Kinetics of allicin potential loss in garlic slices during convective drying

Abstract

Allicin is an organosulfur compound formed in garlics, and it is slightly yellow in colour and gives unique odour to garlic. Allicin has been known to have an antioxidant and antimicrobial activity, and it can react with thiol groups containing proteins. Allicin potential (AP) in Taskopru garlic slices and its loss were monitored during drying in a cabinet drier at three temperatures (50, 60 and 70 °C). Initial AP of fresh garlic samples was 10.91±0.15 mg/g on the basis of dry matter (dm), and it reduced significantly during drying (P < 0.05). APs of garlic samples dried at 50, 60 and 70 °C for up to 480 minutes were 5.35±0.029, 4.32±0.13 and 3.95±0.26 mg/g dm, respectively (P < 0.05). Loss of AP values determined during drying followed a second-order reaction. Drying temperature had a significant influence on the loss of AP in garlic slices. Activation energy for AP loss was 25.48 kJ/mol. Q10 value was 4.18 for the drying temperature increase from 50 to 60 °C, and it reduced to 3.07 for the temperature increase from 60 to 70 °C. Therefore, the effect of the first temperature rise on AP loss was bigger than the second temperature rise. © 2019 Wageningen Academic Publishers.