• Culinary science and hospitality research
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• v.14 no.1
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• pp.144-151
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• 2008

This study investigated the changes in the contents of allicin and diallyl disulfide and in the alliinase activity during the vacuum freeze drying of onion samples treated as the whole, sliced and crushed forms. The contents of allicin and diallyl disulfide in raw onions were 26.40ppm and 2.78ppm respectively. The contents of allicin and diallyl disulfide of onion samples treated as the whole, sliced and crushed forms increased with the progress of vacuum freeze drying. The degree of increase was different in each onion sample form prepared by vacuum freeze drying(p<0.05). The specific activity of alliinase in raw onions was 7.536 units/mg protein. The activity in onion samples treated as the whole, sliced and crushed forms decreased with the progress of vacuum freeze drying. The activity in the whole onion prepared by the vacuum freeze drying for 8 hrs reduced to 5.516 units/mg protein with 73.2% remaining and to 3.304 units/mg protein with 43.8% remaining for 36 hrs. The activity in the sliced onion prepared by the vacuum freeze drying for 36 hrs reduced to 2.366 units/mg protein with 31.4% remaining and the activity in the crushed onion prepared by the vacuum freeze drying for 36 hrs reduced to 2.232 units/mg protein with 29.6% remaining. The alliinase in onion sample treated as the whole form showed the highest remaining activity during the vacuum freeze drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.655-660
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• 2012

The purpose of this study is to evaluate pungency-related factors of field garlic (FG) and rice paddy garlic (RG) from Youncheon province. Allicin, alliin, and S-allyl-L-cysteine (SAC) contents were analyzed by HPLC. In addition, activities of alliinase, GTPase (${\gamma}$-glutamyltranspeptidase), and pyruvate content of garlic were measured. The moisture content of RG (65.86%) was higher than that of FG (63.34%). However, crude lipid, crude protein, crude ash, and carbohydrate contents of RG were lower than those of FG. The alliin contents of FG and RG were 8.97 and 8.22 mg/g, respectively. The allicin content of FG (2.83 mg/g) was higher than that of RG (2.22 mg/g). Further, SAC content of FG (1.74 mg/g) was higher than that of RG (0.104 mg/g). Alliinase activities of FG and RG were similar, whereas the GTPase activity of FG was higher than that of RG. These results show that the stronger pungency of FG is due to the higher amount of alliin and SAC as well as the higher activity of GTPase compared to RG.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.593-599
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• 1996

The effects of high pressure on alliinase and on flavor of garlic (Alliiium sativum L.) were investigated. After pressurized at 150 MPa, 300 MPa, and 500 MPa for 10 min, the activities of purified alliinase were reduced approximately 30%, 80%, and 100%, respectively, while the enzyme activities of pressurized garlic cloves were reduced 0%, 7%, and 100%, respectively. This indicated that the intact garlic has a protective effect against pressure-inactivation of alliinase. Alliinase was more effectively inactivated when high pressure treatment was carried out at high ($>40^{\circ}C$) or low temperature ($>10^{\circ}C$) than ambient temperature. Pressure treated garlic at 500 MPa had little pungency and sulfuryl odor compared to raw garlic indicating that high-pressure processing can be used to produce garlic without pungent flavor.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.600-607
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• 2007

In this study, attempts were made to develop a method for controlling the volatile sulfur compounds in garlic. Crude alliinase extracted from fresh garlic was applied to garlic pulp blanched far 5 min at $100^{\circ}C$, and the changes in the thiosulfinates and volatile compounds of the blanched garlic pulp reacted with the enzyme were investigated. Eight kinds of thiosulfinates from garlic were separated by HPLC, and identified by LC/MS/MS. When the alliinase was added to the blanched garlic pulp at 100, 200, 300, or 400 units, and reacted for 15 min, respectively, thiosulfinates were generated in the amounts of 37, 68, 77, and 80% of the fresh garlic content (control). Under the same conditions, we analyzed the volatile compounds, where 28 peaks were identified by GC/MSD. Of the 28 peaks, 23 were volatile sulfur compounds. The results of the analysis showed that all the volatile compounds were generated at amounts of 25, 36, 66, and 76% of the content of the control, respectively. These results indicate that the sulfur compound content of garlic can be regulated, depending upon the reaction conditions of allinase.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.331-335
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• 2002

Aqueous extracts of garlic (Allium sativum) preparation were prepared after the samples were exposed to various heat treatments. A quantitative assessment of antimicrobial activities was carried out by determining the minimum inhibitory and microbicidal concentrations (MICs and MMCs) of the various extracts against some selected bacteria and fungi. The antimicrobial activity of garlic decreased as the heating temperature increased. This fact implies that alliinase may be the most critical rate-determinant to produce the activity when garlic is heated.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.1-7
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• 2007

Garlic (Allium sativum L.) contains a specific sulfur compound, the S-allyl derivative of L-cysteine sulfoxide, and has long been known for its antimicrobial activity against various microorganisms, including bacteria, fungi, and protozoa. The principal antimicrobial compound of garlic is S-allyl-L-propenethiosulfinate (allicin) which is generated by an enzyme, alliinase (L-cysteine sulfoxide lyase), from S-allyl-L-cysteine sulfoxide (alliin). This compound exists exclusively in Allium as a major non-protein sulfur-containing amino acid. S-Allyl-L-propenethiosulfinate belongs to the chemical group of thiosulfinates and is a highly potent antimicrobial. The potency of garlic extract is reduced during storage since thiosulfinates are unstable and are degraded to other compounds some of which do not have antimicrobial activity. Diallyl polysulfides and ajoene are sulfur compounds derived from allicin that do possess antimicrobial activity. It was recently found that garlic becomes antimicrobial on heating at cooking temperatures, and that the compound responsible for this is allyl alcohol, which is generated from alliin by thermal degradation.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.145-152
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• 2006

Efforts have been made to explore the possibility of using garlic as an antimicrobial therapeutic agent since garlic extract and its individual sulfur compounds show antimicrobial activities against all kinds of microorganisms including bacteria, molds, yeasts and protozoa. Staphylococcus aureus has been the most studied bacteria along with many other Gram positive and negative pathogenic bacteria, including species of the genera Clostridium, Mycobacterium, Escherichia, Klebsiella, Bacillus, Salmonella and Shigella. Candida albicans has been the most studied among the eukaryotic microorganisms. A pathogenic protozoa, Giardia intestinalis, was also tested. All the microorganisms tested was inhibited by garlic extract or its sulfur components. Garlic has been known to be growth inhibitory only when fresh garlic is crushed, since allicin-generating reaction is enzyme-catalyzed. Allicin is known to be growth inhibitory through a non-specific reaction with sulfhydryl groups of enzyme proteins that are crucial to the metabolism of microorganisms. Another plausible hypothesis is that allicin inhibits specific enzymes in certain biological processes, e.g. acetyl CoA synthetase in fatty acid synthesis in microorganisms. Allicin transforms into other compounds like ajoene and various sulfides which are also inhibitory to microorganisms, but not as potent as their mother compound. It is reported recently that garlic heated at cooking temperatures is growth inhibitory especially against yeasts, and that the growth inhibitory compound is allyl alcohol thermally generated from alliin in garlic.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.1-8
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• 2004

Effects of temperature, discoloration, and conditioning on garlic compositions before and after storage were examined. Proximate composition, soluble solids, pH, organic acids, and total sugars of all samples were not significantly different. Sugar contents were sucrose > fructose > glucose, and included such fructooligosaccharide as 1-kestose, 1-nystose, and 1-F-fructosyl nystose. Allicin contents in control, green discolored, and conditioned garlics were 647,9, 613.8, and 648.0 mg%, respectively. Thirty-two flavor compounds were identified by GC/MSD, including 11 sulfide compounds, 5 acids, and 3 aldehydes. Contents of sulfur compounds, including disulfide(di-propenyl), 2-thiophene methanethiol, thiophene, 3,4 dihydro-3-vinyl-1,2-dithiin, and 2-vinyl-4H-1,3-dithin, and water-soluble pectins in low temperature-stored garlic were higher than those in control, and decreased by conditioning or inducing green discoloration. These results show sulfur compounds and water-soluble pectins accumulated in low temperature stored-garlic, and are then converted into green pigments by alliinase in disintegrated garlic tissues.

• Korean Journal of Pharmacognosy
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• v.37 no.2 s.145
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• pp.97-102
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• 2006

Garlic(Allium sativum Linn) is widely used as a common condiment for a variety of foods and beverages. It has been well known that fresh garlic and garlic supplement of commercial preparations have various therapeutic properties including antimicrobial activity, antiplatelet aggregation, antihypertension, and cholesterol-lowering effects, which contribute to its increasing uses for an alternative medicine. Allicin(diallyl thiosulfinate), the major bioactive components of garlic, is formed by alliinase cleavage of the naturally occurring alliin upon crushing or mincing of garlic, and is the progenitor of a number of other products, such as diallyl disulfide. CYP3A4, heme-containing monooxygenase, is a key enzyme responsible for drug metabolism. Therefor, in the present study, we isolated and examined the compounds with CYP3A4-inhibiting activities from garlic. Among EtOAc extracts of garlic, we found that N-p-coumaroyltyramine and N-feruloyltyramine showed remarkable CYP3A4-inhibiting activities, compared to diallyl disulfide. Structures of the isolated active compounds were established by chemical and spectroscopic means.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.730-735
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• 1996

Antibacterial action of garlic extract against Escherichia coli was investigated. When the survival of E. cloi in tryptic soy broth (TSB) containing 50% garlic extract was compared with those of Lactobacillus plantarum, Leuconostoc mesenteroides and Staphylococcus aureus, E. coli was the most sensitive to garlic antibacterial action. When E. coli was inoculated into TSB with different concentrations of garlic extract, viable cell number decreased continuously during the test period even at 1% garlic extract. When E. coli was inoculated into pH-adjusted TSB containing 0.5% garlic extract, viable cell number of E. coli decreased continuously at initial pH of 5.2 and 6.2, while it decreased initially but increased to $8.0{\times}10^{7}\;CFU/ml at 48 hr at pH 7.2. With larger initial populations $(10^{6}\;CFU/ml), E. coli grew without apparent inhibition, while with smaller initial populations $(<10^{5}\;CFU/ml), viable cell number decreased initially but later increased. Thiol compounds like cysteine and glutathione, with free SH group (s), helped E. coli to grow or survive better in TSB with inhibitory level (5%) of garlic extract. The possibility of eliminating E. coli by using garlic extract from foods like kimchi of which garlic is one of regular ingredients is suggested.