the ripening mutants alc and rin delay tomato (lycopersicon esculentum mill.) ripening and affect synthesis of carotenoids pigments and fruit firmness. this paper reports on the comparative effects of heterozygous alc and rin genotipes (alc+/alc and rin+/rin) on chemical, biochemical and physical aspects of tomato fruit during three ripening stages. neither alc+/alc nor rin+/rin influenced total solids contents in the intermediary or fully ripe stages. the genotype rin+/rin brought about a more marked reduction in lycopene than alc+/alc, relative to the normal genotype. in mature fruit, pectinmethylesterase activity was more markedly by rin+/rin, whereas alc+/alc was more effective in reducing polygalacturose activity. in the breaker stage, neither mutant affected cellulose, hemicellulose or pectin contents. in the intermediary stage hemicellulose was reduced by rin+/rin and, in mature stage, rin+/rin reduced cell wall cellulose and pectin fractions. both alc+/alc and rin+/rin can be efficiently deployed in breeding long shelf life tomato hybrids.