Black Garlic Research Articles

Differences of Bio (Chemical) Characterization of Garlic and Black garlic on Antibacterial and Antioxidant Activities

Black garlic is a fermented garlic product that produces black color from the fermentation process at 80°C for 15 days. Interestingly, black garlic has pharmacological effects, but the properties possessed by black garlic are inseparable from the processes that occur during its manufacture which involve the heating process. This study aimed to examine the differences in biochemical characterization of garlic and black garlics that affect the antibacterial and antioxidant activity. Analysis of bio-(chemical) ingredients was conducted by mass spectroscopy method, whereas antibacterial behaviour was carried out against Streptococcus pneumoniae and Klebsiella pneumoniae using the Kirby-Bauer diffusion method. The antioxidant testing was done using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The results showed that black garlics had a different mass spectrum display on the mass/charge (m/z) ratio compared to garlic. The result showed that there was an elevation in the m/z ratio of 39.48, 104.74, 112.69, 175.79, 381.95 and 544.03. These was predicted to cause a change in color, texture and different taste in black garlics. The antibacterial activity of black garlic was not significantly different from garlic both against Streptococcus pneumoniae and Klebsiella pneumonia. Likewise with the DPPH antioxidant activity of black garlic is not significantly different from garlic. Overall, the results of this study indicate that the garlic fermentation process with a heating method at 80°C for 15 days can increase the m/z ratio of black garlics, change color, texture, and taste but do not significantly change the antibacterial activity or antioxidant activity.

Evaluation of Bioactive and Physicochemical Properties of White and Black Garlic (Allium sativum L.) from Conventional and Organic Cultivation

The aim of this study was to evaluate the bioactive and physicochemical properties of white and black garlic (Allium sativum L.) from conventional and organic cultivation. Both white conventional (G) and organic (EG) garlic were processed during 45 days heat treatment at 70 °C temperature and 80% relative humidity. In black garlic (BG) samples the content of soluble solids, total reducing sugars, total polyphenol as well as antioxidant activity significantly (p < 0.05) increased (by about 33.5%, 60.5%, 118.4%, 125.8%, respectively), while a pH significantly (p < 0.05) decreased (by about 41.1%) as compared to white garlic samples. The study showed significant differences between colour of white and black garlic, both in the L*a*b* and RGB colour space, especially in the case of the L* parameter, indicating that the colour of garlic changed from white to dark brown or black during the thermal processing. All organic garlic samples had improved bioactive ingredients and antioxidant activity compared to conventional garlic for both fresh (unprocessed) and heat-treated black garlic. The production of black garlic, especially organic (EBG), allows one to obtain a product with higher amount of bioactive compounds, which can be widely used in the design of health-promoting functional food.

Impact of Black Garlic on Biomarkers of Arterial Stiffness and Frontal QRS-T Angle on Hypertensive Animal Model

<p style="text-align: justify;"><strong>Background: </strong>Hypertension is a silent killer disease that continues to increase every year. Non-optimal treatment of hypertension may heighten the risk of dangerous cardiovascular problems. Black garlic (BG) has been known as an antihypertensive; however, its effect on biomarkers of arterial stiffness and QRS-T angle direction is still not yet understood. <strong>Objectives:</strong> This study to identify the role of BG as an antihypertensive agent on biomarkers of arterial stiffness and QRS-T angle direction. <strong>Materials and Methods:</strong> The study was conducted on 30 male Wistar rats, which were randomly grouped into six, consisting of groups 1 and 2 (receiving drug carrier), group 3 (receiving captopril at 2.5 mg/kg), groups 4, 5 and 6 (receiving BG suspension at doses of 50, 100 and 200 mg/kg, respectively). All groups, except group 1, were given a high-fat diet and 25% fructose in drinking water for 28 days. Test drugs were given from day 15 to day 28 (for 14 days). The parameters measured were blood pressure, nitric oxide (NO) level in the serum, pulse wave velocity (PWV), heart rate and the QRS-T angle direction.<strong> Results:</strong> the BG doses of 50, 100 and 200 mg/kg lowered blood pressure, increase NO serum level; ameliorate PWV and wide QRS-T angle (<em>p</em>&lt;0.05). <strong>Conclusion:</strong> BG has anti-hypertensive activity and its antihypertensive effect of BG through the improvement of arterial stiffness and QRS-T angle direction. <p style="text-align: justify;"><strong>Key words: </strong>Black Garlic, Hypertension, Nitric oxide, Arterial Stiffness, QRS-T angle.

Influence of Thermal Processing on the Bioactive, Antioxidant, and Physicochemical Properties of Conventional and Organic Agriculture Black Garlic (Allium sativum L.)

This study examines the effect of fermentation processes (70 °C temperature; 80% humidity; 45 days) on the content of bioactive compounds (total polyphenols, selected phenolic acids, and flavonoids), antioxidant activity and physicochemical properties of conventional and organic garlic (Allium sativum L.). Raw garlic from conventional cultivation (GR) showed significantly lower content of phenolic components and antioxidant activity compared to raw garlic from organic cultivation (GREcol) (by 22.8% and 25.1%, respectively). The fermentation processes of the garlic from both the conventional (BG) and organic (BGEcol) cultivation significantly increased the content of total polyphenols (more than two times), phenolic acids (more than 1.5 times) and flavonoids (1.5 and 1.3 times, respectively). The garlic fermentation process also significantly increased antioxidant potential: two times for BG and three times for BGEcol. The content of bioactive compounds (total polyphenols, phenolic acids, and flavonoids) was significantly (p &lt; 0.05) higher in organic black garlic (BGEcol) compared to conventional black garlic (BG). Heat treatment leading to changes in both the physicochemical, organoleptic and health-promoting properties allowed to obtain a new product gaining in sensory attractiveness and enabling a wide range of applications.

THE EFFECT OF HUMIDITY AND TEMPERATURE ON TOTAL POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF BLACK GARLIC PRODUCED FROM PEELED CLOVES OF GARLICS

Recently, using peeled cloves of garlics for produce black garlic has been investigated, but the effect of humidity and temperature on antioxidant activity and polyphenol content of black garlic produced from peeled cloves of garlic have not been studied yet. In this study, peeled cloves of garlics were fermented in a variety of temperatures (70oC, 75oC, 80oC, and 85oC), humidity (70%, 80%, and 90%), and aging time (6 days, 15 days, and 20 days), then total polyphenol contents and antioxidant activities of samples were analyzed. The data showed that humidity did not affect polyphenol contents and antioxidant capacities of final products but affected antioxidants formation rate instead. Furthermore, temperature has noticeable impact on polyphenol content and antioxidant capacity. At lower temperatures (70oC and 75oC), polyphenol contents and antioxidant activities were gradually increased during the fermentation. On the contrary, polyphenol contents and antioxidant activities of black garlics incubated at 80oC and 85oC rapidly increased at early stage, then they were stable or decrease during later stage. The optimal conditions (75oC, 90% relative humidity, and 15 days) to produce black garlic with high polyphenol concentration and antioxidant capacity is determined (8.07 ± 0.21 g GAE∙kg-1 DW and 82.21 ± 0.88%, respectively).

Comparative UHPLC-Q-Orbitrap HRMS-Based Metabolomics Unveils Biochemical Changes of Black Garlic during Aging Process.

Aged black garlic (BG) is a functional food in global markets; however, very few studies have ventured into comprehensive profiling of BG metabolomes during the aging process. Herein, we exploited UHPLC-Orbitrap HRMS for a comparative metabolomics analysis. During the heat treatment, organosulfur compounds such as allicin, diallyl disulfide, ajoene, S-allyl-l-cysteine (SAC), and γ-glutamyl-SAC were downregulated. Plenty of glycerophospholipids together with shikimate, aromatic amino acids, and vitamin B6 vitamers were significantly augmented; tryptophan was however consumed to generate downstream products manifested in nicotinate metabolism and aminobenzoate degradation. These secondary metabolites serve as signaling mediators or protectants against extreme thermal exposure. Besides, Heyns compounds and Amadori-rearrangement byproducts with potential mutagenic effects were concentrated. Together, our findings expand the known metabolome space of BG processing and better elucidate the reactivities of the key metabolites. We provide in-depth insights into the biochemical changes of BG that enable further functional or toxicological investigations of this popular food.

Impact of steaming pretreatment process on characteristics and antioxidant activities of black garlic (Allium sativum L.).

Impact of steaming pretreatment processes on physical properties, bioactive compounds and antioxidant activities, of black garlics (Allium sativum L.) was studied. Steaming pretreatment at different times (0, 4 and 6min) was conducted before incubating in 60°C-incubator at different incubation times (0, 9 and 18days). Different steaming pretreatment processes affected the color and hardness of black garlic differently, while total polyphenol content (TPC) and total flavonoid content (TFC) were also determined by the steaming pretreatment time used. TPC and TFC increased with increasing of incubating time, where the highest those bioactive compounds was observed from 18-day incubation, especially with 4min of steaming pretreatment (p ≤ 0.05). Increase of those bioactive compounds was in accordance with increasing of DPPH radical scavenging activity (DPPH) and ferric reducing antioxidant power (FRAP) of black garlic during incubation. In addition, black garlic obtained from 18-day incubation with steaming pretreated for 4min revealed the optimum condition providing the black garlic with high in both DPPH and FRAP, compared with others (p ≤ 0.05). Therefore, steaming pretreatment could effectively improve the efficiency of black garlic production process by increase the generation rate of bioactive compounds as well as induce antioxidant properties of black garlic with shorten process time.

Genomic relationship and physiochemical properties among raw materials used for Thai black garlic processing.

Raw materials used for black garlic (BG) processing were collected from the major garlic production areas in Northern Thailand. Five of those were identified as of Thai origin (accession G1–G5), and accession G6 was of the Chinese variety. They were initially analyzed for varietal differences using morphological characteristics and genetic variation. Fresh materials from each accession were dried to the same moisture content (55%–60%) and BG processed at 75°C, 90% relative humidity (RH) for 15 days. Thereafter, physiochemical and chemical profiles were analyzed and compared. The dendrogram from random amplified polymorphic DNA fingerprints grouped G2, G3, G4, and G5 as closely related while G1 and G6 were out‐groups. Prior to BG processing, the pH of fresh garlic was approximately 6.3 and decreased to 3.7, thereafter. The contents of chemical properties were independent with genotypes. BG processing improved phenolic, flavonoid, and antioxidant but the content of thiosulfinate was minimized in all BG samples. Overall, result indicated that garlics grown in Northern Thailand were genotypically variable. BG processing altered physical and chemical appearance, and these changes were independent with the genotypes.

Effects of the Fermented Black Garlic Extract on Lipid Metabolism and Hepatoprotection in Mice

Effects of the Fermented Black Garlic Extract on Lipid Metabolism and Hepatoprotection in Mice

The Antioxidant Properties of Black Garlic Aqueous Extract in Vero Cell Line

Oxidative stress has been defined as harmful because oxygen free radical attack biological molecules such as lipids, proteins and DNA. Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. Black garlic (BG) is one of the natural resources that has been reported to have antioxidant properties. The aims of this research was to study the potential and effect of BG as antioxidant in LPS induced Vero cells. The methods of this research were used the extraction of BG by maceration method using aqueous solvents, antioxidant activity tested using DPPH assay, cytotoxicity test with WST-1 assay on 96-well plate, and NO level measurement using Griess reagent, after cells induced with LPS. The result showed that in DPPH assays BG showed ability for scavenging free radical activities. The BG aqueous extract did not show cytotoxicity on Vero cells until the concentration of 750µg/ml and NO levels decreased in cells treated with a concentration of 50 µg/mL after LPS induction. This study concluded that the administration of aqueous extract of Black Garlic has the potential as an antioxidant.

Characteristics of Solo Black Garlic Fermented in Kombucha Black Tea

A research has done on the characteristics of solo black garlic fermented by kombucha black tea. Fermentation is carried out for 0, 7, 14 and 21 days and continued to aging process for 0, 7, 14 and 21 days. Observation was done to see the characteristics of functional traits such as antioxidant capacity, total flavonoids and total polyphenols amount. There was a significant interaction (p<0, 05) between the fermentation period and the aging period in the functional properties of a solo black garlic. The study resulted in 68, 34 % of functional values characteristic of antioxidants capacity, 49, 94 mg QE flavonoids total and 185.97 mg GAE/g of polyphenols total. Increased bioactivity resulting from fermented solo black garlic using kombucha tea for 7 days and continued by aging process for 21 days.

Formation, nutritional value, and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans.

Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up-to-date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5-hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste-active and/or biological-active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti-inflammatory, immunostimulatory, anti-allergic, hepatoprotective, cardioprotective and oxidative stress-/hangover syndrome-reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.

Black Garlic: What Do We Need to Know About It?

Black Garlic: What Do We Need to Know About It?

The investigation of the effect of freezing pretreatment on properties of black garlic produced from Kastamonu garlic

Black garlic is obtained by fermentation of fresh garlic in condition under controlled high humidity and temperature.The aim of this study is to investigate the effect of freezing as pre-treatment process on black garlic produced from fresh Kastamonu garlics in terms of various antioxidant activity parameters, phenolic and flavanoid contents, fermentation time and HMF formation. The antioxidant properties analysis results of frozen and non-frozen black garlic samples were shown that higher than those of white garlic and it was observed that total antioxidant capacity, the total phenolic compound and total flavanaoid content values of black garlics increase with the storage period under fermentation conditions. In addition, frozen garlics were found to have higher total antioxidant activities on the 25th and 30th days (9.56 mg AE/g and 10.40 mg AE/g, respectively) of the fermentation than the activities of non-frozen garlics the on the 35th day (8.49 mg AE/g) of fermentation. The toxic compound HMF formation was found of the frozen sample at as high as 110 mg/kg in end of the 35th day. In conclusion, the use of pre-frozen garlics in black garlic production will be more efficient in respect of antioxidant properties and time and cost saving.

Metabolomics for Biomarker Discovery in Fermented Black Garlic and Potential Bioprotective Responses against Cardiovascular Diseases

Fermented black garlic has multiple beneficial biological activities, including cardiovascular protection, anticancer, hepatoprotective, and antibacterial properties. In this study, metabolic differences in the properties of black and fresh garlic were investigated via liquid chromatography quadrupole/time-of-flight-based metabolomics, leading to the identification of characteristic components. Fermented black garlic samples and their Amadori products (AC) promoted angiogenesis, prevented thrombus formation by rescuing chemical-induced vascular lesions in zebrafish, and inhibited H2O2-induced injury of endothelial cells, thus reducing the risk of cardiovascular disease. AC suppressed activation of the mitogen-activated protein kinase pathway through inhibition of p38 and ERK1/2 phosphorylation, in turn, increasing the availability of c-Fos/c-Jun or c-Jun/c-Jun complexes for apoptotic resistance. Clarification of the associated signaling pathways should therefore provide a solid foundation for optimization of black garlic-based therapies.

Lactobacillus bulgaricus improves antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus: a randomized control trial.

Objectives: Lactobacillus bulgaricus may improve antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus (GDM).Methods: Black garlic was prepared with or without L. bulgaricus. Volatile and polysaccharides were analyzed by using LC-MS, Fourier Transform infrared (FTIR) and 13C nuclear magnetic resonance (NMR). The study design was parallel randomized controlled trial and 226 GDM patients were randomly assigned into BG (black garlic and L. bulgaricus) and CG (black garlic) groups, and allocation ratio was 1:1. The treatment duration was 40 weeks. Fasting blood glucose (FBG) and 1- and 2-h blood glucose (1hBG and 2hBG) after oral glucose tolerance test (OGTT) were detected. Antioxidant function of black garlic was determined by measuring plasma malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC) in GDM patients. The comparison between two groups was made using two independent samples t test.Results: The intake of nutrients was similar between two groups (P>0.05). L. bulgaricus promoted the transformation of the glucopyranoside to glucofuranoside. L. bulgaricus increased the abilities of black garlic for scavenging hydroxyl radicals, 2,2′-azino-bis (3-ethylbenzenthiazoline-6-sulfonic) acid (ABTS) and DPPH free radicals. L. bulgaricus reduced the levels of FBG, 1hBG and 2hBG, and incidence of perinatal complications (P<0.01). Plasma MDA level in the BG group was lower than in the CG group, whereas the levels of SOD, GSH-PX and T-AOC in the BG group were higher than in the CG group (P<0.01).Conclusions: L. bulgaricus improves antioxidant capacity of black garlic in the prevention of GDM.

Antioxidant Activities, Phenolic Contents and Electronic Nose Analysis of Black Garlic

Black garlic is a processed garlic product with a moisture-controlled high temperature heat treatment for a long time. In order to determine the secondary metabolites of black garlics treated in the study, firstly, in vitro antioxidant activities of black garlics purchased from Edovital company, Kastamonu, Turkey were determined, followed by qualitative and quantitative measurement of the phenolic compound content by HPLC and finally the electronic nose analysis of the content of nebulizer vapors in wood vinegar extract of black garlics were done successfully. Chlorogenic acid, vanillic acid, benzoic acid, gallic acid contents in detected 13 phenolic acids were quitely high. All quantitative results were expressed as mg gallic acid equivalent (GAE) per g dry matter of black garlic sample. ABTS and DPPH antioxidant activities were very low according to BHT standart and 2-Methylene-4-pentenal (18%) and Furfural (25%) were detected in high amount with electronic nose in nebulvapor contents of black garlic wood vinegar extract.

Protective effect of S-allyl cysteine-enriched black garlic on reflux esophagitis in rats via NF-κB signaling pathway

Abstract The present study was conducted to determine whether black garlic (BG) which is aged by pectinase treatment with high hydrostatic pressure processing has the protective effects in experimental model of acute reflux esophagitis (RE). BG was orally administered at a dose of 100 mg/kg body weight 2 h prior to induction of RE, and the effects were compared with those of raw garlic (RG). Esophageal pathological changes were analyzed using gross and histological examinations. The anti-oxidant and inflammatory protein levels were determined using western blotting. Moreover, RE-induced histological change was markedly suppressed by BG rather than RG. The reduced catalase was increased significantly by BG supplementation; however, superoxide dismutase levels showed a tendency to increase in the esophagus. Overall, the ameliorative effects of BG were superior to those when RG. These data reveal that that BG treatment ameliorates the development of esophagitis via regulation of NF-κB mediated inflammation.

Extracts from Fermented Black Garlic Exhibit a Hepatoprotective Effect on Acute Hepatic Injury.

The mechanism of hepatoprotective compounds is usually related to its antioxidant or anti-inflammatory effects. Black garlic is produced from garlic by heat treatment and its anti-inflammatory activity has been previously reported. Therefore, the aim of this study was to investigate the hepatoprotective effect of five different extracts of black garlic against carbon tetrachloride (CCl4)-induced acute hepatic injury (AHI). In this study, mice in the control, CCl4, silymarin, and black garlic groups were orally administered distilled water, silymarin, and different fraction extracts of black garlic, respectively, after CCl4 was injected intraperitoneally to induce AHI. The results revealed that the n-butanol layer extract (BA) and water layer extract (WS) demonstrated a hepatoprotective effect by reducing the levels of alanine aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and hepatic malondialdehyde (MDA). Furthermore, the BA and WS fractions of black garlic extract increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd), tumor necrosis factor alpha (TNF-α), and the interleukin-1 (IL-1β) level in liver. It was concluded that black garlic exhibited significant protective effects on CCl4-induced acute hepatic injury.

Fermented Garlic Extract Increases Oxygen Consumption and UCP-1 mRNA Expression in Human Adipose-Derived Stem Cells.

Fermented garlic, often called black garlic, is a traditional food ingredient used in Asian cuisine and possesses various health benefits including anti-obesity activity. The anti-obesity effects of fermented garlic might, in part, might be mediated through direct actions of its components on adipocytes. To test this hypothesis, we examined whether fermented garlic extract might stimulate the metabolic activity of human adipose-derived stem cells (ADSCs) in culture. Cell viability measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay exhibited a complex dose- response relationship. The lowest concentration (0.4 mg/ml) reduced cell viability (P<0.05 compared to no extract, Bonferroni’s multiple comparison), whereas higher concentrations (0.8 and 1.0 mg/ml) resulted in higher cell viability (P<0.05 as compared to 0.4 mg/ml). However, the extract at concentrations >2 mg/ml markedly decreased cell viability. Higher cell viability observed following treatment with 0.8~1.0 mg/ml might be associated with raised oxygen consumption. Fluorescent dye-based measurement revealed that the garlic extract at 1.0 mg/ml significantly increased oxygen consumption. We also detected a significant increase in mRNA expression levels of uncoupling protein-1 (UCP- 1). These findings suggest that fermented garlic stimulates the basal metabolic activity of human ADSCs.