AUTHOR=Barakat Hassan , Almemoni Muath , Alsayqal Tariq 

TITLE=Evaluating the nutritional, physicochemical, and quality characteristics of different treated freeze-dried Barhi dates

JOURNAL=Frontiers in Sustainable Food Systems

VOLUME=Volume 9 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2025.1673255

DOI=10.3389/fsufs.2025.1673255

ISSN=2571-581X

ABSTRACT=IntroductionBarhi dates at the Khalal stage exhibit high perishability, which results in considerable post-harvest losses. Implementing freeze-drying, either independently or combined with pre-treatments, represents a promising strategy and enhances the product’s quality. Therefore, the current study evaluated the impact of freeze-drying alone or combined with various pre-treatments on the nutritional, physico-chemical, and quality characteristics of fresh Barhi dates.MethodsThe pre-treatments included soaking in sodium metabisulfite (Met-D) 1 g L−1, ascorbic acid (Asc-D) 1 g L−1, and citric acid (Cit-D) 1 g L−1 for 2 min, blanching (Bla-D) for 5 min, and blanching followed by ascorbic acid soaking (BAs-D) 1 g L−1 for 2 min, compared to untreated freeze-dried samples (RD). The freeze-dried dates were then analyzed for proximate composition, mineral content, total phytochemicals and polyphenolics, antioxidant activity (DPPH, ABTS), sugar profile (HPLC-RID), instrumental color (Hunter Lab), water activity (aw), and in vitro glycemic index (GI) and glycemic load (GL).ResultsFreeze-drying consistently reduced moisture content to a stable range of 6.21–7.16% without a remarkable effect on proximate composition or mineral content. All treatments yielded stable products with low aw (0.22–0.26). Asc-D and Cit-D treatments significantly enhanced the retention of total phenolic compounds (TPC) and flavonoids, with BAs-D exhibiting the highest TPC and most potent antioxidant activity. HPLC analysis observed that Met-D and Cit-D treatments had the highest extractable polyphenols, whereas p-hydroxybenzoic acid was quantified as the predominant phenolic acid. The glycemic index (GI) and glycemic load (GL) remained low 39.72–39.80 and 35.32–35.63, respectively. Color analysis demonstrated that Met-D and Asc-D preserved lightness, while blanching induced browning.DiscussionFreeze-drying combined with ascorbic or citric acid pre-treatments effectively preserves bio-active compounds, antioxidant activity, and shelf stability while maintaining a low glycemic index, providing a viable approach to reduce post-harvest losses and enhance the commercial value of Barhi dates. These findings provide a robust framework for industrial applications, supporting nutrient-dense date products and contributing to sustainable agricultural practices.