Organic Acid Profiles of Thermally Processed Carrot Puree1,2

The aim of this investigation was to examine changes in organic acid concentration in carrot puree during processing at temperatures ranging from 240–300 F, with 20 F increments and an F0 equal to 4.9. Two varieties of carrots from two different geographical regions were packed in Thermal Death Time (TDT) tubes, flushed with nitrogen, sealed, and processed. Following this, analyses were conducted to determine changes in organic acid content and pH. Significant increases in pyrrolidone carboxylic acid (PCA), citric acid, fumaric acid, acetic acid, and malic acid were noted between the fresh product and product processed at 240 F. The PCA concentration was significantly affected by changes in processing temperature, while pyruvic and fumaric acids exhibited possible variations. The greatest change in pH from the fresh (unheated) product occurred with the 240 F processed product in both Texas and California samples. As the processing temperature increased, with a constant F0 value, the pH decreased. The pH readings for the carrot samples from the two different locations were similar.