酸-乙醇介质制备木薯淀粉糊精的工艺及其优化

以木薯淀粉为原料制备木薯淀粉糊精。木薯淀粉在79～81℃温度下．以不同浓度盐酸（2％、4％、6％）、不同浓度的乙醇水解液介质（70％、80％、90％）和不同水解时间（2．5h、3h、3．5h）进行了不同条件的试验水解。测定了酸水解过程中淀粉的DE值，确定了它们酸水解适宜的工艺条件：盐酸6％、乙醇浓度90％、时间3h。     

酸法醇介质制备红薯淀粉糊精的工艺及特性研究

以红薯淀粉为原料制备红薯淀粉糊精。红薯淀粉在79～81℃温度下,以不同浓度盐酸(2%、3%、4%)、不同浓度的乙醇水解液介质(75%、85%、95%)、不同水解时间(1～5h)进行不同条件的水解。实验测定了水解过程中淀粉的水解程度、DE值、糊精黏度和颗粒微观结构的变化情况。结果表明:在相同乙醇浓度下,随着酸浓度增加,水解程度升高。酸解淀粉糊精的黏度与原淀粉相比数值下降。以2%、4%、6%盐酸处理制备的糊精粒子微观结构无明显变化。75%和85%乙醇介质中反应产物的DE值较相对应的95%乙醇介质中低,通过正交实验确定了水解适宜的工艺条件,酸解的最佳工艺条件为盐酸6%、乙醇浓度95%、时间3h。     

酸-乙醇介质制备红薯淀粉糊精的工艺及其优化

红薯淀粉在80～81℃温度下,以不同浓度盐酸(2%、4%、6%)、不同浓度的乙醇水解液介质(75%、85%、95%)和不同水解时间(3 h、3.5 h、4 h)进行了不同条件的水解实验。测定了水解过程中淀粉的DE值,确定了酸水解最佳工艺条件为盐酸6%、乙醇浓度95%、时间3 h。     

南瓜淀粉制备脂肪模拟物的研究

利用酸水解南瓜淀粉制备脂肪模拟物。研究乙醇浓度、盐酸浓度、反应时间对南瓜淀粉水解物DE值的影响,并通过扫描电镜研究南瓜淀粉基脂肪模拟物的形貌。盐酸水解制备南瓜淀粉基脂肪模拟物的最佳工艺条件为:70%乙醇浓度、6.0%HCl浓度、反应时间5h,此时得到DE值4.24的脂肪模拟物,粒径集中分布于7～8μm之间。     

变性木薯淀粉糊精的制备工艺及其性质研究

以木薯淀粉为原料,采用醇介质酸水解制备变性木薯淀粉糊精.通过正交试验确定了淀粉糊精的制备条件,并对此条件下得到的产品进行了性质研究.结果表明,该产品持水性比原淀粉大,吸湿性较强,感官及其理化特性符合麦芽糖标准,酸解淀粉糊精的粘度与原淀粉相比数值下降,酸处理制备的糊精粒子微观结构无明显变化.     

酸法醇介质制备玉米多孔淀粉

研究了以玉米淀粉为原料酸法醇介质制备多孔淀粉的最佳工艺条件.在考察盐酸质量分数、乙醇体积分数、淀粉浆液质量分数和水解时间对产品吸附能力影响的基础上,通过正交实验优化了其制备工艺.实验结果表明,酸法醇介质制备玉米多孔淀粉的最佳工艺条件为:保持水解温度为80～81℃情况下,盐酸质量分数为2%,乙醇体积分数为80%,淀粉浆液质量分数为30%,水解时间为3 h.此条件下,产品吸油率为52.1%,柠檬黄色素吸附量为1.76 ms/g,产品得率为60.3%.     

以机械活化玉米淀粉为原料酶法制备低DE值麦芽糊精

以机械活化玉米淀粉为原料制备低DE（Dextrose Equivalent）值麦芽糊精,通过单因素实验研究了机械活化时间、反应时间、反应温度、酶添加量、底物浓度、pH对产品DE值的影响,并在此基础上进行了正交实验。结果表明,经机械活化预处理后的淀粉酶解反应活性明显提高,酶解速度加快,酶解时间大大缩短,而原淀粉在相同条件下几乎不与酶作用。正交实验确定了制备工艺的最佳条件为：酶添加量3u·g-1淀粉干基,pH6.5,水解温度45℃,底物浓度10%,水解时间4min,按此条件所得的麦芽糊精DE值为2.35%。并用红外光谱和X-射线衍射对麦芽糊精进行了分析。     

淀粉基脂肪替代物的两种制备方法及应用研究

采用酸法、酶法水解大米淀粉制备脂肪替代物,对比研究两种制备方法,并将制备产品应用于蛋糕中,考察其代脂效果.酶解大米淀粉制备的脂肪替代物在淀粉乳质量分数30%,酶用量0.8%,酶解时间100 min,酶解温度80℃时产品凝胶强度最大.酸解产品在淀粉用量25%、酸用量2%、乙醇体积分数70%、酸解时间60 min和温度70℃条件下凝胶强度最大.蛋糕添加试验表明DE值2.05,添加量为30%时,添加效果比对照样好.     

醇酸降解淀粉制备糊精的研究

采用醇酸水解大米淀粉、高直链玉米淀粉和木薯淀粉,发现：在相同条件下,正丁醇-盐酸水解的木薯淀粉溶解性最大,且在水解3 d后无显著增加。因此,从颗粒结构、晶体结构和分子结构等方面系统地研究醇酸降解木薯淀粉制备糊精过程。经正丁醇-盐酸水解后,木薯淀粉颗粒破坏程度严重,且随水解时间的增加,大部分木薯淀粉颗粒均失去了原有的颗粒形状;经正丁醇-盐酸水解7 d后,木薯淀粉的粒径下降了42.0%。X-射线衍射结果表明正丁醇-盐酸水解木薯淀粉在2θ为20°处出现了衍射峰,证明淀粉在正丁醇-盐酸水解过程中形成了直链淀粉-正丁醇络合物。高效分子排阻色谱和淀粉-碘全波长扫描分析表明：木薯淀粉经过正丁醇-盐酸水解后分子量在4 h内急剧下降,水解4 h后下降趋势减缓,水解3 d后分子量无显著变化并趋于稳定。上述结果表明,采用正丁醇-盐酸水解木薯淀粉3 d为制备糊精的最佳条件。     

酸水解制备变性红薯淀粉的工艺及性质研究

以红薯淀粉为原料,采用醇介质酸水解制备变性红薯淀粉糊精.通过正交试验确定了淀粉糊精的制备条件,并对此条件下得到的产品进行了性质研究.结果表明,持水性比原淀粉显著提高,吸湿性较强,感官及其理化特性符合麦芽糊精标准,酸解淀粉糊精的粘度与原淀粉相比数值下降,酸处理制备的糊精粒子微观结构无明显变化.     

唾液酸溶析结晶工艺的研究

大肠杆菌发酵得到聚唾液酸,经酸水解后得到的唾液酸单体纯度较低,需进一步分离和纯化。考察了唾液酸酸水解液的脱色工艺,添加质量浓度为5%的凹土能有效除去水解液中的红色物质。实验中研究了唾液酸单体的溶析结晶工艺,以无水乙醇为主溶剂溶解唾液酸样品,可实现唾液酸与唾液酸二聚体的分离,以乙酸乙酯为析出剂有效地实现了唾液酸单体的结晶析出,当乙醇/乙酸乙酯的比率为1.0时,得到的唾液酸纯度达到90%~92%的质量分数,回收率为55.4%。     

On the Acid Resistance of Starch Granules

When potato starch was hydrolyzed to form Nägeli amylodextrin by 16% sulfuric acid at 30°C, only the amorphous portion of the starch granules was deteriorated. The crystallinity of Nägeli amylodextrin showing the hydrolysis ratio of 0.22 was 1.28 times as large as that of original starch. The hydrolysis process at above 45°C was given by two exponential equations. The value of acid resistance portion (C_o) at 30 and 38°C was 100%, while the values at 45, 50 and 55°C were 67, 38 and 18%, respectively. The high value of C_o generally showed the high acid resistance in the various starches. Sweet potato and waxy rice starches were more easily hydrolyzed than other starches, although they gave the relatively high value of C_o. Thus, it was slightly more difficult for low acid resistance portion of potato starch to be hydrolyzed than for that of other starches. Moreover, that of waxy rice was easily hydrolyzed.     

黄芪多糖的分子量分布

本文通过分级醇沉、分步醇沉和超滤方法研究黄芪多糖的分子量分布。结果表明:分级醇沉浓度对应的得率随醇浓度的升高而呈增加趋势;糖的含量变化起伏较大,醇浓度为60%时所得多糖含量比较低,醇浓度为30%和70%时所得多糖含量较高;分步醇沉的醇浓度为10%时沉淀下来的多糖所占比例最大,醇浓度达到80%时大部分多糖都可以沉淀下来;而所得多糖含量除90%醇浓度时较低外,其余相差不大;超滤后黄芪多糖大部分分布在离心沉淀和截留分子量150千道尔顿(150kDa)以上部分,两者占了57.6%;其含量除3kDa以下和6kDa至50kDa部分较低外,其它部分含量相差不大。黄芪多糖的分布很不均匀,大分子量和小分子量的多糖较多,而3kDa至150kDa这一段的多糖只占总多糖的13.2%。     

向日葵花盘中绿原酸的微波辅助提取工艺条件研究

以向日葵花盘为原料,采用微波法辅助提取向日葵花盘中的绿原酸,研究可能影响绿原酸提取率的每一个因素。实验中以绿原酸的提取率为考查指标,考查乙醇浓度、料液比、微波时间、微波功率、微波温度、浸提温度、浸提时间、pH等八个因素对绿原酸提取率的影响,通过对提取过程中每一个细致因素的分析,得到较佳的工艺条件:乙醇浓度70%;料液比1∶20;微波温度60℃;微波功率300 W;微波时间6 min;浸提温度70℃;浸提时间20 min;pH值为7。此时向日葵花盘中绿原酸的提取率达到3.12%,为向日葵花盘中绿原酸的工业化微波辅助提取提供了借鉴。     

Effect of two pre-treatments on phenolic acid yield in three forage species

A direct comparison of two pre-treatments was undertaken to test their effect on the recovery of phenolic acids (PA) from three forage species. Samples of lucerne (Medicago sativa L), reed canarygrass (Phalaris arundinacea L), and switchgrass (Panicum virgatum L) were refluxed with 95% ethanol (EtOH) or neutral detergent solution (NDS). Subsequently, the resulting ethanol insoluble residue (EIR) and neutral detergent fibre (NDF) were treated with 1 M NaOH, and the extract was assayed for concentrations of p-coumaric acid (PCA) and ferulic acid (FA). In lucerne, the concentration of PCA was 9 times greater in the EIR than in the NDF (0·90 vs 0·11 mg g^?1 dry matter, DM), and the FA concentration was 27 times greater in forage treated with EtOH than with NDS (1·89 vs 0·07 mg g^?1 DM). In reed canarygrass (RCG), the concentrations of PCA and FA were slightly though significantly higher when the forage was pre-treated with EtOH. No significant differences in PA yield were detected between pre-treatments in switchgrass (SG). Extraction of EIR with hot EDTA (0·025 M , pH = 6·8) removed 80 to 90% of the total PA in EIR in lucerne but less than 5% of the PCA and FA in the grasses. These results indicate that almost all the PA in lucerne, in direct contrast to the grasses, are present in a fraction of the plant that is soluble in NDS. The relatively high PA concentration in the NDS soluble fraction suggests that the structure and composition of the fraction to which PA is esterified influence the degree to which PA affects digestibility.     

Enzymatic Modification of Fish Frame Protein Isolate

Protein isolate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 80%. Frame protein hydrolysates were then employed for plastein synthesis. Enzyme induced plastein was optimized at: (1) pH 5 for pepsin and pH 7 for alpha-chymotrypsin; (2) substrate concentration, 40% w/v; (3) time of incubation, 24 hr; (4) enzyme/substrate ratio, 1:100 w/w. Percent plastein yields of 33.8 and 27.3 were found for pepsin and alpha-chymotrypsin, respectively, when trichloracetic acid was used as the precipitating agent. However, when plastein was precipitated by ethanol, the percent yield was found to be 46 and 40.5 for pepsin and alpha-chymotrypsin, respectively.     

Changes in Crystallinity and Gelatinization Phenomena of Potato Starch by Acid Treatment

The hydrolysis of potato starch by 1-N H₂SO₄/30% ethanol aqueous solution at 45°C increased linearly with increasing of hydrolysis time for 14 d. The relative crystallinity of native starch showed 0.343 and 0.350 by symmetrical reflection and transmission techniques, resp. The increasing ratio of relative crystallinity to hydrolysis time corresponded very closely with that of 1/hydrolysis residue up to 14 d. These facts suggest that only the amorphous region of the starch granules will be hydrolyzed by the acid. By differential scanning calorimetry the calorimetric enthalpy of potato starch containing about 200% moisture content was found to stay largely unchanged by acid treatment for 6 d. The swelling power at 70° and 80°C of potato starch reached to the minimum value and, moreover, from the gel-chromatogram patterns of the acid-treated starches, the crystalline region of the starch granules may begin to deteriorate slightly by acid treatment for more than 6 d, although the relative crystallinity by the X-ray diffraction method increased slightly with passing of hydrolysis time.     

RECOVERY OF PALM CAROTENE FROM PALM OIL AND HYDROLYZED PALM OIL BY ADSORPTION COLUMN CHROMATOGRAPHY

Crude palm oil and crude palm olein were hydrolyzed with lipase from Candida rugosa to produce a free fatty acid (FFA) rich oil. The percentages of FFA produced and carotene degradation after the hydrolysis process were determined. The palm oil and hydrolyzed palm oil were subsequently subjected to column chromatography. Diaion HP-20 adsorbent was used for reverse phase column chromatography at 50C. Isopropanol or ethanol, and n-hexane were used as the first and second eluting solvents, respectively. The objective of hydrolyzing the palm oil was to produce more polar FFA-rich oil in order to enhance the nonpolar carotene bind to the nonpolar HP-20 adsorbent in the column chromatography process. Hydrolyzing palm oil with lipase from Candida rugosa gave 30- and 60-fold, respectively, of FFA in the crude palm oil and crude palm olein in 24 h at 50C. Approximately, 15.56 and 17.48% of carotene degraded in crude palm oil and crude palm olein, respectively. For column chromatography, using isopropanol or ethanol as the first eluting solvent, unhydrolyzed oil and hydrolyzed oil showed the carotene recovery infraction two (carotene-rich fraction) of about 36–37 and 90–96%, respectively. Over 90% of carotene recovery was obtained from     

水解工艺对苦荞提取物中槲皮素含量的影响及其药代动力学研究

目的:以苦荞提取物为研究对象,通过正交实验设计优化苦荞提取物中芦丁被酸水解为槲皮素的工艺条件,并结合药代动力学研究探讨酸水解工艺对苦荞提取物中芦丁和槲皮素吸收的影响。方法:以盐酸百分含量、水解时间、乙醇百分含量、水解温度作为因素设计四因素三水平正交实验优化苦荞提取物中芦丁酸水解为槲皮素的工艺条件,以该工艺进行苦荞提取物酸水解,并在水解第1、2、4、6 h取样得到不同槲皮素含量的水解产物1、2、3、4。分别灌胃大鼠200 mg/kg的苦荞提取物及各水解产物,并在不同时间点采血,以黄芩素为内标,高效液相色谱(HPLC)测定血浆中槲皮素的浓度,DAS 2.0计算主要药代动力学参数。结果:苦荞提取物芦丁酸水解的最佳工艺参数为盐酸百分含量0.91%、水解时间6 h、乙醇百分含量50%、水解温度70 ℃,在该工艺条件下64.11%芦丁转化为槲皮素。苦荞提取物、水解产物1、2、3、4槲皮素的AUC_0-t分别为(17.604±5.422)、(42.175±9.435)、(87.917±19.347)、(116.706±46.256)、(178.509±49.478) mg/L·h,C_max分别为(2.743±1.217)、(7.109±2.603)、(12.438±3.197)、(15.727±4.68)、(20.044±5.736) mg/L。与苦荞提取物相比,其水解产物1、2、3、4的药代动力学参数AUC_0-t、C_max具有显著性差异(p<0.05)。结论:苦荞提取物经酸水解后部分芦丁转化为槲皮素,芦丁和槲皮素在大鼠体内的累计吸收量也相应提高。     

乌桕叶抽提物体外抗氧化活性的研究

为了开发国产特色资源乌桕,综合利用乌桕叶,以90℃热水、70%乙醇、乙酸乙酯提取不同乌桕品种叶材料中的抗氧化物质,用清除羟自由基模型、抑制亚油酸过氧化模型和铁氰化钾还原力模型评价抗氧化活性。结果表明:70%乙醇浸提物和热水提取物显示出较强的还原力(200μg/ml样液相当于2×10-4mol/L的硫脲)和清除羟自由基活性(4mg/ml样液清除率:热水提取物为42.41%～63.62%,醇提取物为20.71%～54.49%),且极大地相关于所含的类黄酮含量(水提物上述两种抗氧化性与类黄酮含量相关性系数分别为:0.7793、0.8258;醇的分别为:0.8319、0.9335)。抑制亚油酸过氧化以乙酸乙酯提取物较强。乌桕叶提取物可望开发抗氧化剂和健康佐剂。