玉米秸秆纤维素及玉米磷酸酯淀粉基可食膜的研究

发布时间：2018-05-18 12:19

本文选题：玉米秸秆纤维素 + 玉米磷酸酯淀粉　；参考：《吉林大学》2017年博士论文

【摘要】：本文是国家科技支撑计划项目(2015BAD16B05)“防腐保鲜新型物流包装材料开发”和吉林省教育厅“十三五”科学技术研究规划项目(JJKH20170435KJ)“玉米秸秆微纳纤维素抗菌、可降解包装材料的制备及其在长白山山野菜保鲜中的应用”的部分研究内容。本文以玉米秸秆为原料,优化了玉米秸秆纤维素(CSC)和玉米秸秆纳米纤维素(NCSC)的制备工艺,并将CSC和NCSC应用到玉米磷酸酯淀粉(CDP)基可食膜中,研究了超声波-微波协同作用对可食膜性能的影响;在此基础上,优化了干式复合法制备玉米磷酸酯淀粉基和玉米醇溶蛋白基双层复合可食膜(C/Z膜)的工艺,并对可食膜的结构和性质进行了表征和分析;进一步研究了玉米磷酸酯淀粉基抑菌可食膜的抑菌性能,并将其应用到集安白桃的涂膜保鲜中。研究结果如下:(1)以玉米秸秆为原料,采用单因素试验和响应面试验确定了制备CSC和NCSC的最佳工艺条件。超声辅助碱法制备CSC的最佳工艺条件为:Na OH质量浓度8.7g/100m L、液料比16:1(m L/g)、超声功率180 W、超声时间96 min,CSC得率为35.19%。超声辅助硫酸水解制备NCSC的最佳工艺条件为:硫酸体积分数64%、超声功率160 W、酸解温度48℃、酸解时间78 min,NCSC得率为38.29%。与CSC相比,NCSC的粒径减小,达到纳米级别;NCSC的L值、a值明显增大(p0.05),b值明显降低(p0.05),NCSC更加洁白、细腻,对光的反射增强,吸水膨胀力显著增加(p0.05),持水力显著降低(p0.05)。傅立叶变换红外光谱(FTIR)分析表明,硫酸水解去除了半纤维素和木质素成分,NCSC仍保持着CSC的基本化学结构。X射线衍射(XRD)分析表明,CSC和NCSC的晶体类型基本一致,NCSC的衍射峰更加尖锐和细窄,强度增加,NCSC的结晶度显著提高(p0.05)。热失重(TGA)分析表明,NCSC热分解温度比CSC略低,CSC和NCSC的热分解温度均超过200℃,二者均具有较好的热稳定性。(2)以CDP和CSC作为成膜基材,通过共混流延方法制备可食膜。采用主成分分析法和响应面试验优化得到可食膜的最佳制备工艺参数为:CDP-CSC质量比8.5:1.5,CMC质量浓度0.8 g/100 m L、Gly质量浓度1.0 g/100 m L,可食膜性能综合分为0.737,对应可食膜抗拉强度(TS)、断裂伸长率(EAB)、水蒸气透过系数(WVP)、氧气透过率(OP)和透光率(LT)分别为19.75 MPa、46.89%、1.167×10-12 g/(cm·s·Pa)、2.78×10-2g/(m2·d·Pa)和41.86%,添加CSC可以改善可食膜的机械性能,阻隔性能和透光性。利用超声波-微波协同改性处理,可以改善CDP/CSC膜的机械性能、阻隔性能和透光性。FTIR和XRD分析表明,经过超声波-微波协同处理后的CDP/CSC膜各组分分子间产生了较强的相互作用,改善了膜的性能。SEM分析表明,通过超声波-微波协同处理的CDP/CSC膜表面更光滑平整,截面致密有序,提高了共混体系的相容性。(3)采用超声波-微波协同改性制备玉米磷酸酯淀粉/秸秆纳米纤维素/聚乙二醇(PEG)可食膜(P-CDP/NCSC)。结果表明,通过添加NCSC和PEG,使可食膜的TS和EAB均有不同程度的提高,其中P-CDP/NCSC可食膜的TS和EAB分别达到最大值39.47 MPa和135.75%;CSC、NCSC和PEG的加入亦可有效提高CDP可食膜的阻隔性能,使WVP和OP显著降低(p0.05)。FTIR和XRD分析表明,CSC、NCSC、PEG的添加使膜分子间的氢键作用加强,CDP/NCSC膜的具有更高的结晶性,而PEG的加入,则改善了膜的韧性和相容性。TGA分析表明,CSC和NCSC可提高可食膜的热稳定性。SEM分析表明,添加NCSC对于形成均匀、连续、致密的膜结构具有更好的作用。(4)采用主成分分析法和响应面试验优化得到干式复合法制备玉米磷酸酯淀粉基和玉米醇溶蛋白基双层复合可食膜(C/Z膜)的最佳制备工艺参数为:C膜:Z膜6:4,热压温度135℃、热压次数3次,C/Z膜性能综合分为0.729,对应TS、EAB、WVP、OP和LT分别为39.96 MPa、61.35%、0.4526×10-12 g/(cm·s·Pa)、0.8649×10-2 g/(m2·d·Pa)和43.63%。C/Z膜与CDP/NCSC膜和P-CDP/NCSC膜相比,TS提高,EAB和LT下降,阻湿、阻氧性能增强。FTIR分析表明,Z膜中的羟基、羰基、氨基与C膜中的羟基、羰基、双键等活性基团之间产生了较强的氢键缔合,C/Z膜仍保留着C膜的基本结构。XRD分析表明,C/Z膜的衍射峰强度明显高于C膜,结晶度提高。TGA分析表明,C/Z膜的最大热降解温度305.57℃,高于C膜的最大热降解温度294.18℃,C/Z膜比C膜的热稳定性能提高。宏观形貌和SEM分析表明,C膜、Z膜和C/Z膜的表面均较光滑,无明显的颗粒、褶皱及孔洞,并具有良好的透明性和韧性;C/Z膜表现为双层致密的截面结构,无明显的相分离现象。(5)玉米磷酸酯淀粉基抑菌可食膜的抑菌性能研究表明,乳酸链球菌素(Nisin)添加到可食膜中,可有效抑制革兰氏阳性细菌(金黄色葡萄球菌、枯草芽孢杆菌)的生长繁殖,随着Nisin添加量的增大,可食膜对大肠杆菌的抑制作用和黑曲霉菌丝的生长抑制率明显提高。Nisin和ε-聚赖氨酸(ε-PL)复合使用时,可产生协同抑菌效应,不仅对革兰氏阳性菌有良好的抑菌效果,而且可使其对革兰氏阴性菌的抑菌效果增强;同时使可食膜对黑曲霉菌丝的生长抑制率明显提高。(6)将玉米磷酸酯淀粉基可食膜应用在集安白桃涂膜保鲜中,结果表明,经涂膜保鲜处理的集安白桃样品感官品质、失重率、褐变指数、硬度、可溶性固形物含量、可滴定酸含量、维生素C含量、丙二醛含量、过氧化物酶和多酚氧化酶活性等指标均优于未涂膜处理的样品。涂膜处理可在果实表面形成保护层,减少营养成分损失,延缓果实成熟;亦可抑制微生物对果实的侵染,防止果实腐烂,延长贮藏保鲜时间。
[Abstract]:This article is the national science and technology support program (2015BAD16B05) "the development of new logistics packaging materials for preservation and preservation" and the "13th Five-Year" science and technology research project (JJKH20170435KJ) of the Jilin Provincial Education Department (13th Five-Year) "corn straw micronanosilicon antibacterial, biodegradable packaging materials and its application in the preservation of Changbai Mountain wild vegetables" In this paper, the preparation technology of corn straw cellulose (CSC) and corn straw nanoscale (NCSC) was optimized with corn straw as raw material, and CSC and NCSC were applied to the edible film of corn phosphate starch (CDP) base, and the effects of ultrasonic and microwave co action on the performance of edible film were studied. On this basis, the optimization was made. A dry compound method was used to prepare the double composite edible film (C/Z film) of corn phosphate starch base and corn gliadin, and the structure and properties of the edible film were characterized and analyzed. The bacteriostasis performance of the edible film was further studied and applied to the preservation of the coating film of Ji'an white peach. The results are as follows: (1) the optimum technological conditions for the preparation of CSC and NCSC are determined by single factor test and response interview with corn straw as raw material. The optimum technological conditions for the preparation of CSC by ultrasonic assisted alkali method are as follows: Na OH mass concentration 8.7g/100m L, liquid ratio 16:1 (m L/g), ultrasonic power rate of 180 W, ultrasonic time 96 min, and the rate of ultrasonic assisted sulfur assisted sulfur The optimum conditions for the preparation of NCSC by acid hydrolysis are as follows: the volume fraction of sulfuric acid is 64%, the ultrasonic power is 160 W, the acid hydrolysis temperature is 48, the acid hydrolysis time is 78 min, the yield of NCSC is 38.29%. and CSC, the NCSC size decreases, and the NCSC's L value is obviously increased (P0.05), the b value is obviously reduced, and the reflection of the light is enhanced, The swelling power of water absorption increased significantly (P0.05) and the water holding capacity was significantly lower (P0.05). The Fu Liye transform infrared spectroscopy (FTIR) analysis showed that the hydrolysis of sulfuric acid removed the hemicellulose and lignin components. NCSC still maintained the basic chemical structure of CSC by.X ray diffraction (XRD) analysis, indicating that the crystal types of CSC and NCSC were basically the same, and the diffraction peak of NCSC was more sharp. The crystallinity of NCSC increased significantly (P0.05). The thermal weight loss (TGA) analysis showed that the thermal decomposition temperature of NCSC was slightly lower than that of CSC, and the thermal decomposition temperatures of CSC and NCSC were more than 200 degrees C, and all two had better thermal stability. (2) the edible film was prepared with CDP and CSC as film forming material by CO mixed flow extension method. The optimum preparation parameters of the edible film were as follows: CDP-CSC mass ratio 8.5:1.5, CMC mass concentration 0.8 g/100 m L, Gly mass 1 g/100 m L, the performance of edible film integrated into 0.737, corresponding to edible film tensile strength (TS), elongation at break (EAB), vapor transmission coefficient, oxygen transmittance and transmittance (LT) is 19.75 MPa, 46.89%, 1.167 * 10-12 g/ (cm. S. Pa), 2.78 * 10-2g/ (m2. D. Pa) and 41.86%. Adding CSC can improve the mechanical properties, barrier properties and light transmittance of the edible film. Strong interaction was produced among the components of CDP/CSC film after the sound wave microwave CO treatment. The performance of the membrane was improved by.SEM analysis. The surface of the CDP/CSC membrane was smooth and smooth through the ultrasonic wave microwave CO treatment. The compatibility of the blend system was improved. (3) the co modification of Maize by ultrasonic wave and microwave was used to prepare the corn. Phosphate starch / straw nanoscale / polyethylene glycol (PEG) edible film (P-CDP/NCSC). The results showed that the TS and EAB of the edible film were improved in varying degrees by adding NCSC and PEG, and the TS and EAB of the P-CDP/NCSC edible film reached the maximum value of 39.47 MPa and 135.75% respectively. WVP and OP decreased significantly (P0.05).FTIR and XRD analysis showed that the addition of CSC, NCSC, and PEG enhanced the hydrogen bond between the membrane molecules, and the CDP/NCSC film had a higher crystallinity. The addition of PEG improved the.TGA analysis of the toughness and compatibility of the membrane. NCSC has a better effect on the formation of uniform, continuous and dense membrane structures. (4) the optimum preparation parameters of the dry compound method for preparing corn phosphate starch base and zein bilayer composite edible film (C/Z film) are optimized by principal component analysis and response surface test. The optimum preparation parameters are as follows: C film: Z membrane 6:4, hot pressing temperature 135, hot press 3 times, the performance of C/Z membrane was divided into 0.729, corresponding to TS, EAB, WVP, OP and LT, respectively 39.96 MPa, 61.35%, 0.4526 x 10-12 g/ (cm s. Pa), 0.8649 * 10-2 g/. The active groups such as hydroxyl group, carbonyl group and double bond produced strong hydrogen bond association. The C/Z film still retained the basic structure of C film.XRD analysis showed that the diffraction peak intensity of C/Z film was obviously higher than that of C film. The crystallization degree of.TGA analysis showed that the maximum thermal degradation temperature of C/Z film was 305.57, higher than the maximum thermal degradation temperature of C film, and C/Z film was higher than C. The thermal stability of the membrane was improved. The macro morphology and SEM analysis showed that the surface of C film, Z film and C/Z film were smooth, without obvious particles, folds and holes, and had good transparency and toughness. The C/Z film showed a double dense cross section structure and no obvious phase separation. (5) the antibacterial properties of the edible film of corn phosphate starch based bacteriostasis The results showed that the addition of Nisin to the edible film could effectively inhibit the growth and reproduction of Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). With the increase of the amount of Nisin, the inhibitory effect of the edible film on Escherichia coli and the growth inhibition rate of Aspergillus niger mycelium increased significantly by.Nisin and epsilon (epsilon). PL) combined use, can produce synergistic bacteriostasis effect, not only have good bacteriostasis effect on Gram-positive bacteria, but also enhance the bacteriostasis effect of Gram-negative bacteria, and increase the growth inhibition rate of edible film to Aspergillus niger. (6) the application of corn phosphate starch based edible film to the preservation of Ji'an white peach film The results showed that the weight loss rate, browning index, hardness, soluble solid content, titratable acid content, vitamin C content, malondialdehyde content, peroxidase and polyphenol oxidase activity were superior to those without film treatment in Ji'an white peach samples treated with film preservation. The protection layer can reduce loss of nutrients, delay fruit ripening, inhibit microbial infection of fruits, prevent fruit decay and prolong storage time.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TS206.4

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