Ohmic pasteurization of probiotic chocolate dairy desserts and its quality attributes

Abstract

The study evaluated the effects of conventional pasteurization and ohmic heating (OH) at different electric fields (12, 16, 20, or 24 V/cm^-1) on probiotic chocolate dairy desserts' physicochemical, microbiological, sensory properties and volatile profiles. Both treatments were analyzed for parameters such as pH, syneresis, cream stability index, rheology, bioactive compounds (total phenolics and antioxidant capacity), and probiotic viability (Lactobacillus acidophilus LA-05) over a 28-day storage period. Ohmic heating at higher electric fields (20 and 24 V/cm^-1) showed comparable results to pasteurization for most parameters, with non-significant differences or even higher values for some. Sensory analysis revealed that pasteurized samples were more associated with "creamy" and "firm" textures. In contrast, OH-treated samples were linked to lumps and fluidity, particularly in OH24 and OH16, respectively. Volatile compounds such as propanal and ethyl propanoate were detected across treatments, with ethyl acetate unique to OH24. The results suggest that OH, especially at higher electric fields, is a promising technology for processing probiotic dairy desserts, offering similar or enhanced qualities compared to conventional pasteurization. These findings provide insights into the potential for OH to be routinely applied in functional dairy product production.

Keywords: Dairy dessert; Ohmic heating; Probiotic; Quality indicators.