Effect of storage temperature on physicochemical, physical, microbiological, and sensory characteristics of table grapes (‘Red Globe’ variety)

Abstract

This study assessed the quality attributes and consumer acceptability of ready-to-eat ‘Red Globe’ table grapes from Chile and sold in the Portuguese market. The grapes were stored under different temperatures: refrigerated (T= 5 ± 1 °C) and room temperature (T= 22 ± 1 °C). Physicochemical, physical, chromatic, microbiological, and sensory analyses were conducted at 0, 7, 14, and 21 days of storage. During storage, grapes kept at room temperature had a higher weight loss (28.55 %) compared to those stored under refrigeration (17.05 %). The initial 16.9 °Brix value increased to 18.4 and 21.5 °Brix for grapes stored under refrigeration and at room temperature, respectively. Total acidity, as well as chromatic parameters L*, a*, and b*, remained relatively stable over time, regardless of the storage conditions. Regarding microbiological aspects, table grapes stored under refrigeration maintained satisfactory values for consumption even after 21 days of storage in the laboratory. Grapes stored at room temperature exhibited high mold populations only after 7 days of storage. At the sensory evaluation, refrigerated grapes received a hedonic rating of "liked" (≥ 6) for several sensory parameters. With this study it was possible to demonstrate the importance of the storage temperature of table grapes in the maintenance of their quality and acceptability by consumers.