Non‐freezing points below zero induce low‐temperature breakdown of kiwifruit at harvest

Abstract

To induce low-temperature breakdown (LTB) at harvest, a post-storage disorder of kiwifruit, kiwifruit were exposed to −2 • C (a temperature determined to be above the freezing point), for 0 (control), 6, 12, 18, 24, 30, 36 and 42 h, followed by 5 days at 20 • C. Kiwifruit were also stored at −0.5 • C for 16 and 24 weeks plus 5 days at 20 • C. LTB incidence and severity were measured on the cut surfaces following slicing at the upper, middle and lower parts of each fruit subjected to −2 • C, whereas in stored fruit LTB incidence was measured following slicing at the middle part. Electrolyte leakage (ELL) was also determined. Exposure of fruit to −2 • C resulted in induction of LTB incidence and severity, which increased with the duration of exposure, particularly, on the upper fruit part. Maximum ELL during exposure at −2 • C for 36 h or during storage at −0.5 • C for 16 weeks was as high as 50% of that of the frozen fruit. Fruit exposed to −2 • C or stored at −0.5 • C had similar LTB symptoms but both differed from those observed in frozen fruit. LTB of fruit stored at −0.5 • C for 24 weeks was 27% and corresponded to LTB induced at harvest by exposure at −2 • C for 24 h. The results of this study confirm that LTB is inducible by low but not freezing temperatures at harvest and therefore it might be considered as the physiological basis towards the development of an LTB incidence index for harvested kiwifruit.

High pressure carbon dioxide treatment for fresh-cut carrot slices

“…3). Similar increase in membrane permeability of fresh-cut vegetables was found under stress conditions including irradiation (Fan & Sokorai, 2005), chilling (Gerasopoulos, Chlioumis, & Sfakiotakis, 2006), pulsed electric fields (Ersus & Barrett, 2010) and blanching (Galindo et al, 2005). Fan and Sokorai (2005) reported electrolyte leakage of 13 fresh-cut vegetables increased linearly with higher radiation dose and the radiation resistance had large variation among different test samples.…”

Alternating Magnetic Field Prior to Cutting Reduces Wound Responses and Maintains Fruit Quality of Cut cucumis melo L. cv Hetao

“…In our study, results showed that electrolyte leakage was stimulated by cutting, which supports previous results that electrolyte leakage is a useful parameter to indicate physical damage, because leakage increases to the plasmalemma when wounds to fruit tissue are incurred [29]. Also, Gerasopoulos et al [30] showed that adverse conditions such as low temperature cause considerable losses of quality during the prolonged shelf life of fruits, apparently related to factors that affect membrane function, and thus, to the more electrolyte leakage. Less electrolyte leakage is consistent with better fruit quality.…”

Quality control of fresh sweet corn in controlled freezing-point storage

“…However, the disadvantage of CF storage is the physiological disorder for fruits and vegetables, which is due to chilling stress. Low-temperature breakdown, one form of chilling injury, is a typical disorder phenomenon for kiwifruit in CF storage (at non-freezing points below zero) (Sfakiotakis et al, 2005;Gerasopoulos et al, 2006). Chilling injury was also found in sweet corn during CF storage in our preliminary trails.…”

“…CI was not same with freezing injury, which was a result of damage from ice crystals in tissues stored below their freezing point. Gerasopoulos et al (2006) also concluded that non-freezing points below zero (-0.5 and -2°C) induced the CI of kiwifruit but not freezing damage.…”

“…Gerasopoulos et al (2006) found that the development of low temperature breakdown (the symptom of CI on kiwi fruit) was closely associated with ELL. As shown in Figure 3, ELL was found to increase during storage in all the three treatments.…”