ISHS Acta Horticulturae 1194: VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits - Ethical and Technological Issues
Effect of convective drying pretreatment on the physicochemical properties of black garlic |
| Authors: | K.L. Ríos-Ríos, M. Gaytán-Martínez, E. Mercado-Silva, D.M. Rivera-Pastrana, S. Moreno-Mayorga, M.E. Vázquez-Barrios |
| Keywords: | black garlic, processing time, quality |
| DOI: | 10.17660/ActaHortic.2018.1194.119 |
| Abstract:
Black garlic is produced commercially using traditional processes with high temperature (HT) and high relative humidity (HRH) during 30-60 days until the cloves turn black with a sweet and syrupy taste. The aim of this study was to reduce black garlic production time applying a convective drying pretreatment (CDP). Purple garlic bulbs (Allium sativum L.) sets were subjected to CDP process for 4 days at HT (70°C) and low RH (9%) followed by 4 days at HT (70°C) and HRH conditions (94%). Browning degree, water activity (aw), moisture, pH, total soluble solids (TSS), total phenols content, 5-hydroxymethyl-2-furaldehyde (HMF) levels, reducing sugar content (RSC) and pungency analyses of blacked garlic were performed. Black garlic production time was reduced to 8 days (4 days at CDP conditions, 70°C - 9% RH and 4 days at traditional processing conditions, 70°C - 94% RH). No differences in external (ΔE=62) and internal (ΔE=12) browning degree were observed (p>0.05) between CDP processed and commercial black garlic (control group). Pungency values were 6 times higher in black garlic from CDP (12.87 µmol pyruvic acid g-1) when compared to control group (2.16 µmol pyruvic acid g-1). This observation is consistent with the lower RSC (13.69 mg fructose g-1) in black garlic from CDP. In comparison to control group, moisture, total phenols content and HMF levels decreased in the CDP group, whereas TSS increased. There were no differences (p>0.05) in pH or aw. The results suggest that it is possible to reduce black garlic production time using convective drying. | |
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