New Insights into the Influence of the Characteristic “Stone” Feature of the Date Palm (Phoenix dactylifera L.) Seeds on Its Sustainable Processing Approaches—A Review

Date fruits are a valuable crop that grows well in marginal environments. Date fruit processing generates millions of tonnes of seeds (also known as pits or stones) annually which are used as animal feed and organic fertilizer. At the same time, some are discarded in landfills as waste. Nutritional benefits of date seeds and their laboratory-scale valorization have been reported; however, upscaling and adoption into practical applications are limited and the reasons for this are outlined. This review reports on the date seed’s physical properties and chemical composition in various varieties and maturity stages relative to the textural limitation, characterized by the development of the stone shell and its influence on valorization. Published data indicate that various date seed processing techniques include soaking, roasting, drying, gamma radiation, boiling, and sprouting with diverse changes in processing aptitude and date seed powder characteristics which would affect the applicability of the powder in various food applications. Date powder applications include beverages, baking, meat preparations and dairy products including ice cream flavoring. The evaluation of the existing techniques for converting date seeds into powder aims to identify the areas that require further investigation and optimization for large-scale production. Several studies have been conducted on date seed processing; however, the upscaling process is stalled by the emergence of the “stone defect” characteristic during fruit development among other contributing factors. Therefore, it is imperative to assess the sustainability of existing and developing procedures, alongside evaluating the suitability of date seed powder in diverse product applications. The study’s results will facilitate the development of strategies to enhance the utilization of this agricultural waste for valuable purposes.

Graphical Abstract