Food-derived bioactive peptides, as potential ingredients in health-promoting functional foods targeting diet-related chronic diseases have attracted increasing attention because of their high biological activities and low toxicity. They have been practical in food industry and pharmacognosy. So far, various sources of nutrition such as cereals and pseudo cereals have been identified for this purpose. One of the approaches to achieve bioactive peptides is using the bacterial fermentation process. The aim of this study was to use amaranth as a rich source of proteins and essential amino acids with high bioavailability for the production of bioactive peptides during fermentation through the enzymatic hydrolysis of bacteria. In this present work, Lactobacillus Plantarum subtypes of Plantarum PTTC 1896 were used. The dough yielded at 6, 12 and 18 hours under the fermentation process exposed to optimum circumstances of bacterial growth. The degree of protein hydrolysis was measured by Nielsen method and the statistic result reported as: 11.6, 29.6 and 43.35 percent during 6, 12 and 18hours fermentation, respectively. According to the result of the SDS-PAGE test, the molecular weight ranges were about 23,16 kDa and the highest peptides density were observed in molecular weight below 14 kDa, which indicates the optimal performance of the selected bacterium. The hydrophobicity of sourdough and dough evaluated by RP-HPLC apparatus. Comparison of results showed a decrease in post-fermentation hydrophobicity. Type and amount of each amino acid were determined by amino acid analyzer. The highest amount belonged to tyrosine which shows antioxidant activity. After fermentation, phenolic content of the sample stayed constant while soluble proteins increased. The role of peptides derived from amaranth sourdough in reducing LDL oxidation and hemolytic anemia was evaluated by chemical procedure. The results of this study indicate that the bioactive peptides produced by amaranth sourdough, can be considered as a novel procedure in food industry to promote the healing properties and use as a medicine or additives in functional foods. Key words: Bioactive Peptides, Sourdough, Amaranth, Fermentation, Lactobacillus Plantarum , RP-HPLC, SDS-PAGE, hemolytic anemia, LDL oxidation
