Changes in the quality parameters, bioactive compounds and volatiles of two table grape varieties (Vitis vinifera L. cv Muscat de Hambourg and Alphonse Lavallee) during storage

In this study, some quality parameters (dry matter, mean weight, soluble solids, titratable acidity, sugars, organic acids), the levels of bioactive compounds (vitamin C and E, carotenoids, polyphenolics) as well as those of volatiles have been determined during two successive years in two black table grape cultivars, Muscat de Hambourg' and Alphonse Lavallee', stored up to 4 weeks at 1 degrees C. The descriptive sensory analyses of the samples by a trained panel were also performed. During storage, most of quality parameters (dry matter, mean berries weight, soluble solids content, titratable acidity, sucrose, fructose, and organic acids) were not affected by storage in both cultivars, while the levels of glucose significantly decreased. Regarding bioactive compounds, the levels of carotenoids, tocopherols, and polyphenolics remained almost unchanged, whereas those of vitamin C decreased. Although the levels of linalool drastically decreased with storage in Muscat samples, the trained sensory panel observed no significant difference for the descriptor aroma intensity. All these results show that the overall quality (organoleptic, sensory, nutritive and functional) of the two traditional French cultivars, Muscat de Hambourg' and Alphonse Lavallee', is globally maintained for up to 4 weeks under standard commercial storage conditions.