摘要
以柚皮原料分离得到柚皮纤维,再采用硫酸酸解法制备出柚皮纳米微晶纤维素(Pomelo peel nano-microcrystalline cellulose,PPNCC),对其微观形貌、长径比、红外光谱、结晶度及热稳定性进行表征分析,并研究了PPNCC对羧甲基淀粉(CMS)成膜液流变特性的影响。结果表明:合适的酸解不仅能够有效地去除原料中的果胶、半纤维素以及木质素等无定形区的物质,也能够水解一部分不完美晶区;得到的柚皮纳米微晶纤维素为长径比8~20的棒状晶体,其中长径比大于10的比例超过60%;柚皮纳米微晶纤维素的主体物质还是纤维素,纤维素的主要化学性质并未发生变化;纳米微晶纤维素的相对结晶度由酸解前的55.64%提高到74.35%,但其起始热分解温度由240℃降低至212℃。柚皮纳米微晶纤维素可以作为羧甲基淀粉膜的增强剂,其流变指数n均小于1,表明柚皮纳米微晶纤维素/羧甲基淀粉成膜液为假塑性流体;成膜液的G′>G″,且二者在频率扫描范围内没有发生交叉,表明复合成膜液为弱凝胶结构;黏稠系数KPL值及零剪切黏度η0和动态流变参数中的储能模量G′均与纳米微晶纤维素的添加量呈正相关,表明柚皮纳米微晶纤维素在成膜液中的分散性良好,且有助于增强膜体系网络结构的作用。柚皮纤维纳米化后表现出了较好的功能性质,可以为柚皮的综合利用提供一种新的思路。
Pomelo is an important fruit of citrus.The high fiber content of pomelo peel can be used as a good raw material to extract pomelo peel cellulose.Using pomelo peel cellulose(PPC)as the raw material,the pomelo peel nano-microcrystalline cellulose(PPNCC)was prepared by sulfuric acid hydrolysis method.The micromorphology,aspect ratio,infrared spectrum,crystallinity,and thermal stability of the PPNCC were analyzed.The effect of PPNCC on the rheological properties of carboxymethyl starch film-forming fluid was studied.It was found that the PPNCC was a rod-shaped crystal with an aspect ratio of 8 to 20,and the proportion of aspect ratio greater than 10 was over 60%;the main substance of PPNCC was cellulose;the crystallinity of PPNCC was increased from 55.64%before acidolysis to 74.35%,and its initial thermal decomposition temperature was decreased from 240℃to 212℃.PPNCC could be used as the reinforcing agent of carboxymethyl starch film.According to the equation,the rheological index was less than 1,indicating that pomelo peel nano-microcrystalline cellulose/carboxymethyl starch film forming fluid was pseudoplastic fluid.G′of the film forming liquid was greater than G″,and no crossover occurred between the two within the frequency scanning range,showing that the composite film forming liquid was of weak gel structure.The viscosity coefficient KPL in static rheological parameters,the zero shear viscosity and the energy storage modulus in dynamic rheological parameters were positively correlated with the addition of nanocrystalline cellulose,showing that the dispersibility of PPNCC in the film-forming liquid was good,which was helpful to strengthen the interaction of the internal structure of the film-forming liquid.The nanofilm of pomelo peel fiber showed better functional properties and can be used as a significant direction for comprehensive utilization of pomelo peel.
作者
唐清苗
涂晓丽
余奔
王鲁峰
TANG Qingmiao;TU Xiaoli;YU Ben;WANG Lufeng(College of Food Science and Technology,Huazhong Agricultural University,Wuhan 430070,China;Key Laboratory of Environment Correlative Dietology,Ministry of Education,Huazhong Agricultural University,Wuhan 430070,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2020年第S02期499-506,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(31601504)。
关键词
柚皮
纳米微晶纤维素
羧甲基淀粉
流变
pomelo peel
nanocrystalline cellulose
carboxymethyl starch
rheology
作者简介
唐清苗(1998—),女,硕士生,主要从事果蔬加工研究,E-mail:3290348670@qq.com;通讯作者:王鲁峰(1983—),男,副教授,主要从事果蔬加工与低热量食品研究,E-mail:pipilu001@foxmail.com。
