Evaluación del Valor Nutricional de la Tilapia Rja (Oreachromis spp.) en Filetes Procesados por Liofilización

Abstract

Evaluation of the nutritional value of Red Tilapia (Oreochromis spp.) fillets processed by freeze-drying was carried out at ESPOCH and the INIAP Laboratory. In order to maintain its quality and extend its shelf life, it was freeze-dried and compared with freezing. Nutritional value, sensory quality, microbiological quality and volatile basic nitrogen (V.B.N.) were analyzed. The data were subjected to ANOVA analysis of one factor, and when significant differences appeared at P= 0.05, Tukey's Honestly Significant Difference HSD test was used for comparison of means. The thickness of the fillet to be evaluated was determined based on the percentage of humidity and sensory characteristics; this was 1 cm. The next stage consisted of freezing and freeze-drying fillets with this thickness in the LABCONCO Freeze Dry System freeze dryer at the INIAP Food Research and Development Area laboratory. The results showed that there were no statistically significant differences in protein, fat, ash and chlorides between the two treatments. The microbiological analysis showed a high count at 15 days (240 CFU/g) and decreased at 30 days (100 CFU/g) in the freeze-dried product, correlating with the high N.B.V., and the presence of Staphylococcus aureus, fecal coliforms and E coli was not detected. The sensory analysis carried out after 3 days showed no differences for the two treatments. Concluding that the nutritional and sensory value is equal in both freeze-dried and frozen fillets due to the short storage time when analyzing the samples. It is recommended to extend the shelf life analysis of the product for both frozen and freeze-dried samples to determine the nutritional value obtaining a product with organoleptic and nutritional characteristics.