蚕蛹中蛋白质与甲壳分离的研究

以脱脂蛹为原料,采用电子光学显微分析技术,观察酸、碱浸泡样组织结构变化,确定了碱法为蛋白质与甲壳素的分离方法。选定了NaOH溶液为分离试剂,就工艺条件(温度、碱浓度、固液比、时间)对蚕蛹蛋白与甲壳素分离效果的影响进行了研究。结果表明,在本实验条件下,最佳工艺条件:温度80℃,固液比1:12,时间10min,碱浓度1(wt)%。甲壳得率为2.46%,粗蛋白回收得率为78.91%。     

中国鲎甲壳素的制备及其性能研究

研究了在中国鲎壳中分离出甲壳素 ,得出最佳工艺条件为 :先用 1 mol/L盐酸浸泡鲎壳 ,水洗至中性后用 2 mol/L的氢氧化钠溶液浸泡 ,再用 1 mol/L的盐酸浸泡 ,最后在 80°C下与 2 mol/L的氢氧化钠溶液反应 3h;产率为 30 %。用红外光谱和 X-衍射对产物进行了表征。保湿和吸湿实验表明中国鲎甲壳素有较好的保湿和吸湿性能     

中国鲎甲壳素的制备及其性能研究

研究了在中国鲎壳中分离出甲壳素，得出最佳工艺条件为：先用1mol/L盐酸浸泡鲎壳，水洗至中性后用2mol/L的氢氧化钠溶液浸泡，再用1mol/L的盐酸浸泡。最后在80℃下与2mol/L的氢氧化钠溶液反应3h，产率为30％。用红外光谱和X-衍射对产物进行了表征。保湿和吸湿实验表明中国鲎甲壳素有较好的保湿和吸湿性能。     

微晶纤维素的合成

作为天然植物纤维原料制品,微晶纤维素在医药食品工业中具有先天的优势和独特的性质,是多功能的辅料[1]。国外微晶纤维素产品主要是以特殊等级的高α-纤维素含量的纯木材纤维素为原料,而国内传统采用棉为原料,其中棉短绒中纤维素含量较高,约在90%以上,是制备微晶纤维素的良好原料[2]。本实验主要探讨由棉短绒制备微晶纤维素的条件。实验发现脱脂过程中氢氧化钠浓度和脱脂时间有较大影响,最佳条件为20%氢氧化钠溶液室温下浸泡72 h,然后在90~95℃水浴温度下搅拌约220 min。脱脂后的棉短绒经过氧化氢漂白后直接用盐酸催化水解,水解过程中盐酸浓度、时间和温度对最终产物影响较大,结晶最好的条件为10%盐酸、90℃搅拌水解145 min。测试了产物的XRD,证明所得的产物有较好的结晶度。     

蚕蛹中油脂的提取

<正> 蚕蛹中含蛋白质多,从中可提取蛹酪素,聚蛋白、水解蛋白或复合氨基酸等。用蚕蛹制备复合氨基酸时,蛹体中油脂残余量的多少,对产品的质量有较大的影响。为了获得满足食用氨基酸所用的脱脂蚕蛹,我们在浙江湖州生化厂设计安装了一套蚕蛹脱脂装置。经反复试验表明,该装置生产的脱脂蛹,完全符合制备合格复合氨基酸的要求。     

壳聚糖碱液法制作工艺的优化试验

以天然虾壳为原料,对碱液法制备甲壳素、壳聚糖的工艺进行了优化试验.结果表明,二次酸碱法反应制备甲壳素的常规工艺中盐酸的使用浓度为3%～8%,在此范围盐酸使用浓度愈高甲壳素的品质越好;在壳聚糖的制作过程中,当反应温度为100 ℃,反应时间为8 h,氢氧化钠溶液浓度为60%时,得出的壳聚糖产品脱乙酰度高.     

蟹壳制备壳聚糖的工艺研究

以干燥蟹壳为原料,采用盐酸脱钙,稀碱脱蛋白,浓碱脱乙酰基的工艺,通过实验得到由蟹壳制备壳聚糖的最佳工艺条件:6%盐酸常温脱钙反应6 h;6%氢氧化钠80℃搅拌反应4 h脱蛋白;得到的甲壳素产品中加入50%氢氧化钠70℃搅拌反应4 h以脱除乙酰基,过滤干燥后即可得到壳聚糖产品。     

橡胶表面处理对环氧树脂/橡胶混凝土力学性能的影响

为了增强橡胶颗粒与环氧树脂胶粘剂之间的界面粘接强度,提升环氧树脂/橡胶混凝土的力学性能,采用清水、盐酸溶液、氢氧化钠溶液、二氯甲烷、四氯化碳分别对橡胶颗粒浸泡处理,考查了不同处理方式对环氧树脂/橡胶混凝土力学性能和橡胶颗粒表面形貌的影响。结果表明,除Na OH溶液使环氧树脂/橡胶混凝土弯曲强度和压缩强度降低外,其余溶剂均使弯曲强度和压缩强度提升;除清水使峰值应变和峰值应变能降低外,其余溶剂均使峰值应变和峰值应变能提升。随着盐酸溶液处理时间的延长,环氧树脂/橡胶混凝土的弯曲强度和压缩强度均先增大后减小,弯曲峰值应变也先增大后减小,压缩峰值应变基本无变化,橡胶颗粒表面形貌发生变化。建议橡胶颗粒采用盐酸溶液浸泡处理8 h,环氧树脂/橡胶混凝土具有较好的综合力学性能、经济性和环保性。     

蝇蛆壳中提取甲壳素工艺研究

以蝇蛆壳为原料提取甲壳素,并用盐酸除无机盐、氢氧化钠除蛋白质、次氯酸钠脱色.实验确定较佳工艺条件为:除无机盐,m(蝇蛆壳)∶V(HCl)=1 g∶5 mL(c(HCl)=2 mol/L),室温反应2 h;除蛋白质,m(蝇蛆壳)∶V(NaOH)=1 g∶5 mL(w(NaOH)=2%),室温下反应6 h.经质量分数为0.5%的NaClO室温3 h脱色后得到白色的甲壳素,收率30%(以干燥蝇蛆壳质量计).     

可控酶解蚕蛹蛋白制备抗氧化活性多肽的研究

以脱脂、脱色后的蚕蛹蛋白粉为原料,选取碱性蛋白酶、胰蛋白酶、中性蛋白酶、木瓜蛋白酶和胃蛋白酶对超声处理后的蚕蛹蛋白溶液进行单酶以及复合酶水解实验,以蛋白水解度、多肽得率和水解产物的抗氧化活性为指标筛选出最适单酶和最适复合酶,采用响应面法确定可控酶解蚕蛹蛋白制备抗氧化活性多肽的最佳工艺条件为:选用碱性蛋白酶+中性蛋白酶(碱性蛋白酶∶中性蛋白酶=1.3∶1)作为最适水解酶,超声处理(10min,工作3s,间歇2s)蚕蛹蛋白溶液,pH值7.47、固液比1∶10(g∶mL)、加酶量2.1%、水解时间2.7h、温度59.2℃。在此工艺条件下,蛋白水解度为41.73%,多肽得率为33.29%,水解产物的羟基自由基清除率为59.48%、超氧阴离子自由基清除率为40.57%。     

柠檬酸钠生产工艺中脱色后的活性炭再生研究

柠檬酸钠生产过程中,因柠檬酸由发酵而来,其溶液中含有残糖、碳氢化合物、蛋白等杂质,高温过程中会发生相应的化学反应,造成溶液颜色加深,经活性炭处理后．进入下一工序,处理后的活性炭依据环保要求不能排放,因而必须妥善处理。本实验采用盐酸预处理、微波降解、氢氧化钠洗脱、氢氧化钾活化的方法对活性炭再生。研究表明：用20％的HCl进行对活性炭预处理;微波加热温度采用800--900℃,活性炭湿度在30％～40％;用20％的NaOH洗脱,90℃下反应1h,最后用熔融的无水氢氧化钾括化处理,再生后的活性炭活性恢复到原来的94％左右。     

海藻酸钙纤维非织造布的水凝胶化改性及机理

采用HCl水溶液和NaOH乙醇溶液,通过两步法对海藻酸钙纤维针刺非织造布进行水凝胶化改性,研究改性工艺对样品结构与性能的影响,并探究改性机理。结果表明,HCl水溶液的最佳浓度为0.05%～0.1%（质量）,NaOH乙醇溶液的最佳浓度为0.008%～0.016%（质量）,此时改性样品的遇水凝胶性能最佳,吸水量提高了1.45倍,但厚度、断裂强力等物理性能变化不大。HCl处理破坏了纤维的“egg-box”结构和结晶结构,降低了其结晶度和Ca²⁺含量,但在纤维分子间形成了酯键。NaOH处理使新形成的酯键水解,削弱纤维分子间的作用力,使得大量水分子扩散进入到纤维大分子之间,并通过氢键作用形成三维网络结构,从而转变成凝胶体。     

Optimum parameters for production of chitin and chitosan from squilla (S. empusa)

Chitin and chitosan of high quality were produced from squilla, a by‐catch of Indian Ocean fisheries, by demineralization, deproteination, and deacetylation. Optimum conditions for the production of chitin and chitosan were determined. The quality of chitin was assessed from its ash and protein content. Ash content was below 1% after treatment with 4% HCl for 12 h at 50°C. A protein content of less than 1% could be achieved by treatment with 4% NaOH in 12 h but only at a temperature of 70°C or higher. Production of chitin was also tested by a three‐stage treatment with altering sequence of sodium hydroxide and hydrochloric acid (HCl–NaOH–HCl or NaOH–HCl–NaOH). This three‐step treatment appeared to be successful to achieve a mineral content and protein content below 1% within 30 h and at a temperature not exceeding 50°C. The chitin obtained under optimum conditions was tested for deacetylation using NaOH concentrations of 40 and 50% for 12–44 h at 30, 50 and 70°C. The chitosan obtained had a degree of deacetylation of 77–86%, a viscosity of 8.2–16.2 × 10² cps, solubility of 98%, and molecular weight of ? 1 × 10⁶ dalton. The data show that processing of squilla waste can lead to a high quality chitosan, useful for a broad range of applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 103: 3694–3700, 2007     

Variation in Properties of Chitosan Prepared at Different Alkali Concentrations from Squid Pen and Shrimp Shell

Chitin from squid pen (Loligo sp.) and kiddi shrimp shell (Parapenaeopsis stylifera) were treated at room temperature (30 ± 2°C) with four different concentrations of sodium hydroxide: 20, 30, 40, and 50% w/w. With 50% sodium hydroxide solution, within 108 h, the chitin from squid pen was deacetylated to give chitosan. But it required 126 h at 40% and 144 h at 30% concentration of sodium hydroxide. In the case of chitin from Parapenaeopsis stylifera, complete deacetylation took place after 120 h and 168 h at 50 and 40% concentrations of sodium hydroxide, respectively. But shrimp shell on treatment with 20 and 30% sodium hydroxide solutions and squid pen kept at 20% sodium hydroxide were not sufficiently deacetylated even after 480 h. Properties like degree of deacetylation, viscosity and molecular weight of the prepared chitosan samples were studied. Minimum alkali concentration required for the formation of chitosan at room temperature was found to be 30% for squid chitin and 40% for shrimp chitin. With the increase in the time of deacetylation, decreases in molecular weight and viscosity were observed in chitosan from both sources. Maximum viscosity was recorded by chitosan prepared from squid pen using 30% sodium hydroxide solution at room temperature.     

Protein fractionation and properties of salicornia meal

Salicornia bigelovii Torr. is an annual salt-marsh oilseed plant. Hexane-defatted salicornia meal was extracted sequentially with 0.5 M sodium chloride (2x), water, 70% ethanol, and 0.1 N sodium hydroxide (2x). Each sodium chloride extract was dialyzed against deionized water and centrifuged to separate a water-soluble fraction (albumin) from a salt-soluble fraction (globulin) before freeze-drying. Ethanol extracts and neutralized sodium hydroxide extracts (glutelin) were dialyzed against water and freeze-dried. Globulin accounted for the highest amount of protein nitrogen, followed by glutelin and albumin. SDS-PAGE of reduced albumin, globulin, and glutelin showed a number of protein bands. Nitrogen solubility of defatted salicornia meal from pH 2 to 11 indicated a minimum solubility of 22%, around pH 4.5. Nonprotein nitrogen of defatted meal was 23% of total nitrogen, higher than defatted soybean, sunflower, and rapeseed meals. Albumin had the highest proportion of lysine and sulfur amino acids per 16 g nitrogen among all the fractions analyzed.     

<Emphasis Type="Italic">Lesquerella fendleri</Emphasis> protein fractionation and characterization

Lesquerella fendleri is a promising new crop whose seed contains hydroxy FATG with potential industrial uses as well as substantial amounts of valuable gums. The defatted L. fendleri seeds also contain more than 30% protein. The objective of this study is to process and characterize this protein component for possible future uses in food. Hexane-defatted seed has more than 30% protein content. Defatted lesquerella meal was extracted sequentially with 0.5 M sodium chloride (2×), water, 70% ethanol, and 0.1 N sodium hydroxide (2×). Each sodium chloride extract was dialyzed against deionized water and centrifuged to separate the water-soluble fraction (albumin) from the salt-soluble fraction (globulin) before freeze-drying. The ethanol extract and the neutralized sodium hydroxide extracts (glutelin) were dialyzed against water and freeze-dried. Albumin had the highest proportion of lysine and sulfur amino acids per 16 g nitrogen among all the fractions analyzed. Glutelin and globulin accounted for the highest amount of protein nitrogen. SDS-PAGE of the reduced albumin, globulin, and glutelin showed the presence of several protein bands with M.W. ranging from 7 to 98 kDa. Nitrogen solubility of defatted lesquerella meal from pH 2 to 12 indicated a solubility minimum of 15% around pH 4.2 and a solubility of 75% at pH 11.5. Nonprotein nitrogen of defatted meal was 12% of total nitrogen. Defatted lesquerella meal has the potential for food use based on good nitrogen solubility and good amino acid composition.     

Extraction of alkaloids and oil from bitter lupin seed

Quinolizidine alkaloids and the oil were recovered from seeds of bitter lupin,Lupinus mutabilis, by 2 extractions using hexane as the only organic solvent, Ground and flaked lupin seed was extracted first with hexane, which recovers the oil and those alkaloids that occur as free bases. Subsequently, the hexane-insoluble salts of the alkaloids retained in the defatted flakes were converted into hexanesoluble free bases by treatment with aq sodium carbonate or ammonium hydroxide and removed by another extraction with hexane. A low-alkaloid proteinaceous meal was obtained with practically no loss of protein. The alkaloids dissolved in the oil were completely recovered by extraction with aq hydrochloric acid.     

盐酸深解吸工艺的改进

简述常规的浓盐酸解吸工艺和传统的稀盐酸深解吸工艺,建议对现有处理工艺中产生的大量质量分数为1％的盐酸废液在氯化钙浓缩釜中用氢氧化钙中和后再蒸发,改进后,采用碳钢设备,不产生废液,实现了清洁生产,降低了成本.