# Non-Thermal and Thermal Physical Procedures--Optimistic Solutions in the Winemaking Industry
## 1 Introduction  
Wine's features have been extensively investigated due to its diverse composition and health-promoting properties. Its quality depends on various factors, including cultivation techniques, raw material features, winemaking practices, and fermentation conditions [1]. Nowadays, consumers are looking for natural, safe, healthy beverages with low concentrations of external chemical substances, thereby maintaining their nutraceuticalual properties [2]. To meet these demands and reduce costs, winemakers are increasingly using both thermal (e.g., microwave treatment) and non-thermal (e.g., ultrasound and cold plasma technologies) processes to optimize winemaking methods [2]. Current trends focus on using these techniques in wine aging to create innovative products with complex sensory profiles that align with consumer expectations. Figure 1 illustrates the primary thermal and non-thermal procedures effectively applied in the food and beverages industry. **Heat processing** is a common treatment used in the food and beverage industry but may have unfavorable effects on the nutritional quality and physicochemical and sensory characteristics of heat-sensitive products, such as grape juice. However, **microwave technology** is a faster alternative that helps maintain beverage quality by acting on molecules with permanent dipoles, leading to internal cell heating and dehydration. This process improves the extraction of different primary aromas and phenolic compounds from grapes, particularly during maceration in red wine production, resulting in wines with stronger fruity and floral aromas. For example, this method achieves the swift extraction of phenolic compounds, particularly in grapes where the cellular wall tissue needs more extractivetechniques to destroy its pectin structure (in American hybrids for juice like Chambourcin). Microwaves can also accelerate the aging process of wine by intensifying the extraction of components from wood (phenolic compounds, amino acids, polysaccharides, etc.) [3]. On the other side, **cryomaceration** involves the direct contact of the grape mash with a cryogenic gas, providing a quick and efficient cooling technique that prevents yeast proliferation, alcoholic fermentation, and the loss of volatile compounds. Pre-fermentative cryomaceration enhances the varietal character of white wine by extracting the skin aroma under controlled conditions [4; 5]. Cold pre-fermentative maceration (between 4 and 10 \({}^{\circ}\)C) positively affects the extraction of aroma substances and phenolic compounds, thus increasing varietal aromas. Direct contact with the cryogen reduces the diffusion of atmospheric oxygen, decreasing the oxidation of phenolic and volatile compounds and affecting the color, taste, and structure of the wine. Cryomaceration equipment typically uses liquid CO2 for rapid cooling, temperature control being crucial to prevent ice formation, which can alter the physicochemical properties of wines [5]. **Non-thermal practices** (radiofrequency, pulsed electric fields, ultrasounds, supercritical carbon dioxide, high pressure processing, electrolyzed oxidizing water, oscillating magnetic fields, and cold plasma) can be used to partially or totally replace conventional thermal treatments [6]. **Cold atmospheric plasma** represents a partially ionized gas that contains an array of reactive species, including electrons, positive and negative ions, free radicals, photons, and ultraviolet photons, capable of breaking covalent bonds and initiating various chemical reactions [4]. This system can utilize different gases such as air, nitrogen, argon, or helium, either directly or indirectly (via a liquid medium), for antiseptic purposes [2]. Recently, this sustainable technique has been validated for sterilizing laboratory and biomedical devices and treating biological materials, and it even extends to food processing [7].