Garlic Content Research Articles

Exploring the influence of garlic on microbial diversity and metabolite dynamics during kimchi fermentation

Garlic (Allium sativum) is a key ingredient in Korean cuisine, particularly in the preparation of kimchi, contributing to its flavor and taste. Garlic has been a potential resource for lactic acid bacteria (LAB) in kimchi. However, the mechanism by which it influences microbial diversity and metabolite production is unclear. This study investigated the effect of garlic on the bacterial composition of and metabolite changes in kimchi. To achieve this, four separate batches of kimchi were prepared with varying garlic concentrations (w/w): 0 %, 1 %, 2 %, and 4 %, and the bacterial communities and metabolite production were monitored. In the early stages of fermentation, the count of LAB, operational taxonomic units (OTUs), and Shannon index increased linearly with the increase in garlic content. This indicated that garlic is a rich resource and contributes to the diversity of LAB during kimchi fermentation. Compared with the kimchi samples with a lower garlic content, those with a high garlic content (≥2 %) exhibited increased abundance of Lactobacillus and Leuconostoc as well as noticeable differences in functional diversity, including carbohydrate, amino acid, and energy metabolisms. Correlation analysis between sugars, organic acids, and predominant LAB in the garlic-containing kimchi samples suggested that in kimchi samples with high garlic content, LAB played a significant role in the fermentation process by metabolizing sugars and producing organic acids. Overall, this study demonstrated that the addition of garlic has a positive impact on the bacterial diversity and metabolite production during kimchi fermentation, potentially affecting the fermentation process and flavor profile of kimchi.

마늘 첨가량에 따른 김치의 발효 중 품질 특성 변화

마늘의 함량에 따른 김치를 제조하여 품질 특성을 비교한 결과 마늘의 함량이 적을수록 pH의 감소와 산도의 증가 속도가 빠른 경향을 보여 김치의 적숙기에 빠르게 도달하였다. 또한, 마늘을 첨가하지 않을 경우 초기 균수가 많아서 발효가 빨리 진행되고, 마늘의 함량이 증가할수록 초기 발효가 느리게 진행되는 것을 확인할 수 있었다. 이러한 결과는 유기산과 유리당의 변화에서도 확인할 수 있었다. 유기산의 경우 초기 김치에서는 acetic acid를 제외한 5종의 유기산이 검출되었으며, lactic acid와 acetic acid는 저장기간 동안 증가하였다. 특히 초기 김치에서 citric acid는 마늘 함량이 많을수록 그 함량이 많았으며, lactic acid는 마늘 함량이 많을수록 그 함량이 적게 나타났다. 주된 유리당은 maltose, glucose, galactose, fructose, mannitol이었으며, 모든 처리군에서 glucose와 fructose가 가장 큰 비중을 차지하였다. Glucose는 저장 초기에 많이 감소한 반면에 fructose는 저장 초기보다는 후기에 감소하는 경향을 나타내었다. 향기패턴은 마늘의 함량이 높을수록 제1주성분인 F1이 negative(-)에서 positive(+)로 이동하는 경향을 나타내었을 뿐만 아니라 처리군 간의 차이도 큰 것을 확인할 수 있었다. 관능적 특성에서는 마늘 첨가군의 경우 마늘의 함량이 많을수록 초기 발효 진행이 느려 이취, 이미의 점수는 낮고, 조직감에서 높은 점수를 받았다. 따라서 김치 제조 시 마늘을 첨가하지 않은 것보다 첨가하는 것이, 그리고 그 함량이 많을수록 김치의 적숙기에 늦게 도달하는 것으로 생각한다.

흑마늘의 첨가량과 초기 알코올 농도를 달리한 발효 식초의 품질특성

The quality characteristics of black garlic vinegar produced by acetic acid fermentation were analyzed over a 25 day period. Black garlic vinegar was produced using black garlic 3, 6, 9 and 12 folds with water, and initial alcohol concentrations of 6~12%. The pH values of the vinegar samples were in range of 3.85~4.46 after 25 days fermentation, and the sugar contents were highest after 9 days of fermentation (12.00~13.50 °Brix). The total polyphenol concents of vinegars were in the range of 20.65~52.04 mg/100 mL 25 days fermentation. Pyrogallol and vanillic acid were detected in the completely fermented vinegars, and their contents increased with black garlic content. Five organic acids (lactic acid, acetic acid, citric acid, succinic acid and propionic acid) were detected after 25 days of fermentation, with the total amount of organic acids being 5,327.34~6,307.64 mg/100 mL, and the total abetic acid contents beging the highest of the organic acids at 4208.90~5,570.29 mg/100 mL. After 25 days of fermentation, the total minerals contents were higher, and depending on the quantity of black garlic added. Of the minerals, the of potassium content was the highest (366.23~1,619.67 mg/L).

마늘 첨가 된장의 숙성 중 품질특성 변화

마늘을 0, 10, 20 및 30% 첨가하여 된장을 제조한 후 6주간 숙성시키면서 1주 간격으로 된장의 품질 관련인자의 변화를 분석하였다. 명도는 마늘 농도와는 상관없이 모든 시료가 숙성기간이 길어짐에 따라 그 값이 감소하였으며, 마늘 첨가 농도가 높아질수록 더 낮았다. 황색도는 숙성 후기에 그 값이 감소하였는데, 대조군보다 마늘 첨가된장에서 더 낮았다. 제조 직후와 비교하여 숙성 1주차에 pH는 크게 감소하고 산도는 증가하였으나 그 이후로는 불규칙한 증감을 보였으며, 마늘의 첨가 농도에 따른 통계적인 유의차도 없었다. 아미노태 질소는 숙성 5주차까지 지속적으로 증가하는 경향을 나타내었는데, 숙성 5주차와 6주에는 시료군간에 유의적인 차이가 없어 마늘의 첨가가 된장의 아미노태 질소 함량에 큰 영향을 미치지 않음을 확인할 수 있었다. 환원당 역시 숙성기간이 길어짐에 따라 그 함량 역시 증가하였는데, 제조 직후에 비하여 숙성 6주 뒤에는 모든 시료군에서 약 2.5배 증가하였다. 이소플라본 함량은 숙성시간의 경과와 더불어 감소하는 경향을 보였으며 숙성 초기에는 배당체 형태의 함량이 높았으나 후기로 갈수록 그 함량은 감소하고 비배당체 형태는 증가하는 경향이었다. Bacillus는 마늘의 첨가량에 따른 차이가 없었으나 효모수는 마늘의 첨가량이 높을수록 적었다. In this study, we investigated the quality characteristics of Korean soybean paste, Doenjang, fermented for 6 weeks at room temperature with the addition of 0, 10, 20 and 30% garlic. Samples were analyzed in one-week intervals. The lightness decreased in all samples as the fermentation period and garlic concentration increased. Yellow index decreased in weeks 5~6 compared with weeks 0-1, for which the values were lower for the garlic-added Doenjang than the control. The pH increased, greatly reducung the acidity in week 1 compared with week 0. Significant differences in the pH and acidity were not observed among the sample groups. Amino type nitrogen contents increased continuously up to weeks 5, displaying no significant differences among the sample groups at weeks 5 and 6. In addition, reduction in the sugar content increased depending on the fermentation period. It increased in all sample groups by about 2.5 times after 6 weeks compared with the initial levels. Isoflavone content was also reduced generally depending on the fermentation period. In the early fermentation periods, the aglycone contents were the higher than the glycosides, while the glycoside contents increased over the fermentation period. The presence of Bacillus was not significantly different among the garlic added groups, but yeast was lower in the Doenjang with high garlic content.

Towards the electrochemical quantification of the strength of garlic

A simple but sensitive technique has been demonstrated towards the electroanalytical quantification of the strength of garlic. This technique can also be used to quantify dialkyldisulfides. The cyclic voltammetry of bromide was found to be a sensitive electrochemical probe, electrogenerated bromine reacting with dialkyldisulfides to catalytically regenerate bromide, resulting in a significant increase in peak current. A linear response of current vs. concentration was observed between 0.1 and 15 mM dipropyldisulfide at edge plane pyrolytic graphite (EPPG) electrodes; a smaller range up to ca. 5 mM was available at screen printed carbon electrodes (SPCEs), with a detection limit (from 3σ) of 0.067 mM. The response of diallyldisulfide was found to be essentially identical. Shaking garlic puree in acetonitrile for 5 minutes, followed by dilution with water then recording the voltammetry at the cheap, disposable SPCE gave a linear trend in current with respect to the quantity of garlic present, corresponding to the diallyldisulfide extracted. This has potential applications in monitoring the garlic content of medicinal supplements, batch-to-batch variation and the stability of garlic during storage.

The effects of garlic preparations against human tumor cell proliferation.

Epidemiological studies in China provide reason to suspect that a rich garlic content in the diet might reduce the proliferation of tumors in humans. We conducted experiments on human tumor cell lines and determined the influence of a garlic powder preparation, a garlic extract (reported as 8-10% L(+)-alliin enriched), and a combination thereof, on cellular proliferation in cell cultures, employing the widely used indirect neutral red procedure. Garlic powder failed to inhibit the growth of human hepatoma HepG2 or human colorectal carcinoma Caco2 cells at concentrations of up to 1000 micrograms/ml. Garlic extract, in which the alliin content was highly enriched was also unable to inhibit the growth of these cells. However, when the garlic extract was supplemented with garlic powder (to 10% final concentration) there was a concentration-dependent clear inhibition of tumor cell growth (IC50 values of 330 micrograms/ml for HepG2 and 480 micrograms/ml for Caco-2 cells). The growth of the human lymphatic leukemia cell line CCRF CEM was significantly inhibited in a dose-dependent manner by both garlic powder and garlic extract at concentrations as low as 30 micrograms/ml. However, no potentiation of this effect occurred upon mixing of the two preparations. Our results suggest that the antiproliferative effects of garlic may be due to breakdown products of alliin, such as allicin or polysulfides, rather than alliin itself, since the addition of an alliinase system (garlic powder) to an alliin enriched preparation without alliinase (garlic extract) potentiated the effects observed with the two preparations alone.

Inhibition of 7,12-dimethylbenz[a]anthracene-induced mammary tumors and DNA adducts by garlic powder.

The present studies determined the influence of dietary supplements of garlic powder (0, 1, 2 or 4%) on 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors and on the in vivo occurrence of mammary DMBA-DNA adducts in rats. Diets were offered 2 weeks before and 2 weeks following DMBA treatment (25 mg/kg body wt). An additional group was fed the 2% garlic powder diet throughout the 20 week study. Although food intake and weight gain were not influenced, dietary garlic powder supplementation did significantly delay the onset of first tumors (P < 0.01) and did reduce the final mammary tumor incidence (P < 0.01). Consumption of garlic powder also significantly depressed the in vivo binding of DMBA to mammary cell DNA. Binding of both anti- and syn-dihydrodiol epoxides to DNA was depressed in rats fed supplemental garlic powder. The activity of glutathione S-transferase (GST) in mammary and liver tissue from rats fed 2% dietary garlic powder was higher than observed in tissues from rats fed the basal diet. No further increase in GST activity occurred when the dietary garlic content was increased from 2 to 4%. Final mammary tumor incidence was found to correlate positively with total DMBA-DNA binding and the quantities of individual DMBA-DNA adducts. The present studies demonstrate that garlic powder is effective in inhibiting DMBA-induced mammary tumors, possibly by reducing DMBA-DNA binding.

Beneficial Effect Associated with Use of Watery and Alcoholic Extract of Garlic as a Supplement in Hyperlipidemic Guinea Pigs

Background: Garlic is naturally occurring sulphur containing dietary agent belong to Allium family. Members of this family i.e. Garlic, Onions are found to have beneficial effect on atherosclerosis and ischemic heart diseases in both experimental animals and in human beings. Objective: To compare the potency of garlic as antihyperlipidemic and antiplatelet and antithrombotic between its watery and alcoholic extract for their effects. Methods: 25 guinea pigs were fed cholesterol (0.5g/kg body weight) for an initial period of 4 weeks. Cholesterol was then discontinued and the animals were divided into 3 groups. Group-I (n=7) was fed with stock diet and was taken as control. Group-II (n=9) was given 1ml of watery extract and Group-III (n=9) was fed with 1ml of alcoholic extract of garlic with normal diet daily for 4 weeks. The garlic content of both the extract was 2 gm/ml by wt/vol. Fasting blood samples were collected at the end 4 weeks and finally at the end of the study i.e.8 weeks for estimation of serum cholesterol, serum triglyceride, LDC-C, HDL-C, VLDL-C, atherogenic index and platelet adhesiveness index. Bleeding time and clotting time were also detected in all the 3 groups. Results: In the present study, the watery and alcoholic extract of garlic shows significant hypolipidemic activity as they reduced significantly serum cholesterol, serum triglyceride, LDC-C, VLDL-C and atheriogenic index in hyperlipidemic guinea pigs (p&lt;0.01) compared to control. The significant rise in HDL-C was observed in group II but not in group III animals. On comparison between two extracts, watery extract of garlic was more potent hypolipidemic agent, compared to alcoholic extract. Both extract significantly reduces platelet adhesiveness and bleeding time. But between two extract the watery extract was found more potent anti-thrombotic agent as it showed significant decrease in platelet adhesiveness (P&lt;0.01). BT was significantly increased in group II compared to group I and III. Conclusion: It can be concluded that watery extract of Allium Sativum is more potent hypolipidemic and antiplatelet, and anti-thrombotic agent. Key Words: Allium Sativum; Hyperlipidemia; platelet adhesiveness index; watery and alcoholic extracts. DOI: http://dx.doi.org/10.3329/jbsp.v6i1.8079 J Bangladesh Soc Physiol. 2011 June; 6(1): 22-26