Zizyphus spina-christi L. is one of the wide varieties of plant grown in Al-Ahsa Oasis in Saudi Arabia and known locally as Alnabaq (buckthorn). The objective of this investigation was to study the effects of postharvest calcium chloride applications on fruit quality of buckthorn under cold storage condition at 2°C and 90% RH for 5 weeks.¬¬ Fruits were dipped in calcium chloride at different concentrations (0, 2 and 4% W/V) for 10 min. Weight loss, total soluble solids (TSS), ascorbic acid content, fruit firmness and peroxidase activity were determined after Ca++ treatment and during cold storage every one week. The results revealed that, both the storage periods and treatments significantly affected the postharvest quality of Alnabaq fruits during cold storage condition. A reduction in fruit firmness and ascorbic acid content was observed during storage period. In addition, the results showed that, fruit treated with calcium chloride recorded higher firmness than the control, while lower peroxidase activity was recorded during cold storage at 2°C for 5 weeks. Generally, these results indicated that post-harvest Ca treatments delayed fruit softening and decreased weight loss.
Key words: Storage, Ziziphus spina-christi, weight loss, firmness, CaCl2, peroxidase activity, ascorbic acid.