Effects of Pre-germination Treatment on the Phytate and Phenolic Contents of Almond Nuts

• Main Authors: Liang Lin Lin, Freda Xin You Giam, Xin Min Foo, Nadia Marie Hui Lian Yeo, Charlene Jia Ling Koh, Nur Hatika Binte Sa’Aban, Wai Mun Loke
• Format: Article
• Language: English
• Published: Islamic Azad University 2017-05-01
• Series: Journal of Nuts
• Subjects: Almond kernels; Phytic acid; Pre-germination; Total antioxidant capacity; Total phenolic content
• Online Access: http://ijnrs.damghaniau.ac.ir/article_530394_6eca0bf15a8d9f6ecdc4b638b98d4dd4.pdf

This study examined if pre-germination altered the water content and water activity, contents of phytate, total phenolic, (±)-catechin, quercetin and total antioxidant capacity of almond  (Prunus dulcis)kernel. Raw almond kernels were submerged for 15 hours in water, 0.02 mol dm-3 phosphate buffer solution (pH 5.0) and 0.02 mol dm-3 phosphate buffer solution (pH 7.0) at 25 and 40ºC, respectively. The content and activity of water in the kernels before and after the pre-germination treatments were measured by oven drying and dew point water analysis, respectively. The total phenolic and phytic acid contents of the kernels were quantified by using Folin-Ciocalteu and a published spectrophotometric assay, respectively. (±)-Catechin and quercetin contents in the almond kernels were determined using gas-chromatography mass spectrometry. The total antioxidant capacity of the kernels were measured by 2,2’-diphenyl-1- picrylhydrazyl assay. Treatment with water, PBS pH 5 and PBS pH 7 significantly increased the water, total phenolic, (±)-catechin contents and total antioxidant capacity of the almond kernels regardless of the treatment temperatures (25 or 40°C). The phytic acid and quercetin contents were significantly elevated after the  three treatments at 40°C. The total phenolic, (±)-catechin, quercetin and phytate contents in the almond kernels contributed significantly to its antioxidant property. Our results suggested that the phytochemical compositions of the almond kernels changed during pre-germination. The temperature and pH of the medium exert differential influence on the phytochemical compositions of the pre-germinated almond kernels.