in skin color during the storage, demonstrating the loss of red color. The physical and chemical analyzes have showed good correlation (> 0.868) with the Quality Index, showing the statistical support for the use of the scheme. Based on these results, suggested that the consumption bigeye by up to 9 days of storage, which corresponded to 15 IQ points