Antioxidant Activity, Antinutritional Factors and Technological Studies on Raw and Germinated Barley Grains (Hordeum vulgare. L)

Abstract

This study was revealed for investigate the effect of germination on physical, chemical, mineral composition, vitamins content and nutritional characteristics of each variety of Egyptian barley grains (Hordeum vulgare L.) Giza128 (hull- less barley), and Giza134 (hulled barley) were obtained from Agricultural Research Center, Giza. Egypt. Raw barley grains were soaked in water for (12hr.), then germinated for 24, 48, 72 hr. In addition, sensory evaluation was carried out for Talbina prepared from raw barley and germinated (72hr.) barley flours for both varieties (Giza 128, Giza 134) was evaluated. The results showed that the mean weight and volume of the thousand grains were 50.73± 0.19 (g) and 85 ± 5 (ml). Also, the density was 0.60± 0.02 (g/ml) for Giza 128, while the mean weight and volume and density for Giza 134 were 52.72± 1.78 (g), 85 ± 5 (ml), 0.62 ± 0.02 (g/ml), respectively. Moreover, the highest moisture content for both Giza 128 and Giza 134 was noticed during the germination period for 72hr. (11.6% and 12.4%), respectively. Also, the crude protein content was decreased significantly due to soaking treatment, and there were no significant differences for the three germinated treatments compared to the raw sample for Giza128 variety. On the other hand, there were a significant differences between the germinated samples compared with raw and soaked samples. The ash content for soaked barley (12hr.) was decreased for the three germinated samples compared to the raw sample for both varieties. Also, there were significant differences between the five treatments for the mineral composition, there was a decrease in the content of the calcium, magnesium, iron, zinc and manganese in the germinated grains for 72hr. compared with raw grains for both varieties under study. Moreover, there was an increase in vitamin (A, D, Niacin and C) for both Giza 128,134 varieties in germinated grains (72 hr.) compared with the raw grains. Also, Giza 128 variety exhibited higher content of the minerals and vitamins in the raw and the germinated grains (72hr.) compared with Giza 134 variety. On the other hand, the nutritional compounds (total phenol, flavonoids, antioxidant activity (DPPH) and the antinutritional factors (phytic acid, tannic acid and oxalic acid) were decrease in the germinated barley. The decrease in the total phenols, flavonoids antantioxidants activity (DPPH) content in Giza 128 variety was more pronounced (20.3%, 44.4%, 12.8%) than that the in Giza 134 variety (7.5%, 11.1%, 9.8%), respectively. Also, sensory evaluation for Talbina prepared from raw and germinated (72hr.) barley flours for Giza 128 and 134 varieties was studied. The data revealed that, there were significant differences in case of the color, taste and the overall acceptability between the Talbina prepared from the raw barley flour for Giza 128 and Giza 134 variety, although there were no significant differences in case of the texture and odor for both varieties