effects of pre-germination treatment on the phytate and phenolic contents of almond nuts

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.