Microwave-assisted pasteurization of beverages (tamarind and green) and their quality during refrigerated storage

Abstract

Abstract Microwave-assisted treatments for the pasteurization of a tamarind and green (formulated with pineapple, nopal, guava, and lemon juice) beverages were studied. The beverages were treated with microwaves (490 W, 2450 MHz) in batches of 480 mL until reach the target temperature for the inactivation of the enzyme pectinmethylesterase (90 °C, with holding time of 12 s). Thermal images were taken after the treatments to guarantee the heating uniformity. Bottles were closed, cooled and stored in refrigeration for 21 days. The heating time was 255 s and 280 s for the green and tamarind beverages, respectively. Enzymatic activity was reduced 100% and microbiological accounts were depressed after MW-pasteurization. There were no significant changes in pH, titratable acidity and total soluble solids in tamarind beverage in comparison with untreated samples (p > 0.05). However, MW-pasteurization affected sensory attributes and color in the green beverage (p Industrial relevance Microwaves (MW) are an alternative among the emerging technologies for preservation of diverse fluid foods, with advantages such as, high efficiency, sustainability and reduction of time and costs. This study found viable MW-pasteurization to preserve the sensory, physicochemical and microbiological properties of the tamarind beverage even for 21 days under refrigeration. Despite a safe and stable product may be obtained, the color and sensory attributes should be improved for green beverage. The proposed batch microwave-assisted pasteurization is a short treatment, which can be applied in small facilities or rural zones, with potential to be scaled up it to an industrial level.