The consumption of black garlic (BG) has been attributed to various biological functions with benefits to human health; such as antioxidant, anti-allergic, anti-diabetic, anti-inflammatory and anti-carcinogenic effects. BG is a product derived from the thermal process of fresh garlic, reducing its characteristic pungent odor and taste considerably due to the organosulfur compounds that fresh garlic has. Common processing to obtain BG is carried out under controlled conditions of high temperature (60 – 90°C) and relative humidity (55 – 90%) where the Maillard reaction is promoted. The necessary period to obtain a quality product can vary from 30 to 90 days, depending on the variety of bulb, size, content of fructans and reducing sugars. One of the alternatives to reduce the process time is applying ohmic heating (OH) as pre-treatment; this causes the hydrolysis of fructans, obtaining free fructose, a reducing sugar that is degraded during storage in conditions of 70°C/94% RH through the Maillard reaction, accelerating the formation of compounds responsible for the flavor and color of garlic black, compared to black garlic without pretreatment. The characteristic color of black garlic from bulbs treated with ohmic heating (OH-BG) was obtained in 12 days; while in untreated bulbs (CT-BG) 30 days were needed. The content of 5-hydroxymethyl-2-furaldehyde (HMF) was 3.6 times higher in OH-BG than in CT-BG. Polyphenol content and antioxidant capacity did not show statistical differences between CT-BG and OH-BG, but their levels were higher than a commercial sample. Both products (OH-BG and CT-BG) presented high °Brix values (36.8 and 31.6 °Bx, respectively) which are perceived as sweet taste, and also have a chewy consistency and pleasant aroma, achieving excellent sensory acceptance. These results highlight the potential of ohmic heating pretreatment in reducing the time to obtain good quality BG.
My name is Ma. Estela Vázquez-Barrios, I’m Chemicopharmacobiologist, I have a master’s degree in Food Science and Technology and a Ph in food sciences. I am a full-time category VII professor at the Faculty of Chemistry; and member of the research group “Emerging Technologies to promote Food Security” at the Autonomous University of Querétaro (UAQ). I am an active reviewer of scientific articles in the journal Horticulturae. I’m professor from 1999 – 2013 at ITESM and from 1998 to date at UAQ where she also conducted research in the Food Science and Technology Program at the Faculty of Chemistry from 2013 to date. The main line of work deals with the application of technologies for the use of horticultural products. I have trained human resources at the undergraduate level (8), postgraduate (3 master’s) and I participate and advise doctoral projects (6). The results of the investigations have been presented at national and international conferences and I am the author (5), co-author (15) of articles published in national and international journals. I have agreements with food companies for advice and development of new products based on agro-industrial waste, for its use (new uses), contributing to the reduction of post-harvest losses of fruits and vegetables to obtain value-added ingredients.
I have collaboration with the University of Almeria; with the Food Science Research Institute in Spain and with the Application of technologies for the processing of garlic bulbs (onion bulbs, black garlic).