Polpa de tamarindo (Tamarindus indica L.) em pó: obtenção em spray dryer e aplicação em smoothie de frutas

Abstract

Tamarind pulp (Tamarindus indica L.), (PT), can be marketed in powder form and as an ingredient in beverages. This work is justified by the need to add value to the PT and expand its application in foods with functional claims. With this, the objective was to produce tamarind pulp powders (PPT) in spray dryer and evaluate its physicochemical, morphological and fluidity properties in order to apply it in fruit smoothie. The topic of tamarind drying has been studied since 1993, being explored mainly in the area of food science and technology. In this study, when evaluating the effect of drying temperature and addition of the adjuvants maltodextrin, inulin and whey protein isolate (WPI), in equal proportions, on the properties of PT by means of the Central Rotational Composite Design, it was observed that the best condition was dried at 174.2 ºC with 20% of adjuvants, presenting circular particles, smooth and rough, without agglomeration and easy to drain. The effects of the three adjuvants on PT were analyzed individually regarding moisture, hygroscopicity, yield, solubility, total extractable polyphenols (TEP), color (L*, a* and b*), particle morphology and fluidity, using the Powder Flow Tester. Moisture, yield, solubility, TEP and b* were significant (p ≤ 0.05). The PPT containing WPI had the lowest solubility (80.26%) and the highest yield (35.21%). The PPT with inulin showed the highest TEP contente (355.21 mg of GAE.100 g -1 b.s), with retention of 25.24%. The spherical geometry was predominant, but with roughness and smaller agglomerations in the PPT containing WPI. The PPT containing WPI, maltodextrin and inulin were classified as easy to flow, cohesive and very cohesive, respectively. The flow parameters showed high linear correlations with each other (p ≤ 0.01). Then, we sought to obtain PPT using the experimental design of mixtures, Augmented Centroid Simplex element. The PPT containing WPI had a strong influence on the higher moistures, yields, lower hygroscopicities, solubilities and L* (p ≤ 0.05). Inulin contributed little to the yield, but promoted greater solubility when mixed with maltodextrin. WPI is the most prominent and best optimized adjuvant for mixing with maltodextrin (5:5 g.g -1 , best condition), presenting easy flow. During 240 days of storage, the best condition showed a reduction in moisture, hygroscopicity, solubility and TEP contents, but an increase in pH (p ≤ 0.05). When the PPT of the best condition was applied to a smoothie based on banana, melon and soursop pulps in the proportions of 5% (T5%) and 10% (T10%), T10% presented the highest energy value (85.52 kcal.100 g -1 ), carbohydrates (15.88%), proteins (3.97%), lipids (0.68%), ashes (0.50%) and TEP (166.77 mg of GAE.100 g -1 ). All formulations were non-Newtonian pseudoplastic fluids (n < 1), with greater microbiological stability in glass packages until the 7th day of cold storage (4 ºC). Control was statistically equal to T5% for all sensory attributes (> 6.0) (p > 0.05), with a global acceptability index of 74.78 and 71.90%, respectively. Therefore, the smoothie containing up to 5% of the PPT is viable for marketing.