Effect of fermentation on pasting and some nutritional properties of cornelian cherry tarhanas

Cornelian cherry (Cornus mas L.) tarhana (CCT), which is a non-fermented traditional product in Bolu and its province, is prepared by mixing cornelian cherry pulp, wheat flour and salt followed by drying in sunless environment. In this research, it was separately produced using wholegrain hull-less barley flour, clear flour and buckwheat flour instead of wheat flour with or without fermentation process. Then, soluble and insoluble dietary fibres, fructan (fructooligosaccharide), phytic acid and some mineral contents, pasting properties and protein profiles of CCTs were investigated after producing with/without fermentation process. Cornelian cherry tarhana produced with wheat flour was used as control. Soluble and insoluble dietary fibres, fructan and macro mineral contents of the CCTs significantly increased (P<0,05) when they were produced with wholegrain hull-less barley flour and clear flour in both processes. The insoluble dietary fibre and fructan contents of fermented CCTs increased on dry weight basis. The phytic acid contents of CCTs produced without or with fermentation process changed in the ranges of 0.64-6.10 mg/g and 0.58-5.68 mg/g, respectively. The fermentation process had positive effect in terms of decreasing of phytic acid contents of CCTs. The soup properties of CCT powders were studied in the rapid visco-analyzer (RVA). Peak viscosity, hot-paste viscosity and final viscosity values of fermented CCTs produced with wheat flour, buckwheat flour and clear flour were higher than that of the non-fermented ones (P<0,05). Fermented CCTs produced with clear flour and buckwheat flour had higher contents of Na, Mg, K, S and Ca macro minerals than that of the non-fermented ones. The fermented control sample had higher macro minerals, except for S mineral, than that of the non-fermented one. The contents of Na, Mg and S macro minerals of fermented CCT produced with clear flour significantly decreased when compared to the other CCTs (P<0,05). The contents of Fe heavy metal decreased in all fermented CCTs. Besides, the contents of Zn heavy metal in all fermented CCTs also reduced except for the CCT produced with buckwheat flour (P<0,05). The contents of Pb and Ti heavy metals were generally higher in fermented cornelian cherry tarhanas than that of the non-fermented ones. The SDS-PAGE profiles of non-fermented and fermented CCTs were generally similar in terms of their protein bands.