Journal of Applied Horticulture. 2000: 2(2): 79-83

Effect of CaCl2 sprays, heat, and combined CaCl2-heat treatments on the quality of apples (Malus domestica Borkh.)

Dris, R; Niskanen, R; El Assi, N

Department of Applied Biology, Horticulture, University of Helsinki, P.O. Box 27, FIN-00014, Finland.

'Lobo' apple fruits were subjected to preharvest CaCl2 spraying treatment, pre-storage heat treatment, and CaCl2+heat treatment and were held at 2 degrees C and 90-95% RH for six months. Respiration and ethylene production rates were monitored and soluble solids, juice pH, firmness, total dry matter and macronutrient (P, K, Ca, Mg, and N) contents were determined. Additionally, the incidence of physiological disorder and pathological disease were recorded. Respiration and ethylene production rates slightly decreased in heat-treated apples and increased in CaCl2-treated apples. CaCl2 treatment did not increase fruit firmness or Ca concentration. Combined CaCl2+heat treatment and heat treatment increased pH. At the beginning of storage, the firmness of heat- and CaCl2+heat-treated fruits was lower but greater than that of the control fruits at the end of the storage period. After 6 months of storage, the lowest incidence of disorder and disease symptoms was observed in the CaCl2+heat treatment.