摘要
以米根霉乳酸发酵废菌体制备壳聚糖,并对其成膜性能进行研究。结果表明,米根霉发酵100 g/L葡萄糖48 h,可获得51.59 g/L的乳酸和4.36 g/L的米根霉菌体,废菌体中可提取壳聚糖占菌体干质量的13.5%。米根霉菌体提取的壳聚糖脱乙酰度89.4%,高于商品壳聚糖的脱乙酰度86.6%。20 g/L的米根霉壳聚糖溶液黏度5.13 mP a·s,重均分子质量(68.61 ku)与螃蟹壳来源的商品壳聚糖重均分子质量(70.17 ku)相近,两者的红外光谱基本一致。厚度为(0.025±0.002)mm壳聚糖膜,米根霉壳聚糖膜和商品壳聚糖膜的弹性模量分别为42.72和14.64 N/mm2,拉伸强度分别为132.31和44.13 N/m,吸水率分别为52.90%和175.80%,最大失重速率温度分别为281.4和285.4℃,起始和终止分解温度存在差异。米根霉壳聚糖的成膜性能优于商品壳聚糖,适合于食品包装薄膜的制备。
Preparation of chitosan from waste biomass of lactic acid fermentation and its membrane characteristics were investigated. The results indicated that 100 g/L of glucose was fermented by R. oryzae for 48 h, then 51.59 g/L of lactic acid and 4.36 g/L of biomass were obtained, and chitosan extraction yield about 13.5 % of the cell dry weight was achieved . The deacetylation degree of R. oryzae chitosan was 89.4%, which was higher than that of commodity chitosan （ 86. 6% ）. The viscosity of 20 g/L of R. oryzae chitosan solution was 5. 13 mPa·s, and the molecular weight of R. oryzae chitosan（Mw = 68.61 ku, Mn =48.13 ku） was similar to commodity c hitosan （Mw = 70. 17 ku, Mn = 53.53 ku）, which was extracted from crab shell. The results of FT-IR proved that the R. oryzae chitosan was similar to commodity chitosan. When the thickness of membrane was （ 0. 025 ± 0. 002 ） mm, the modulus of elasticity of R. oryzae chitosan membrane and commodity chitosan membrane were 42.72 and 14.64 N/mm^2, respectively. The tensile strengths were 132.31 and 44.13 N/m, respectively. The water absorption rates were 52.90% and 175. 80%, respectively. The temperatures at maixmum decomposition rate were 281.4℃ and 285.4℃, respectively. The onset and final temperature of decomposition were different. The film-forming performance of R. oryzae chitosan was better than that of commodity chitosan, and the R. oryzae chitosan was suitable for food packaging film preparation.
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
2015年第4期35-40,共6页
Chemistry and Industry of Forest Products
基金
江苏高校自然科学重大基础研究项目(11KJA220004)
江苏省六大人才高峰项目(无编号)
江苏省自然科学基金项目(BK20131426)
关键词
米根霉
废菌体
壳聚糖
膜性能
R. oryzae
waste biomass
chitosan
membrane performance
