干法酯化多孔淀粉的吸油性研究

用十二烯基琥珀酸酐（DDSA）对多孔淀粉进行干法酯化,制得高吸油率的酯化多孔淀粉。研究表明：十二烯基琥珀酸酐的用量为淀粉干质量的6％,无水碳酸钠用量为淀粉干重的4％,加水量为淀粉干质量的40％。在此条件下制得的酯化多孔淀粉吸油率可达78．6％．吸油能力比未酯化前提高了25．5％。     

干法酯化多孔淀粉的吸油性研究

用十二烯基琥珀酸酐（DDSA）对多孔淀粉进行干法酯化,制得高吸油率的酯化多孔淀粉。研究表明：十二烯基琥珀酸酐的用量为淀粉干质量的6％,无水碳酸钠用量为淀粉干重的4％,加水量为淀粉干质量的40％。在此条件下制得的酯化多孔淀粉吸油率可达78．6％．吸油能力比未酯化前提高了25．5％。     

玉米多孔淀粉制备工艺研究

首先研究了吸油率作为考察淀粉成孔指标的可行性;研究酶解工艺时,在单因素实验基础上再进行正交实验,得到最佳酶解工艺条件为:温度55℃,时间28h,pH5.6,淀粉浆浓度60％,加酶量50％,并进一步把此条件运用到放大实验中,取得了较好结果。      

玉米多孔淀粉制备工艺研究

首先研究了吸油率作为考察淀粉成孔指标的可行性;研究酶解工艺时,在单因素实验基础上再进行正交实验,得到最佳酶解工艺条件为:温度55℃,时间28h,pH5.6,淀粉浆浓度60％,加酶量50％,并进一步把此条件运用到放大实验中,取得了较好结果。     

多孔淀粉粉末薄荷油的吸油与缓释性能研究

用多孔淀粉吸附并包埋制备的粉末薄荷油，含油量34％，制备工艺简单，具有较好的缓释性能，适用于添加到固体食品及药品中。     

高粱多孔淀粉制备工艺的优化及理化性质研究

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。     

2种前处理方法对多孔淀粉吸油率的影响

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。     

复合酶法制备多孔淀粉条件的优化

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.     

疏水多孔淀粉的制备及其吸油性能

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。     

粳米多孔淀粉的制备工艺研究

以粳米淀粉为原料,利用生物酶解工艺,在其糊化温度下作用于原淀粉形成多孔性蜂窝状产物———多孔淀粉。在单因素实验基础上进行正交实验,以吸油率为检测指标,得到最佳酶解工艺条件为:温度30℃,反应时间8 h,pH值4.0,底物浓度0.5 g/L,加酶量30%。以期为我国的粳米和淀粉资源综合开发提供一条有效途径,并为推动我国多孔淀粉工业化生产提供参考数据。     

红薯微孔淀粉的制备及性质研究

以红薯淀粉为原料，探讨α-淀粉酶用量、反应温度、反应pH值和反应时间等因素对其微孔化反应的影响，并对微孔淀粉的吸水率、吸油率和X射线衍射以及扫描电子显微镜结构表征进行了研究。     

半连续法生产多孔淀粉的工艺研究

研究半连续法生产多孔淀粉的生产工艺.通过分批加酶和定时除去反应液中的葡萄糖,减小葡萄糖对酶活的抑制,提高酶的利用效率,在单因子试验基础上进行正交试验,得到最佳工艺条件:淀粉浓度40%,加酶量按理论水解55%淀粉的量,pH6.5,温度50℃,时间16 h,转速120 r/min,与连续工艺相比,反应时间从30 h缩短到16 h.     

FRACTURE PROPERTIES OF STARCH GELS AND THEIR RATE DEPENDENCY

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.     

VARIOUS DIETARY FIBERS DECREASE THE RATE OF LIPASE-CATALYZED HYDROLYSIS OF OLIVE OIL IN VITRO

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.     

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.     

辛烯基琥珀酸淀粉微胶囊化浓缩鱼油的研究

主要研究采用辛烯基琥珀酸淀粉喷雾干燥微胶囊化浓缩鱼油时,几种碳水化合物和食用酵母对其溶剂浸油率、氧化稳定性以及鱼腥异味的影响。实验结果,采用多聚糊精替代20%的辛烯基琥珀酸淀粉可有效降低溶剂浸油率;采用15%的食用酵母就能完全消除鱼腥异味,而且还能显著地提高氧化稳定性。     

交联氧化复合变性甘薯淀粉在粉丝生产中的应用

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。     

INFLUENCE OF GLASS TRANSITION TEMPERATURE ON RATE OF RICE STARCH RETROGRADATION DURING LOW-TEMPERATURE STORAGE

An increasing amount of research suggests a relationship between the glass‐transition temperature (T_g) and the optimum storage temperature for a frozen food. In addition, the T_g 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 T_gon 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 T_gand 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 T_gwere higher than at storage temperatures below T_g.