果胶酶降解混合浆果胶的条件优化及热裂解分析

Optimization of Degradation of Pectin in High-concentrated Mixed Slurry by Pectinase and Thermal Analysis of Pyrolysis Products

为研究黑曲霉产果胶酶生物降解在再造烟叶所含果胶的含量,改善烟草薄片的品质,以河南中烟再造烟叶工艺生产线上的高浓混合浆为原料,采用单因素及正交试验法对果胶酶降解果胶工艺条件进行优化。结果表明,果胶降解最佳反应条件为酶活力为10 000 U/m L、料液比1∶1(g∶m L)、反应温度50℃、处理时间3.0 h,果胶降解率达到最大,为29.26%±1.06%。高浓混合浆经酶解后经在线裂解气相色谱/质谱法(PY/GC-MS)分析发现,裂解产物成分的组成、含量均发生了明显的变化。酶处理前后醛酮类和杂环类化合物的相对含量分别增加2.03和1.96个百分点,酸类、酯类、萜烯类、苯环及酚类、醇类化合物的含量分别降低了0.50、1.17、0.80、1.32、0.04个百分点。对比裂解前后的产物的种类、数量与相对含量发现,利用黑曲霉产果胶酶降解高浓混合浆中的果胶,作用明显。感官评价表明,酶解后的样品添加于卷烟中,使得卷烟香气更加柔和,刺激性减轻,透发性好,但香气量略有不足。

In order to reduce the pectin content and improve the quality of reconstituted tobacco, high-concentrated mixed slurry from Henan Cigarette Industry Tobacco Sheet was used as raw material, the pectin degradation process conditions were optimized by single-factor and orthogonal test methods. The results showed that the optimum reaction conditions were pectin degradation enzyme activity 10 000 U / m L, the ratio of material to liquid 1∶1（g∶m L）, reaction temperature 50 ℃, time 3.0 h,pectin degradation rate reached the maximum, which was 29.26% ＋1.06%. After enzymolysis, the high-concentrated mixed slurry was analyzed by online pyrolysis gas chromatography / mass spectrometry（PY / GC-MS）, the composition and content of pyrolysis product were changed obviously, comparing with the control. The relative contents of aldehydes / ketones compounds and heterocyclic compounds prior to and after enzyme treatment were increased by 2.03 and 1.96 percentage points, respectively, the contents of carboxylic acids, lipids, terpenes, benzene（including phenols） and alcohols were decreased by 0.50,1.17,0.80,1.32,0.04 percentage points, respectiverly. Compared with the compounds, quantity and the relative content of pectin content of the pyrolysis products prior to and after enzymolysis, it was found that Aspergillus niger pectinase has significant effect on reducing the pectin content of high-concentrated mixed slurry. Sensory evaluation showed that after the samples after enzymolysis were added to the cigarette, the aroma of the cigarettes became softer, less irritation, better permeability, but slightly less aroma amount than control.