Characterization and Valorization of Dietary Fibre Concentrate from Parthenocarpic Date Fruits

Parthenocarpic date fruits are good sources of antioxidant and fibre, which could be changed into valuable by-products. There is no attempt to use it in technological processes and could provide a natural additive to enhance the quality of the product. In this study, fibre concentrate from partenocarpic dates (FCPD) was extracted, dried, and characterized. Two drying techniques, namely oven and freeze drying, were carried out, and then the FCPD were characterized. Thereafter, its ability to substitute flour in muffins was studied. The freeze-drying gave the highest yield of FCPD revealing lignin richness but cellulose and hemicellulose insufficiency. Drying techniques gave similar FCPD WHC and OHC but antioxidant capacity was higher in the case of freeze-dried fibre. Electronic microscopy showed that the more FCPD was introduced in the flour, the more the muffin crumb contained disrupted matrices. This could enhance the muffin freshness by improving the moisture retention. Moreover, although flour substitution by FCPD increased muffin volume and its OHC value, its WHC, moisture, mineral and sugar contents were not affected. Calorific value, phenol content and antioxidant activity were greater in the case of muffins with 5% of freeze-dried FCPD. Sensory analyses showed that fibre-enriched muffins had good scores as the control ones. In this study, we used oasis raw materials with good source of fibres and antioxidant capacity that could be used in the production of high value-added foods. Additionally, the research demonstrated that freeze-dried FCPD flour fortification enhances the physicochemical characteristics of the muffin. The parthenocarpic date fruits is an agricultural residue with interested chemical and functional properties that could be undertaken in food process industries.