Background and Objectives: Wheat germ is the most nutritious part of wheat grains, which has a short shelf-life due to its high lipid contents and presence of lipase and lipoxygenase enzymes. Thus, wheat germs are separated from the whole wheat grains during the flouring process, mostly used as animal foods. The objective of this study was to investigate effects of fermentation by Lactobacillus acidophilus and Lactobacillus plantarum on lipase, lipoxygenase activity and antioxidant characteristics of wheat germs.
 Materials & Methods: Various concentrations of wheat germs were inoculated individually with a certain number of the bacteria (10⁹ Log CFU / mL). After incubation at 37 °C for 24 h, pH changes and antioxidant, lipase and lipoxygenase activities were compared to those of unfermented samples and effects of various starters on the highlighted characteristics of wheat germs at various concentrations were investigated.
Results: Fermentation by the two bacteria significantly decreased activities of the lipase and lipoxygenase enzymes. Furthermore, 20% concentration of fermented wheat germs by Lactobacillus plantarum showed the highest decreases in activities of the two enzymes (71/43 for lipase and 65% for lipoxygenase). Raw wheat germs included good antioxidant activities that significantly increased after fermentation by the bacteria. Investigation of the starter type and substrate concentration showed that the highest (29.97%) and the lowest (21.55%) increases in antioxidant activities after fermentation were linked to fermented samples by Lactobacillus plantarum at 20% and Lactobacillus acidophilus at 10% concentrations of wheat germs, respectively.
Conclusion: Fermentation by Lactobacillus acidophilus and Lactobacillus plantarum significantly improves antioxidant activities of the wheat germs and increases its shelf-life by significantly decreasing lipase and lipoxygenase activities.