Shelf life, physicochemical and antioxidant properties of red cactus pear pulque processed by ohmic heating and by conventional pasteurization

Abstract

Red cactus pear pulque has bio-compounds and Lactobacillus sp. that confer functional properties. This beverage has a short shelf life (≤4 days) due to a high microbial load that causes its decomposition. Ohmic heating (OH) and conventional pasteurization (CP) are technologies for processing foods and beverages that contribute to preserving their quality. The aim of this study was to apply OH and CP for processing red cactus pear pulque in order to evaluate its effect on its microbiological, physicochemical, sensory, and antioxidant properties, and prolong its shelf life. Conditions at 60 °C (for 8 min and for 10 min) and at 65 °C (for 7 min and for 9 min) were used to process by OH, and CP was performed at 63 °C for 30 min. Unprocessed beverage was used as a control. The shelf-life study was carried out of storing the samples for 15 days at 4 ± 1 °C. Parameters such as pH, color, alcohol content, total soluble solids, Lactobacillus sp., yeasts, polyphenols, betalains, and antioxidant activity were determined every 72h. The obtained results demonstrated that shelf life was prolonged for up to 12 days preserving the physicochemical properties employing OH and CP. OH revealed better retention of sensory quality, a higher content of Lactobacillus sp., betalains, polyphenols, and antioxidant activity than CP during storage. Best conditions for processing by OH were at 60 °C for 8 min and for 10 min. Lactobacillus acidophilus, L. kefiri, and Saccaromyces cerevisiae were identified in red cactus pear pulque processed by OH.