Physicochemical character of fresh and black garlic: 12-day thermal aged process

Abstract

Garlic has long been known possessing many benefits for health and used as a pivotal spice for daily meals in many countries. Recent studies showed that black garlic has many advantages such as no strong odor and still remaining bioactivities of fresh ones, even better. Commercial black garlic products in Vietnam have not showed the physicochemical analysis as well as the original source. This study concentrated on Allium sativum L. garlic bulds collected at Ninh Thuan province, an area of which garlic is one of main agricultural products. The essential oil of the fresh garlic was analyzed by GC-MS. From the fresh garlic bulds, two compounds, uracil (1) and butyl 4-hydroxybenzoate (2) were isolated and structurally determined. Fresh garlic bulds were then prepared to black garlic. The physicochemical analysis methods showed that the S-allyl cysteine, reducing sugar, total polyphenol and total protein content of 12-day black garlic were much higher than those of fresh one. For instance, the S-allyl cysteine content in fresh garlic and black one were 53.2 and 663.6 μg/g, the reducing sugar were 9.73 and 36.51 g/100g, respectively.