Adding value to hard date ( Phoenix dactylifera L.): Compositional, functional and sensory characteristics of date jam

Abstract

Second-grade dates (with a hard texture) from three potential Tunisian cultivars (Deglet Nour, Allig and Kentichi) showed the same sugar (∼73.30–89.55 g/100 g dry matter), fibre (∼7.95–18.83 g/100 g dry matter) and total phenolics (∼280.6–681.8 mg of GAE/100 g) content as dates of high quality. Deglet Nour and Kentichi varieties were characterised by a high content of sucrose and low reducing sugar content; contrary to Allig and the majority of other date varieties tested. This work intended to add value to these raw materials by using them in jam production. The corresponding jams were characterised in terms of chemical composition, physical (texture and water retention capacities) and sensory properties. Results showed a significant effect of the date variety on the composition and physical characteristics of date jams. Indeed, Allig jam was richer in reducing sugars and was characterised by its higher firmness and water retention capacity. To test the acceptability of these new products, we compared them with quince jam (the most consumed in Tunisia). Results showed that Allig and Kentichi jams presented a higher overall acceptability. However, quince and Deglet Nour jams did not show any significant differences ( P > 0.05). Results from this work revealed essential information that could promote the commercialization of dzate jam.