Physicochemical and functional properties of pectin from Premna microphylla Turcz leaves cultivated in Taiwan

Abstract BACKGROUND This study evaluated Premna microphylla Turcz leaves as a potential source of pectin for industrial applications. Alcohol‐insoluble solids (AIS) were obtained through alcohol precipitation, yielding 77.67% AIS with a pectin content of 28.55%. Various extraction methods, including water, ammonium oxalate, hydrochloric acid and sodium hydroxide, were employed to extract pectin from AIS. RESULTS Water extraction produced the highest yield at 25.60% with a 42.49% pectin content. The degree of esterification for water‐extracted pectin was 44.52%, classifying it as low methoxyl pectin and demonstrating effective DPPH (i.e. 2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging. AIS (2%) exhibited superior gelling capacity, whereas pectin extracted using 2% sodium hydroxide showed notable gelation properties. Additionally, pectin extracted with 2% ammonium oxalate had a remarkable water‐holding capacity of 91.12%. Rheological analysis indicated liquid‐dominant behaviour, with the G ″ value consistently exceeding G '. CONCLUSION These findings suggest that pectin extracted using sodium hydroxide is more suitable for use as a thickening agent, whereas AIS‐derived pectin at a 2% concentration demonstrates potential as a gelling agent. This study offers valuable insights into the characteristics of pectin from P. microphylla Turcz leaves, supporting its application in edible pectin‐based formulations and functional products, thereby promoting the value‐added utilization of this underexplored botanical resource. © 2025 Society of Chemical Industry.