Degumming of ramie bast fibers by Ca2+-activated composite enzyme

In recent years, special attention has been paid to the application of biotechnology in the textile industry. In this study, composite enzyme (contained pectatelyase/hemicellulase/laccase) was employed to degum the ramie bast successfully. Interestingly, the activities of enzymes were enhanced by promotion of Ca²⁺ activated remarkably. The test of degummed ramie fiber performance demonstrated that fiber fineness, breaking strength, whiteness, and residual gum of fibers have greatly improved. Further, the structure and morphous of the fibers before and after degumming was examined and analyzed. The results showed that the gum, hemicellulose, and lignin were removed effectively and treated fibers had the typical cellulose I structure suitable for direct textile and other applications. These outcomes suggested that Ca²⁺-activated composite enzyme could degum the gum of ramie bast effectively, which provided a method to improve the quality of ramie fibers and a theoretical basis for flax degumming technique on an environmentally-friendly basis.     

The effect of oxidation–reduction potential on the degumming of ramie fibers with hydrogen peroxide

Oxidation–reduction potential (ORP) was applied to monitor and control the oxidation reaction of peroxide hydrogen in the degumming process of ramie fibers. The effects of original pH, hydrogen peroxide dosage, oxidation temperature, and reaction time on ORP variations and fiber degumming efficiency were fully investigated. Central composite design method was used to optimize the degumming process. The optimum operating parameters were original pH 11.0, hydrogen peroxide dosage of 5.0 g/L, oxidation temperature of 85°C, and reaction time of 60 min, respectively. When the ORP value in the solution varied from +320 to +350 mV, it could achieve desired and reasonable degumming result. Under this range, the residual gum percentage of treated fibers was relatively lower and the mechanical property was better compared with other ORP values. This study could be instructive in online monitoring and control of ramie fiber preparation process using ORP as an indicating factor.     

Comparative study of degumming of silk varieties by different techniques

Different varieties of silk differ from each other in their chemical composition as well as the physical, chemical and mechanical properties. Silk degumming is a primary important process, which needs to be carried out uniformly to a sufficient level to get good quality in further processes such as dyeing. In the present study, we have compared the efficiencies of five different degumming treatments for eri, tasar and mulberry silk fabrics using conventional, ultrasonic and microwave techniques. Among the various treatments, soda ash plus hydrogen peroxide and enzyme (papain) degumming recipies gave the best results in terms of weight loss and absorbency. As compared to the conventional technique, the treatments under ultrasonication and microwave enhanced the efficiency. The microwave technique was found to be superior, with the advantage of drastic reduction in treatment time, better retention of tensile strength and smooth appearance of silk. The dye uptake also increased after degumming. The molecular conformation of the different silk varieties, as estimated by FTIR spectroscopy, and the crystalline structure, as elucidated by X-ray diffraction, remained unchanged. SEM showed distinct morphological changes on degumming.     

红麻纤维的化学脱胶工艺

 由于红麻纤维木质素含量较高,脱胶工艺效果不佳,严重制约了人们对其的开发利用。本文通过预氧、碱煮、脱胶后处理（尿素浸泡和机械开松）工艺,运用化学与物理相结合的方法对红麻纤维进行脱胶加工,对影响脱胶效果的因子进行了探讨。试验结果表明：双氧水用量为10%（o.w.f）,NaOH用量为6.5%（o.w.f）、Na2S用量为8%（o.w.f）,煮练温度为95℃,煮练时间为140min,尿素浸泡时,质量浓度为3g/L时可达到最佳溶胀效果;机械开松前后,纤维细度（支数）提高了15%、断裂强度仅下降4.7%。经上述工艺可使红麻纤维断裂强度达到3.85 cN/dtex,细度（支数）可达738公支,其可纺性指标以及纤维品质均有明显改善,为后续纺纱利用奠定了基础。     

青豆油脱胶工艺研究

对青豆毛油水化脱胶工艺路线中所添加酸的种类进行了研究,探讨了柠檬酸、磷酸、柠檬酸与磷酸1∶1的混合液等3种酸溶液对青豆油脱胶率的影响效果,并对影响水化脱胶工艺的主要因素进行了单因素试验,以水化时间、水化温度、酸的添加量、加水量等4个因素为研究对象进行进行二次回归旋转正交试验,得出了该工艺的主要影响因素在该工艺中的最佳操作条件,添加的酸为磷酸:柠檬酸为1∶1的混合溶液、脱胶时间55 min、脱胶温度64℃、酸添加量0.4％、加水量6.9％.该条件下得到的青豆油最大脱胶率为11.08％.     

大豆油酶法脱胶的生产应用

以大豆毛油为原料,添加磷脂酶进行酶法脱胶,通过生产实际应用,确定酶法脱胶工艺参数为:磷脂酶A1和磷脂酶C混合酶用量45 mg/kg,pH 5,加水量2％,反应温度52℃,反应时间2h.在此条件下,脱胶油磷含量可降至5 mg/kg,精炼成品油总磷含量可降至1.4 mg/kg,非水化磷脂去除率达到99.3％以上,精炼成品油得率可达97.3％.对比特殊脱胶方法,精炼成品油经济效益提高了74.42元/t.     

酶法脱胶耦联化学精炼技术的研究

以4批大豆毛油为原料,分别采用PLA1、PLC及3G 3种磷脂酶和传统水化法进行脱胶,后续采用化学精炼法制备一级大豆油,并对一级大豆油质量、总体油脂得率和经济收益等影响进行系统评价。结果表明,在一级大豆油质量方面,3种磷脂酶脱胶与传统水化脱胶耦联化学精炼技术制备的一级大豆油,在常规理化指标、营养伴随物、风险因子等方面无显著性差异。在油脂得率方面,上述3种磷脂酶脱胶较传统水化脱胶均有显著性提升,分别可以提升0.85 %、1.20 %、1.28 %;同时,油胶出率及油胶含油均相应减少。在经济收益方面,酶法脱胶耦联化学精炼技术较水化脱胶耦联化学精炼技术经济收益更高,其中采用PLA1酶脱胶经济收益可以增加37.38元/吨,采用PLC脱胶可以增加68.89元/吨,采用3G脱胶可增加76.50元/吨。     

湿法加工关键环节对咖啡品质的影响

目的:优化咖啡湿法加工工艺。方法:探究果胶酶添加量、温度及咖啡干燥方式对咖啡豆风味前体物质、滋味呈味物质含量的影响,通过灰色关联度分析获得质量排序并开展挥发性物质分析。结果:不同果胶酶添加量、温度及晒干、烘干处理样品的蛋白质、粗脂肪、咖啡酸、咖啡因、绿原酸含量及挥发性物质相对含量之间有显著性差异,灰色关联度分析得到2%果胶酶+27℃+晒干处理组咖啡质量排序第一,其生豆中蛋白质含量为14.04%,粗脂肪含量为9.05%,熟豆中咖啡酸含量为1.05 mg/g,咖啡因含量为1.41%,绿原酸含量为13.89 mg/g,主要挥发性物质酯类、酸类的相对含量分别为40.87,7.62μg/g。结论:2%果胶酶+27℃+晒干处理得到的咖啡综合品质最佳。     

不同脱胶方法对浓香菜籽油品质的影响

旨在为实际生产中选择合适的浓香菜籽油脱胶方法提供参考,以浓香菜籽原油为原料,分别采用水化法、饱和食盐水法和柠檬酸法进行脱胶,测定脱胶油磷脂残留量及脱胶前后浓香菜籽油酸值、过氧化值、水分含量、脂肪酸组成及挥发性物质含量,研究不同脱胶方法对浓香菜籽油品质的影响。结果表明：3种脱胶方法脱胶油磷脂残留量从大到小依次为水化法>柠檬酸法>饱和食盐水法;与脱胶前比较,脱胶浓香菜籽油的酸值显著下降,过氧化值、水分含量及油酸、亚油酸含量升高,但3种脱胶方法之间总体无显著差异;3种脱胶方法处理的浓香菜籽油挥发性物质及特征风味物质含量均降低,降低幅度大小顺序均为水化法>饱和食盐水法>柠檬酸法。实际生产中可以结合工艺和产品需求等相关因素选择不同脱胶方法。     

不同提取方法对辣木籽原油和精炼油品质的影响

为探索辣木籽油的高效提取方法,以辣木籽为原料,分别采用索氏抽提法、乙醇水法和水酶法提取辣木籽原油,通过脱胶、脱酸工艺制备辣木籽精炼油,测定辣木籽原油和精炼油的理化指标、叶绿素和类胡萝卜素含量及脂肪酸组成,分析不同提取方法对辣木籽原油和精炼油品质的影响。结果表明：乙醇水法对辣木籽油的气味有一定影响,3种提取方法对辣木籽原油和精炼油的色泽和透明度影响不大;3种提取方法中,水酶法辣木籽原油的酸值,其原油和精炼油的碘值、水分及挥发物含量均最大,氧化诱导时间最长,叶绿素和类胡萝卜素含量最低;3种提取方法对辣木籽油的脂肪酸组成及相对含量无显著影响(p>0.05)。综上,3种提取方法中水酶法提取的辣木籽油的品质总体上较优。