烟梗果胶酶解条件优化及热裂解分析

Optimization of degradation of pectin in tobacco stem by pectinase produced from Aspergillus niger and thermal analysis of pyrolysis products

为降低烟梗中果胶含量,采用单因素及正交实验法对黑曲霉(Aspergillus niger)SW06降解再造烟叶工艺生产线上的二级解纤纯梗中的果胶工艺条件进行了优化。并采用在线裂解气相色谱/质谱法(PY/GC-MS)对烟梗酶解前后热裂解产物进行分析并添加至卷烟中进行感官评价。结果表明,果胶降解最佳反应条件:酶活力29 000 U·m L-1、料液比1∶3、反应温度50℃、处理时间2 h,最大降解率34.82%。二级解纤纯梗经酶解后,裂解产物成分的组成、含量均发生了明显的变化:醇类香味成分由(5.25±0.03)%增加至(6.06±0.02)%;乙酸含量由(9.07±0.15)%减少到(8.31±0.12)%,减少了烟气吸味的辛辣和刺激性;氮杂环类、羰基化合物则分别下降0.11%和1.20%,使烟气中有害物质减少,吸食品质提升。

In order to reduce pectin in tobacco stem, four factors including the amount of pectinase from Aspergillus niger SW06, liquid-material ratio, temperature and time were optimized for the degradation process of tobacco stem by single factor and orthogonal experiment methods. The pyrolysis products of degraded tobacco stem was investigated by on-line pyrolysis gas chromatography/mass spectrometry （PY/GC-MS） prior to and after enzymolysis. The results showed that the maximum degradation rate of 34. 82% was achieved with an enzyme activity of 29 000 U·mL^-1, and a 1 ： 3 ratio of liquid to solid at 50℃ for 2 h. After enzymolysis, the composition and content of pyrolysis of tobacco stem changed obviously. Compared with the control, the alcohol flavor components increased from （5.25 ± 0. 03） % to（6. 06 ± 0. 02） %. While, the acetic acid content decreased from （ 9.07 ± 0. 15 ） % to （ 8.31 ± 0. 12 ） %, The pungent and irritating taste also reduced, and N-heterocycles, carbonyl compounds decreased by 0. 11% and 1.20% , respectively. In general, the harmful compounds in smoke were reduced and smoke quality was improved.