Effects of pH, High Pressure Processing, and Ultraviolet Light on Carotenoids, Chlorophylls, and Anthocyanins of Fresh Fruit and Vegetable Juices

Abstract

Health consciousness and the need to maintain immune system have increased the demand for fresh fruit and vegetable juices due to the presence of nutritional benefits including colorful pigments such as chlorophylls, carotenoids, and anthocyanins. Besides providing green, yellow, and red color in fruits and vegetables, these phytochemical compounds play an important role in health maintenance through their antioxidant activity. However, natural pigments have been known to be susceptible to adverse conditions including pH and temperature. Heat treatment is commonly applied in the processing of fresh juices in order to extend shelf-life. Nevertheless, thermal treatments have been reported to cause detrimental impacts on the quality of juices. Thus, non-thermal treatments such as high pressure processing (HPP) and ultraviolet (UV) light have become alternative methods to preserve the juices without high impact on nutritional and sensory characteristics. This review underlines the chlorophyll, carotenoid, and anthocyanin pigments in green, yellow, and red fresh juices obtained from several fruits and vegetables, with the influence of pH and non-thermal treatments (HPP and UV) on the color and stability of pigments in the fresh juices.

Elaboration of an organic beverage based on grape juice with positive nutritional properties

“…Additionally, the color change based on pH conditions is also influenced by the type of anthocyanins, cyanidin shows red color at pH < 3, violet color at pH 7 and 8, and blue color at pH > 11. However, peonidin has higher stability at high pH than other anthocyanidins; at acidic conditions, it shows red color to cherry, and at pH 8 shows a deep blue color (Chandra et al., 2021 ). Moreover, color stability also depends on the water concentration as the decrease in the concentration of water improves the deprotonation rate of the flavylium, lowering the stability of color (Chandra et al., 2021 ).…”

“…However, peonidin has higher stability at high pH than other anthocyanidins; at acidic conditions, it shows red color to cherry, and at pH 8 shows a deep blue color (Chandra et al., 2021 ). Moreover, color stability also depends on the water concentration as the decrease in the concentration of water improves the deprotonation rate of the flavylium, lowering the stability of color (Chandra et al., 2021 ). Hydration reactions break the pyrylium ring aromaticity producing the loss of absorption properties and the transformation of the structure to an uncolored carbinol pseudobase that turn to an open chalcone shows a light‐yellow color (Morata et al., 2019 ).…”

“…Different letters for the same category of anthocyanins mean significant differences (p < .05). Chandra et al (2021) reviewed that cyanidin, pelargonidin, peonidin, and malvidin are the anthocyanidins responsible for the red color. Nevertheless, each red fruit has its own anthocyanin content, which makes its properties different from other fruits.…”

Structural identification and in vitro antioxidant activities of anthocyanins in black chokeberry (Aronia melanocarpa lliot)

“…According to research reports [1,2] , A. melanocarpa is the plant with the highest content of anthocyanins, 80-180 times that of grapes and 1000-2000 times that of bananas. Anthocyanin of A. melanocarpa is a natural edible pigment with nutritional and pharmacological effects [11,12] . It has great application potential in the development of food and medicinal products.…”

“…Anthocyanin of A. melanocarpa is a natural edible pigment with nutritional and pharmacological effects [11, 12] . It has great application potential in the development of food and medicinal products.…”