Synthesis and Characterization of Hydroxypropyl Acorn Starch (HPAS) From Oak Acorn

Abstract

The utilization of forest auxiliary products and their conversion into products with higher added value is important for the use of renewable resources. For this purpose, acorns belonging to the Q. coccifera species were collected in November, which is their ripening period, and dried and ground in the laboratory. Then, acorn starch (AS) was isolated from the sieved acorn flour. For 5 g of this isolated AS, hydroxypropyl acorn starch (HPAS) with the highest molar substitution (MS = 0.319) was synthesized by optimizing at 45 °C for 5 h with 30 g of propylene oxide and 1.88 g of NaOH. The structures of HPASs synthesized were characterized by FT-IR, XRD and 1H (13C)-NMR spectroscopy, and their MS values were determined. In addition, surface morphologies with SEM images and thermal stability with DTA-TG thermograms were examined. Since hydroxypropyl acorn starch has not been synthesized from acorn starch before, this study contributed to the literature and science. It has been understood that HPASs can also be used in many areas where hydroxypropyl starch is used.