Changes in the contents of carotenoids, phenolic compounds and vitamin C during technical processing and lyophilisation of red and yellow tomatoes

We present the results of the first study on the impact of thermal processing and lyophilisation on three major micronutrient families: carotenoids, total polyphenols and vitamin C in two different tomato cultivars: a red tomato (RT) and a yellow one (VT). Micronutrients were analysed in fresh tomatoes, tomato pur e and lyophilised tomatoes. YT contained no lycopene, lower beta-carotene, similar vitamin C and higher total polyphenol contents than RT. Processing did not affect the carotenoid content in RT, but significantly lowered beta-carotene in YT and also the contents of total polyphenol and vitamin C in both cultivars. Lyophilisation lowered the carotenoid content in RT but not in YT; in contrast, the total polyphenol content was preserved in RT but lowered in YT, and the vitamin C content was not affected in both cultivars. These results provide new data on the effect of thermal processing and lyophilisation on the content of the three main families of micronutrients in red and yellow tomatoes. (C) 2010 Elsevier Ltd. All rights reserved.