Response of Six Cultivars of Tuna Fruits To Cold Storage

Abstract

Prickly pears, called tunas, are nonclimacteric fruits. That is, their respiration declines with
time and is not different for fruits harvested at different stages of ripeness (Lakshminarayana
et al., 1979). Nonclimacteric fruits are also characterized by a lack of starch as a carbohydrate
reserve. Therefore, there is no significant increase in sugar content of nonclimacteric fruits after
harvest (Tucker, 1993; cited by Cantwell, 1995). According to Cantwell (1991), the ethylene
production rate in tuna fruits is also very low, so their physiological activity is low. Therefore,
the perishability of tunas lies not in their physiology, but mainly in physical damage to the
peel and stem end during harvest and postharvest handling.