Miltiadis Christopoulos

Effects of two pre-harvest calcium treatments on physiological and quality parameters in 'Vogue' cherries during storage

Summary The effects of two pre-harvest spray treatments with calcium chloride (CaCl2) concentrations up to 58.5 mM on physiological and quality parameters were investigated in ‘Vogue’ cherries during storage from 1 – 23 d in air at 1° – 3.5°C, at 85 – 95% RH, in two experimental years. No foliar or fruit toxicity was observed. Ca-treated fruit showed greater firmness, lower soluble pectin content, more resistance to stem removal, and less stem browning than watersprayed control fruit during storage. Ca spraying had no effect on fruit weight, fruit size, pH, titratable acidity, total soluble solids, Mg content, or peel colour; whereas there was an increase in Ca content and inconsistent changes in malic acid concentrations in fruits measured after 1 d in storage. Ca did not affect carbon dioxide (CO2) production rates, and showed only slight effects on the already low ethylene production rates, and on the low 1-aminocyclopropane-1-carboxylic acid (ACC) content during storage. In conclusion, treatment with 45 mM CaCl2 had positive effects on most of the quality parameters measured, with no negative effect under our particular experimental conditions.

Short-term treatments with high CO2 and low O2 concentrations on quality of fresh goji berries (Lycium barbarum L.) during cold storage

BACKGROUND Goji berries (Lycium barbarum L.) are functional fruits but are usually marketed as a dried product. The aim of this study was to investigate the storability of fresh goji berries treated with high CO2 and low O2 concentrations before air storage at 1 °C for 21 days. RESULTS Berries harvested without stems were exposed to air (controls) or subjected for 2 days at 1 °C to the following controlled atmosphere (CA) treatments: 21% O2 + 0% CO2 (21+0), 5% O2 + 15% CO2 (5+15), 10% O2 + 10% CO2 (10+10) and 20% O2 + 20% CO2 (20+20). During 14 days of storage, all treatments decreased weight loss, while treatments 5+15 and 20+20 prevented fungal decay. No fermentation was observed. The treatments did not affect color changes, decreases in soluble sugars and increases in total soluble solids, titratable acidity, ascorbic acid, total carotenoids, total phenolics and ferric-reducing antioxidant power (FRAP) during storage, apart from the marginally reduced FRAP by treatment 20+20 on day 7. Treatments 5+15, 10+10 and 20+20 resulted in residual decreases in respiration rates and pH values early during storage. After 14 days of storage, panelists rated the CA-treated samples as sweet, with good acceptance. CONCLUSION Treatments 5+15 and 20+20 showed the best results after 14 days of storage.