Kinetics of bioactive compounds in aged Brazilian garlic

Garlic has been widely used in cooking for centuries, because of its unique flavor and pungent odor. It has been found to be high in fiber, minerals and amino acids, but its composition depends on cultivar, growing conditions and bulb maturity. This work aimed to study the differences of bioactive compounds produced in black garlic (BG) from Brazilian cultivars (LSQUOSanta CatarinaRSQUO, LSQUOAmaranteRSQUO, LSQUOGigante RoxoRSQUO). Aged black garlic was produced by a drying process at 70-80°C during 40 days. The sample extracts were prepared by grinding 0.5 g of bulb samples in a mortar and pestle with 20 mL of water at 25°C. After 5 min, samples were centrifuged at 7,000 ×g and the supernatant was used to determine the total soluble solids content (SSC), pH, titratable acidity (TA) and total phenolic compounds (Folin-Ciocalteu), according to AOAC methods. The effect of process conditions (temperature and humidity) was also investigated. All cultivars of aged garlic had the contents of SSC, TA and total phenolic compounds enhanced. In all cultivars the pH decreased: LSQUOAmaranteRSQUO (from 6.3 to 4.5), LSQUOGigante RoxoRSQUO (from 6.5 to 5.5) and LSQUOSanta CatarinaRSQUO (from 6.4 to 3.9). LSQUOSanta CatarinaRSQUO presented the best characteristics for black garlic production, based on the consumer acceptance (data not shown). This cultivar also had the highest level of phenolic compounds, 602 mg GAE 100 g^-1 after 30 days of processing. The lower relative humidity of BG moisture content during its processing, the lesser was the concentration of phenolic contents.