Abstract
Date press cake (DPC) is a by-product of the date syrup industry with a high content of dietary fibers, minerals, and antioxidant compounds. Accordingly, the present study aimed to evaluate the inclusion of DPC on the color parameters, texture profile, sensory evaluation, microstructure properties, total phenolics, and antioxidant capacity of date jam. The DPC was included in the preparation of date jam in an increasing level of 0, 3, 6, 9, and 12% (w/w). The results revealed that increasing DPC levels significantly increased the hardness, cohesiveness, adhesiveness, and chewiness properties of date jam. The increase in DPC inclusion levels significantly decreased the L* values and increased the a*, b*, and Delta E values of the jam. The DPC addition significantly increased the phenolics content and antioxidant capacity in a dose-dependent manner and the highest value reported in the jam contained 12% DPC by 40.02 and 11.50% compared to the control, respectively. The scanning electron microscopy results revealed that the addition of DPC up to 9% resulted in a jam surface with a denser network, homogeneous structure, and without cracks and pores, indicating improvement in the morphological properties. The sensory evaluation results showed that date jam prepared with 9% DPC had the highest overall acceptability score. This study revealed the potential use of DPC in date jam formulation up to 9% as a natural, functional, and low-cost ingredient to improve the jam's textural properties, antioxidant capacity, and overall acceptability.