• The Korean Journal of Food And Nutrition
• /
• v.34 no.2
• /
• pp.187-195
• /
• 2021

This study was performed to investigate the antioxidant and antidiabetic activities of soybean fermented with Monascus. Also, the changes in the content of isoflavones and Monacolin K were analyzed. It was observed that the glycoside forms of daidzin and genistin were converted to aglycones of daidzein and genistein within 6 days of fermentation. The product can be used as a health functional material that can increase bioavailability. Monacolin K production was found to increase significantly with the progression of fermentation with an increase to 0.04 mg/g and 0.44 mg/g on 6 and 12 days of fermentation, respectively. The DPPH radical scavenging activity of soybean fermented with Monascus was significantly increased compared to that of soybean. The protein expression of inflammation-related genes (TNF-α, IL-6, and COX-2) in the MIN cell was significantly increased in the presence of alloxan compared to the normal group, but a decrease was observed in the presence of soybean fermented with Monascus. In conclusion, soybean fermented with Monascus showed the highest antidiabetic and antioxidant effects. These results suggest that soybean fermented with Monascus has the potential to be used as a beneficial ingredient with antidiabetic and antioxidant effects.

• Journal of the Korean Society of Food Culture
• /
• v.25 no.6
• /
• pp.795-800
• /
• 2010

The objective of this study was to develop high quality Riceyeotgangjung (RYG) with high antioxidant activity and a longer shelf-life. Spirulina (1, 2, and 3%) with added RYG was prepared, and antioxidant activities were examined under storage at $60^{\circ}C$ for 15 days. The total phenol content remaining in the spirulina with added RYG at 15 days of storage was much higher than that of fresh RYG without spirulina. The IC50 values for DPPH and hydroxyl radical scavenging activities decreased with increasing amounts of spirulina, whereas these values increased with storage time. TBA and peroxide values decreased with increasing amounts of spirulina. From these results, adding spirulina to RYG delayed lipid rancidity and prolonged shelf-life. Adding spirulina powder to RYG, which is a healthy functional food material, improved antioxidant activity and delayed deterioration during storage.

• Journal of the Korean Society of Food Culture
• /
• v.38 no.6
• /
• pp.456-464
• /
• 2023

The purpose of this study was to investigate nutritional and functional ingredients and antioxidant activity after fermenting rice bran using Lactobacillus brevis for 24, 36, and 48 hours. The results of the analysis of the nutritional ingredients revealed that there was no significant difference in the carbohydrate, crude protein, crude fat and ash content regardless of the fermentation process and fermentation time. The amount of dietary fiber was significantly different between the unfermented and fermented rice bran and was observed to be the highest after a 48-hour fermentation. The γ-oryzanol, gamma-aminobutyric acid (GABA) and total phenolic contents were significantly higher in the fermented rice bran compared to the unfermented rice bran (p<0.05) and the GABA and total phenolic contents increased significantly as the fermentation time increased (p<0.05). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide and hydroxyl radical scavenging activities used to measure antioxidant effects significantly increased as the fermentation time increased (p<0.05). From these results, it was confirmed that the antioxidant effect and functional components, namely γ-oryzanol, GABA, and the total phenolic content of rice bran improved with fermentation. Based on these results, fermented rice bran could be presented as a functional material for use in high value-added industries.

• Food Science and Preservation
• /
• v.30 no.3
• /
• pp.434-445
• /
• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Korean Journal of Agricultural Science
• /
• v.50 no.3
• /
• pp.569-580
• /
• 2023

The aim of this study was to investigate the antioxidant effects of O. robusta stem extract (ORE) and to determine the total polyphenol and flavonoid contents. Free radical scavenging properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and ·OH (hydroxyl radical) scavenging assays. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods, respectively. Active compounds of ORE were determined using high-performance liquid chromatography (HPLC). The results of the study showed that ORE exhibited DPPH, ABTS, and ·OH radical scavenging activities in a dose-dependent manner. Especially, 1,000 ㎍/mL of ORE showed the strongest radical scavenging properties against DPPH, ABTS, and ·OH. ORE contained total polyphenol content of 57.4 mg GAE/g and total flavonoid content of 5.4 mg QE/g, which may contribute to their antioxidant effects. As a result of HPLC, the contents of active compounds in ORE, dihydrokaempferol (0.65 ㎍/mL), and 3-O-methylquercetin (1.10 ㎍/mL) were confirmed. In conclusion, ORE may be useful as a functional material with antioxidant properties.

• Korean Journal of Plant Resources
• /
• v.23 no.5
• /
• pp.451-457
• /
• 2010

In order to elucidate the antioxidant potential of non-edible parts of oriental melon, antioxidant activities and total phenolic compound contents of six samples including peel, placenta, stem leaf, flesh and seed were determined. Antioxidant activities were evaluated using in vitro DPPH, ABTS, FRAP, and SOD assay. Among non-edible parts of oriental melon, stalk showed the highest antioxidant activity and its antioxidant potential increased significantly in a dose-dependent manner. The contents of total phenolic compound were also higher than other parts. The relationship between antioxidant activities and the contents of total phenolic compound were analyzed and showed higher correlation coefficients between ABTS radical scavenging activity and contents of total phenolic compound. The above results suggest that the stalk of oriental melon may have potential as a good source for functional material.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.6
• /
• pp.949-956
• /
• 2018

This study investigated chemical components, antioxidant compounds, and activity of brown rice cultivars, to select good cultivar to be used for processing of mixed-rice in the food industry. Proximate compositions, phytic acid, phenolic compounds, and antioxidant activity of brown rice were significantly different among cultivars. Moisture, crude ash, fat, protein, and carbohydrate contents of brown rice were 9.51~12.82, 1.05~1.93, 1.84~6.24, 5.90~9.60 and 71.75~80.34 g/100 g, respectively. Phytic acid content of brown rice cultivars was 7.39~0.87 mg/g. Total polyphenol content of Joeunheukmi and Geonganghongmi cultivars, were 615.25 and $311.14{\mu}g\;GAE/g$, total flavonoid content was 267.75 and $100.67{\mu}g\;CE/g$, respectively. DPPH radical scavenging activity of Geonganghongmi, Joeunheukmi and Hyeugkwang cultivars was 89.17, 87.94 and 43.17%, ABTS radical scavenging activity was 113.57, 113.34, and $93.53{\mu}mol\;TE/g$, and ferric reducing antioxidant potential was 951.67, 1,075.75, and $508.33{\mu}M/g$, respectively. As a result, phenolic compounds and antioxidant activities of pigmented brown rice were high, and it could be used as a functional material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.252-253
• /
• 2005

The dielectric relaxation properties of $^{60}Co$ gamma-ray irradiated Poly(vinylidene fluoride) (PVDF) containing various antioxidants have been investigated for radiation degradation. Cole-Cole's circular arcs were induced from the results of temperature and frequency dependency of dielectric properties with radiation dose. The magnitude of polarization of PVDF was decreased by adding antioxidants. The values of dielectric relaxation intensity calculated by using the Cole-Cole's circular arcs showed a certain tendency for radiation degradation.

• 한국약용작물학회:학술대회논문집
• /
• 2011.04a
• /
• pp.386-387
• /
• 2011

• Food Science and Preservation
• /
• v.18 no.6
• /
• pp.817-823
• /
• 2011

Angelicae gigas Nakai has been used as a traditional medicine as well as an edible vegetable in South Korea. In this study, the total phenolic and flavonoid content and antioxidants of A. gigas Nakai leaves were examined in vitro via hydroxyl-radical-scavenging activity, reducing power activity, metal chelating assay, and DPPH-free -radical-scavenging assay. Among all the extracts from A. gigas Nakai leaves, the ethanol extract showed the strongest effects in all of the assays. The $EC_{50}$ values for the DPPH-radical-scavenging activities of ethanol, methanol, and water extracts were 31.47, 42.14, and $58.47{\mu}g/mL$, respectively. Among the extracts from A. gigas Kakai leaves, the ethanol extract had the highest levels of total phenolics ($7.84{\pm}1.46$ mg TAN/g) and total flavonoids ($4.23{\pm}0.03$ mg QE/g), which correlated strongly with the individual phenolic-compound (p-hydroxybenzoic acid, vanillin, and trans-ferulic acid) contents. The ethanol extract also showed stronger antioxidant activity than tocopherol in hydroxyl- radical-scavenging activity assay. These results indicate that the ethanol extract of A. gigas Kakai leaves possesses significant antioxidant properties, which suggests its great potential as a functional-food ingredient in the food industry.