The Health Benefits of Jeju Gamgyul ( Citrus unshiu Marc.) Brandy and Wine

Abstract

Beneficial health effects of fruits and vegetables in the diet have been attributed to the reduction of risk for some diseases, such as diabetes, chronic diseases, cancer, or cardiovascular diseases. Citrus and its peels have been used in Asian folk medicine due to abundant flavonoids and the fact that their pulp are usually consumed like juice or jam, although their functional effects are much higher than those of fruit peels. This investigation inquired into the effects of Gamgyul wine, which is derived from whole fruits of Citrus unshiu, with respect to antioxidant property, anti-diabetic activity, low density lipoprotein (LDL) oxidative inhibition and flavanones. In particular, antioxidant and antidiabetic activities of both Gamgyul wine and brandy were measured. However, the differences of the antioxidant and antidiabetic effects of Gamgyul wine were trifling between dynamite and microfiltration processes. In particular, the effect of antidiabetic activity was rather significant as demonstrated in the Gamgyul brandy. The results showed that α-glucosidase inhibition rates at 20 µL/mL for Gamgyul brandy and wine were 50% and 20%, respectively. Almost 100% inhibition rate was shown at 80 µL/mL treatment for all the samples. Antioxidant activities and LDL oxidative inhibition were also measured. Gamgyul wine showed increased concentration-dependent antioxidant activities, while epigallocatechin gallate (EGCG) revealed an almost same level of activities. On the other hand, Gamgyul brandy presented little activity at any treatment concentration. Gamgyul wine in 20 µL/mL inhibited LDL oxidation approximately three times more than that of the comparative negative control, D.W. Flavanone analysis showed detections of both narirutin and hesperidin, while narirutin was the most abundant flavanone in Gamgyul wine. These overall results suggest that Gamgyul wine has the potential to be used as a functional dietary supplement and is an effective α-glucosidase inhibitor, which may be beneficial only for low to moderate intake.