Effects of postharvest calcium treatments on respiration and quality attributes in lemon fruit during storage

Summary The effects of postharvest calcium (Ca) treatments on respiration and quality attributes in ‘Maglino’ lemons, harvested at the yellow-green or light yellow state, were investigated during storage for up to 60 d. Lemons were immersed in solutions of calcium chloride (CaCl2) at concentrations up to 0.36 M, for 25 min. Weight loss (WL) during storage was not affected by Ca treatment in either colour state of fruit. In yellow-green fruit, Ca treatment prevented decreases in firmness and the highest firmness retention was achieved with 0.09 M CaCl2 after 40 d of storage. However, light yellow fruit did not exhibit changes in firmness in relation to storage time or to Ca treatment. In light yellow lemons, Ca treatment promoted the decreases in carbon dioxide (CO2) production by the fruit and prevented decreases in hue angle values in flavedo, but had no effect on the decreased oxygen (O2) consumption by the fruit, on the decreased L* and increased chroma values in flavedo, and on the unchanged pH values, on the increased ascorbic acid concentration (AA), soluble solids content (SSC) and titratable acidity (TA) of juice during storage. Hue angle decreases in flavedo were best prevented with 0.09 M CaCl2.