Ohmic heating pretreatment accelerates black garlic processing

Black garlic (BG) is obtained by the Maillard reaction under controlled conditions of temperature and humidity. This study describes the traditional processing (TT-BG) and the use of ohmic heating (OH) as pre-treatment (OH-BG) to improve time processing. Physicochemical composition and sensory properties were of particular interest in this study. The OH as a pretreatment causes the hydrolysis of fructans to fructose, which are degraded during storage under traditional treatment conditions (70 °C/94% RH) through the Maillard reaction causing the faster formation of compounds responsible for the color of black garlic compared to black garlic without pre-treatment. This reaction cuts down the time to attain the characteristic color of black garlic from 30 to 12 days. The 5-hydroxymethyl-2-furaldehyde (HMF) content was 3.6 times higher in OH-BG than in TT-BG. The polyphenol content and antioxidant capacity did not show differences between TT-BG and OH-BG, but their levels were superior to commercial sample. Both products (OH-BG and TT-BG) were sweet (36.8 and 31.6 °Bx, respectively) and had an excellent organoleptic acceptance (75 and 70%). These results highlight the potential of ohmic heating pretreatment in reducing the time to obtain good quality BG.