Minju Kim

Anti-aging Potential of Extracts Prepared from Fruits and Medicinal Herbs Cultivated in the Gyeongnam Area of Korea

Many recent studies have focused on maintaining a healthy life by preventing and/or postponing the aging process. Numerous studies have reported that continuous exposure to reactive oxygen species can stimulate skin aging and that excessive accumulation of fat can cause an impaired skin barrier and tissue structure alterations. Thus, the maintenance of antioxidant homeostasis and the suppression of adipose accumulation are important strategies for skin anti-aging. Here, we prepared three types of extracts [whole juice, acetone-perchloric acid (PCA), and ethanol] from 20 fruits and medicinal herbs native to the Gyeongnam area of Korea. The total phenolic content of each extract was analyzed, and we observed higher total phenolic contents in the medicinal herbs. Consistent with this, the results of the oxygen radical absorbance activity capacity assay indicated that the in vitro antioxidant activities of the medicinal herb extracts were stronger than those of the fruit extracts. The fruits and medicinal herbs had strong effects on cell-based systems, including H2O2-induced oxidative stress in human keratinocytes and 3T3-L1 lipid accumulation. Nishimura Wase persimmon, Taishu persimmon, wrinkled giant hyssop, sweet wormwood, Chinese cedar, red perilla, tan shen, hiyodori-jogo, and cramp bark may be natural anti-aging materials with effective antioxidant and anti-adipogenic activities. Taken together, our findings may provide scientific evidence supporting the development of functional foods and nutraceuticals from fruits and medicinal herbs.

Quality evaluation of fresh tomato juices prepared using high-speed centrifugal and low-speed masticating household juicers

The aim of this study was to evaluate and compare the physicochemical, nutritional, and sensory properties of homemade fresh tomato juices prepared using 2 types of household juicers, a high-speed centrifugal juicer (HSC juicer) and a low-speed masticating juicer (LSM juicer). Juice yield, soluble solids, and the contents of total polyphenol, vitamin C, and lycopene in LSM tomato juice were significantly higher than those in HSC tomato juice. The DPPH radical scavenging activity of LSM tomato juice was also higher than that of HSC tomato juice. HSC tomato juice easily separated into 2 layers with many fine bubbles, while LSM tomato juice was homogeneous. Sensory evaluation revealed that panels significantly preferred LSM tomato juice to HSC tomato juice. In conclusion, the LSM juicer shows several advantages over the HSC juicer for preparing tomato juice of superior quality and taste that is rich in antioxidant phytochemicals at a high yield.

Effect of Mixed Fruit and Vegetable Juice on Alcohol Hangovers in Healthy Adults

The purpose of this study was to investigate the effects of mixed fruit and vegetable juice on alcohol hangover in healthy adults in a randomized crossover trial. Angelica keiskei/green grape/pear juice (AGP juice) was a mixture of A. keiskei juice, green grape juice, and pear juice at 1:1:1 ratio. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities of AGP juice were measured in vitro. Fifteen healthy adults consumed alcohol (1.25 g/kg weight), and either water (control group) or AGP juice (AGP juice group). Blood was collected and expiratory-air alcohol levels were measured at 0~360 min after drinking the alcohol. Compared with control, AGP juice had higher ADH and ALDH activity in vitro. The peak alcohol levels in expiratory-air and plasma after drinking AGP juice were significantly lower than those after drinking water. The area under the curves for expiratory-air and plasma alcohol of the AGP juice group were lower than those of the control group. Thirst and headache scores after intake of alcohol were significantly reduced by AGP juice consumption compared with the control group. These data demonstrated that AGP juice could contribute to eliminate alcohol toxicity and hangover symptoms by enhancing alcohol metabolizing enzyme activities.

Effect of Low Temperature Storage on Proteolytic and Antioxidant Activities of Fresh Pineapple and Kiwi Juices Extracted by Slow-speed Masticating Household Juicer

The aim of this study was to evaluate proteolytic and antioxidant activities of fresh pineapple and kiwi juices extracted using a slow-speed masticating household juicer during low temperature storage. While over 90% of vitamin C and total polyphenols in both juices were retained after storage for 30 days at -20°C, reduction of 56.8% for vitamin C and 31.9% for total polyphenols in pineapple juice were detected after storage at 4°C. In the case of kiwi juice, 32.9% of vitamin C and 22.4% of total polyphenols were lost. A high initial content of vitamin C in kiwi juice resulted in a slower reduction rate than that for pineapple juice. A similar result was obtained for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Proteolytic activities of both juices were maintained efficiently with less than 10% loss during storage for 30 days at -20°C. Protease stability of pineapple juice was better than that of kiwi juice during storage at 4°C, and the same result was obtained when boiled chicken breast was used as a substrate. From these results, when storing pineapple and kiwi juices, which are widely used as a natural meat tenderizer and digestive aid, cold storage at -20°C seemed to be more suitable for maintaining antioxidant and proteolytic activities than cold storage at 4°C.