Four brands of canned guava were submitted to physico-chemical, sensory (preference test) and instrumental color and texture analyses, in order to evaluate the differences between commercial products. The same analyses were made on a fresh, mature guava, to evaluate possible effects of processing on the quality of the final product. There were considerable differences between the distinct brands, and occasionally differences could be found between samples from the same manufacturer. The chemical analyses showed that most of the samples contained between 22 and 30% of sugar, except for one sample, which had a higher content, around 40%. The preference test showed that the consumers preferred the sweetness of the sample with the highest sugar content. Lower values for the chroma parameter a* were found in the commercial samples than in the fresh fruit, probably due to carotenoid degradation. The canned guava samples were lighter (higher values for L*) than the fresh fruit, due to the presence of sugar. The penetration of sugar into the fruit during heat processing may have caused pectin gelation, increasing the hardness, firmness and elasticity of some of the processed samples as compared to the fresh fruit. However in some samples, drastic process conditions were readily apparent, leading to loss of cellular structure, which could be observed from the low values obtained for the mechanical properties. With respect to texture, the hardest sample was preferred.
guava; mechanical properties; color
