Effects of ripeness and cultivar on chemical composition of strawberry (Fragaria × ananassa Duch.) fruits and their suitability for jam production as a stable product at different storage temperatures

Effects of ripeness (nearly ripe, ripe, fully ripe) and cultivar ('Blink', 'Polka' and 'Senga Sengana') on colour and chemical composition of strawberry fruits and their suitability for jam production, evaluated as stability during storage at 4 and 20 °C for 3 and 6 months, were investigated. Quality traits of fruits and jams were significantly affected by both ripeness stage and cultivar. However, after 6 months of storage, particularly at 20 °C, the effects of fruit ripeness and cultivar were considerably reduced. During jam storage, anthocyanins, ascorbic acid, chroma and hue were least stable in jams made from the least ripe fruits. Quality traits in jams made from 'Senga Sengana' were best preserved during storage, while quality and chemical composition in jams made from 'Blink' changed the most. In conclusion, fully ripe fruits were best suited for jam processing. Storage at low temperature was preferable and 'Senga Sengana' was the most and 'Blink' the least suitable cultivar for processing.