Sorvete com potencial funcional adicionado de resíduo agroindustrial de uva

Abstract

The agricultural industry produces high volume of waste and between the fruits; the waste from grapes from has been incorporated into the development of new products. Thus, the objective of this study was to produce waste flour of grape (WFG) and add it in grape ice cream in order to evaluate the effects on sensory acceptability, nutritional composition, content of bioactive compounds and antioxidant capacity. The residue was ceded by a processing unit of frozen pulp located in Goiana - PE, whose grapes variety Isabel (Vitis labrusca) were cultivated in the city of Saint Vincent Ferrer-PE. The centesimal composition, the content of compounds phenolics, flavonoids, flavonols and anthocyanins as well as the antioxidant activity of WFG and ice cream that was more accepted, beyond the objective color evaluation (CIELAB), were determined. Extracts obtained with ethanol (60%) acidified (0.01% HCl) were subjected to the quantification of total phenolics, flavonoids, flavonols and the determination of antioxidant activity using the DPPH• radical (1,1-diphenyl-2-picrylhydrazyl) and the ABTS•+ (2,2'-azino-bis (3-ethylbenzthiazoline sulfonic acid-6). In relation to the ice cream, four formulations were prepared with different WFG concentrations (P 0%, F1 2% F2 6% F3 10%) and evaluated for attributes of color, aroma, flavor, texture and overall quality using scale hedonic structured in 9 points. The WFG was submitted to fecal coliform count and Salmonella sp. and the results attended to the Brazilian legislation. Regarding to the chemical composition of WFG the values found for moisture, ash, protein, lipid, carbohydrate and dietary fiber were, respectively: 8.15%; 7.49%; 9.66%; 15.55%, 14.09% and 44.88%. With relation to physical and chemical analysis the values found WFG were: water activity (0.46); pH (3.88); titratable acidity (3.37%); total sugar (20.84%); reducing sugars (18.83%) and nonreducing (2.01%); total energy (236.24 kcal). Phytochemicals quantified in WFG showed values for phenolic, flavonoids; flavonols and anthocyanins, respectively: 40.28 mg g-1; 1335.53 mg 100g-1; 81.86 mg 100g-1 and 55.49 mg 100 g-1. Also regarding to WFG, the polymer color percentage was 80.77% and the color parameters were L* = 40.21; a* = 15.46; b* = 15.65. The antioxidant capacity against the free radical DPPH• (IC50) and ABTS•+ were respectively 7,66μg mL-1 and 13.130μmol TEAC g-1. The ice cream F1, with 2% WFG, showed good sensory attributes that allowed to be appointed by the panel of tasters as the best formulation. The addition of 2% of WFG in to grape ice cream provided an increase in protein, lipids, ash, dietary fiber, total energy value, reducing sugars, total phenolics, flavonoids, flavonols and anthocyanins. Consequently, the radical scavenging ability of DPPH• (EC50) e ABTS•+ was higher than the standard sample (without WFG) (p <0.05). Thus, the addition of waste flour of grape (2%) in to ice cream may be considered a viable and healthy technology application, to obtaining a product with organoleptic and nutritional characteristics satisfactory, higher levels of dietary fibers, bioactive compounds and antioxidant potential, and contribute to the usefulness of this waste.