Abstract:

Tarhana soup is a traditional food in Türkiye with high nutritional value. Tarhana is prepared using tomato, green pepper, onion, yogurt and wheat flour; boiling, fermentation and drying are the main steps. Buckwheat is a major ingredient in the daily diet of celiac patients. Water kefir has a great potential as a probiotic product for vegans. The aim of the study was to produce tarhana with improved functional properties. The addition of pumpkin, buckwheat flour, and water kefir fermentation was used to improve the functional properties. The conventional method and lyophilization techniques were used for drying and the properties of tarhana samples were determined. After fermentation of tarhana dough, it was dried using conventional drying (CDT) at 30°C for 48 h and lyophilized (LDT) at -55°C for 24 h. Tarhana samples were packaged in 100 µm low-density polyethylene bags and stored at 4°C. Microbiological analysis (Lactobacillus spp., Lactococcus spp. and yeasts), chemical properties (pH, total solids %, ash %), total phenolic substances, total antioxidant activity (DPPH and TEAC), color and sensory evaluation were carried out during shelf life. CDT samples contained 6.80 log CFU/g Lactobacillus spp.; 6.40 log CFU/g Lactococcus spp.; and 5.30 log CFU/g yeasts. LDT samples contained 7.10 log CFU/g Lactobacillus spp.; 7.0 log CFU/g Lactococcus spp.; and 5.20 log CFU/g yeasts. Water kefir microbiota was able to grow in tarhana dough. Total phenolic contents of CDT and LDT samples were 59.1±7 and 55.5±13.2 mg/L, respectively. TEAC values of CDT and LDT samples were determined as 38.2±17.5 and 36.9±13.2 mM, respectively. DPPH values of CDT and LDT samples were found as 3.90±0.78 and 12.30±2.09 mM, respectively. Pumpkin addition improved the total antioxidant capacity of tarhana samples. LDT samples had the higher scores for sensory properties

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