Variations in level of oil, protein, and some antioxidants in chickpea and peanut seeds

Background Chickpea and peanut are two legume species not frequently used in human diets. Chickpea is rich in starch and proteins, while peanut is mainly a source of oils and proteins and they could be successfully used as protein sources in vegetarian diets. Seeds of 19 chickpea and 13 peanut landraces were colorimetrically analyzed in respect to antioxidant content (i.e., free soluble phenolics, total glutathione, and phytate). Oil and protein contents in grain were also determined. Results Free soluble phenolics content varied in range from 520 to1,050 mg kg −1 in peanut and from 720 to 1,370 mg kg −1 in chickpea. Total glutathione content ranged from 1,495 to 2,365 mmol kg −1 in peanut and from 955 to 1,232 mmol kg −1 in chickpea. Relatively low content of phytic phosphorus was found in grain of both species, ranging from 2.5 to 4.5 g kg −1 in peanut and from 1.4 to 3.0 g kg −1 in chickpea, respectively. Considering the lack of data for phytate variability in Macedonian chickpea and peanut local landraces up to date, the observed high variation in phytic phosphorus content could represent the great basis for further breeding programs for phytate decrease in seeds of those genotypes. This is significant, since phytate is an important antinutrient which affects availability of mineral elements. Regression analysis revealed positive and highly significant interdependence between oil content and total glutathione in chickpea seeds, as well as between oil content and phytic phosphorus in peanut seeds. In chickpea, significant and negative correlation between oil and phytic phosphorus content was also observed. Conclusions Results obtained indicated that chickpea genotypes with higher oil content could have increased nutritional value due to higher glutathione and lower phytate content observed. However, lower level of phytate content, along with higher level of soluble phenolics and total glutathione found in peanut seeds with lower oil content, indicated higher digestibility and increased antioxidant activity of those genotypes.