Novel Mechanism of Modulating Natural Antioxidants in Functional Foods: Involvement of Plant Growth Promoting Rhizobacteria NRRL B-30488

摘要

The significance of plant growth-promoting rhizobacteria (PGPR) mediated increase in antioxidant potential in vegetables is yet unknown. The plant growth-promoting bacterium Bacillus lentimorbus NRRL B-30488 (B-30488) mediated induction of dietary antioxidant in vegetables (Trigonella foenum-graecum, Lactuca satlva, Spinacia oleracea, and Daucus carota) and fruit (Citrus sinensis) after minimal processing (fresh, boiled, and frozen) was tested by estimating the total phenol content, level of antioxidant enzymes, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide scavenging activities along with integral radical scavenging capacity by photochemiluminescence assay and inhibition of lipid peroxidation. Minimal processing of vegetables showed that T. foenum-graecum had the highest phenol content in B-30488-treated plants followed by L sativa, D. carota, and S. oleracea. Thermally treated vegetables T. foenum-graecum (26-114.5 GAE μg.mg~(-1)) had an exceptionally high total phenolic content, followed by D. carota (25.27-101.32 GAE μg mg~(-1)), L. sativa (23.22-101.10 GAE μg mg~(-1)), and S. oleracea (21.87-87.57 GAE μg mg~(-1)).