Kyung Young Yoon

Potato juice fermented with Lactobacillus casei as a probiotic functional beverage

This study was conducted to evaluate probiotic potato juice as a potential substrate for the production of Lactobacillus casei, and the change in the functionality of potato juice was monitored during fermentation. L. casei grew well in potato juice without nutrient supplementation, and lactic acid bacteria of fermented ‘Haryoung’ juice reached 1.7×109 CFU/mL after a 48 h fermentation. DPPH radical scavenging activities of the potato juices decreased after a 72 h fermentation, but fermented colored potato juice still maintained >50% radical scavenging activity. The survival rate of L. casei fermented in’ Haryoung’ juice was 89.0% after exposure to an acidic condition, and L. casei in all fermented potato juice samples showed the ability (50–85%) to survive in the presence of bile. These results suggest that fermented potato juice might serve as a probiotic functional beverage for vegetarians or consumers who are allergic to dairy products.

Enzymatic production of soluble dietary fiber from the cellulose fraction of Chinese cabbage waste and potential use as a functional food source

Use of Chinese cabbage waste as a raw material for production of soluble dietary fiber was investigated. Chinese cabbage was treated with a mixture of 1 M NaOH and hydrolyzed using Celluclast 1.5 L. A supernatant was then treated using 85% ethanol, and separated into alcohol-soluble dietary fiber (ASF) and alcohol-insoluble dietary fiber (AIF) fractions. AIF effectively hindered diffusion of glucose and bile acid from dialysis membranes, and exerted a significantly (p<0.05) greater effect on retardation of bile acid activity than both carboxymethylcellulose and pectin. Water-soluble dietary fiber obtained from the cellulose fraction of Chinese cabbage using enzymatic hydrolysis is a potential source of dietary fiber with prebiotic, hypoglycemic, and hypolipidemic effects.

Cultivar differences in phenolic contents/biological activities of color-fleshed potatoes and their relationships

The current study was performed to evaluate colored potatoes (Solamum tuberosum L.) as a potential source of functional food material. We compared the total phenolic content (TPC) in potato tubers of a white-fleshed potato variety with six color-fleshed potato cultivars. We also examined their antioxidant and antiproliferative activities. The TPC of the analyzed cultivars varied between 113.3 mg·100 g−1 powder (‘Superior’) and 153.3 mg·100 g−1 powder (‘Blue’). The colored potato extracts showed higher radical scavenging activities than the white fleshed potato extract (‘Superior’), and all colored potato extracts, except for ‘Rose’ and ‘Haryoung’, induced significant antiproliferative activities against THP-1 cells at the tested concentrations. In particular, ‘Jaseo’ and ‘Jasim’ showed 35% and 31% cell viability, respectively, at the concentration of 10μg·mL−1. The greatest positive correlation was found between TPC and hydroxyl radical scavenging activity (r = 0.912, p < 0.01), and TPC also showed a strong positive correlation with nitrite scavenging ability (r = 0.808, p < 0.01). Our results indicate that color-fleshed potatoes have higher antioxidant and stronger antiproliferative activities than white-fleshed potatoes.

Effects of blanching on antioxidant activity and total phenolic content according to type of medicinal plants

The present study was conducted in order to evaluate the effects of blanching on the total and individual phenolic and antioxidant activities of 4 young sprouts of medicinal plants: dureup (Aralia elata), caster aralia (Kalopanax pictus), tree-of-heaven (Cedrela sinensis), and ogapi (Acanthopanax sessiloflorus). Caster aralia and dureup displayed significant reduction of Fe2+ chelation following blanching, but no alteration of DPPH or ABTS radical scavenging activity. Blanched ogapi displayed lower Fe2+ chelation as well as decreased DPPH and ABTS radical scavenging activities compared to raw sample. In contrast, tree-of-heaven displayed significantly increased antioxidant activity after blanching. Major phenolic compounds in mountain vegetables were chlorogenic acid and vanillic acid. In particular, chlorogenic acid contents increased by 11.2–68.1% in all vegetables except for ogapi after blanching. The results of this study show that blanching might be a useful tool for improving the beneficial properties of tree-of-heaven.

Isolation and Characteristics of Anti-Inflammatory Peptides from Enzymatic Hydrolysates of Sandfish (Arctoscopus japonicus) Protein

ABSTRACT In the present study, a peptide showing anti-inflammatory activity was isolated from Arctoscopus (A.) japonicus sandfish protein hydrolysate by hydrolysis and analyzed using ultrafiltration (UF), prep-high-performance liquid chromatography (HPLC), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Effects of heat, pH, salt, and intestinal proteases on stability of the isolated anti-inflammatory peptide were determined. The nitric oxide (NO) scavenging activities of the peptide from meat and roe hydrolysates were 18.43 ± 3.21% and 52.35 ± 8.85%, respectively, at a concentration of 0.1 mg/mL. The anti-inflammatory peptide maintained a similar level of NO scavenging activity to the control in the presence of salt, whereas it showed no resistance to heat, pH, and intestinal proteases. These results suggest that the anti-inflammatory peptide derived from A. japonicus could be used for producing functional foods, protein supplements, and pharmaceutical agents. However, it is necessary to find methods for protection against heat, pH, and proteolysis.

Production and Characteristics of Cello- and Xylo-oligosaccharides by Enzymatic Hydrolysis of Buckwheat Hulls

This study was conducted for the production of water-soluble dietary fiber (SDF) from buckwheat hulls by using Celluclast or Viscozyme. The functionality of this SDF, including antioxidant activity, glucose- and bile acidretardation effects in vitro, was measured. SDF yields from cellulose and hemicellulose fractions were 60.5 and 123.7 g/kg dry matter, respectively. Analysis of molecular weight distribution of SDF by using gel chromatography showed that SDF degradation increased with increase in reaction time. The antioxidant activity of SDF obtained by enzymatic hydrolysis was higher than that of dietary fiber without enzyme treatment. SDF showed higher retardation effects on glucose and bile acid than the sample without dietary fiber did. The results of this study suggested that SDF produced from buckwheat hull by enzymatic hydrolysis is a good source of functional food material because of its high antioxidant activity and glucose- and bile acid-retardation effects.This study was conducted to produce oligosaccharides from buckwheat hull by using commercial enzymes. Yields of oligosaccharides obtained by enzymatic hydrolysis of the cellulose and hemicellulose fractions were 132.37 and 393.04 g/kg, respectively. Xylose, glucose, fructose, xylobiose, xylotriose, cellobiose, and cellotriose were detected in the hydrolysate produced from buckwheat hull. Antioxidant activity of oligosaccharide from cellulose fraction (OSC) reduced with increasing hydrolysis time; however, the antioxidant activity of oligosaccharide from hemicellulose fraction (OSF) increased as the hydrolysis time was prolonged. OSF and OSC showed higher increase in viable counts compared to the control. As a result, oligosaccharides produced from buckwheat hull by enzymatic hydrolysis showed antioxidant activity and prebiotic effects. It is suggested that utilization of oligosaccharides produced from buckwheat hull as functional food materials may be improved when hydrolysis time and conditions are controlled for this purpose.

Production of Soluble Dietary Fiber of Buckwheat Hulls by Enzymatic Depolymerzation and its Characteristics

Hee Jin Im, Bo Yeon Park, and Kyung Young Yoon*Department of Food and Nutrition, Yeungnam UniversityAbstract This study was conducted for the production of water-soluble dietary fiber (SDF) from buckwheat hulls byusing Celluclast or Viscozyme. The functionality of this SDF, including antioxidant activity, glucose- and bile acid-retardation effects in vitro, was measured. SDF yields from cellulose and hemicellulose fractions were 60.5 and 123.7 g/kg dry matter, respectively. Analysis of molecular weight distribution of SDF by using gel chromatography showed thatSDF degradation increased with increase in reaction time. The antioxidant activity of SDF obtained by enzymatichydrolysis was higher than that of dietary fiber without enzyme treatment. SDF showed higher retardation effects onglucose and bile acid than the sample without dietary fiber did. The results of this study suggested that SDF producedfrom buckwheat hull by enzymatic hydrolysis is a good source of functional food material because of its high antioxidantactivity and glucose- and bile acid-retardation effects.Keywords: buckwheat, glucose-retardation effects, bile acid-retardation effects, antioxidant activity, soluble dietary fiber

Degradation products of mangiferin by gamma irradiation with inhibitory effects on NO production

The xanthone glucoside mangiferin (1) was converted by γ-irradiation into three new compounds, mangiferdiol (2), mangiferinol (3), and isomangiferinol (4). The new compound 2 containing two hydroxymethyl groups instead of a ketone moiety exhibited significantly improved inhibitory activity against nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC50 value 47.1 ± 1.7 μM, compared to the mother mangiferin.

Production of Enzymatic Hydrolysate Including Water-soluble Fiber from Hemicellulose Fraction of Chinese Cabbage Waste

This study was performed to determine the optimal hydrolysis conditions for the production of hydrolysates, including water-soluble dietary fiber from Chinese cabbage, with commercial enzymes. The optimal pH and temperature for hydrolysis of the hemicellulose fraction were pH 5.0 and 40oC, and optimal enzyme concentrations were 45 units and 21 units for Shearzyme plus and Viscozyme L, respectively. The yields of the hydrolysate including the water-soluble dietary fiber from the hemicellulose fraction by Shearzyme plus and Viscozyme L were 22.64 and 24.73%, respectively, after a 72 h reaction. The molecular weight distribution of alcohol-insoluble fiber was characterized by gel chromatography; degradation of hemicellulose increased with increasing reaction time. Our results indicate that the hemicellulose fraction was degraded to water-soluble dietary fiber by enzymatic hydrolysis, and its hydrolysate could be utilized as new watersoluble food materials.

Antioxidant Activities of Cedrela sinensis Hydrolysates Prepared Using Various Enzymes

This study was conducted to analyze the functional component contents and antioxidant activities of Cedrela sinensis extracts hydrolyzed using four different enzymes. The yield of Viscozyme extract was the highest among the samples, and all enzymatic extracts, except for the commercial glucoamylase (AMG) extract, had significantly higher total polyphenol and flavonoids contents compared to the non-enzymatic extract (p＜0.05). Viscozyme extract showed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and Fe 2+ chelating ability among the samples. All enzymatic extracts showed high＞90% 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, and there was no significant difference between the enzymatic and non-enzymatic extracts. The reducing power of the extracts using Shearzyme or Viscozyme was significantly higher than that of the other samples (p＜0.05). Therefore, the results indicated that all enzymatic extracts (especially Viscozyme extract), except for the AMG extract, showed high antioxidant activity compared to the nonenzymatic extract. These result suggested that the enzymatic extracts of C. sinensis can be used in functional foods.This study was conducted to analyze the functional component contents and antioxidant activities of Cedrela sinensis extracts hydrolyzed using four different enzymes. The yield of Viscozyme extract was the highest among the samples, and all enzymatic extracts, except for the commercial glucoamylase (AMG) extract, had significantly higher total polyphenol and flavonoids contents compared to the non-enzymatic extract (p<0.05). Viscozyme extract showed the highest 1,1-diphenyl2-picrylhydrazyl (DPPH) radical scavenging activity and Fe chelating ability among the samples. All enzymatic extracts showed high>90% 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, and there was no significant difference between the enzymatic and non-enzymatic extracts. The reducing power of the extracts using Shearzyme or Viscozyme was significantly higher than that of the other samples (p<0.05). Therefore, the results indicated that all enzymatic extracts (especially Viscozyme extract), except for the AMG extract, showed high antioxidant activity compared to the nonenzymatic extract. These result suggested that the enzymatic extracts of C. sinensis can be used in functional foods.