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Evaluación de atributos sensoriales y parámetros bioquímicos en frutos de tomate transgénico con reducida actividad de poligalacturonasa / Evaluation of sensory attributes and biochemical parameters in transgenic tomato fruit with reduced polygalacturonase activity

Quiroga, G.O. Sozzi, Fraschina, A.A.
Food science and technology international 1997 v.3 no.2 pp. 93-102
alleles, beta-galactosidase, color, cracking, enzyme activity, fresh market, fruits, gene expression, heterozygosity, hybrids, polygalacturonase, ripening, shelf life, storage time, sweetness, tomatoes, total soluble solids, transgenic plants
Sensory, physicochemical and biochemical parameters of fresh market tomatoes were monitored in order to determine the nature and extent of quality changes in transgenic tomato fruit with reduced polygalacturonase activity. Acceptability was significantly higher (p < 0.0001) in CR3 transgenic tomatoes than in a commercial long shelf-life hybrid heterozygous for the ripening inhibitor (rin) allele. Preference ratings for CR3 fruits were also significantly superior in some sensory attributes such as colour (p < 0.0002) and flavour (p < 0.0001). A descriptive evaluation of sweetness yielded statistically (p < 0.0143) higher scores for the CR3 control and transgenic fruit, consistent with objec tive measures of soluble solids. Significant increases in survival during longer storage periods were found in polygalacturonase antisense fruits, which were less susceptible to damage or cracking and less prone to infection. In transgenic tomato fruits with reduced polygalacturonase gene expression, the softening rate was not significantly inhibited during ripening but was retarded in the over- ripening stage. Activity assays of α- and β-galactosidases did not show significant differences between antisense and control fruit, except for the β-galactosidase in the breaker stage.