Farinha funcional elaborada com resíduos de frutas tropicais da Cooperativa Agrícola Mista de Tomé Açú-PA: caracterização e aplicação em gelado comestível

Abstract

Due to inadequate disposal and the large amount of residues from the fruit pulp production line in agro-industries, the use of these for the production of new food products is very important due to environmental, social and economic issues. Therefore, this study aimed to elaborate and optimize a flour with the residues of tropical fruits (pineapple, acerola and passion fruit) processed in the agroindustry of the Tomé-Açú Mixed Agricultural Cooperative (CAMTA) and to develop an edible sorbet ice cream enriched with the flour. To determine the drying time and temperature of the fruit residues, a kinetics was performed using eight mathematical models. After drying, the residues were crushed, sieved and vacuum packed. The nine different proportions of the mixtures between the flours were carried out by means of simplex-centroid planning. A sorbet formulation was developed and enriched with the nine ternary mixtures of fruit residue flour (FRF) planned from the designer simplex-centroid. In the nine formulations of edible ice creams with the addition of FRF, analyzes of pH, total acidity, ° Brix, instrumental, microbiological color (thermotolerant coliforms at 45 ºC and Enterobacteriaceae and Salmonella spp.), sensory parameters and acceptability index were performed. After optimization, in the FRF the physical-chemical parameters, centesimal composition, phenolic compounds and antioxidant capacity were evaluated, and the sorbet formulation containingthe optimized FRF mixture was correlated with the control formula and another standard of the cooperative, regarding their centesimal compositions. The dry residues at 70 °C for 180 minutes showed better results for moisture reduction, with greater availability of total carotenoids (11.43 to 53.65 μg/g). The mathematical models obtained a coefficient of determination (R2) above 0.97, an estimated mean error (SE) less than 0.0110 and a mean square error (RMSE) less than 0.0522, with emphasis on the Wang and Sing model. Among the triangular models provided by the response surface methodology (RSM), the cubic presented higher values of determination coefficient for the responses of flavor (R2 = 0.96; p = 0.02), texture (R2 = 0.90; p = 0.05) and global impression (R2 = 0.94; p = 0.01). The designer simplex-centroid indicated as an optimal mixture with the addition of 60.98%, 7.32% and 31.71% for the flours of pineapple, acerola and passion fruit residues, respectively. The mean scores for the sensory attributes was higher for the sorbet formulation that contained the ternary mixture with 60% pineapple, 30% passion fruit and 10% acerola. FRF had a high content of dietary fiber (34.07%), with total phenolic content (14.05 mg GAE/g) and antioxidant activity (16.62 μmol Trolox/g) indicating potential for exploration as a functional food. The physical-chemical parameters of the edible ice cream formulations showed pH ranging from 4.12 to 5.01, acidity from 0.19 to 0.45, °Brix between 17.00 to 24.40, and the instrumental color vestments indicated low luminosity and tendency to red color, due to the addition of acai pulp. As for the results of the proximate composition of the sorbets, the values of moisture, ash, lipids, proteins and carbohydrates had an influence with the incorporation of FRF in the enriched sample, however they were demonstrated in accordance with current legislation. With the incorporation of FRF in sorbet, the total fiber content increased significantly (5.20%) in comparison with the other formulations. The results indicate feasibility for the application of flour in products from the edible ice cream segment and with perspectives in other agri-food sources, due to the relevant physical-chemical, microbiological and sensory parameters, in addition to providing the consumer with a product that can be consumed by different audiences, including vegans, celiac and lactose intolerants.