Investigation of gluten-free lentil biscuit production by applying different pre-processes

The aim of this study was to reduce the amount of phytic acid by applying different soaking processes to green lentil flour and to increase the effect of the chemical, physical and sensory properties of biscuits by using them in the production of gluten-free biscuits. Green lentil flour was treated with ultrasound soaking and soaking in whey powder (PAST) diluted in a ratio of 1:19. With in the scope of the study, 3 different temperatures (50, 60 and 70 °C) and 2 different durations (2 and 4 hours) were applied by keeping 35 KHz and 80% amplitude constant in ultrasound wetting, 3 different temperatures (25, 40 and 50 °C) and 4 different durations (2, 4, 8 and 12 hours) were applied in wetting with PAST. Initially, the phytic acid value of green lentil flour was found to be 1460.74 mg/100 g dry matter. After soaking processes in an ultrasonic water bath of green lentil flour, phytic acid values varied in the range of 913.40-589.37 mg/100 g dry matter, and after soaking pretreatment with PAST, phytic acid values varied in the range of 1437.79-717.92 mg/100 g dry matter. It has been found that the pre-treatment of soaking with PAST is more effective than soaking with pure water. With a 59.6% reduction in the amount of phytic acid in green lentil flour, the most effective method was achieved by soaking for 4 hours at 70 °C at an amplitude of 35 Khz 80% in an ultrasonic water bath. With a 64% reduction in the amount of phytic acid in green lentil flour, the most effective method was achieved by soaking for 4 hours at 70 °C at an amplitude of 35 Khz 80% in an ultrasonic water bath. 3 different gluten-free biscuits were produced from green lentil flour with reduced amount of phytic acid. In gluten-free biscuit samples, moisture, ash and fat values were close to birvir (p>0.05), while the biscuit sample prepared by soaking with PAST was the sample with the highest protein value (p<0.05). The antioxidant activity values of the biscuit samples ranged from 84.16 to 103.77 μmol TE/100 g dry matter, total phenolic substance amounts ranged from 140.88 to 193.21 mg GAE / 100 g dry matter and phytic acid amounts from 368.79 to 634.03 mg / 100 g dry matter range. It was determined that the biscuits were close to each other in terms of L*, a*, b* and hardness values. In sensory evaluation, all biscuit samples scored between good and very good on the hedonic scale and it was found that there was no difference between them in terms of statistics (p>0.05).