Inactivation of apple (Malus domestica Borkh) polyphenol oxidases by radio frequency combined with pulsed electric field treatment

Abstract

Summary Radio frequency (RF) preprocessing combined with pulsed electric field (PEF) processing was employed to inactivate polyphenol oxidase (PPO) in apple juice. PPO enzyme levels, loss of total phenolic content (TPC), colours and volatile components in the apple juice were subsequently determined and compared with conventional processing methods (60 °C for 10 min and 70 °C for 10 min). Results indicated that, when the apple tissue was preprocessed using RF for 10 min, the residual activity of PPO decreased to 13.57%; when the squeezed juice was processed by PEF, the residual activity decreased to about 5% at 15–35 kV cm−1 for 400 μs. RF treatment caused no significant loss in TPC. Compared with the conventionally processed samples, the apple juice that was RF‐treated for 10 min and PEF‐treated at 15 kV cm−1 for 400 μs increased its lightness and maintained its fresh‐like flavour.

Combined effect of microwave and ultrasonication treatments on the quality and stability of sugarcane juice during cold storage

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Novel processing techniques and spinach juice: Quality and safety improvements

“…So, there is a need for the preservation and availability of safe, fresh and healthy spinach juice through some novel processing techniques (Zhang et al., 2019). A combination of PEF and US have synergetic effect in higher inhibition of microbial and enzymatic activity and enhancement of nutrition and product quality of juices (Aadil et al., 2015; Siddeeg et al., 2019b; Tian et al., 2018). Furthermore, these techniques are being used together due to their simplicity, economy, efficiency, and constancy for reducing the activity of microorganisms, which prove the better way to treat fruit juice (Li et al., 2017).…”

Effects of pulsed electric fields pretreatment on the quality of jujube wine

“…Pulsed electric fields (PEF), regarded as an emerging non‐thermal treatment technology, has been used in inactivation of pathogenic microorganisms in food processing, which can also improve the colour, texture and flavour (Lee et al ., ; Fauster et al ., ; Tian et al ., ) of food compared with other thermal processing approaches (Gonzalez‐Casado et al ., ). Besides, PEF techniques have been employed to modify the structures of the polymer compounds such as starch (Hong et al ., , ) and ovalbumin nanotube (Wei et al ., ).…”