• Food Science and Biotechnology
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• v.14 no.1
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• pp.123-130
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• 2005

Hydrogen-donating capacity, scavenging activity of reactive oxygen including superoxide anion radical and hydrogen peroxide, metal-chelating activity, and reducing power of garlic extracts were investigated. All tested garlic extracts exhibited in vitro antioxidant activities, with Uiseong extract showing highest hydrogen-donating and hydrogen peroxide-scavenging activities, and reducing power, followed by Seosan and Samchek extracts, in proportion to total thiosulfinate contents. Higher scavenging activity of superoxide anion radical was observed in Uiseong than Seosan and Samchek extracts. Metal-chelating activity increased in order of Uiseong < Seosan < Samchek, showing inverse relations to total thiosulfinate content. Garlic extracts of Uiseong and Seosan showed weak prooxidant activities and that of Samchek showed strong antioxidant activity against $Cu^{+2}$-induced human LDL oxidation. Protective effects on peroxyl and hydroxyl radical-induced DNA strand damages were observed in all tested garlic cloves. These results indicate growing conditions of garlic cloves affect total thiosulfinate content and antioxidant activities.

• Food Engineering Progress
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• v.13 no.2
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• pp.92-98
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• 2009

An investigation was carried out to study the effects of extraction, heat treatment, and storage temperature on functional ingredients of onion. Extracts of onion paste and freeze dried onion were prepared by treatments with several solvents including hot water, methanol, and ethanol, and then contents of functional ingredients such as total phenol, flavonoid, quercetin, and thiosulfinate were determined. The highest levels of functional ingredients were observed in samples extracted using water at 100$^{\circ}C$ or ethanol. The skin extract contained 60-fold more quercetin than onion paste extract, whereas no thiosulfinate was detected in onion skin extract. Heat treatment of onion extracts at 60, 80, 105, and 121$^{\circ}C$ did not effect on the levels of all functional ingredients tested. During four-week storage, the levels of total phenol, flavonoid, and quercetin were not significantly changed regardless of storage temperature. However, the total thiosulfinate was rapidly reduced as the storage temperature increased.

• Food Science and Preservation
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• v.22 no.6
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• pp.867-877
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• 2015

In this study, antioxidant and anti-inflammatory activities of water, methanol, and ethanol extracts obtained from Allium hookeri root were evaluated. The ethanol extract of A. hookeri was found to possess the strongest reducing power and also exhibited dominant effects on scavenging of nitrites, DPPH radicals, and superoxide radicals. The water extract showed more efficient DPPH and hydroxyl radical-scavenging activities than those of the methanol extract. Furthermore, the inhibitory activity against nitric oxide (NO) production in RAW 264.7 macrophages was evaluated to elucidate the anti-inflammatory properties of the extracts. Results indicated that all the extracts of A. hookeri exerted inhibitory activities against NO production, especially the ethanol extract ($IC_{50}29.13{\mu}g/mL$). Total phenolic and total flavonoid contents were found to be abundant in the ethanol extract, with values of 24.96 mg gallic acid equivalent/g extract and 4.27 mg rutin equivalent/g extract, respectively. Total thiosulfinate content was determined for the first time and a high amount was present in the ethanol extract ($14.2{\mu}M/g$ extract). These results suggest that A. hookeri root has antioxidant and anti-inflammatory properties and could be used as a natural source for the development of pharmaceutical agents or functional foods.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1321-1326
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• 1998

Extraction and storage conditions of oleoresin were studied from root portion of peeled garlic, an waste of garlic industry. Extraction with ethanol and methanol showed an high solid yields of $27{\sim}37%$ at the temperature range of $30{\sim}50^{\circ}C$. Two hours of extraction were found to be economic because of no significant increase in furthur extraction. Storage of the oleoresin under anaerobic condition such as vaccum or nitrogen resulted in a less changes in pH, total acidity, color and thiosulfinate content, than those changes under aerobic condition. Most of the thiosulfinate was decreased for all conditions after 14 days of storage at $25^{\circ}C$. Glucose and sucrose were increased and most of organic acids were decreased during storage under nitrogen condition. Addition of ascorbic acid and cysteine into oleoresin retained the garlic flavor, effectively.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.189-197
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• 2014

Onion juices were prepared by various heat treatments (at $105-120^{\circ}C$ for 4.5-5.5 h), from the onions cultivated with increasing numbers of sulfur applications (once for Sulfur-1, four times for Sulfur-4). As heat treatment intensity increased, the onion juices darkened (p<0.001), which adversely affected the sensory preference. In addition, increasing the heating temperature significantly increased the organic acid content of onion juices (p<0.001), and therefore, decreased pH (p<0.001). Heat intensity did not affect the thiosulfinate content of onion juices, suggesting that the rate of decomposition of thiosulfinate into low-molecular weight sulfur derivatives is similar over the temperature range of $105-120^{\circ}C$. Total flavonoids were higher in onion juices derived from Sulfur-4 than in Sulfur-1 onions, and increased with heat treatment intensity (p<0.001). These results indicated that heat-facilitated conversion of bound forms of flavonoids to their free forms increases the extractability of flavonoids from onions.

• The Korean Journal of Food And Nutrition
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• v.11 no.3
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• pp.278-282
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• 1998

An attempt was made in this study to investigate the possibility of processing fresh garlic into an fresh garlic paste. The characteristics of fresh garlic paste and processing properties were investigated and the effect of salt, maltodextrin, acid and heat on product quality during storage were studied. After the processed fresh garlic paste was stored at 3$0^{\circ}C$ and 5$^{\circ}C$ without light for 6 months. The weight and pH of colve were 93% of total and 5.95, respectively. Addition of 10% salt, 10% maltodextrin, 01.% dl-malic acid, and heat on fresh garlic paste maintain color of fresh garlic could be preserved for 6 months at 5$^{\circ}C$. Judging from thiosulfinate and pyruvate content, and sensory evaluation, quality damage of fresh garlic paste which was make of 10% salt, 10% maltodextrin, 0.1% dl-malic acid, and heat on fresh garlic paste hardly occurred at 5$^{\circ}C$ but occurred considerable level at 3$0^{\circ}C$ during storage for 6 months.

• Journal of agriculture & life science
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• v.46 no.5
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• pp.91-100
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• 2012

Physicochemical and antimicrobial activities of 12 different garlic cultivars were investigated. Width and weight of California late cultivar (60.44mm, 53.73g) was the biggest and heaviest but Changyoung cultivar (44.04mm, 25.15g) was the smallest and lightest among the variety of garlic. The range of L, a and b color characteristics of garlic surface from different variety were 84.13~90.56, -1.10~0.77 and 18.24~26.61, respectively. Shear force was the lowest in California early, but 94-12-2 cultivar ($4211.35cm/kg^2$) was higher than another cultivars. Soluble solid range was 6.40~11.33 %brix, and Changyoung cultivar was the highest than the others, significantly. pH of garlics from different cultivar were 5.57~6.53. Total thiosulfinate content of California late cultivar (146.05mM/g) was higher, but Italy cultivar (93.23mM/g) was lower than the others. Total pyruvate content was the highest in Yugo cultivar ($162.50{\mu}M/g$) and the lowest in California early cultivar ($147.41{\mu}M/g$).

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.213-220
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• 2013

Two types of onions cultivated with different methods of sulfur application (designated as S-1 and S-2) were examined for their physicochemical and sensory properties, and then compared with onions without sulfur application as a control. During cultivation, dietary sulfur methylsulfonylmethane (MSM) was sprayed on the leaves twice starting at 2 months before harvest, with one month intervals for S-1. For S-2, the MSM was applied once onto surface soils before sowing, and then once again on the leaves at 2 months before harvest. Thiosulfinate, a major sulfur-containing compound in onions, increased in the order of control, S-1, and S-2, without noticeable differences in the strength of spicy hot taste and flavor. The S-2 onions demonstrated a total reducing capacity three times higher than control and S-1 did. It indicates that the application of sulfur would positively affect the quality of onions under the condition where sufficient time is given for soil mineralization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.111-117
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• 2015

This study investigated quality characteristics of commercial frozen chopped garlic. We collected six kinds of commercial frozen chopped garlic, four of which were domestic and the remaining two made in China. The moisture contents and drip loss of domestic frozen chopped garlic were significantly lower than those of Chinese garlic. Drip loss was positively correlated with moisture content (r=0.918, P<0.01). Total pyruvate contents of frozen chopped garlic ranged from $118.69{\pm}5.97{\sim}224.81{\pm}9.92{\mu}mol/g$ in domestic garlic and $75.27{\pm}5.91{\sim}79.35{\pm}1.79{\mu}mol/g$ in Chinese garlic. Allicin contents of frozen chopped garlic ranged from $8.91{\pm}0.34{\sim}13.09{\pm}0.35mg/g$ in domestic garlic and $5.91{\pm}0.08{\sim}6.05{\pm}0.27mg/g$ in Chinese garlic. Total thiosulfinate content of commercial frozen chopped garlic ranged from $0.60{\pm}0.07{\sim}1.33{\pm}0.12$ optical density/g. Total thiosulfinate content of commercial frozen chopped garlic was positively correlated with allicin content (r=0.892, P<0.01). Flavor patterns of commercial frozen chopped garlic measured by an electronic nose showed no difference between domestic and Chinese garlics.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.478-487
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• 2013

Onions were treated with different amounts of sulfur (S) during cultivation and examined for their physicochemical properties and flavor. Onions cultivated without S application were the control group; the treatment groups were grown in soil that had been pretreated with S and received additional S applications or four times before harvest. As the number of S applications increased, the levels of crude protein, quantified with total nitrogen; ash, approximating total amounts of minerals; and dietary fiber of the onions tended to increase. The mineral compositions also improved, with noticeable increases in the levels of Mg, K, Fe, and Zn. In particular, the reducing capacity of the onions increased appreciably (p<0.05), without increases in the levels of S-containing compounds such as thiosulfinate or S-containing amino acids. Nevertheless, the spicy hot taste and flavor, which is generated mainly from S-containing compounds, were perceived more strongly in the onions that had received more S applications.