SOLUBLE SOLIDS REVISITED: A MATURITY OR HARVEST INDEX FOR KIWIFRUIT
Postharvest performance of fruit is dependent on the physiological state of the fruit at harvest in conjunction with the management of the postharvest environment. Soluble solids content (SSC) has been used as a measure of maturity and as a harvest index for Hayward kiwifruit in New Zealand since 1980. At that time, a SSC of 6.2 °Brix was set as a minimum threshold for fruit to be harvested for long-term storage and export. Since then, 6.2 °Brix, or other SSC thresholds, have been adopted as criteria for harvest/handling/export elsewhere in the world. In New Zealand, the 6.2 °Brix harvest index was based on fruit having an increased rate of soluble solids accumulation at that stage, associated with lower night temperatures resulting in starch conversion to soluble sugars. More recently, with increasing yields and changes in management practices, as well as increasing numbers of new cultivars being commercialised, maturation in kiwifruit is being re-evaluated. This includes a closer look at soluble solids accumulation as well as consideration of other fruit attributes, including flesh colour for yellow-fleshed cultivars. In this paper, the topic of SSC has been reviewed in the context of understanding kiwifruit maturation and harvest indices.
Burdon, J. (2015). SOLUBLE SOLIDS REVISITED: A MATURITY OR HARVEST INDEX FOR KIWIFRUIT. Acta Hortic. 1096, 257-266
postharvest, storage, quality, carbohydrates, starch, acclimation, cultivars