• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.771-775
• /
• 2009

Antimicrobial activity of garlic (pH 6.0) heated at $120^{\circ}C$ reached its maximum at 45 min of heating and maintained the level for the rest of heating time (300 min) when tested against Candida utilis ATCC42416. The principal antimicrobial compound was allyl alcohol (AA), a highly volatile compound without sulfur in its molecule. The concentration of AA in heated garlic gradually increased to over 2,000 ppm for the first 90 min and stayed at the level without appreciable changes in spite of further heating. Other antimicrobial compounds secondary to AA were lowly volatile sulfur compounds including diallyl polysulfides (diallyl trisulfide, diallyl tetrasulfide, and diallyl pentasulfide) and heterocyclic sulfur compounds (4-methyl-1,2,3-trithiolane, 5-methyl-1,2,3,4-tetrathiane, and 6-methyl-1,2,3,4,5-pentathiepane). When the pH of the garlic extract was lowered before heating, considerably more secondary antimicrobial sulfur compounds were formed and the antimicrobial activity was stronger than the pH unadjusted garlic. Lowly volatile sulfur compounds contributed a significant part of antimicrobial activity of heated garlic only during the early period (45-120 min) of heating regardless of pH treatment.

• Food Science and Preservation
• /
• v.15 no.4
• /
• pp.568-575
• /
• 2008

The antimicrobial activities of raw garlic and garlic juice heated for 30 min at $65^{\circ}C,\;80^{\circ}C,\;and\;95^{\circ}C$ were investigated. Activities against food poisoning bacteria were measured. Raw garlic and garlic juice heated at $65^{\circ}C$ showed strong antimicrobial activities, but the antimicrobial activity of garlic juice heated at $80^{\circ}C$ was much less, and no antimicrobial activity was seen in garlic juice heated at $95^{\circ}C$. Raw garlic and garlic juice heated at $65^{\circ}C$ completely inhibited the growth of Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Salmonella typhymurium, and Salmonella enteritidis at levels below 0.2%(w/v) of garlic solids. The inhibitory effects of garlic juice heated at $80^{\circ}C$ were much lower, against all bacteria tested.

• Food Science and Biotechnology
• /
• v.16 no.5
• /
• pp.822-827
• /
• 2007

The aroma characteristics and antioxidative activity of volatile compounds in heat-treated garlic (Allium sativum L.) were evaluated. The garlic was heated to various temperatures (100, 110, 120, and $130^{\circ}C$) for different lengths of time (1, 2, and 3 hr). The volatile compounds of heated garlic were extracted by simultaneous steam distillation extraction (SDE). Aroma compound profiles were analyzed by gas chromatography/mass spectrometry (GC/MS) and antioxidative activity was measured by 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation decolorization assay. The major aroma compounds were sulfur compounds such as dimethyl disulfide, 2-propen-1-ol, methyl-2-propenyl disulfide, dimethyl trisulfide, diallyl disulfide, methyl-2-propenyl trisulfide, and di-2-propenyl trisulfide. DPPH radical scavenging activity (EDA, %) and the ascorbic acid equivalent antioxidant activity (AEAC) of volatile compounds in heated garlic increased significantly with the increase of temperature and time (p<0.001). The EDA (%) and AEAC of raw garlic were 26.8%/10 mg garlic and 39.05 mg ascorbic acid equivalent per g sample. After heat treatment, the highest values were 40.50%/10 mg garlic for EDA (%) and 46.43 mg ascorbic acid equivalent per g sample for ABTS.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.1
• /
• pp.103-108
• /
• 1997

It has been known that garlic, one of the essential ingredients of spices in Korean food, has a hypotensive effect. The following experiments were done to compare the effect of heat treatment of garlic on change in blood pressure. We selected SHR(Spontaneously Hypertension Rat) for experimental animals since, in the case of human beings, 85~90% of high blood pressure is in hereditary origin. Animals were divided into 3 groups, control group(no garlic), 3% raw garlic group and 3% heated garlic group. Serum was analyzed for lipid concentration, and plasma for prothrombin time and fi-brinogen concentration. The effects of heat treatment of garlic were as follow. There was no significant differences in body weight gain and feed efficiency ratio except that feed intake of 3% heated garlic-fed group was significantly lower than that of control group and 3% raw garlic-fed group. Garlic-fed groups, in contrast to the control group, showed significant difference in cholesterol content in pro-thrombin time and in fibrinogen concentration. Taken together, hypotensive effects of garlic on high blood pressure were significant. Regardless of heat treatment both heated garlic and raw garlic showed hypotensive effects.

• Preventive Nutrition and Food Science
• /
• v.13 no.4
• /
• pp.334-339
• /
• 2008

This study was designed to determine the optimum conditions of heating temperature, heating time and dilution rates for producing heated garlic juice by using central composite design of response surface methodology. Garlic 3Department of Biosystems Engineering, Chungbuk National University, Cheongju 361-763, Korea was heated using a high temperature and pressure treatment apparatus. Total soluble solid contents ranged from 4.4 at $130^{\circ}C$ 3 hr and 6 fold dilution to 5.89 at $115^{\circ}C$ for 2 hr and 8 fold dilution. The highest total acidity was 0.55% at $120^{\circ}C$ for 3 hr and 2 fold dilution. The pH ranged from 4.01 at $130^{\circ}C$, 3 hr and 6 fold dilution to 5.85 at $120^{\circ}C$, 1 hr and 6 fold dilution. From the results of statistical analysis on the sensory evaluation the predicted optimum processing conditions for best color, taste, flavor and overall acceptance were $119.41^{\circ}C$, 3.11 hr, 5.85 fold dilution, $118.23^{\circ}C$, 3.57 hr, 3.15 fold dilution, $120.54^{\circ}C$, 3.47 hr, 5.01 fold dilution and $119.54^{\circ}C$, 3.18 hr, 5.66 fold dilution, respectively. The application of response surface methodology for preparing heated garlic juice processing showed a good correlation with high significance.

• Food Science and Biotechnology
• /
• v.14 no.1
• /
• pp.16-20
• /
• 2005

Additions of ground garlic, chili and ginseng powder did not affect the breaking force and strain of directly heated gel of Alaska pollack surimi. In comparison, these additives reduced the setting effect achieved by incubation of the salted surimi at $25^{\circ}C$, and resulted in a decreased breaking force and strain for the two step heated gel. Garlic almost completely inhibited the myosin cross-linking reaction, an important reaction for improving the gel properties occurring in the setting process. However, chili and ginseng powder minimally inhibited the cross-linking reaction. Thus, this study proposes that the mechanism for the suppression of the setting effect by chili and ginseng is different from that of garlic.

• Food Science and Biotechnology
• /
• v.15 no.3
• /
• pp.469-473
• /
• 2006

Film-forming yeasts generate an undesirable yeasty flavor in fermented vegetables such as kimchi in the presence of oxygen. Antimicrobial materials including garlic oil (GO), heated garlic (HG), and allyl alcohol (AA) were investigated for use as alternative natural food preservatives to inhibit the growth of film-forming yeasts in fermented vegetables. Using the fermentation of cucumber pickles as a model system, GO, HG, and AA were effective in preventing film formation at concentrations of 0.006, 3.0, and 0.02%, respectively. The effectiveness of HG in preventing the growth of a film yeast, Hansenula anomala, was not influenced by pH, while that of potassium sorbate, a typical anti-yeast food preservative, was highly dependent on pH. All tested materials were effective when added at the beginning of fermentation due to their negligible inhibitory activity toward lactic acid bacteria.

• Korean journal of food and cookery science
• /
• v.17 no.2
• /
• pp.117-122
• /
• 2001

Ground fresh garlic and 50% ethanol garlic extracts were added into ground porks in order to investigate their effects on pH, peroxide and TBA values of ground porks during storage at 4$\^{C}$. The grounded porks tested were devided into two groups of fresh and heated forks at 100$\^{C}$ for 10 minutes. A significant control effect of ground garlic and extracts was found on peroxide and TBA values during storage, particularly for those added with 20% ground garlic and 10% garlic extracts. The effects were maximum after storage of 4-6 days and then decreased thereafter The pH was generally decreased until 6 days followed by the increase. Addition of garlic and garlic extracts caused a little increase in pH and the pH changes were less than the changes of control. Eventhough the effects of garlic on pH, peroxide and TBA values were similar for both heated and fresh pork, heat treated one showed more changes than fresh pork.

• Preventive Nutrition and Food Science
• /
• v.13 no.4
• /
• pp.327-333
• /
• 2008

To develop a functional juice using garlic (Allium sativum L.), heated garlic juice was investigated using a central composite design set with variables of treatment temperature (110, 115, 120, 125, and $130^{\circ}C$) and time (1, 2, 3, 4, and 5 hr) using high temperature and pressure treatment apparatuses. Total soluble solid, total acidity, reducing sugar, total pholyphenol contents, electron donating activity (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) in heated garlic juice were increased with increasing heating temperature and time. The highest total soluble solid content was $17.81\;^{\circ}brix$ at $123.10^{\circ}C$ for 1.10 hr. The highest total acidity was 1.43% at $127.35^{\circ}C$ for 4.35 hr. The highest reducing sugar content was 86.67 mg/mL at $119.90^{\circ}C$ for 4.35 hr. The highest total polyphenol content was 8.42 mg/mL at $127.75^{\circ}C$ for 4.26 hr. The highest EDA and AEAC were 60.09%, and 7.40 mg AA eq/mL at $127.85^{\circ}C$ for 4.23 hr, and $128.10^{\circ}C$ for 4.18 hr, respectively.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1583-1588
• /
• 1999

Garlic pieces without peeling were subjected to hot air heating at $60{\sim}90^{\circ}C$ for 30 min. and microwave oven heating for 10 sec to reduce the strength of garlic flavor. Volatile compounds of the treated garlic were decreased, as the heating temperature was raised. Garlic heated at 70, 80 and $90^{\circ}C$ had 20%, 31% and 49% less volatile compounds, respectively, compared to those of the control. Microwave oven heating revealed a similar trend to those heated at $60{\sim}80^{\circ}C$. As the heating temperature was raised, glucose, fructose and fructooligosaccharide contents in the heated garlic were decreased. Pyruvic acid contents in garlic, a degradation product of alliin, was decreased as the heating temperature was raised, but contents of the other organic acids were not affected. Arginine, the main amino acid in garlic was decreased by the hot air heating, but was not affected by the microwave heating. Glutamic acid and tyrosine contents were decreased in all the treated garlic samples.