The partial dehydration of grapes after harvest and aimed wine-making, has been shown to be a process that brings increased concentration of sugar and phenolic compounds in the must, which results in the quality of the wines produced. However, the works developed so far studied the process for temperatures up to a maximum of 25°C and air velocity less than 1 m.s-1. This study aimed to analyze the physical and chemical changes (concentration of total soluble solids (TSS) and phenolic compounds (CPC)) after partial dehydration of 'Niagara Rosada' grapes at the temperature subjected to two treatments combining two temperatures and one air velocity (T 1 = 22.9°C/1.79 m.s-1 and T 2 = 37.1°C/1.79 m.s-1), and relative humidity of approximately 40%. The loss of water in the grapes was approximately 14% and the drying process lasted between 20 to 50 h for the treatments T 1 and T 2 , respectively. We experimentally and statistically verified that the treatments promoted significant increase in TSS and CPC; however, for CPC at the temperature of 37.1°C, the increase accounted for approximately 29%, whereas, for the temperature of 22.9°C, it was only 5%. For TSS, the increase was on average 14.4 ± 3.9% between both treatments.

This study aimed to verify the influence of partial dehydration of "Niagara Rosada" grape clusters in physicochemical quality of the pre-fermentation must. In Brazil, during the winemaking process it is common to need to adjust the grape must when the physicochemical characteristics of the raw material are insufficient to produce wines in accordance with the Brazilian legislation for classification of beverages, which establishes the minimum alcohol content of 8.6 % for the beverage to be considered wine. Therefore, given that the reduction in the water content of grape berries allows the concentration of chemical compounds present in its composition, especially the concentration of total soluble solids, we proceeded with the treatments that were formed by the combination of two temperatures (T 1 -37. ADEQUAÇÃO DO MOSTO DE UVAS NIAGARA ROSADA PARA VINIFICAÇÃO ATRAVÉS DE DESIDRATAÇÃO PARCIAL DOS CACHOSRESUMO: Este estudo teve como objetivo verificar a influência da desidratação parcial de cachos de uva Niagara Rosada na qualidade físico-química do mosto pré-fermentativo. No Brasil, durante o processo de vinificação, é comum a necessidade de adequação do mosto de uvas quando as características físico-químicas da matéria-prima são insuficientes para a obtenção de vinhos em conformidade com a legislação brasileira para classificação de bebidas, a qual estabelece o teor alcoólico mínimo de 8,6% para que a bebida seja considerada vinho. Portanto, tendo em vista que a redução do teor de água das bagas da uva possibilita a concentração de compostos químicos presentes em sua composição, principalmente a concentração de sólidos solúveis totais, procedeu-se aos tratamentos que foram constituídos pela combinação de duas temperaturas (T 1 -37, apresentado o maior incremento na concentração de sólidos solúveis totais, seguido do segundo melhor resultado para a concentração de compostos fenólicos. PALAVRAS-CHAVE:composição química, mosto, secagem.Adaptation of "niagara rosada" grape must to winemaking by partial cluster dehydration Eng.

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