Influence of Two Different Cryoextraction Procedures on the Quality of Wine Produced from Muscat Grapes

Abstract

Freezing grapes is a winemaking technique known as cryoextraction that intends to modify the composition of the final wines. The changes that take place in the frozen grapes facilitate the transfer of certain compounds from the grape skins into the musts because of the grape’s unstructured tissues. For this study, the white grape variety Muscat of Alexandria was selected. Two different cryoextraction procedures have been analyzed as follows: (i) Ultrafast freezing, and (ii) liquid nitrogen freezing. The wines obtained using liquid nitrogen freezing exhibited higher levels of terpenoids, as well as higher levels of hydroxylic compounds and fatty acids than both the wines obtained through traditional methods and ultrafast freezing wines. In any case, both freezing techniques produced wines of a more intense aroma compared with those wines obtained by traditional methods. In fact, liquid nitrogen freezing produced the wines with the most intense aroma and were the best valued by the tasting panel.

Effects from the Freezing of Either Whole or Crushed Grapes on the Volatile Compounds Contents in Muscat Wines

“…Specifically, when working with the Muscat variety, ultrasound applied during a pre-fermentative maceration at 10 °C favors the extraction of compounds and produced more aromatic wines [ 9 ]. A freezing process applied over whole berries of Muscat of Alexandria, followed by 3 h skin maceration, produced significantly different wines with increases up to 300% in volatile terpenoids; moreover, higher scores for fruit and flower notes in a tasting panel analysis were reported [ 10 ]. Additionally, wines with higher aromatic intensity were obtained with prefermentative maceration (15 °C for 6 and 12 h) in Muscatel de Bornova and Narince varieties [ 6 ].…”

“…Grapes can be frozen using different methods, and the freezing step can be carried out instantly using dry ice or freezing chambers for several hours or even days at −20 °C [ 10 ]. The freezing process breaks the grapes’ skin cells and facilitates the transfer of the compounds located in the solid parts into the must when it returns to room temperature [ 10 ]. A study on the effects of freezing rates of grapes on the final wine was carried out on the Muscat variety.…”

Does u.v. light affect the total phenolic compound, anthocyanin, antioxidant capacity, and sensory profiles in wines?

“…This trend is manifested in wine production technology, with studies aimed at obtaining a wine with a high organoleptic quality and a higher amount of antioxidant phenolic compounds. For example, reducing the fermentation temperature and prolonging the maceration (Panprivech et al ., 2015), increasing the fermentation temperature with thermovinification (Lisov et al ., 2021), cryoextraction procedures (Ruiz‐Rodríguez et al ., 2020), saignée method (Lukić et al ., 2017), and enzyme application (Osete‐Alcaraz et al ., 2019) techniques are applied to increase the extraction of phenolic compounds to wine.…”

Changes in the Aromatic Compounds Content in the Muscat Wines as a Result of the Application of Ultrasound during Pre-Fermentative Maceration

“…A related technique is cryo-freezing or cryoextraction. By freezing the berries, the cells of the skins are broken and, when they return to room temperature, the compounds located in the solid parts are more easily released into the medium [ 12 ].…”