Modified atmosphere improves storage ability, controls decay, and maintains quality and antioxidant contents of Barhi date fruits

Author: K. N. Al-Redhaiman

Received 11 January 2004, accepted 18 April 2004.

Abstract

Full mature ´Barhi´ date fruits (Phoenix dactylifera) were exposed to modified atmosphere storage conditions with three carbon dioxide concentrations (5, 10 or 20%) during storage at cold storage (0°C). The control fruits were stored at cold storage (0°C) under the common air components conditions (0.03% CO₂). Fruits storage ability, decay percentage, and physiochemical changes during the storage period were studied. High CO ₂concentrations extended fruit storage ability, retarded fruits decay, maintained fruit quality, prevented fruit softening, and reduced postharvest losses. Fruits stored at 0°C under 20% CO₂ showed significantly longer storage period (lasted for 26 weeks) than all other treatments (i.e. 5 and 10% CO₂ which lasted for 17 weeks) and the control (lasted for 7 weeks). Moreover, fruits stored under MA conditions showed lower decay and weight loss percentage. At the end of the experiment, MA treatment with 20% CO₂ prevented fruit darkening and maintained fruit color (as control fruit turned brown after only two months of storage), firmness, SSC%, total sugar content, and total tannins, which are the most dominant antioxidant compounds in date fruits. In addition, CO₂ treatment retarded significantly the degradation of caffeoylshikimic acid (CSA), which is one of the major phenolic compounds of date fruits. Sensory panelists rated fruits stored at 0°C in modified atmosphere contained 20% CO₂ firmer and identical to the fresh harvested fruits than fruits stored in 0.03%, 5%, or 10% CO₂. This study indicated that ´Barhi´ date fruits could be stored under modified atmosphere conditions in cold storage (at 0°C) to achieve the longest possible storage period (more than 6 months, compared with 2 months for those stored at 0°C under common air composition) with the best fruit color and firmness, and most proper eating quality, which ultimately improves market ability.