Iranian Research Organization for Science and Technology (IROST) Innovative Food Technologies 2783-350X 3 1 2015 11 22 Study of Antioxidant and physicochemical properties of fermented beverage whey- pistachio by kefir starter Study of Antioxidant and physicochemical properties of fermented beverage whey- pistachio by kefir starter 69 84 231 10.22104/jift.2015.231 FA Zohreh Mohammadi Yeganeh Graduate M.Sc. Student, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran Faramarz Khodaiyan Associate Professor, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran S. Saeed Hosseini M.Sc. Student, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran Mohammad Safari Professor, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran Keramtollah Rezaee Professor, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran S. Mohammad Mousavi Professor, Department of Food Science and Engineering, College of Agriculture & Natural Resources, University of Tehran, Iran Journal Article 2015 08 23 The presence of unsaturated fatty acids and phenolic compounds in pistachio and pistachio products, including pistachio milk, are useful for health, especially for preventing cardiovascular disease. Fermentation with probiotic microorganisms present in kefir grain increases the functional properties of the products. Therefore, the purpose of this study was to evaluate the antioxidant (total phenol content, scavenging effect upon free radicals, reducing power), physicochemical (pH, kefiran concentration and viscosity) and microbial (lactic acid bacteria and yeast) properties a new fermented beverage of pistachio milk with kefir grains. For this purpose, whey was used instead of water in pistachio milk and the effect of different levels of whey lactose (2.5 and 5 % W/V), the pistachio (4 and 8 % W/V) and inoculum sizes of kefir grains (2, 5 and 8 % W/V ) was studied at 25°C for 48 hours. The results showed that the highest total phenol content (130.91 ± 1.29 mg GA/L), scavenging effect upon free radicals (EC₅₀ = 0.01 ± 0.03 <em>mL/1mL</em>), reducing power (0.80 ± 0.02), kefiran concentration (91.80 ± 2.67 µg glucose/L) and viscosity (2.20 ± 0.03 mPa.s) were obtained in the presence of 5%, 8%, and 8% w/v of lactose, pistachio and kefir grains, respectively. In addition, the lowest pH (3.20 ± 0.02) and the highest lactic acid bacteria and yeast count were observed under the mentioned conditions, too.  The presence of unsaturated fatty acids and phenolic compounds in pistachio and pistachio products, including pistachio milk, are useful for health, especially for preventing cardiovascular disease. Fermentation with probiotic microorganisms present in kefir grain increases the functional properties of the products. Therefore, the purpose of this study was to evaluate the antioxidant (total phenol content, scavenging effect upon free radicals, reducing power), physicochemical (pH, kefiran concentration and viscosity) and microbial (lactic acid bacteria and yeast) properties a new fermented beverage of pistachio milk with kefir grains. For this purpose, whey was used instead of water in pistachio milk and the effect of different levels of whey lactose (2.5 and 5 % W/V), the pistachio (4 and 8 % W/V) and inoculum sizes of kefir grains (2, 5 and 8 % W/V ) was studied at 25°C for 48 hours. The results showed that the highest total phenol content (130.91 ± 1.29 mg GA/L), scavenging effect upon free radicals (EC₅₀ = 0.01 ± 0.03 <em>mL/1mL</em>), reducing power (0.80 ± 0.02), kefiran concentration (91.80 ± 2.67 µg glucose/L) and viscosity (2.20 ± 0.03 mPa.s) were obtained in the presence of 5%, 8%, and 8% w/v of lactose, pistachio and kefir grains, respectively. In addition, the lowest pH (3.20 ± 0.02) and the highest lactic acid bacteria and yeast count were observed under the mentioned conditions, too.  https://jift.irost.ir/article_231_5259616c2d6ccbae1c5d544c640f07fc.pdf