Grape juice nutritional profile
The nutrient profile of grape juice is presented on the basis of reference books data analysis, scientific publications and research results. The profile contains more than 30 food and biologically active substances (BAS). Grape juice does not have high acidity, it contains on average 0.4 g of organic acids per 100 cm3. Tartaric acid and L-malic acid are major acids in grape juice. The presence of tartaric acid is a distinctive feature of grape juice, in other juices it presents extremely rare and only in traces. Potassium, magnesium, iron, manganese, as well as flavonoids and hydroxycinnamic acids are the most important for grape juice from the point of view of providing humans with micronutrients and minor BAS. Juices from red/purple grapes varieties contain anthocyanins (on average 3 mg/100 cm3), the color of grapes and grape juices are associated with them, about 50% of the anthocyanins are malvidin glycosides. Resveratrol (an average of 0.01 mg/ 100 cm3), a stilbenoid, is also found in grape juices, this substance is widely studied recently due to its high antioxidant activity. Caftaric acid prevails among hydroxycinnamic acids presented in grape juice (on average 5 mg/100 cm3). A portion of industrial grape juice contains, on average, 6-10% of human daily need for potassium, about 5-8% for magnesium, iron and manganese. The content of flavonoids per serving is about 25% of the adequate level of daily consumption, and the content of hydroxycinnamic acids exceeds it. Studies of fresh grapes purchased in commercial networks show that the content of magnesium, iron and manganese in grape juices of industrial production is comparable to the content of these micronutriens in fresh fruit.
Keywords:grape juice, nutrient profile, food substances, micronutrients, flavonoids, hydroxycinnamic acids, biologically active substances
Voprosy pitaniia [Problems of Nutrition]. 2018; 87 (6): 95-105. doi: 10.24411/0042-8833-2018-10071.