Microwave‐induced free radicals production in red wine and model wine by electron paramagnetic resonance spin trapping

Abstract

As an alternative to traditional processing methods, advanced food processing technology such as microwave radiation has been widely used in food industry. Microwave as a new food processing technology used the advantages of microwave energy to overcome the shortcomings of traditional and some new food processing methods. Therefore, microwave irradiation was considered to be a promising technology in food technology such as drying, heating, and sterilizing (Chizoba Ekezie et al., 2017;Guo et al., 2017). In wine-making, the application of microwave in wine aging may have been emphasized (Liu et al.,

Microwave Irradiation: Effects on the Change of Colour Characteristics and Main Phenolic Compounds of Cabernet Gernischt Dry Red Wine during Storage

“…In the aging process, free anthocyanins participated in condensation reactions to form new oligomeric and polymeric pigments, thus changing the colour of the wine [ 24 ]; colourless non-anthocyanin phenols (including flavan-3-ols and flavonols) could form yellow pigments through multi-oxidation and decarboxylation reactions [ 25 ], which could also change the colour of the wine. Microwave irradiation could induce the production of free radicals and further initiate chemical reaction in red wine [ 9 ]. These results showed that microwave treatment induced the production of free radicals and triggered chemical reactions to accelerate the production of some stable pigments in red wine.…”

“…Due to the gradual accumulation of coloured pigments in red wine (M 0 , M t3 , and M t6 ), WC increased with the extension of storage time, increasing the visible spectrum at 520 nm [ 1 ]. In addition, the increase of WC in microwave-treated wine was higher, which may be because the microwave-induced free radicals were the most important trigger for chemical reactions related to red wine colouring at 520 nm [ 9 ].…”

“…In addition, the high-frequency electromagnetic waves destroy the stabilization of weak hydrogen bonds by strengthening the rotation of polar molecules [ 8 ]. Free radicals are induced under microwave irradiation [ 9 ]; the existence of free radicals leads to complex chemical reactions in the aging process. Microwave treatment could reduce the use of SO 2 [ 10 ] and improve sensory qualities of red wine [ 11 ].…”

“…Our laboratory conducted a preliminary studies on the change of the physicochemical characteristics of wine after a short period of microwave treatment [ 16 ], content change and degradation phenomena of phenolic compounds caused by microwaves [ 17 ], 1-hydroxyethyl free radicals induced by microwave [ 9 ], and the change of properties and activities of PPO effected by microwaves in the grape maceration stage [ 18 ]. As far as we know, the dynamic changes in the colour, main anthocyanins, and phenolic compounds in red wine under microwave irradiation during storage and aging have not been reported.…”

Investigation of the effect of hydrodynamic cavitation treatment on the aging of tender coconut–palmyra wine

“…While conventional aging has many benefits, it has the disadvantages of the high cost, cask space, the longer maturation time required, and loss of wine through evaporation. For this concern, alternative techniques have been followed to simplify the process of aging, like the addition of oak chips during bottling (Călugăr et al, 2020; Del Alamo Sanza et al, 2004; Teodosiu et al, 2019), micro‐oxygenation (Canas et al, 2019), ultrasound (Del Fresno et al, 2018; Delgado‐González et al, 2017), microwave (Jing, 2011; Yuan et al, 2021), etc.…”