Investigation of colour and antioxidant properties of sourdough bread with different proportions of red beet added

In this study, it is aimed to prepare a functional product by using red beet (Beta vulgaris L.) in sourdough bread, which is understood to be important for human health and its consumption has become widespread. Within the scope of the research, beet powders dried and ground by microwave, drying cabinet and hot air drying methods were added to the sourdough dough at the rates of 0%, 4%, 8% and 12%. The pH values, dry matter and ash amounts of the samples were determined. The antioxidant activity; Cu2+-Cu+ reducing capacity, Fe3+-Fe2+ reducing capacity, 1,1-diphenyl-2-picryl-hydrazil free radical (DPPH·) scavenging activity, 2,2´-azino-bis(3 ethylbenzthioazoline-6- sulphonic acid) radical (ABTS∙+) scavenging activity, was determined by the methods of total phenolic compound amount total flavonoid compound and total betalain amount determination methods. BHA, BHT, α-tocopherol and trolox were used as reference antioxidants and compared. To determine the color changes, Hunter L*, a*, b* values were measured and Hue, Chroma and Browning Index parameters were calculated. ABTS inhibition was highest in samples with 12% beet powder added. Total flavonoid content was found to be 24.74 µg KE/mg higher in beet powder samples obtained by microwave drying method. The highest betalain content was observed in the microwave dried samples at 75.41 mg/kg. The highest a* , b*, chroma and browning index values were observed in breads with added beet powder dried by microwave technique. It was observed that the addition of beet powder increased the ABTS radical scavenging activity and the total flavonoid content.