Ws. Conway et al., ADDITIVE EFFECTS OF POSTHARVEST CALCIUM AND HEAT-TREATMENT ON REDUCING DECAY AND MAINTAINING QUALITY IN APPLES, Journal of the American Society for Horticultural Science, 119(1), 1994, pp. 49-53
'Golden Delicious' apples (Malus domestica Borkh.) were treated with h
eat or CaCl2 Solutions or a combination thereof to determine the effec
ts of these treatments on decay and quality of fruit in storage. Heat
treatment at 38C for 4 days, pressure infiltration with 2% or 4% solut
ions of CaCl2, or a combination of both, with heat following CaCl2 tre
atment affected decay and firmness during 6 months of storage at 0C. T
he heat treatment alone reduced decay caused by Botrytis cinerea (Pers
.:Fr.) by almost-equal-to 30%, while heat in combination with a 2% CaC
l2 Solution reduced decay by almost-equal-to 60%. Calcium chloride sol
utions of 2% or 4 % alone reduced decay by 40% and 60%, respectively.
Heat treatments, either alone or in combination with CaCl2 treatments,
maintained firmness (80 N) best, followed by fruit infiltrated with 2
% or 4% solutions of CaCl2 alone (70 N) and the nontreated controls (6
6 N). Instron Magness-Taylor and Instron compression test curves show
that heat-treated fruit differed qualitatively and quantitatively from
nonheated fruit. Heat treatment did not increase the amount of infilt
rated Ca bound to the cell wall significantly, and a combination of he
at treatment after CaCl2 infiltration increased surface injury over th
ose fruit heated or infiltrated with CaCl2 solutions alone.