Study of the effect of ripening stages and climatic conditions on the physicochemical and sensorial parameters of two varieties of Vitis vinifera L. by principal component analysis: influence on enzymatic browning

Abstract

The present paper describes the effects of maturation on the physicochemical, biochemical and color components of Napoleon and Dominga grape varieties, and on any differences between them. Climatic conditions were taken into account to explain the results obtained. Protein levels increased during ripening and were correlated with pH. Polyphenoloxidase activity was affected by climatic conditions (rainfall) and increased to a greater degree in Dominga than in Napoleon. Taste tests were conducted to determine the contribution of physicochemical and biochemical parameters to the sensorial properties of the grapes. Principal components analysis showed that parameters were correlated in different ways during the ripening period in Napoleon and Dominga varieties. In Dominga AE were correlated to the b parameter and in Napoleon to the L parameter.

Effect of ripening on protein content and enzymatic activity of Crimson Seedless table grape

“…The statistical correlation between seasons for PPO activity during ripening is shown in Table 1, where statistically significant correlation between the 3 years studied is evident. This PPO activity is similar to that obtained by Serrano-Megías et al (2006) for table grapes in the Southeastern Spain but lower than that observed by Wissemann and Lee (1980) in wine grape varieties.…”

“…Since these factors are beyond human control, meteorological data during the growth and maturation periods must be taken into account to understand trends in PPO activity (Serrano-Megías et al, 2006). PPO activity of Dominga and Napoleon table grapes showed a maximum in the middle of ripening, coinciding with substantial rainfall (Serrano-Megías et al, 2006). The PPO of Crimson Seedless seemed to be less sensitive to weather conditions and no relationship between weather conditions and PPO activity was observed.…”

“…Weather conditions have been considered as an explanation of changes in enzymatic activity (Wissemann andLee (1980), Sánchez-Ferrer et al (1989) and Serrano-Megías et al, 2006). Temperature and rainfall are two important factors related with the physiological and biochemical changes that take place during the development and maturation of grapes.…”

“…Temperature and rainfall are two important factors related with the physiological and biochemical changes that take place during the development and maturation of grapes. Since these factors are beyond human control, meteorological data during the growth and maturation periods must be taken into account to understand trends in PPO activity (Serrano-Megías et al, 2006). PPO activity of Dominga and Napoleon table grapes showed a maximum in the middle of ripening, coinciding with substantial rainfall (Serrano-Megías et al, 2006).…”

A Standard Addition Method to Assay the Concentration of Biologically Interesting Polyphenols in Grape Berries by Reversed-Phase HPLC

“…(+)-catechin, (-)-epicatechin [13,21]. On the other hand, investigations on the concentration of polyphenolic antioxidants in grapes concern mostly the assay of grape berries during different stages of their maturation or when they have been injured by disease or UV irradiation [22,23]. There are only few reports on the antioxidant content of grapes produced under conditions similar to those of a commercial vineyard and mainly concern the determination of their resveratrol concentration.…”