Effect of Processing Stage on the Bioactives of Tomato Purees Supplemented Preserved by Microwaves

Tomatoes are a natural source of bioactive compounds. Most of these substances accumulate in the tomato skin and seeds and are scarce in the pulp, which is the main ingredient of tomato products. The application of technological processes as well as plant variety, cultivation, and harvesting conditions, can significantly affect the content and composition of phenolics in tomato fruit and tomato-based products. To increase the content of bioactive, in the present investigation a tomato puree supplemented with the seeds and skin of the fruit was prepared using tomatoes of Mexican origin. The bioactive compounds at each stage of the process were evaluated. The variation in bioactive compounds occurred during the tomato juice concentration stage. The retention of bioactive compounds was similar when conventional pasteurization and microwave treatment were applied independently, however, the microwave used a lower time. Tomato puree supplemented with seeds and skin presented a higher content of bioactive. There were no significant differences in the microbiological activity between pasteurization and microwave treatment since both heat treatments achieved similar microbial inactivation. Chlorogenic acid, rutin, resveratrol, quercetin, and naringenin were identified by HPLC. The microwave-treated tomato puree presented a less acidic taste, a more intense red color, and a more pleasant aroma compared to the pasteurized tomato puree. The PCA analysis showed that the processing stages that affect the polyphenolic content in the elaboration of tomato purees corresponded to the heat treatments appliednd and the concentration stage.