title: Physicochemical and antioxidant properties of black garlic.
abstract: Black garlic (BG) is a processed garlic product prepared by heat treatment of whole garlic bulbs (Allium sativum L.) at high temperature under high humidity for several days, resulting in black cloves with a sweet taste. BG has recently been introduced to the Korean market as a product beneficial to health. To clarify how BG changes during the 35 day aging period, the physicochemical characteristics, antioxidant contents, and antioxidant activities were evaluated under controlled conditions of 70 °C and 90% relative humidity. Reducing sugar and total acidity of BG increased during the aging period, whereas pH decreased from pH 6.33 to 3.74. Lightness and yellowness values of BG radically decreased during the aging period, whereas redness values increased significantly. Antioxidant components, including the total polyphenol and total flavonoids contents of BG, increased significantly until the 21st day of aging (p < 0.05) and correspondingly, the antioxidant activities of BG, measured by DPPH, ABTS, FRAP, and reducing power assays, were highest on the 21st day of aging. These results indicate that BG can be considered to not only possess antioxidant properties during the aging period, but also to reach its optimal antioxidant properties at the 21st day of aging.
authors.affiliation: Department of Food and Nutrition, Kyung Hee University, 1 Hoeki-dong, Dongdaemun-Ku, Seoul 130-701, Korea. choiis02@khu.ac.kr.
authors.forename: Il Sook
authors.initials: IS
authors.lastname: Choi
authors.affiliation: Department of Food and Nutrition, Kyung Hee University, 1 Hoeki-dong, Dongdaemun-Ku, Seoul 130-701, Korea. abcing02@gmail.com.
authors.forename: Han Sam
authors.initials: HS
authors.lastname: Cha
authors.affiliation: Department of Food and Nutrition, Kyung Hee University, 1 Hoeki-dong, Dongdaemun-Ku, Seoul 130-701, Korea. yysllee@hanmail.net.
authors.forename: Young Soon
authors.initials: YS
authors.lastname: Lee
mesh_terms: D000375:Aging; D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D052160:Benzothiazoles / Q000032:analysis / Q000737:chemistry; D001713:Biphenyl Compounds / Q000032:analysis / Q000737:chemistry; D055598:Chemical Phenomena; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D005737:Garlic / Q000737:chemistry*; D006358:Hot Temperature; D006813:Humidity; D010851:Picrates / Q000032:analysis / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry; D059808:Polyphenols / Q000032:analysis* / Q000737:chemistry; D013451:Sulfonic Acids / Q000032:analysis / Q000737:chemistry
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D005419:Flavonoids; D010851:Picrates; D010936:Plant Extracts; D059808:Polyphenols; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl