Abstract：
Pectin was extracted from red dragon fruit (Hylocereus polyrhizus) peel using two different extraction methods: subcritical water extraction (SCWE) and conventional acid extraction (AE), from two different types of peels, fresh peel puree and dried peel powder. SCWE method on fresh peel puree showed an ∼18.88 % increase in pectin yield compared to AE. Extracted pectin is classified as low methoxyl pectin (DE: 8.51-50.64 %), with an average molecular weight ranging from 115.23 kDa to 577.84 kDa and a Gal-A content of 44.09 % - 53.90 %. The potential of pectin from fresh peel puree to be applied as a biodegradable film was further explored. Different pectin concentrations (3-5 % w/v) were used to prepare the films. Regarding the film performance, PF-S5, which was produced from SCWE with 5 % of pectin concentration, exhibits better thermal stability (Tdmax 250 °C, residue of 28.69 %) and higher moisture barrier (WVP 5.59 × 10-11 g.cm-1.s-1.Pa-1). In comparison, PF-A showed lower water solubility (45.14-69.15 %), higher water contact angle (33.01° - 44.35°), and better mechanical properties (TS: 2.12-4.11 MPa, EB: 48.72-61.39 %). Higher molecular weight accompanied by higher DE and Gal-A content contributes to better pectin film properties.
摘要：
使用两种不同的提取方法：亚临界水提取（SCWE）和常规酸提取（AE），从红火龙果（Hylocereuspolyrhizus）果皮中提取果胶。来自两种不同类型的果皮，新鲜果皮泥和干果皮粉。对新鲜果皮果泥的SCWE方法显示，与AE相比，果胶产量增加了〜18.88％。提取的果胶被归类为低甲氧基果胶（DE：8.51-50.64％），平均分子量为115.23kDa至577.84kDa,Gal-A含量为44.09%-53.90%。进一步探索了来自新鲜果皮泥中的果胶作为生物可降解膜的潜力。使用不同的果胶浓度(3-5%w/v)来制备膜。关于电影表演，PF-S5，由SCWE生产，果胶浓度为5％，表现出更好的热稳定性(Tdmax250°C，残留28.69%）和更高的防潮屏障（WVP5.59×10-11g.cm-1。s-1.Pa-1）。相比之下,PF-A显示较低的水溶性（45.14-69.15%），较高的水接触角（33.01°-44.35°），和更好的机械性能（TS：2.12-4.11MPa，EB：48.72-61.39%）。较高的分子量伴随较高的DE和Gal-A含量有助于更好的果胶膜性质。
