Elaboração e caracterização de almôndegas de tilápia do nilo (Oreochromis niloticus) e pirarucu (Arapaima gigas) cultivados: aplicação na merenda escolar.

Abstract

The development of value-added fish products has generated a large number of research studies, especially with species from aquaculture, aimed at addressing the technological and nutritional aspects of fishery that might boost industrial development. This Doctorate Thesis seeks to develop and characterize the physiochemical, microbiological, nutritional and sensorial character of the meatballs made from mechanically deboned (MDM) meat of farm-grown Nile tilapia (Oreochromis niloticus) and pirarucu (Arapaima gigas), and their application in school meals. The specific goals were to prepare, calculate the yield, obtain the cost spreadsheets and ultimately carry out their characterization, by assessing their physical, chemical, microbiological, nutritional and sensory aspects. The choice of species used in this study was based on the industry’s demand and the Nile tilapia and pirarucu were collected from fish farms in two cities in the state of Ceará, both processed in the industry in a standard process. The characterization of fish meatballs and the MDM was determined by a physiochemical analysis (pH and water activity Aw), proximal composition (moisture, protein, lipids, ashes and carbohydrates) and the amino acid profile. The microbiological analyses were carried out for positive coagulase Stafilococos tests, coliforms at 45° C and Salmonella sp. For the meatballs were made the same microbiological analyzes considering a shelf life of 90 days. The sensory analysis conducted for the meatballs was accomplished through the application of global accessibility test, in accordance with the standards of PNAE(2010). The average yield of 34.5% for the Nile tilapia fillet and 26.7% for the MDM, in relation to the whole fish and 70.0% as compared to the headless carcass. The average yield for the pirarucu fillet was about 52.2% and 9.0% for MDM, as compared to the whole fish and 47.7% in relation to the headless carcass. The results of the cost spreadsheets for Nile tilapia fillet had values of BRL 36.14/kg (USD 11.06) and for the pirarucu fillet the values amounted to BRL 31.0/kg (USD 9.49), values that are not suitable for school meals. In the case of MDM for Nile tilapia meatball production, the value stood at BRL 8,16/kg (USD 2.50) and for pirarucu meatballs the value was BRL 10.4/kg (USD 3.18), values that are acceptable and viable for school meals products, as they rank below what is practiced in the school lunch market (BRL 15.00/kg) (USD 4.59). Both MDM presented higher protein contents (21% and 20%) and higher humidity (76% and 76.8%) as compared to fish meat balls of the same species, respectively (17% and 18% for protein) and (72% and 71% for moisture), which are quite acceptable values as well. On the other hand, the meatballs (Nile tilapia and pirarucu) showed higher levels of lipids (7% and 8.1%), carbohydrates (2.5% and 1.3%) and ashes (1.5% and 1.6%) than MDM, due to the use of inputs (salt, seasonings and binders). The amino acid profiles of the fish meatballs were similar, showing high nutritional value, due to their composition of essential amino acids. The microbiological analysis has shown that derivatives of the two species are within the sanitary standards required by the legislation in force, and that the shelf life test turned out to be satisfactory. Sensory analysis demonstrates that the school meals in the form of fish meatballs were widely accepted by most children, within the concepts of the hedonic scale: Like it (pirarucu 80%) and Love it (tilapia 65.5%). Based on the results obtained, one may conclude that the fish meatball prepared from MDM of Nile tilapia and pirarucu, strongly indicates that they are recommended for use in school meals, since the amount of essential amino acids found in this study surpassed recommended daily requirements of these amino acids by FAO / WHO, as they have all the desirable physiochemical, nutritional, microbiological and sensory attributes, besides stimulating the full utilization of fishery inputs in value-added products.