Anthocyanins as Functional Food Factors— Chemistry, Nutrition and Health Promotion —

Abstract

Anthocyanins are widely known as pigments responsible for the rich reds and purples in fruits, vegetables and legume seeds. Many flower colors are also attributed to anthocyanins. The physiological functions of anthocyanins as components in food have attracted attention, and research on their bioavailability and physiological functionality has progressed over the last 20 years. This review focuses on the health benefits of anthocyanins. It first describes the chemistry, metabolism, and absorption of anthocyanins and next summarizes the trends in research on the anti-diabetic and anti-obesity effects of anthocyanins. It then describes the other health benefits of anthocyanins, namely, the prevention of cancer and improvement of visual and brain functions, and finally discusses the challenges in and prospects of anthocyanin research.Keywords: anthocyanin, bioavailability, diabetes, obesity, cancer, vision, brain function Abbreviations: AMPK, AMP-activated protein kinase; BA, blackcurrant anthocyanins; BBE, bilberry extract; CS, Caffeoylsophorose; Cy, cyanidin; C3G, cyanidin 3-glucoside; Del, delphinidin; Glut4, glucose transporter 4; NF-κB, nuclear factor-kappa B; PPAR, peroxisome proliferator activated receptor; RBP4, retinol-binding protein 4; TNF-α, tumor necrosis factor-alpha; WBP, whole blueberry powder *To whom correspondence should be addressed. E-mail: tsudat@isc.chubu.ac.jp IntroductionAnthocyanins are widely known as pigments responsible for the rich reds and purples in fruits such as apples, strawberries, and blueberries, as well as in eggplants, perilla herbs, and legume seeds. Many flower colors are also attributed to anthocyanins (Harborne and Grayer, 1988). In food chemistry, anthocyanins have been studied in relation to changes and stability of colors in foods such as fruits during processing and storage and also for their use as natural colorants. Indeed, many types of anthocyanin food colorants have been developed and are now available to customize the appearance of foods. In horticulture, color conversion of flower pigments has become possible based on new findings of anthocyanin research. Creation of flowers in new colors enriches our life; for example, the creation of blue roses is a noteworthy achievement (Tanaka et al., 2010). Genetic engineering is the key technology for converting flower color, and it became possible after the discovery of genes involved in anthocyanin biosynthesis and elucidation of their expression mechanisms. In addition to the above properties and mechanisms, the physiological functions of anthocyanins as components in food, have attracted attention, and research on their bioavailability and physiological functionality has progressed over the last 20 years.This review focuses on the health benefits of anthocyanins. It first describes the chemistry, metabolism, and absorption of anthocyanins and next summarizes the trends in research on the anti-diabetic and anti-obesity effects of anthocyanins. It then describes the other health benefits of anthocyanins, namely, the pr...

Antioxidant Capacity of Anthocyanin Pigments

“…As it has been mentioned throughout the chapter, anthocyanins are potentially used in food and pharmaceutical industries since their practical applications as natural colourants [13,49,58,76,79,327] as well as their potential health benefits to humans [13,56,90,110,114]. Nevertheless, the incorporation of anthocyanins into food and medical products is a challenging task due to their low stability and susceptibility to degradation [292] towards environmental conditions during processing and storage.…”

“…Sources rich in anthocyanins are very interesting options as functional foods [53][54][55][56][57][58]. Here, the oxidative process, the antioxidant effect and the biological properties of the anthocyanin pigments, described in last years, are reviewed.…”

“…The favourable effects of anthocyanins on improvement of vision in humans (increase in visual acuity), one of the first reported, were described in 1966, which prompted their introduction into ophthalmology [56,57]. It continues to be an interesting field of study due to the prevalence of myopia in today's society [118].…”

“…Anthocyanins have been associated with substances that strengthen the capillaries, reinforce the action of vitamin C and favour the accumulation of this vitamin in the liver and in the suprarenal glands. Blackcurrant anthocyanins inhibit transient myopia, reduce eye fatigue, improve dark adaptation and enhance retinal blood flow with glaucoma [56]. Anthocyanin-rich bilberry extract has a protective effect on visual function during retinal inflammation [116].…”

“…Apart from their well-known potential for their practical applications as natural colou rants [13,48,49,58,76,79,281,328], anthocyanins show antioxidant activity and a wide variety of health-promoting properties for human health [12,56,81,85,90,111,112,120,130,264,343], ranging from cytoprotective, antimicrobial and antitumor activities to neuropr otective, antiobesity and lipidomic potential. Moreover, epidemiological evidence suggests [12,111,112,362] a direct correlation between anthocyanin intake and a lower incidence of chronic and degenerative diseases.…”