Effect of cold storage on fruit quality of blood oranges

Abstract

Traditionally the production of blood oranges has been destined to the juice industry. However, in the last years the demand for this citrus fruit for fresh consumption is considerably increasing. Nowadays there is not enough information about the optimum storage conditions of ‘Sanguinelli’ and ‘Tarocco Rosso’, the most important cultivars in the Spanish Mediterranean area. In this study the effect of cold storage at different temperatures on fruit quality was evaluated in both cultivars. In two different seasons, after harvest, the fruit was stored up to 45 days at 1, 5, or 9°C. Periodically a sample of fruit was transferred to 20°C during 6 days simulating shelf-life conditions. The following quality parameters were evaluated: maturity index, external colour, firmness, ethanol concentration and physiological disorders. Although there were slight differences between seasons, ‘Sanguinelli’ showed higher sensitiveness to low temperatures than ‘Tarocco Rosso’, which manifested chilling injury symptoms after 30 days of cold storage at the three studied temperatures. The lower temperature storage the higher disorders incidence was observed. During storage the acidity slightly decreased and total soluble solids remains constant in both cultivars. The increase in the external colour was affected by the storage temperature; fruit stored at 5 and 9°C exhibited the highest colour index. The increase of ethanol concentration throughout the storage period was not associated with a sensory quality loss.