Microbial production of dicarboxylic acids from edible plants and milk using GC-MS

Abstract Objective The present experiment was designed to assess the contents of organic acids such as citric acid, succinic acid, fumaric acid, and malic acid in edible food plants and milk under the influence of Eschericia coli. Methods Gas chromatography-mass spectrometry (GC-MS) was used to estimate the contents of organic acids in edible plants and milk. Two microliters of samples was injected into the GC-MS, and the contents of organic acids were computed using standard curves. Results Maximum citric content (204 mg/g DW, 24 h E. coli treatment) was observed in tomato followed by papaya (175 mg/g DW). Papaya and grapes (715 and 504 mg/g DW, 24 h E. coli treatment respectively) can be good sources of succinic acid. Malic acid content was highest in E. coli-treated milk (168 mg/g DW). In general, there was a decrease in average citric acid and increase in succinic acid contents in the food sources tested on treatment with E. coli. Conclusion It was found that among the tested raw food items and milk, with or without E. coli inoculation, tomato and papaya hold a good potential for citric acid production, grapes and papaya for succinic acid, and milk for malic acid production. The study can be a basis for utilization of vegetables, fruits, and milk for the production of dicarboxylic acids to boost the agrarian economy