Effect of moderate electric field on peroxidase activity, phenolic compounds and color during ohmic heating of sugarcane juice

Abstract

The influence of moderate electric field was evaluated during thermal treatment of sugarcane juice. Conventional and ohmic heating (OH) experiments at temperatures of 60 and 80°C were conducted to investigate the effect of frequency (0–105 Hz), waveform (sine, square, and triangle) and voltage gradient (0–16.7 V/cm) on inactivation of peroxidase (POD), phenolic compounds stability and color changes. Enzyme activity was significantly (p < .05) affected by OH; the nonthermal effects promoted POD activation at 60°C (mainly at 10 Hz) and inactivation at 80°C (mainly at 100 kHz). It was not found variation of phenolic compounds with the different operational conditions applied. Moreover, the color of the juice was modified using low frequency (possibly due to electrochemical reactions) and different waveforms. Overall, OH is suitable for POD inactivation at 80°C with the usual process parameters (sine wave and 60 Hz) or higher frequencies. Practical applications Sugarcane juice is a popular energy drink, nonalcoholic, with sweet and pleasant taste. It is commercialized predominantly in the informal marketplace because its processing and marketing are limited due to its rapid deterioration. The objective of this work is to provide an alternative technology for sugarcane juice processing, ensuring safety, and lower impact on nutritional compounds, allowing its commercialization in formal markets. Ohmic heating (OH) is a faster heating technology, appropriate for pasteurization of heat‐sensitive products. The study of the effect of the process variables (temperatures, electric field frequency, waveform, and electric field strength) on enzyme inactivation, degradation of total phenolic compounds, and color stability is important to support modeling and optimization, making OH a viable technology for sugarcane juice pasteurization.

Technological Applications of Natural Colorants in Food Systems: A Review

“…This feature is the main innovation of OH, making it a highly energy-efficient process suitable for rapid and uniform plant material processing. Using this technology, plants are not over-processed, and minimal changes in phytochemicals and color are produced [ 43 ].…”

Enhancement of the Antioxidant, Anti-Tyrosinase, and Anti-Hyaluronidase Activity of Morus alba L. Leaf Extract by Pulsed Electric Field Extraction

“…However, high voltage of PEF has been reported to increase degradation of some natural products, including phenolics. As phenolics donate electrons to other compounds, they respond to the alternate electric field [40]. Nevertheless, degradation was detected only by the thermal effect [40].…”

“…As phenolics donate electrons to other compounds, they respond to the alternate electric field [40]. Nevertheless, degradation was detected only by the thermal effect [40]. Therefore, suitable conditions of PEF would result in enhanced extraction efficiency without degradation of biological compounds.…”

Degradation kinetics of anthocyanin, flavonoid, and total phenol in bignay (Antidesma bunius) fruit juice during ohmic heating

“…Many studies on the effects of ohmic heating on degradation of phenolic compound and anthocyanin in processed foods have been reported (Brochier et al, 2019;Ferreira et al, 2019a;Hardinasinta et al, 2019;Loypimai et al, 2015;Makroo et al, 2017;Mercali et al, 2015Mercali et al, , 2013Sarkis et al, 2013Sarkis et al, , 2019Yildiz et al, 2009). Salari & Jafari (2020) conducted a review on the results of various studies and concluded that the effects of ohmic heating on the degradation of phenolic compounds and anthocyanin are not consistent since some researchers reported that ohmic heating resulted in higher degradation compared to conventional heating, while others reported that ohmic heating resulted in lower phenolic and anthocyanin degradation or similar to that of conventional heating.…”