Background Ohmic heating (OH) is a sustainable alternative to conventional thermal processing in dairy foods, providing rapid and uniform heating with lower nutrient degradation. The addition of xylooligosaccharides (XOS) to whey dairy beverages may improve their functional and health‐promoting properties. However, the effects of OH conditions on XOS stability, bioactivity and peptide profile remain poorly understood. Scope and Approach This study evaluated the effects of voltage (20 and 40 V) and frequency (100, 200 and 300 Hz) during OH processing on the stability of XOS in an orange‐flavoured whey dairy beverage (70:30 v/v sweet whey: orange juice +2.5% w/v XOS). The analyses included performance of OH technology, biological activity (DPPH inhibition, ACE‐inhibitory inhibition, α‐amylase inhibition, α‐glucosidase inhibition and ascorbic acid content), XOS chemical stability, proteomic profile, as well as physicochemical, rheological, microbiological and sensory analysis. Key Findings and Conclusions OH significantly enhanced the biological activity, including DPPH inhibition, ACE‐inhibitory inhibition, α‐amylase inhibition and α‐glucosidase inhibition, as well as acid ascorbic content when compared to conventional processing, while reducing heat load. The 40 V treatment yielded the highest bioactivity and preserved ascorbic acid content close to that of untreated samples. OH at 40 V also promoted the formation of a greater diversity of peptides with different biological activities, whereas the 20 V condition showed reduced peptide diversity with increasing frequency. In addition, XOS remained chemically stable across all treatments, maintaining its chemical structure. Overall, OH was able to maintain the physicochemical, rheological, sensorial and microbiological properties of the product. Significance and Novelty This study demonstrates that optimised OH conditions (40 V, 100–300 Hz) can simultaneously preserve prebiotic structure and enhance bioactivity in dairy beverages. The findings highlight OH as a promising green processing technology for developing functional prebiotic whey beverages with improved nutritional quality and lower thermal load.
Oliveira et al. (Wed,) studied this question.