Variation in Major Antioxidants and Total Antioxidant Activity of Yuzu (Citrus junos Sieb ex Tanaka) during Maturation and between Cultivars

Abstract

Epidemiological studies suggest that a high consumption of fruits can reduce the risk of some cancers and cardiovascular disease, and this may be attributable to the antioxidant activity of vitamins and phenolic compounds. The present study investigated the variations in vitamin C, total phenolic, hesperidin, and naringin contents, and total antioxidant activity of yuzu (Citrus junos Sieb ex Tanaka)-which is a popular citrus fruit in Korea and Japan-between cultivars and during maturity. The amounts of phenolics and vitamin C and the antioxidant activity in all tested yuzu cultivars were higher in peel than in flesh. Ripening increased the total antioxidant activity and vitamin C content in both peel and flesh of yuzu. However, the amounts of all total phenolics, hesperidin, and naringin in peel increased with ripening, whereas they decreased slightly in flesh. There was a highly linear relationship between the vitamin C content and the total antioxidant activity in both peel (r(2) = 1.000) and flesh (r(2) =0.998), suggesting that vitamin C plays a key role in the antioxidant activity of yuzu. In addition, the contribution of each antioxidant to the total antioxidant activity of yuzu was determined using a 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and is expressed here in terms of the vitamin C equivalent antioxidant capacity (VCEAC). The means of vitamin C, naringin, and hesperidin in yuzu were 90.4, 63.8, and 65.7 mg/100 g fresh yuzu, respectively. The relative VCEAC values of these compounds were in the following order: vitamin C (1.00) > naringin (0.195) > hesperidin (0.162). Therefore, the estimated contribution of each antioxidant to the total antioxidant capacity of 100 g of fresh yuzus is as follows (in mg of VCEAC): vitamin C (90.36 mg) > naringin (12.44 mg) > hesperidin (10.64 mg). Our results indicate that mature yuzu contains higher amounts of vitamin C and phenolics than other citrus fruits and could therefore be used as a significant dietary source of antioxidants.

Effects of Olfactory Stimulation from the Fragrance of the Japanese Citrus Fruit Yuzu (Citrus junos Sieb. ex Tanaka) on Mood States and Salivary Chromogranin A as an Endocrinologic Stress Marker

“…The Japanese also use yuzu to make various sweets, including marmalade, jellies, and cakes. According to food and nutritional science studies, yuzu also possesses antioxidant, 2 anticarcinogenic, 3 anti-inflammatory, 4 and antidiabetic properties 5 and exhibits preventive effects on cognitive dysfunction. 6 The pale yellow essential oil extracted from yuzu rind by the cold expression method emits an exquisite citrus aroma.…”

Antioxidant capacity of hesperidin fromCitruspeel using electron spin resonance and cytotoxic activity against human carcinoma cell lines

“…Citrus peel is characterized by the presence of phenolics and vitamin C; however, in some cultivars the peel contents are higher than flesh contents (Yoo et al, 2004). These compounds were found to have antioxidant activity and can reduce the risk of some cancers and cardiovascular diseases (Yoo et al, 2004;Palma et al, 2005).…”

“…These compounds were found to have antioxidant activity and can reduce the risk of some cancers and cardiovascular diseases (Yoo et al, 2004;Palma et al, 2005).…”

Effects of Chronic Administration of Fruit Extract (Citrus unshiu MARC) on Endothelial Dysfunction in Streptozotocin-Induced Diabetic Rats

“…Although our data suggest that citrus fruit administration may preserve endothelial function by alleviating oxidative stress in diabetic rats, we did not directly investigate which ingredient(s) of these fruits might exert this beneficial effect. Indeed, citrus fruits contain antioxidants such as vitamin C, 21,39) polyphenol, 40) flavonoids 41) and b-cryptoxanthin. 42) Further investigation is required on this point.…”