以蒸餾系統區分柚子與紫蘇精油、純露、多酚與多醣

Abstract

本研究以柚子 (Citrus maxima) 皮和三種紫蘇 (Perilla frutescens) 葉－青紫蘇、赤紫蘇與白紫蘇為材料，透過蒸餾系統分離與收集多種具生物活性成分－精油、純露、多酚和多醣區分物，研究結果顯示，蒸餾能有效分離富含揮發性萜類的精油與純露至蒸餾所得的水相，同時促進多酚與多醣釋放於殘留水層中並達到濃縮之效果。在揮發性成分分析顯示，柚子皮中主要揮發性化合物為 ᴅ-檸檬烯 （ᴅ-Limonene），綠紫蘇與紅紫蘇中富含紫蘇醛 (perillaldehyde)，白紫蘇中則富含紫蘇酮 (perilla ketone)，進一步以各種液相層析技術分析非揮發性成分，結果顯示，結果顯示柚子、青紫蘇與白紫蘇的多醣主要由半乳糖醛酸組成，而紅紫蘇則以葡萄糖為主。分子量分析顯示所有樣品皆為非均勻分布，其具有甲基化修飾之結果亦證實其屬於高甲氧基多醣。這些發現突顯蒸餾系統的潛力，不僅可同時分離且回收揮發性與非揮發性成分，更可作為一個整合平台，進一步獲得具有功能性與營養保健價值的多重區分物進行後續鑑定。柚子果皮展現出成為食品加工用果膠型多醣的潛力，而紫蘇葉則提供結構多樣的多醣，具有潛在的生物活性。整體而言，本研究為農業副產品的高值化利用提供了一種永續的萃取策略。

This study investigated the use of a steam distillation system for the fractionation and recovery of multiple bioactive components¬¬¬—essential oils, hydrosols, polyphenols, and polysaccharides—from pomelo (Citrus maxima) peel and three types of perilla (Perilla frutescens) leaves: green, red, and white perillas. Results demonstrated that steam distillation successfully recovered essential oils and hydrosols rich in volatile terpenes, while also facilitating the release of polyphenols and polysaccharides into the aqueous distillates and residues. Volatile compounds analysis with gas chromatography-mass spectrometry revealed that ᴅ-Limonene dominates pomelo peel, green and red perillas are rich in perillaldehyde, while perilla ketone is the major component in white perilla. Profiling analysis with various liquid chromatography techniques characterized the non-volatile fractions. Pomelo, green perilla, and white perilla polysaccharides were primarily composed of galacturonic acid, whereas red perilla is mainly comprised of glucose. Molecular weight analysis indicated heterogeneous distributions for all samples, and degree of methylation confirmed their classification of high-methoxyl polysaccharides. These findings highlight the potential of steam distillation not only for recovering volatile and non-volatile compounds but also as an integrated platform for obtaining multiple fractions for subsequent characterization for their functional and nutraceutical properties. Pomelo peel emerged as a promising source of pectin-type polysaccharides suitable for food processing applications, while perilla offered structurally diverse polysaccharides with potential bioactivities. Overall, this work contributes to the valorization of agricultural by-products through sustainable extraction strategies.