This study aimed to investigate the changes in the γ-aminobutyric acid (GABA) content of bitter melon (Momordica charantia L.) cultivated from different regions, with different harvest times and at various maturation stages. Methods for observing the changes in GABA content were validated by determining the specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), and precision and accuracy using the HPLC-FLD system. Results showed high linearity in the calibration curve with a coefficient of correlation (R2) of 0.9999. The LOD and LOQ values for GABA were 0.29 and 0.87 μg/mL, respectively. The relative standard deviations for intra- and inter-day precision of GABA were less than 5%. The recovery rate of GABA was in the range of 98.77% to 100.50%. The average content of GABA was 0.93 mg/g and Cheongju showed highest GABA content of 1.88 mg/g. As the time of harvest increased from May to September, the GABA content decreased from 1.56 to 0.86 mg/g. Also, maturation of the bitter melon fruit was associated with a decreased in GABA content.

In this study, we assessed antioxidant, anti-diabetic, and anti-Alzheimer activities of Opuntia ficus-indica var. saboten (OFI) at harvest time. OFIs were cultivated December 2015~November 2016 in Jeju island. The 70% ethanol extracts of OFI were used to investigate total polyphenol and flavonoid contents, antioxidant(DPPH and ABTS radical scavenging assay), anti-diabetic(yeast α-glucosidase and rat α-glucosidase inhibition assay), and anti-Alzheimer(Acetylcholinesterase and butyrylcholinesterase inhibition assay) activities. Total polyphenol and flavonoid contents of OFIs were 17.40~23.11 μg garlic acid/mg Ex and 2.17~6.22 ug (+)-catechine/mg Ex, respectively. DPPH and ABTS radical scavenging activity of OFIs were 131.98~184.90 mg ascorbic acid(AA) eq/100 g and 63.60~101.83 mg AA eq/100 g, respectively. In the anti-diabetic and anti-Alzheimer activities, 70% ethanol extracts of OFI exhibited moderate inhibition activity, compared to control (acarbose and beberine). Total polyphenol and flavonoid contents, antioxidant, anti-diabetic, and anti-Alzheimer activities were no significant differences by season, respectively. Therefore, information on comparative biological evaluations of OFI may be a beneficial in exploring functional food and drug development.

This study was performed to investigate the quality characteristics of Yanggaeng, including color, pH, total polyphenol contents, and antioxidant activities, with the addition of aged garlic extract (0, 3, 6, 9 or 12%), aged at low temperatures. Among the color characteristics, the lightness value decreased, and the redness and yellowness values increased, proportional to the amount of garlic extract concentrate added to Yanggaeng. The pH of Yanggaeng significantly (p<0.05) decreased according to the amount of aged garlic extract added. Total phenol contents of control (0% aged garlic extract added Yanggaeng) was the lowest, followed by 3, 6, 9, 12% aged garlic extract added to Yanggaeng (88.15, 118.39, 156.91, 208.79 mg/g, respectively). Antioxidant activities, such as DPPH and ABTS radical scavenging activity, significantly increased with increase in the aged garlic extract concentration. In the sensory evaluation for Yanggaeng, 6% aged garlic extract added to Yanggaeng had the highest score in taste, flavor, and overall acceptance. Based on these results, it is suggest that the addition of 6% aged garlic extract to Yanggaeng can be developed as a product for the elderly.

The aim of this study was to evaluate key properties of the prickly pear cactus (Opuntia ficus-indica var. saboten (OFI) ie, levels of key chemicals (carotenoids, flavonoids and polyphenolic compounds as well as phenolic acid) and its antioxidative potential, depending on where the plant had been cultivated in Korea. The levels of flavonoids and polyphenolic compounds in OFI were 55.45~65.32 mg (+)-catechin/g and 149.00~181.15 mg gallic acid/g, respectively. Protocatechuic acid was the most abundant phenolic acid in the ON1 and ON2 (161.90 and 196.25 μg/g DW (dry weight)). Nineteen flavonoids were identified and analyzed by LC-ESI-MS in cladodes from OFI. Narcissin was the most abundant flavonoid in all of the samples (1,241.89~1,775.10 μg/g DW). Capxanthin and zeaxanthin were the most abundant carotenoids in OFI (64.88~128.08 and 48.10~93.82 μg/g DW). The level of DPPH radical and ABTS radical scavenging activities in OFI were 10.78~25.35 and 16.85~34.16 mg AA eq/100 g, respectively. OFI by cultivar has different kind of phenolic acid, flavonoids, and carotenoids. Therefore, dietary intake of cladodes from OFI may be helpful for improving human health

This study was conducted to investigate changes in the proximate composition, antioxidant activities, and α-glucosidase inhibitory activity of Opuntia ficus-indica (OFI) cladodes cultivated in Jeju (JJ1, JJ2, JJ3) and Jeonnam (JN1, JN2). The difference in the proximate composition (crude protein, lipid and ash content) of OFI between the two regions was not significant. Ca, Mg and Na were the major mineral components of OFI. The ascorbic acid content of OFI ranged from 57.87 to 143.72 mg/100 g. A 70% ethanol extract was used to investigate the antioxidant content and activity as well as the α-glucosidase inhibitory activity. The total polyphenol and flavonoid contents of OFI were 38.69~55.29 and 3.33~4.03 mg/g, respectively. The antioxidant activities based on the DPPH and ABTS free radical scavenging assays were 45.19~ 61.52% and 39.15~51.96%, respectively, at a concentration of 1 mg/mL. The inhibitory activity of OFI extracts against rat intestinal α-glucosidase was 29.72~45.73% at 1 mg/mL concentration, and JN1 showed the highest α-glucosidase inhibitory activity. This information could be very useful for authentication of Opuntia species with the highest potential as sources of nutritional and therapeutic elements.

This study aimed to investigate the concentration of vitamin C in Momordica charantia (MC) by cultivar, harvest time, and maturity. The methods for determining vitamin C levels were validated by measuring their linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using HPLC. Results showed high linearity in the calibration curve, with a coefficient of correlation (R2) of 0.9994. The LOD and LOQ values for vitamin C were 0.05 and 0.16 μg/mL, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of vitamin C measurements were 2.34 and 1.34%, respectively. Depending on cultivar, the concentration of vitamin C in MC varied from 20.75~107.31 mg/100 g, fresh weight, with an average level 68.85±25.57 mg/100 g, FW. When MC was analyzed by harvest time, the 20150612 MC showed the highest amount of vitamin C (113.20±1.89 mg/100 g, FW). On the other hand, the highest vitamin C content by maturity was 48.59±0.87 mg/100 g, FW (15 day old MC). This information on the comparative vitamin C levels of MC might be useful to food scientists and should be explored for functional food development.

This study performed to investigate the changes in S-allyl-L-cysteine (SAC) content of garlic with different cooking methods. Methods for determining SAC was validated by determining specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy using HPLC-FLD system. Results showed high linearity in the calibration curve with a coefficient of correaltion (R 2 ) of 0.9999. The LOD and LOQ values for SAC were 0.15 and 0.49 μg/mL, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of SAC were less than 5%. The recovery rate of SAC was in the range from 97.35% to 97.47%. The SAC content of raw garlic was 2.77 mg/g, and there are no significantly difference among blanching and microwave treatment in SAC content. However, SAC content of boiling, autoclaving at 110℃ and 121℃ increased in the range of 3.50~9.19 mg/g, 6.52~16.21 mg/g and 14.15~50.24 mg/g as increasing cooking temperature and time, respectively.

본 연구에서는 숙성 온도와 기간에 따른 마늘의 품질특성 변화를 살펴보기 위하여 통마늘을 60℃에서 60일간, 70℃에 서 40일간 숙성 처리하여 pH, 총산도, 갈변도, 5-HMF 함량, fructose 함량, SAC 함량, 총 폴리페놀 함량 및 DPPH radical 소거활성 측정하였다. 숙성 온도가 높고 숙성 기간이 길어질 수록 마늘의 pH는 감소하고, 총 산도, 갈변도 및 5-HMF 함량 은 증가하는 경향을 보였다. 특히, 5-HMF 함량은 60℃ 숙성 처리 시 0.08~3.30 mg/100 g으로 증가량이 적은 반면, 70℃ 숙 성 처리 시 0.05~106.07 mg/100 g으로 숙성 25일차부터 급격 히 증가하는 것으로 나타났다. Fructose 함량은 60℃의 숙성 온도에서는 0.77~14.57%으로 지속적으로 증가한 반면, 70℃ 숙성 온도에서는 30일차까지 1.07~19.75%까지 증가 후 15.11% 로 감소하는 것으로 나타났다. SAC 함량은 생마늘의 경우 48.11 mg/100 g이었으며, 60℃에서 20일 숙성 시 100.50 mg/ 100 g으로, 70℃에서 5일 숙성 시 85.55 mg/100 g까지 증가한 후 숙성 기간이 경과할수록 SAC 함량은 감소하였다. 생마늘 의 총 폴리페놀 함량은 98.38 mg/100 g이었고, 60℃ 숙성 처 리 시 591.82 mg/100 g까지, 70℃ 숙성 처리 시에는 665.22 mg/100 g까지 생마늘에 비해 각각 6.01배 및 6.67배 증가하였 다. DPPH radical 소거활성의 경우, 숙성 온도가 높고 숙성 기 간이 길어질수록 증가하는 경향을 보였다. 따라서 마늘 섭취 가 용이하고 항산화 활성이 우수한 숙성 마늘 제조를 위해서 는 70℃에서 30일, 숙성 마늘의 유효성분인 SAC의 다량 생산 을 위해서는 60℃에서 15일간 숙성 처리하는 하는 것이 적합 할 것으로 판단되며, 이상의 결과는 항산화 효과가 강화 및 SAC 함량 증진 등 선택적인 숙성 마늘의 제조에 활용이 가능 할 것으로 기대된다.