Antioxidant and Health Properties of Black Garlic During Processing
Black garlic's antioxidant and health-promoting properties are not lost during fermentation and drying to powder; in fact, these processes typically enhance these beneficial properties compared to fresh garlic.
Transformation of Garlic During Processing
Black garlic is produced through aging fresh garlic under controlled temperature (60-90°C) and humidity (70-90%) conditions, primarily through the Maillard reaction and fermentation processes 1. This transformation creates significant changes in the bioactive compound profile:
- The fermentation process increases water-soluble antioxidant compounds including S-allyl cysteine and S-allyl-mercapto cysteine 1
- Thermal processing enhances the development of 5-hydroxymethylfurfural, organosulfur compounds, polyphenols, and other Maillard reaction products 1
- Black garlic typically shows higher antioxidant capacity than fresh garlic due to these transformations 2
Effects of Different Processing Methods
Different processing techniques affect the final antioxidant properties of black garlic:
Drying Methods
- Vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying produce black garlic with the highest phenolic content (1123.54 and 1125.36 mg/100g dry matter, respectively) 3
- These methods also yield the highest antioxidant capacity as measured by ABTS (6.05 and 5.06 mmol Trolox/100g dry matter) 3
Non-thermal Pretreatments
- Application of pulsed electric field (PEF), constant electric field (CEF), and magnetic field (MF) significantly reduce drying time while maintaining high antidiabetic potential 3
- Constant electric field pretreatment shows particularly good results for preserving antidiabetic properties (IC50 = 99 and 56 mg/mL for α-amylase and α-glucosidase inhibition) 3
Heat Processing vs. Freeze Drying
- Heat-dried garlic (especially when subsequently fermented) contains approximately three times more S-Allylcysteine (SAC) than freeze-dried garlic 4
- Heat-dried garlic fermented with Lactobacillus plantarum KCTC21004 shows the highest flavonoid content, phenolic compounds, antioxidant activity, and immune-stimulating effects 4
Synergistic Effects of Compounds
The holistic view of food compounds is important when considering black garlic's health benefits:
- Combinations of antioxidant compounds often demonstrate synergistic effects, where the combined activity exceeds the sum of individual components 5
- The complex food matrix of black garlic includes interactions between compounds that may enhance overall bioactivity 5
- Whole food extracts typically show higher antioxidant and antiproliferative activities than isolated compounds 5
Health Benefits of Black Garlic
Research demonstrates that black garlic offers numerous health benefits:
- Anti-oxidation and anti-inflammation properties 1
- Anti-obesity effects 1
- Hepatoprotective and hypolipidemic actions 1
- Anti-cancer and anti-allergy properties 1
- Immunomodulation capabilities 1
- Cardiovascular and neuroprotection 1
Practical Considerations
When selecting black garlic products:
- Choose products that specify their processing methods, as this significantly impacts the final antioxidant content
- Consider that properly processed black garlic powder can retain or even enhance the beneficial properties of fresh garlic
- Be aware that the physical structure and compound interactions in whole black garlic may provide different benefits than isolated compounds or supplements 5
In conclusion, the fermentation and drying processes used to create black garlic powder typically enhance rather than diminish its antioxidant and health-promoting properties, with the specific processing methods significantly influencing the final beneficial properties.