Minimally processed fruit salad enriched with Lactobacillus acidophilus: Viability of anti-browning compounds in the preservation of color
Minimal processing promotes browning of some vegetal tissues due to cell membrane disruption, which results in the release of oxidative enzymes. This study evaluated the efficiency of citric acid, ascorbic acid, sodium metabisulfite and L-cysteine hydrochloride to retard enzymatic browning of minimally processed fruit salad and enriched this product with Lactobacillus acidophilus LA-5. Control treatment was fruit salad immersed in water. Polyphenol oxidase (PPO) and color (L*, a*, b*, index color - CI, browning index - BI, c*, and h°) were analyzed. The viability of L. acidophilus was also evaluated using Rogosa agar in fruit salads containing anti-browning compounds in higher concentrations. PPO presented a significant difference among control and fruit salad treated with ascorbic acid and L-cysteine hydrochloride, indicating the highest anti-browning activity of these compounds. The fruit color was affected by processing and storage time, with a reduction in the values of L* over time. Values of a*, c*, h° angle and CI indicated a predominance of red color in the fruit salad. Salads containing anti-browning compounds in higher concentrations presented viability of L. acidophilus above 7.43 log CFU/g up to the fifth day of storage, indicating that the product can be promised as probiotic. Thus, the fruit salad treated with anti-browning compounds has potential use as a probiotic carrier.
Keywords: Fresh-cut fruits, color, ascorbic acid, vegetable matrix, probiotic culture.