Amount of phenolic substances and antioxidant capacity in a purple sweet potato puree “ipomea batata”

Abstract

Objective: The purpose of this work was to find the amount of phenolic substances and their antioxidant capacity of a purple sweet potato puree "Ipomea Batata" Satsumahikari. Material and methods: Three treatments were applied: A (50% sweet potato, 0.4% citric acid and 42% water), B (55% sweet potato, 0.3% citric acid and 37% water) and C (60% sweet potato, 0.2% citric acid and 32% water). The process flow was: combine ingredients (sweet potato, sugar, water, citric acid, starch, cloves, cinnamon and potassium sorbate), pre-cook, package, heat, cool and label. Results: The physicochemical tests carried out for treatments A, B and C had the following results: for citric acid 0.450; 0.442 and 0.437 %, for pH 4.38; 4.41 and 4.42, for soluble solids 30.00; 32.23 and 34.40%, for phenolic substances 51.50; 52.65 and 54.38mg gallic acid/100g puree and antioxidant capacity 454.60; 462.30 and 471.90 umol Trolox/100g pure, respectively; statistical dissimilarity was found for the last two analyses to the ANVA test (5%). In the sensory assessment, using an ordering scale from 1 to 10 and 10 panelists for treatments A, B and C The following results were found: for flavor 5.2; 5.6 and 6.4, for texture 3.9; 5,4; 6.2 and color 3.9; 5.7 and 6.3; at 5% Friedman's test there were statistical differences for texture and color. Treatment C was chosen due to its sensory properties, amount of phenolic substances and antioxidant capacity. Conclusion: The amount of phenolic substances and antioxidant capacity in treatments A, B and C are statistically dissimilar, with treatment C being the best. The same happened with the sensory characteristics evaluated, therefore treatment C offered a higher degree of satisfaction.