Effects of spray freeze drying and pulsed electric fields on fenugreek seed extract properties

Plant extracts are increasingly recognized for their potential health benefits, creating a growing demand for efficient extraction and preservation methods. In this study, a pulsed electric field (PEF) system was applied to maximize the extraction of plant bioactives, followed by encapsulation using spray freeze drying (SFD), a novel preservation technique. Among solvents tested, ethanol yielded the highest extract recovery (166.66 mg GAE/g), whereas methanol (sample-to-solvent ratio 1:10) resulted in the highest total polyphenol content. In the encapsulation process, gum acacia (GUA) at a 1:6 extract-to-binder ratio with a 30-hour lyophilization period produced powders with the lowest moisture content (3.9% w.b.), and SFD particles exhibited an average size of 9.0 μm. Furthermore, GUA as a binder and guar gum at a 20-hour lyophilization period achieved the highest polyphenol encapsulation efficiency. These findings highlight PEF-assisted extraction combined with SFD encapsulation as a cost-effective and efficient strategy for industrial-scale preservation of plant bioactives.