ABSTRACT
Wine is consumed by humans worldwide, but the functional components are lost and the color changes during its production. Here, we studied the effects of mannoprotein (MP) addition (0, 0.1, and 0.3 g/L) upon crushing and storage. We measured anthocyanins, phenolic acids profiles, color characteristics, and antioxidant activities of wine. The results showed that the addition of MP before fermentation significantly increased the total phenolic content (TPC), total anthocyanin content, total tannin content (TTC), total flavonoid content, and total flavanol content in wine, whereas the addition of MP during storage had the opposite effect. The addition of MP before alcohol fermentation significantly increased the amount of individual anthocyanins and individual phenolic acids, maintained the color, and increased the antioxidant capacity of wine. In addition, the addition of 0.3 g/L MP during storage increased the content of individual phenolic acids and TPC of wine. However, the addition of 0.1 g/L MP during storage significantly reduced the TPC, TAC, TTC, and individual anthocyanin content (except for malvidin-3-glucoside and malvidin-3-acetly-glucoside); meanwhile, the treatment attenuated the color stability and antioxidant capacity of wine. The results demonstrated that the addition of MP before alcohol fermentation could increase the functional components and improve the color stability and antioxidant capacity of wine.
ABSTRACT
To study the effects of supplemental lighting with ultraviolet (UV), blue and red-blue lights on quality development of grape berries under protected cultivation to promote early maturing, four-year-old vines of 'Ruidu Xiangyu' grape using 'Beta' as rootstock were used in this experiment. The results indicated that blue and ultraviolet lights were poor in greenhouse environment. Compared with the control, blue and ultraviolet lights lasting 6 hours at night significantly accele-rated the increase of berry mass, fruit diameter, sugar content and the decrease of acidity content during the grape development, but the effect of red-blue light was not obvious. At the fruit maturation, berries supplemented with the three types of light were heavier, and those treated with the UV light were the heaviest. Additionally, grape berries supplemented with blue light had the highest glucose, fructose and total sugar contents, while the sugar contents in berries supplemented with UV light was lower than that under blue light and higher than that under the red-blue light. Volatile linalool, geraniol, terpineol and nerol reached their peak contents ear-liest in berries supplemented with blue light during the developmental stage. At fruit maturation, berries supplemented with blue light had the highest linalool and citronellol contents, while those with UV light had the highest geraniol, hexanal and E-2-hexenal contents, and supplemented with red-blue light had lower linalool content than the control. Moreover, supplementary light was also beneficial for the accumulation of volatile aldehydes and ketones. In conclusion, blue supplementary light could accelerate the development of grape berries as their sugar content was highest and main terpenes reached their peak contents earliest.Grape berries supplemented with UV light had the largest single berry mass and most abundant volatile compounds, while red-blue light treatment was not so effective on quality improvement.
Subject(s)
Carbohydrates , Vitis , FruitABSTRACT
Taking'Kyoho' as the test material, the effect of white, green, red and blue bags on volatile compounds in mature grape berries was explored in this study. The results indicated that bags with different colors could create special light conditions, which resulted in the difference of volatile compounds in grape berries. A total of 37, 38, 32, 34 kinds of volatile compounds which included esters, aldehydes, alcohols, ketones, terpenes and aromatic compounds, were detected in 'Kyoho' berries covered with the white, green, red and blue bags respectively, and 33 in the control. Compared with the control, the contents of ethyl acetate, ethyl hexanoate and some other esters decreased, while hexanal, E-2-hexenal and decanal increased in berries with white bags, the contents of the major common compounds, except ethyl 3-hexenoate, ethyl (E)-hex-2-enoate, ethyl 3-hydroxybutyrate, E-2-hexenal, (E,E)-2,4-hexadienal, decanal, and phenethyl alcohol, decreased in berries with green bags, the contents of ethyl acetate, ethyl hexanoate and hexanal, E-2-hexenal decreased in berries with red bags, the contents of ethyl acetate, ethyl hexanoate and some other esters changed slightly in berries with blue bags, except for the increase of hexanal and E-2-hexenal. For those characteristic compounds, the kinds of alcohols in berries covered with bags decreased while the kinds of terpenes and aromatic compounds increased. In general, the fruits with the blue bags had the highest volatile esters, and those with the white bags had high volatile esters and aldehydes, while those with the green and red bags had low aromatic compounds.
