2nd International Conference on Food Science and Bioprocess Technology
October 1-2, 2018 Frankfurt, Germany
Evaluation of Yeast and Lactic Acid Bacteria Starters for the Production of Rice Injera
1Hawassa University, School of Nutrition, Ethiopia
2Mekerere University, Uganda
3University of Hohenheim, Germany
Injera is a yeast-risen flatbread with a unique, slightly spongy texture. It is a national staple in Ethiopia that is eaten daily in every household. Despite the fact that injera is a favorite staple food, starters have not been evaluated for the production of rice-based injera combinations of Lactic acid bacteria (Lactobacillus plantarum) and yeast (Saccharomyces cerevisiae), lactic acid bacteria (Lactobacillus fermentum) and yeast (Saccharomyces cerevisiae), LAB (L. plantarum and L. fermentum) and yeast (S. cerevisiae) and irsho (back slopping) were used as starters in the fermentation of rice injera batter during 96 h. Changes in pH, titratable acidity (TA) and microbial count were analyzed at 6 h intervals. The acceptability of rice injera baked after 24 and 48 h fermentation were determined using a consumer panel (n=30). LAB starters (L. plantarum and L. fermentum and their co-cultures S. cerevisiae decreased pH from 6.35 to 4.5 and increased TA from 0.33 to 0.95 % (lactic acid w/w) within 18 – 24 h while the spontaneous fermentation with traditional irsho took 48 -54 h to attain 0.38 pH value and 0.93 % TA. LAB and yeast counts in L. plantarum and its co-culture S. cerevisiae starter increased from 5.13 to 8.36 and 4.11 to 7.5 log cfu g-1 respectively within 24 h. LAB and yeast counts in L. fermentum and its co-culture S. cerevisiae increased from 5.09 to 8.45 log cfu g-1 and 4.11 to 7.43 log cfu g-1 . respectively. LAB and yeast count in L. plantarum and L. fermentum. LAB starter and their co-cultures S. cerevisiae grew from 5.25-8.42 log cfu g-1 and 4.14 to 7.40 log cfu g-1 respectively. In contrast LAB counts in naturally fermented rice injera batter increased from 5.08 log cfu g-1 to 8.30 log cfu g-1 after 48 h and yeast counts increased from 4.1 log cfu g-1 to 7.20 log cfu g-1 in 24 – 48 hrs. With regards to acceptability, rice injera prepared using the L.plantarum + S.cerevisiae starter scored the highest value 8.83 (like extremely) which is most acceptable while injera prepared with irsho (traditional starter) scored 7.40 (like moderately). Therefore, the L.planturum+S. cerevisiae starter combination can be can be used for commercial production of acceptable rice injera.
Keywords: Rice injera; Lactobacillus plantarum; Lactobacillus fermentum; Saccharomyces cerevisiae
Yassin Hassen Umar has completed M.Sc degree from Makerere University in Food Science and Technology, Uganda. Yassin Hassen is a lecturer and researcher in the areas of Nutrition, Food Science and technology.