The effectiveness of pressurized hot-water extraction conditions for obtaining galactoglucomannans (GGMs) from Pinus halepensis suitable for applications like coatings and films packaging was investigated. For this purpose, high molar masses with high yields are required, presenting a serious challenge for hot-water extraction processes. The extraction of GGMs was carried out in an accelerated solvent extractor (ASE) and the isolation was performed by precipitation in ethanol. Three temperatures in the range 160–180 °C and five extraction times 5–90 min were tested in order to optimize extraction parameters of GGMs, avoiding thermal and chemical degradation in hot-water. Total dissolved solids (TDS) were determined gravimetrically after freeze-drying and weight average molar masses (M w ) were determined by high-performance size exclusion chromatography (HPSEC). Total non-cellulosic carbohydrates were determined by gas chromatography (GC) after acid methanolysis. Free monomers were additionally analyzed by GC. Lignin in water extracts was measured by an ultraviolet (UV) method. Acetic acid was determined after alkaline hydrolysis of acetyl groups and analyzed by HPSEC. The main parameters influencing the extraction processes of the GGMs, namely, extraction time and temperature were studied. Optimal extraction parameters of GGMs were identified at 170 °C and 20 min extraction time, with average M w of extracted fraction of 7 kDa leading to a GGM yield of approximately 56 mg go.d.m−1${\text{mgg}}_{\text{o}.\text{d}.\text{m}}^{-1}$, corresponding to 6% on dry wood basis.

中文翻译：

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黑松半乳葡甘露聚糖的提取工艺优化

研究了加压热水提取条件从黑松中获得半乳葡甘露聚糖 (GGM) 的有效性，适用于涂料和薄膜包装等应用。为此，需要高产率的高摩尔质量，这对热水提取过程提出了严峻的挑战。GGMs 的提取在加速溶剂提取器 (ASE) 中进行，并通过在乙醇中沉淀进行分离。测试了 160-180 °C 范围内的三个温度和 5-90 分钟的五个提取时间，以优化 GGM 的提取参数，避免热水中的热降解和化学降解。冷冻干燥后通过重量分析法测定总溶解固体（TDS），并通过高效尺寸排阻色谱法（HPSEC）测定重均摩尔质量（M w）。在酸甲醇分解后通过气相色谱法 (GC) 测定总非纤维素碳水化合物。通过GC另外分析游离单体。通过紫外线 (UV) 方法测量水提取物中的木质素。乙酰基碱水解后测定乙酸并通过HPSEC分析。研究了影响GGMs提取过程的主要参数，即提取时间和温度。GGM 的最佳提取参数在 170 °C 和 20 分钟提取时间下确定，提取部分的平均 M w 为 7 kDa，导致 GGM 产量约为 56 mg go.dm−1${\text{mgg}}_ {\text{o}.\text{d}。