OHMIC HEATING APPLIED AS ALTERNATIVE PROCESSING FOR WHEY-BASED POPSICLES: BIOACTIVE COMPOUNDS AND QUALITY PARAMETERS

Emerging technologies can assist in preserving bioactive compounds and contribute to improving the quality parameters of dairy products. This study aimed to assess the impact of ohmic heating (OH) on processing parameters and physicochemical characteristics of watermelon and whey-based popsicles. Popsicles were processed using OH under different electric fields: 30V (3.33V/cm; T1), 60V (6.67V/cm; T2), and 90V (10.00V/cm), and by pasteurization (70°C/30 minutes; TP). An untreated sample (TC) was used as a control. After processing, the following analyses were conducted: antioxidant capacity, total phenolics, ascorbic acid, inhibition of angiotensin I-converting enzyme (ACE-I), α-amylase, and α-glucosidase, hydroxymethylfurfural (HMF), and whey protein nitrogen index (WPNI). Analysis of bioactive compounds revealed that intermediate electric field intensity was favorable for preserving antioxidant capacity (32.42%) and total phenolic compound content (0.686 mg GAE/100g), significantly differing (p<0.05) from other intensities. The highest preservation of ascorbic acid content (0.487 mg/100g) was observed at the highest applied intensity, not differing (p>0.05) from the intermediate electric field. Inhibition of ACE-I activity (37.5–58.2%), α-amylase (23.7–49.5%), and α-glucosidase (37.3–55.8%) were greater in all electric fields applied compared to conventional treatment (25.53%, 16.6%, 22.5%, respectively; p<0.05). The highest HMF content (10.333 μmol/g) and the lowest WPNI content (2.843 mg WPN/mL) were observed in the pasteurized sample, significantly differing (p<0.05) from the samples treated with OH. The results indicate that OH was more effective in preserving bioactive compounds than conventional pasteurization, especially at medium and intermediate electric field intensities. Furthermore, higher voltages were more effective in preventing the formation of HMF, while lower voltages were better at preventing protein denaturation. In this sense, OH proved favorable for processing popsicles, while pasteurization was responsible for greater thermal degradation.