Colour, phenolic content and antioxidant activity of grape juice

Evaluation of physicochemical parameters of grape juices produced in the Serra Gaúcha

“…Carpen and Torezan [21] observed results of 3.13 (sample 'A') and 4.10 (sample 'B'), the latter being a much higher number than the highest observed in this study (3.59 for a white grape juice in the year of 2013). Burin et al [11] analyzed 3 homemade grape juices for which pH values were 3.30, 3.51 and 3.64; 7 commercial juices which varied from 3.25 to 3.56 and 2 organic juices with measurements of 3.32 and 3.40, their results were compatible with this work. Canadian researchers [23] prepared juices from 10 different cultivars and found pH values of 2.38 to 3.13, displaying a lower number than the lowest observed in this study (2.81 for a white grape juice from the crop of 2013).…”

“…It is well known that the concentration of polyphenols is greater in purple grape juices than in whites, since that dark colored grapes have higher contents of phenolic compounds and antioxidant capacity [9][10][11][12]. Moreover the technology used for preparing the juice, mainly related with the temperature and time of extraction, regulates the intensity of solubility and diffusion of the compounds, from the skin to the must, and is hence a fundamental influence on the chemical composition of the final product [13][14][15][16][17].…”

Phenolic Compounds and Antioxidant Activity in Grape Juices: A Chemical and Sensory View

“…This characteristic is directly dependent on the juice phenolic composition, namely on the anthocyanins present in the grape skin. Anthocyanins participate in many reactions that promote changes in grape juice colour, mainly through copigmentation and formation of polymeric pigments [90]. Hue and colour intensity can provide information with respect to possible defects or quality of the raw material [91].…”

Sensory profile and drivers of liking for grape nectar among smoker and nonsmoker consumers

“…Recently, society has shown a remarkable interest in the commercialization of juices and nectars in various forms (Carvalho et al, 2005). There is an incentive to produce grape juice because it has important nutritional properties (Burin et al, 2010) such as antioxidant activity due to the presence of phenolic compounds (Rizzon & Mielle, 2012).…”