This work aimed to evaluate the effect of mechanical injuries, impact, compression or cuts on firmness and epidermal color of fruits of two guava cultivars, harvested at mature-green ripeness stage at room temperature. Impact injury was obtained by dropping the guavas twice, from a height of 1.20 m on a hard surface. Compression injury was done with the fruits submitted to a 3 kg load for 15 minutes. Cutting fruits obtained cut injury, twice longitudinally to 30 mm in length and 2 mm depth. Injured fruits were placed on trays and stored at ambient conditions (23.4±1 °C, 62±6 % RH). The firmness of fruits submitted to impact and compression injuries was calculated by the relationship of weight (N)/injured area (m²). Epidermal color changes were determined by a Minolta CR 200b reflectometer. Daily color measurement was done to compare the color of the injured area with the non-injured area of the same fruit. The compression test indicates that there are no significant differences between the tested cultivars as for flesh firmness. However, 'Paluma' fruits had better firmness than 'Pedro Sato' fruits, when submitted to impact damages. The injured area was darker than intact areas while Hue angle was always higher in these areas, indicating retard in yellowing, typical of guava ripening. Chroma values were always lower in injured areas, for both cultivars. 'Pedro Sato' fruits were characterized as darker and more greenish than 'Paluma' along the storage period, independently of the injuries.
Psidium guajava; postharvest; impact; compression; cut; flesh firmness; color
