Physicochemical, sensory, and nutriitive qualities of hardy kiwifruit (Actinidia arguta 'Ananasnaya') as affected by harvest maturity and storage

The influences of harvest maturity (6.0%, 8.7%, 9.1%, and 15.1% average soluble solids content [SSC]) and storage conditions (22 +/- 1 degrees C and 45% RH, or 2 degrees C and 88% RH for 3 wk followed by a ripening period at 22 +/- 1 degrees C and 45% RH) on the physicochemical, sensory, and nutritive qualities of 'Ananasnaya' hardy kiwifruit were investigated. The effects of refrigeration depend largely on maturity of the fruit at harvest. Chroma values of refrigerated fruit ranged from 16.41 to 19.09 and were similar to vine-ripened fruit (15.1% SSC). Hue angles ranged from 75.41 to 97.50; the only significant (P < 0.05) difference was refrigerated fruit harvested at 9.1% SSC, which had lower hue angles than all other treatments. Refrigeration significantly (P < 0.05) reduced titratable acidity and increased SSC of ripened fruit, regardless of harvest maturity, and reduced firmness of fruit harvested at 6.0% and 8.7% SSC. However, storage conditions had no effect on firmness of fruit harvested at 9.1% SSC. Free-choice profiling revealed that panelists perceived significant (P < 0.05) differences between refrigerated and room-stored samples in aroma and flavor descriptors as well as differences between harvest maturity treatments. Refrigerated fruit harvested at 6.0% and 8.7% SSC measured highest in total phenolics with over 2 mg gallic acid equivalents/g fresh weight. Antioxidant activity ranged from 1.6 to 2.3 ascorbic acid equivalents/g fresh weight with no significant difference between treatments. This study demonstrated that quality of ripened hardy kiwifruit can be optimized through identification of ideal harvest date for this Actinidia species and by controlling storage conditions.