Iogurte sabor beterraba (Beta vulgaris L. var. rubra): composição centesimal, determinação de vida útil e avaliação sensorial

Abstract

Beet (Beta vulgaris L. var. rubra) is one of the most cultivated vegetables in Brazil. It is a source of vitamins, minerals and is one of the richest and most accessible sources of betalains, nitrogenous pigments responsible for its purple color and antioxidant activity. The average content of betalains in this food has been estimated at 120 mg / 100g in fresh weight. The forms of industrialization of beet are limited, which makes it difficult to use the national excess of production. Thus, the objective of this study was to develop a beet drinkable yogurt and study its processing, aiming at developing a microbiologically safe product, sensory acceptable and with good nutritional aspect. To determine the control formulation that would be used in the hedonic threshold methodology, a 9-point hedonic scale acceptance test (n=100) and a 5-point purchase intention scale were performed, using the concentrations of (F) 0%, 5%, 10%, 15%, 20% and 24% of beet. The formulation F5% was chosen. To determine the CAT (compromised acceptance threshold) and RT (rejection threshold), consumers (n = 163) were divided into two groups: “like beet” (LB) (n = 87) and “dislike beet” (DB) (n=76). CAT=6.71% and RT=20.14% of beet addition were found for LB and CAT=7.15% and RT=10.27% for DB. The addition of 6.71% was chosen for the next analyses. In the centesimal analysis, there was no significant difference for moisture, ash and lipids, in relation to F0%. Futhermore, F6.71% showed more fibers, carbohydrates and less proteins (p ≤0.05). The shelf life of the beet yogurt was evaluated through microbiological analysis (coliforms 30ºC and 45ºC, molds and yeasts), pH (pHmeter), titratable acidity (% lactic acid) and color (colorimeter), at times 0 (T0), 20 (T20) and 40 (T40) storage days at 5ºC. It was evaluated as well, the antioxidant activity (DPPH and ABTS) and its sensory aspect (acceptance and purchase intention) at times 0 (T0) and 40 (T40) storage days. Yogurt with 6.71% of beet was able to reach the 40 days evaluated with a safe microbiological profile for both coliforms, molds and yeasts. Its acidity was within the standards required by law, the color suffered a loss of intensity, but it remained acceptable for sensory analysis at T40. Antioxidant activity was detected until the end of the evaluated shelf life. No sensory changes were found that could cause negative perceptions, and the flavor and global impression attributes had higher acceptance averages at T40. The purchase intention was greater than 4 (probably would buy) at T40. Analyzing the influence of information on sensory evaluation of the yogurt, the averages were higher for both LB (n = 64) and DB (n = 50) in the test with information for flavor, consistency, global impression and purchase intention. For the color and aroma attributes, in the same test, there was no difference (p> 0.05) only in the DB group. Yogurt with 6.71% of beet had a shelf life of 40 days. Information about the yogurt had a positive influence on consumers' acceptance and purchase intention