Quality of red raspberry Rubus idaeus L. cultivars after storage in controlled and normal atmospheres

Summary

Five raspberry cultivars ‘Glen Ample’, ‘Glen Lyon’, ‘Malling Admiral’, ‘Malling Orion’ and ‘Veten’, were grown in the southeastern part of Norway. The potential for the fresh market after different storage treatments was evaluated, by measuring respiration rates, physical and chemical properties and decay. It was focussed on postharvest changes of nutritionally valuable components. Principal component analysis showed that cultivars originating from the same source (Glen-cultivars, Malling-cultivars and ‘Veten’) could be grouped together concerning to their physical and chemical characteristics. ‘Glen Ample’ and ‘Glen Lyon’, cultivars with firm berries, showed a good potential for the fresh market. Storage in controlled atmosphere suppressed rotting significantly. Berry colour was darker, and pigment levels increased during seven days storage in normal atmosphere. Raspberry cultivars with a lighter red colour with less blue like ‘Malling Admiral’ and ‘Glen Lyon’ kept a better colour compared with darker and more bluish cultivars like ‘Veten’. Measurements of the optical density in the berry juice were highly correlated with total anthocyanin content. Total and soluble solids were unchanged after storage, and titratable acids decreased. The Glen-cultivars and ‘Malling Orion’ had higher levels of L-ascorbic acids, which were unchanged or slightly increased after a one-week storage period.