• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.447-454
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• 2017

A new amperometric biosensor has been developed for the detection of hydrogen peroxide ($H_2O_2$). The sensor was fabricated through the one-step deposition of a biocomposite layer onto a glassy carbon electrode at neutral pH. The biocomposite, as a $H_2O_2$ sensing element, was prepared by the electrochemical deposition of a homogeneous mixture of graphene oxide, aniline, and horseradish peroxidase. The experimental results clearly demonstrated of that the sensor possessed high electrocatalytic activity and responded to $H_2O_2$ with a stable and rapid manners. Scanning electron microscopy, cyclic voltammetry, and amperometry were performed to optimize the characteristics of the sensor and to evaluate its sensing chemistry. The sensor exhibited a linear response to $H_2O_2$ in the range of 10 to $500{\mu}M$ concentrations, and its detection limit was calculated to be $1.3{\mu}M$. The proposed sensing-chemistry strategy and the sensor format were simple, cost-effective, and feasible for analysis of "food-grade $H_2O_2$" in food samples.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1761-1769
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• 2018

Enzyme-assisted extraction is a cost-effective, safe, and efficient method to obtain bioactives from plant materials. During this study, 10 different marine algae from Sri Lanka were individually extracted by using five commercial food-grade carbohydrases. The enzymatic and water extracts of the seaweeds were analyzed for their antioxidant and anti-inflammatory activities. The highest DPPH, hydrogen peroxide ($H_2O_2$) and intracellular $H_2O_2$ scavenging abilities were observed from the Celluclast extract of Sargassum polycystum (CSp). CSp exerted protective effects against oxidative stress-induced cell death in hydrogen peroxide-induced Chang cells and in model zebrafish. The Celluclast extract of Chnoospora minima (CCm) showed the strongest anti-inflammatory activity against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 macrophages ($IC_{50}=44.47{\mu}g/mL$) and in model zebrafish. CCm inhibited the levels of iNOS, COX-2, $PGE_2$, and TNF-${\alpha}$ in LPS stimulated RAW 264.7 macrophages. Hence, CSp and CCm could be utilized in developing functional ingredients for foods, and cosmeceuticals.

• Nutrition Research and Practice
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• v.4 no.3
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• pp.183-190
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• 2010

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against $H_2O_2$-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against $H_2O_2$-induced cell damage in vitro.

• Journal of Marine Bioscience and Biotechnology
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• v.9 no.2
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• pp.43-48
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• 2017

Temperature is a major factor that affects the physiochemical properties of compounds. This study focus on the determination of thermostability and the effect of temperature on antioxidant activities of Ecklonia cava (E. cava) ethanoic extract. The ethanoic extracts of E. cava were evaluated at $30^{\circ}C$, $60^{\circ}C$ and $90^{\circ}C$ for 0 to 7 days. The antioxidant activities were determined by DPPH, hydroxyl radical and hydrogen peroxide scavenging activities. The intracellular reactive oxygen species (ROS) scavenging activity was investigated using DCFH-DA assay. Results revealed that the ethanoic extract of E. cava incubated at different temperatures for 0 to 7 days, showed stable scavenging activities on DPPH, hydroxyl radical and hydrogen peroxide. The ROS scavenging activities of ethanoic extract and ascorbic acid were also investigated. The extract showed a stable ROS scavenging activity from 0 to 7 day at $90^{\circ}C$. However, the scavenging activity of ascorbic acid at $90^{\circ}C$ decreased starting from day 3. These results indicated that the antioxidant effects of this food grade ethanoic extract of E. cava could remain stable during the employed temperatures of food processing.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.162-167
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• 2009

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at $60{\sim}100^{\circ}C$ for $10{\sim}20$ min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.227-236
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• 2010

The objective of this study was to evaluate the potential use of ginseng leaf as a cosmetic material. In this research, we employed enzymatic treated ginseng leaf by using Ultraflo L to improve the recovery of ginsenosides from the ginseng leaf and studied the biological activities and skin safety of the enzymatic treated ginseng leaf for use as a cosmetic material. The total ginsenoside contents of the non-enzymatic treated ginseng leaf (NEGL) and Ultraflo L treated ginseng leaf (UTGL) were 271 and 406 mg/g, respectively. The level of metabolite ginsenosides (sum of Rg2, Rg3, Rg5, Rk1, compound K, Rh1, Rh2, and F2) was higher in UTGL (93.1 mg) compared to NEGL (62.4 mg) in one gram ginseng leaf extract. The increase in amounts of ginsenoside types in UTGL compared to NEGL was generally 140% to 157%. UTGL exhibited relatively higher 2,2-diphenyl-2-picrylhydrazyl hydrate ($IC_{50}$, 2.8 mg/mL) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt ($IC_{50}$, 1.6 mg/mL) radical scavenging activities compared to NEGL (4.8 mg/mL and 2.2 mg/mL). The UTGL group showed normalized hydrogen peroxide, lipid peroxidation and visual wrinkling grade induced-UVB exposure. The UTGL did not induce any adverse reactions such as erythema and edema on intact skin sites; however, some guinea pigs treated with UTGL on abraded skin sites showed very slight erythema. The primary irritation index (PII) score of UTGL was 0.05 and it was classified as a practically non-irritating material (PII, 0 to 0.5). In skin sensitization tests with guinea pigs, UTGL had a positive rate of skin sensitization at 40%, and the mean evaluation score was 0.4.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1139-1145
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• 2006

In this study, antioxidant activities of enzymatic and methanolic extracts from E. cava stem and leave were evaluated by measuring the scavenging activities on 1,1 diphenyl 2 picrylhydrazyl (DPPH), hydroxyl radical, hydrogen peroxide and the inhibitory effects on DNA damage induced by oxidative stress of cells. Enzymatic extracts were prepared by enzymatic hydrolysis of both stem and leave using food grade five different carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, Alcalase). The enzymatic extracts were lower than methanolic extracts in polyphenol contents, but higher in extraction yield by approximately 30%. The enzymatic extracts were superior to methanolic extracts in DPPH and H2O2 scavenging activities and DNA damage protective effect. There were no significant antioxidant activity difference between stem and leave, but the extracts of leave were relatively better than those of stem. In this study it is suggested that E. cava stem as well as its leave would be a good raw materials for antioxidants compound extraction and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.