Variations in Organic Acid Profiles of Thermally Processed Green Beans (Phaseolus vulgaris L.) of Different Varietals

Four varieties of green beans, Phaseolus vulgaris L. (Lake Shasta, Lake Geneva, Slimgreen, and Cascade), grown under the same conditions were analyzed for organic acid content and pH. Each variety was comminuted and processed in TDT tubes with an FO value of 4.9 at temperatures of 240 and 280 F. All analyses were conducted in duplicate using an Automatic Organic Acid Analyzer (Waters Associates, Milford, Mass.). Differences in the organic acid content were determined statistically at the 95% significance level for each acid. The organic acid profiles for the beans showed qualitative variations which appeared to be somewhat variety dependent and changes in the acid profile to a particuler variety on processing appeared to be dependent on the variety. The effects of processing on the pH of the samples appeared to be quite similar. All varieties contained acetic, fumaric, lactic, succinic, α-ketoglutaric, malic, and citric acids both initially and after processing.