共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
以高粱淀粉为原料,优化高粱多孔淀粉的制备工艺并对多孔淀粉的理化性质进行了研究。结果表明:高粱多孔淀粉最佳酶解工艺条件为酶配比1∶5(g/g)、底物浓度25%、酶添加量3%、酶解时间10 h、酶解温度50℃、pH4.6,在该条件下制得的多孔淀粉的吸油率为132.04%,比容积为2.39 g/cm~3、溶解率为3.97%、膨胀率为13.80%、透光率为11.89%,较原淀粉分别提高了92.81%、21.31%、69.65%、38.41%、7.2%;扫描电子显微镜(SEM)显示多孔淀粉颗粒完整,表面形成类似蜂窝状孔洞,孔径大小及孔深适中,淀粉内部形成中空结构,成孔效果较好。 相似文献
7.
为了制备高吸油率的马铃薯多孔淀粉,分别采用超声波和加热预处理辅助酶法处理马铃薯淀粉,研究超声波条件与加热预处理条件对多孔淀粉吸油率的影响。研究结果表明:超声波法最佳条件为超声时间30 min、超声功率600 W、酶解温度55℃、pH 6.5、酶用量1.5%,所得多孔淀粉的吸油率为71.34%;加热预处理最佳反应条件为淀粉乳质量浓度30 g/100 mL,加热温度50℃,加热时间为15 min,过筛细度80目,酶解条件同超声波法,制备的多孔淀粉吸油率为69.05%。因此,两种前处理方法都可用于制备多孔淀粉,但超声波辅助酶法优于加热预处理辅助酶法。 相似文献
8.
复合酶法制备多孔淀粉条件的优化 总被引:1,自引:1,他引:1
采用α-淀粉酶和糖化酶复合水解法,以玉米淀粉为原料制备具有较高吸油率的多孔淀粉,研究了复合酶的作用条件对多孔淀粉吸油率和得率的影响,通过测定多孔淀粉的吸油率及扫描电镜分析,对多孔淀粉制备条件进行了优化.试验结果表明,α-淀粉酶在50℃、pH 6.0、水解14 h后,再在pH 4.0、50℃加入糖化酶水解14 h,α-淀粉酶和糖化酶配比为1:2,总酶量为2%时,制得多孔淀粉的吸油率56.62%、得率88.79%.扫描电镜结果显示淀粉颗粒表面小孔分布均匀,孔径适中,孔较深. 相似文献
9.
本文结合酶解预处理、辛烯基琥珀酸酐(OSA)疏水改性和Al3+交联复合改性制备疏水多孔淀粉。探讨了加酶量对疏水多孔淀粉结构及理化性质的影响,并对其吸油性能进行探讨。研究发现:α-淀粉酶与淀粉葡萄糖苷酶协同处理,使玉米淀粉颗粒表面形成了孔洞,成为多孔淀粉。在相同OSA添加量下,随着加酶量的增加,疏水多孔淀粉的取代度降低。激光共聚焦显微镜显示酯化处理后辛烯基琥珀酸(OS)基团在整个颗粒均有分布,随着酶水解率的提高,OS基团更多地分布在疏水多孔淀粉颗粒的内部。疏水多孔淀粉的吸油率随水解率的增大而增大,最高可达52.30%。对玉米油、机油、柴油的吸附率分别为80.41%,52.30%和41.93%。在油水体系中吸水率在6%左右,表现出很好的油水选择性,且保油性好。 相似文献
10.
11.
12.
13.
14.
Fracture properties of potato starch gels, consisting of swollen granules, were studied by bending, uniaxial compression, tension and cutting experiments at various strain rates. The effects of starch granule size and retrogradation were also investigated. Starch gels are very notch-sensitive. Fracture starts from inherent defects in the gel with a size comparable to that of the swollen granules. Fracture parameters like stress and strain at fracture and fracture energy depend on the rate of deformation, in contrast with the rate independent elastic behaviour observed at small deformations. This rate dependency can be different for the different parameters. A possible explanation for the rate dependent fracture is discussed. It implies that the granular structure of the gels is essential for fracture behaviour. 相似文献
15.
An in vitro method was used to evaluate the effect of different types of dietary fiber on the initial rate of hydrolysis of olive oil catalyzed by porcine pancreatic lipase. Lipolysis was measured at pH 6.5 and 37C while stirring at 20 rpm. Excellent recoveries of added known amounts of oleic acid were obtained in control and fiber-containing samples. Dietary fibers tested (all 3% by weight unless otherwise noted) were: red wheat bran, white wheat bran, oat bran, soyfiber, sugarbeet fiber, chitin, chitosan, cellulose, pectin-LM and psyllium seed (1.5%). All inhibited lipolysis (35–85%) except cellulose and pectin. The contribution of aqueous extracts of the insoluble fibers to the total inhibitory properties of the fibers were: 0% for the two wheat brans; 100% for oat bran, chitin, chitosan and sugarbeet fiber; and 63% for soyfiber. 相似文献
16.
MECHANISMS INVOLVED IN the INFUSION of STARCH BASED POROUS FOOD MATERIALS BY OIL BASED LIQUID FOODS.
Mechanisms involved in "infusion", defined as filling in the pores of starch based solid foods with high calorie liquid foods to obtain calorically dense food products, were investigated. Parameters under investigation were the effect of: Pore structure of the solid matrix on infusion uniformity, wettability of the solid matrix on the rate of liquid uptake, viscosity (apparent viscosity for non-Newtonian liquids) and surface tension of the infusing liquid on the rate of liquid uptake and the pressure gradient to be imposed. Infusion uniformity could not be achieved with chocolate syrup, no matter whether the porous solid matrix was highly expanded (Bread, porosity = 0.9) or relatively compact (Cookies, porosity = 0.6), due to the filtration of particulate solids. Infusion was found to be a fast, efficient process which takes place between a moderate vacuum and barometric pressure. For Newtonian oils, wettability was found to be the major mechanism of infusion. 相似文献
17.
18.
本文讨论了用氧化剂处理甘薯淀粉,使其增白。在轻度氧化处理的基础上进一步用交联剂处理,提高淀粉凝胶的强度,即抗剪切、抗水、热能力。交联氧化复合变性甘薯淀粉与蚕豆淀粉配合使用制成的粉丝,与全蚕豆粉丝相比,品质没有显著差异。生产过程简单,易于控制。 相似文献
19.
An increasing amount of research suggests a relationship between the glass‐transition temperature (Tg) and the optimum storage temperature for a frozen food. In addition, the Tg for a frozen food is related to the cooling rate through the temperature range of phase transition for water. The objectives of this study were to investigate the influence of Tgon the rate of starch retrogradation during low‐temperature storage. Rice starch with 65% w/w water content was heated to obtain starch gel as a model food. The influences of cooling rate, storage temperature and time on rate of retrogradation were evaluated. Differential scanning calorimetry was used to measure the Tgand the enthalpy during retrogradation. Results indicated that the retrogradation rate during storage was reduced at a slower cooling rate. The retrogradation rates at storage temperatures above Tgwere higher than at storage temperatures below Tg. 相似文献
20.