The objective of this study was to evaluate the microbiological, physicochemical and functional quality of an innovative goat whey orange juice beverage (GOB) processed by microfiltration. The microfiltration (0.2 µm) of the GOBs had a variation on the feed temperature (20, 30, 40, 50 °C) and were compared to the conventional heat treatment LTLT (63 °C/30 min). Microbiological (aerobic mesophilic bacteria, mold and yeast and lactic bacteria), physicochemical (pH, color, rheology and volatile compounds) bioactive compounds (acid ascorbic, total phenolics) and functional activity (DPPH, ACE, α-amilase and α-glucosidase) analysis were performed. The GOB processed by microfiltration using at least 30 °C presented adequate microbial counts (less than 4, 3 and 4 log CFU/mL, for AMB, molds and yeasts and LAB, respectively). In general, the pH, color parameters, volatile and bioactive compounds were not influenced by microfiltration temperature, but presented a difference from the LTLT processing. The rheological parameters were influenced by MF temperature and the utilization of temperatures of 20° and 30 °C maintained the consistency similar to the LTLT sample, preserving the compounds responsible for the texture. Therefore, it is suggested a processing of GOB by microfiltration using mild temperatures (between 30° and 40 °C) to preserve consistency and also obtain a desirable microbial quality, beyond the preservation of many functional properties and volatile compounds.
Keywords: Dairy product; Functional activity; Membrane technology; Microbiology; Rheology.
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