• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.377-384
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• 2020

Paprika is a popular vegetable with high visual appeal and desirable flavor, the health benefits of which are increasingly attracting interest. In this study, the physical qualities, antioxidant content, and activities of six mini paprika cultivars were investigated. Both the edible part (flesh) and the by-products were studied. The average total phenolics and total antioxidant activities were higher in the flesh than in the by-products. The total flavonoids of the flesh and the byproducts were 16.41 and 37.80 mg/100 g FW, respectively. "YW glory" and "Raon yellow" flesh had the highest (245.52 mg/100 g FW) and lowest (179.96 mg/100 g FW) total phenolics among the six cultivars, respectively. However, the "RD glory" cultivar showed the highest total phenolic content (232.70 mg/100 g FW) among the by-product samples. The total phenolics in the flesh and by-products were highly correlated to the ABTS radical scavenging activity, with R=0.961 and 0.984, respectively.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.

• Mycobiology
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• v.51 no.6
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• pp.445-451
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• 2023

Shiitake mushroom (Lentinula edodes) hold high nutritional and medicinal value as they contain an abundance of health-promoting compounds. However, the effect of long-term postharvest storage on the variation in the levels of health-promoting compounds has not been extensively studied. In this study, we investigated the changes in the levels of phenolic compounds, antioxidants, eritadenine, and ergothioneine in shiitake mushrooms stored at three different temperatures (1, 3, and 5 ℃) for 4 weeks. Compared to mushrooms stored at lower temperatures, those stored at 5 ℃ exhibited a higher level of total phenolics in their pileus after 2 weeks of storage; however, storage at 5 ℃ also increased the deterioration of the fruiting body of these mushrooms. In mushrooms stored at all temperatures, the eritadenine content in the pilei tended to increase up to 2 weeks of storage. In contrast, the ergothioneine content in the pileus decreased during storage, with a significantly lower level detected in mushrooms stored at 5 ℃ for 4 weeks. Together, these results suggest that the mechanisms underlying the accumulation of phenolics and eritadenine may be related to mushroom deterioration during storage. Our findings indicate that the levels of health-promoting compounds in shiitake mushrooms are influenced by storage temperature, suggesting the potential to control adjustments of specific bioactive compounds by regulating storage conditions.

• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.364-369
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• 1999

The changes of phenolics in Korean apple(Fuji) during maturation were analyzed by HPLC and spec-tropotometry. The phenolics were separated through C18 Sep-Pak cartridge in series. Chlorogenic acid caffeic acid p-coumaric acid ferulic acid and ($\pm$)-catethin were indentified by the direct comparison with authentics on HPLC. The total amounts of phenolics were determined by Folin-Dennis's method. The amounts ranged from 70.19mg% to 97.57mg% of wet basis. The concentration of phenolics in apple decreased during the early stage of development and then remained relatively constant during matu-ration .

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.199-205
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• 2004

The effect of chitosan on enzymatic activities and on bioactive compounds was characterized during germination at $25^{\circ}C$ for 7 days to search for a method to produce a germinated black rice. The germination rate was reduced by the addition of lactate and chitosan. The rotting rate was greatly decreased by chitosan, suggesting that the addition of chitosan into a germination solution might be an effective method for controlling fungal contamination during the germination of cereals. The addition of 100 and 200 ppm chitosan increased $\alpha$-amylase activity after 7 days by up to 152 % and 197 %, respectively. The activities of $\beta$-amylase and $\beta$-glucosidase were lower with 200 ppm chitosan than in distilled water and 100 ppm lactate. The amount of total soluble phenolics and total flavonoids decreased rapidly for four days and thereafter remained constant until the seventh day. The antioxidant activity of germinated black rice, in terms of hydrogen-donating activity, increased slowly and did not correspond to the changes of total soluble phenolics and total flavonoids. The amount of phytic acid was reduced by the addition of 200 ppm chitosan compared to distilled water, indicating that chitosan could be used as an elicitor for the increase of phytase activity during the germination of black rice.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.105-114
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• 2014

We established a high throughput screening system of African yam tuber lines which contain high contents of total carotenoids, flavonoids, and phenolic compounds using ultraviolet-visible (UV-VIS) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate analysis. The total carotenoids contents from 62 African yam tubers varied from 0.01 to $0.91{\mu}g{\cdot}g^{-1}$ dry weight (wt). The total flavonoids and phenolic compounds also varied from 12.9 to $229{\mu}g{\cdot}g^{-1}$ and from 0.29 to $5.2mg{\cdot}g^{-1}$dry wt. FT-IR spectra confirmed typical spectral differences between the frequency regions of 1,700-1,500, 1,500-1,300 and $1,100-950cm^{-1}$, respectively. These spectral regions were reflecting the quantitative and qualitative variations of amide I, II from amino acids and proteins ($1,700-1,500cm^{-1}$), phosphodiester groups from nucleic acid and phospholipid ($1,500-1,300cm^{-1}$) and carbohydrate compounds ($1,100-950cm^{-1}$). Principal component analysis (PCA) and subsequent partial least square-discriminant analysis (PLS-DA) were able to discriminate the 62 African yam tuber lines into three separate clusters corresponding to their taxonomic relationship. The quantitative prediction modeling of total carotenoids, flavonoids, and phenolic compounds from African yam tuber lines were established using partial least square regression algorithm from FT-IR spectra. The regression coefficients ($R^2$) between predicted values and estimated values of total carotenoids, flavonoids and phenolic compounds were 0.83, 0.86, and 0.72, respectively. These results showed that quantitative predictions of total carotenoids, flavonoids, and phenolic compounds were possible from FT-IR spectra of African yam tuber lines with higher accuracy. Therefore we suggested that quantitative prediction system established in this study could be applied as a rapid selection tool for high yielding African yam lines.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.329-333
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• 2021

Subcritical water extraction (SWE) is an eco-friendly extraction method that uses only purified water as a solvent under high temperature and high pressure conditions. In this study, total phenolics, and antioxidant activity were evaluated in Ziziphus jujuba Mill extracts from subcritical water obtained by varying the extraction temperature (110-190℃) and extraction time (1-20 min). Total phenolics was maximized with extraction at 190℃ for 15 min (67.79±3.45 mg gallic acid equivalent/g jujube). The 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (48.84±4.74%) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity (84.75±1.15%) were maximal at extraction conditions of 190℃, for 20 min. All jujube extracts prepared using SWE had higher total phenolics and antioxidant activities than extracts prepared using organic solvent extraction (60℃, 120 min), including methanol and ethanol. SWE could be an excellent alternative to organic solvents for extracting phenolics and antioxidant compounds.

• Food Engineering Progress
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• v.15 no.3
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• pp.195-202
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• 2011

Physiological characteristics of brown rice and black rice were investigated to provide the fundamental information of physiological property of rice and to show the potential of rice as a functional ingredient. Bioactive compounds were extracted from brown and black rices with aqueous solvents like 80% ethanol. Total phenolics, flavonoids and antioxidative capacity of brown and black rices' extracts were determined. Brown rice showed much higher amount of total phenolics and flavonoid contents as well as antioxidative capacity than those of milled rice indicating that most of bioactive compounds are located in the bran layer. Black rice showed higher total phenolics and flavonoid contents and antioxidative capacity than those of brown rices. The highest antioxidative capacity was obtained from Heugjinju followed by Heugseol, Sinnongheug-chal, Hopum and Samkwang. This result indicated that antioxidative capacity is affected by total phenolics and flavonoid contents. Both brown and black rices contained higher amount of ferulic acid than that of p-coumaric acid.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.375-384
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• 2011

The aim of this study was to evaluate 30 phenolic compounds in adzuki bean germplasm. Adzuki 21653 had the highest content of total phenolics compounds ($6597\;{\mu}g\;g^{-1}$) while 104372 had the lowest concentration. The average total phenolic content of Japanese ($2432\;{\mu}g\;g^{-1}$) adzuki beans was higher than that of Korean ($2256\;{\mu}g\;g^{-1}$) adzuki beans. The average total phenolic contents were $2507\;{\mu}g\;g^{-1}$ in small sized adzuki beans from Japan and $2459\;{\mu}g\;g^{-1}$ in those from Korea. In large sized adzuki beans, the average total phenolic contents were $1315\;{\mu}g\;g^{-1}$ in Japanese seeds and $1232\;{\mu}g\;g^{-1}$ in Korean seeds. The average total phenolic contents in medium seeds were $2369\;{\mu}g\;g^{-1}$ in Japanese adzuki beans and $1397\;{\mu}g\;g^{-1}$ in Korean ones. In small seeds, the total phenolic contents of adzuki beans varied from $524\;{\mu}g\;g^{-1}$ to $6597\;{\mu}g\;g^{-1}$ in Japanese ones and from $375\;{\mu}g\;g^{-1}$ to $6569\;{\mu}g\;g^{-1}$ in Korean ones. Japanese and Korean adzuki beans were divided into landraces and wild adzuki beans. In this study, the wild adzuki beans showed higher contents of total phenolics than the native varieties. Specifically, the wild adzuki beans from Korea had the highest concentration of phenolics ($3403\;{\mu}g\;g^{-1}$). All adzuki bean germplasms were measured for their color and were classified into four groups accordingly: A; L < 30, +a, +b; B; L < 30, +a, -b, C; L > 50, +a, +b, D; L > 50, +a, -b. Especially, group B had the highest concentration of total phenolic compounds ($2827\;{\mu}g\;g^{-1}$), whereas group C had the lowest concentration ($1882\;{\mu}g\;g^{-1}$).

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.604-609
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• 2020

This study analyzed the antioxidant contents and activities of the pedicel and sepals from 12 colored cherry tomatoes ('Green Joy', 'TY Item', 'Dotori Red TY', 'TY Sispen', 'KT Orange TY', 'White Joy TY', 'Dotori Norang TY', 'Beta Tiny', 'Blacklin', 'KT Red TY', 'KT Norang TY', 'Black Joy 200') for their potential use as bioactive ingredients. 'Green Joy' had a significantly higher content of total flavonoids (92.55±3.20 mg CE/100 g FW), total phenolics (261.94±8.32 mg GAE/100 g FW), and total antioxidant activity than the other varieties. The main polyphenols were rutin, chlorogenic acid, and methyl gallate. For all 12 samples, the total flavonoids content was highly correlated with the total phenolics content and the total antioxidant activities. Non-edible parts of cherry tomato have high potential as functional food materials because they contain similar or more antioxidants and antioxidant properties than the pulp of tomato and cherry tomato or other fruits.