Evaluation of date palm pollen (Phoenix dactylifera L.) encapsulation, impact on the nutritional and functional properties of fortified yoghurt

Abstract

The aim of this study was to evaluate Egyptian date palm pollen (DPP) grains composition, physical and functional potentials in comparing with two forms; 80% ethanol extract, and nanoencapsulated form. Functional yoghurt fortified with DPP in three forms was prepared and their physicochemical, microstructure, texture and sensory characteristics were assessed. The micro morphology was explored via Scanning Electron Microscope (SEM). Fourier Transform Infrared (FTIR) spectroscopy was employed for functional groups detection. Phenolic compounds were detected by High Performance Liquid Chromatography (HPLC) while fatty acids were identified via Gas Liquid Chromatography (GLC). Cytotoxicity of DPP nanocapsules was evaluated against RPE1 cell line (BJ1). The Egyptian date palm pollen grains evaluation revealed its rich content of protein and carbohydrate (36.28 and 17.14 g/ 100g), high content of Fe, Zn and Mg (226.5, 124.4 and 318 mg/100g), unsaturated fatty acids ω-3, ω-6 and ω-9 (8.76, 20.26 and 7.11 g/100g, which was increased by ethanol extraction) and phenolic compounds especially catechin (191.73 μg/mL) which was pronounced in DPP antioxidant potentials (IC50 35.54 mg/g). The FTIR analyses indicated the presence of soluble amides (proteins) and polysaccharides (fibers) functional groups in DPP. Fortification with nanoencapsulated DPP proved to be safe and the recommended form due to the announced positive characteristics. Yoghurt fortification with DPP forms enhanced viscosity, syneresis and Water Holding Capacity (WHC), which can be considered a symbiotic functional product as it contained both probiotics (106 CFU/g) and prebiotics represented in DPP forms.