Grape juice blends treated with gamma irradiation evaluated during storage

Abstract

The blend is an important resource for the offering of differentiated beverages in the market and the influence of this non-thermal technology (gamma irradiation) on grape-based products has yet to be investigated in terms of microbial and quality attributes. The preparation of grape juice blends may be an alternative to further improve its potential, aggregating nutritional and functional benefits. In addition, use of radiation in beverages has been studied as an alternative to minimize the loss of components that occurs in thermal processes. The aim of this study was to verify the efficacy and effect of gamma irradiation at different doses on the nutritional, microbiological, and sensorial characteristics of grape juice blends during storage. Blends with 33% Isabel Precoce, 33% Bordô, and 34% BRS Violeta were submitted to different gamma irradiation doses (0.0; 1.0; 1.5, and 2.0 kGy), and stored at room temperature for 120 days. Grape juice blends (2.0 kGy) presented the highest antioxidant content and the highest vitamin C increase until 90 days compared to the other treatments. At 120 days the soluble solids content and total phenolic values were higher in the blends 1.0 kGy and 1.5 kGy, respectively, when compared to other treatments. Sensory tests showed that the quality of the grape juice blends (2.0 kGy) remained unchanged, and gamma irradiation reduced fungi and yeasts during storage at room temperature. The gamma irradiation technique can be considered a viable alternative for quality preservation of grape juice blends during storage, as well as to replace the heat treatment methods.