Qualidade do pirarucu (arapaima gigas, schinz 1822) procedente de piscicultura, estocado em gelo, congelado e de seus produtos derivados

Abstract

Investigated alterations in the cultivated pirarucu, the changes sensory, physical, chemical and microbiological aimed at determining the time of conservation in ice and frozen (-18 oC) of whole fish and filet. Also evaluated was the technological potential of this species, in the form of filet hot smoked, dry-salted, "panceta" and "carpaccio". In all sixteen sample of pirarucus cultivated in masonry tank, and fed for six months with feed for fattening trade, until they reach weights that ranged from 3 to 9 kg. The live fish were sacrificed by hypothermia in cold water bath. For the study of conservation in ice, the fish were stored in boxes insulated, followed then by two variants of research: 1) the entire samples were stocked during 180 minutes, for monitoring changes since the pre-rigor until the phase of post-full rigor mortis, through parameters of the index of accuracy (IR), pH and hardness muscle. Also the influence of the time of capture of morning and evening on these parameters; 2) storage of fish for 36 days, where he evaluated at each interval of six days, the changes of quality post-mortem, through chemical analysis (nitrogen bases of total volatile - N-BVT and pH), sensory (method of the index of quality-QIM of whole fish and taste and odor of fish boiled second modified table of Torry Research Station for lean fish) hardness instrumental in the whole fish and in filé and microbiological (counting mesófilos, psicrótrofilos, psicrófilos and mesófilos, molds and yeasts, and total coliforms and fecal). For the study of frozen storage, the filés of pirarucus were frozen in freezer plate (-30 oC) and stored in freezer to -18 oC, during 150 days, which were followed in each interval of 30 days, changes in the regions lumbar and ventral of filés, pH, the N-BVT, test TBA, ability to retain water (CRA), protein soluble in salt (PSS), sensory analysis (modified scheme of Torry Research Station), instrumental hardness of filé and the same microbiological analysis conducted for the fish preserved in ice. Besides the study on the conservation and processing, data were obtained on the income of filés and other organs of prarucu and composition centesimal of fish processed and in natura. In product defumado determined is the pH, N-BVT, TBA, PSS, CRA, sensory evaluation, and microbiological analysis during storage to -18 oC. In salted dried product has been established the curve of drying, sensory analysis, measured the activity of water and salt content. The results of the experiment of pirarucu stored in ice showed that with 36 days of storage the pH was 7.08, the time of acceptability to the consumer in accordance with the sensory panel was of 27 ± 1.57 days in ice. The method QIM showed a significant correlation with time (R2 = 0.92), while the scheme of Torry was R2 = 0.98 in the characteristic of odor. The pH also showed good correlation with the time of storage (R2 = 0.79). There were variations in total counts of bacteria over the 36 days of testing at temperatures of 7 oC (1.0 x10 to 6.0 x 105 CFU / g), of 20 oC (1.2 x 102 to 4.2 x 106 CFU / g) and of 35 oC (1.0 x 10 and 1.4 x 104 CFU / g), with which followed the limits recommended by current legislation. However, from the 28 days of the experiment had already features fish unfit for consumption, demonstrating that the sensory evaluation was decisive in determining the product lifetime. In the study of filé frozen, it was obvious the stability physico-chemical, physical, microbiological and sensory soon to the time of storage. The sensory analysis showed good acceptance of the product defumado. The study lays the groundwork for the pirarucu of captivity, and the alternatives for processing of products for this species.