共查询到20条相似文献,搜索用时 15 毫秒
1.
Hui Chi Kun Xu Xiuli Wu Qiang Chen Donghua Xue Chunlei Song Wende Zhang Pixin Wang 《Food chemistry》2008
Acetylated corn starches with different degrees of substitution (DS 0.85, DS 1.78, DS 2.89) were synthesized by the reaction of corn starch with acetic anhydride in the presence of acetic acid under varying reaction temperatures. The product was characterized by FTIR spectroscopy, 1H NMR, X-ray diffraction and contact angle measurement. Acid-base titration and 1H NMR methods were employed to determine the degree of substitution of product. FTIR spectroscopic analysis showed that the characteristic absorption intensities of esterified starch increased with increase in the degree of substitution, and the characterized peak of hydroxyl group almost disappeared in the spectrum of DS 2.89 acetylated starch. The detailed chemical microstructure of native starch and acetylated starch was confirmed by 1H NMR, 13C NMR and 13C–1H COSY spectra. Analysis of 1H NMR spectra of acetylated starches was assigned accurately. Strong peaks in X-ray diffraction of acetylated starch revealed that new crystalline regions were formed. Compared with native starch, the hydrophobic performance of acetylated starch esters was increased. The contact angle of acetylated starch with DS 2.89 was 68.2°. 相似文献
2.
3.
4.
5.
6.
7.
Hongbo Mi Shangyun Liang Zhenghan Li Shumin Yi Jingxin Chen Xuepeng Li Jianrong Li 《International Journal of Food Science & Technology》2021,56(6):2843-2852
Effects of corn starch on structure, physicochemical and gel properties of myosin were investigated. Particle size, turbidity, surface hydrophobicity and total sulphhydryl groups of myosin were significantly increased with the increasing of starch concentration, and the increase range of high amylose corn starch (HACS) group was the most significant. Tryptophan residue of myosin was buried, and fluorescence quenching occurred after starch was added. HACS made myosin secondary structure was changed from α-helix to β-sheet. Confocal laser scanning microscopy (CLSM) photographs showed starch was encapsulated by aggregated myosin, which made the protein binding tighter and more beneficial to the formation of gel. Moreover, strength and water holding capacity of heat-induced myosin gels containing starch were significantly higher than that of pure myosin. Starch, especially HACS, could induce myosin aggregation before heating gelatinisation and promote myosin self-assembly at low temperature, which may be conducive to forming a higher quality gel after heating. 相似文献
8.
目的 确定玉米淀粉/卡拉胶/甘油复合膜的最佳成膜工艺.方法 以玉米淀粉为基材,与卡拉胶和甘油共混,通过流延法制备复合膜,以薄膜的机械性能为评价指标,通过单因素实验及正交实验来确定最佳成膜工艺.结果 正交实验结果表明当玉米淀粉添加量为3%、卡拉胶添加量为30%、甘油添加量为25%时,玉米淀粉薄膜的机械性能最佳.结论 本研... 相似文献
9.
Heidi A. Fonseca-Florido Juan Hernández-Ávilab Adriana I. Rodríguez-Hernández Javier Castro-Rosas Otilio A. Acevedo-Sandoval Norberto Chavarria-Hernández 《International Journal of Food Properties》2017,20(3):611-622
Native corn and potato starches were mixed in different proportions. Blends presented similar values to potato starch at onset temperature and at ending temperature to corn starch. CS20PS80 blend had the highest values for hardness between blends due to the formation of a three-dimensional network with corn starch granules that act as composite material. Some blends exhibited higher recovery viscosity than native starches, possibly due to interactions. Gelatinization temperature, swelling power, phosphorous content, granule size, and x-ray pattern played an important role in the resulting properties, however, the amylose content did not show influence due to both starches having a similar content. 相似文献
10.
11.
为探究球磨机械活化处理对绿豆淀粉理化性质的影响,对机械活化后绿豆淀粉的颗粒形貌和粒度分布进行观察,并进一步对其热力学性质、糊化性质、溶解度、膨胀度、持水能力和冻融稳定性等理化性质进行测定。结果表明,淀粉颗粒形貌发生了改变,表面变得粗糙不光滑,形状不规则,淀粉颗粒粒度分布范围为2~200 μm,70%以上分布在20~75 μm区间,粒度中位径增大到43.09 μm,热焓值降低至2.32 J/g,糊化温度显著降低,衰减值及回生值分别为原淀粉的1/30和1/31,微细化绿豆淀粉具有较好的热糊和冷糊稳定性,溶解度和膨胀度随着温度的升高而增大,持水能力和冻融稳定性为原淀粉的3.2倍和2.0倍。 相似文献
12.
13.
乳酸菌发酵能够产生淀粉酶。为考察含有活性乳酸菌的酸奶对淀粉黏弾特性的影响,本文以玉米淀粉为原料,分别加入1%(v/v)的蒙牛酸奶、完达山酸奶、伊利酸奶,并在37℃保温1小时;用流变仪研究发酵后玉米淀粉的流变学性质。实验结果表明:剪切流变曲线服从Herschel-Bulkley模型 (R>0.90)。屈服应力τ0、粘度系数k增加,流动指数n减小(n<1),显示发酵后的玉米淀粉仍然是非牛顿、屈服假塑性流体。震荡流变曲线显示添加酸奶的样品组的贮能模量G''与损耗模量G''均大于空白组、且均随着剪切频率的增大而增大。本项研究首次发现经乳酸菌发酵的玉米淀粉,具有更高的黏弹特性。 相似文献
14.
15.
Starch samples separated from oat were modified with two different levels of POCl3 (0.5 and 1.0 g kg−1) as a cross-linking agent and two different levels of acetic anhydride (6% and 8% (w/w)) for acetylation. Swelling factor, thermal properties and retrogradation measurements were evaluated to characterise the influence of phosphorylation and acetylation on oat starch. Cross-linking decreased the swelling factor and did not improve gelatinization temperature while it increased synaeresis in comparison with native starch. Acetylation increased swelling factor but reduced gelatinization temperature and synaeresis of oat starch. 相似文献
16.
AbstractThe objective of this work was to investigate the influence of hydroxypropylsulfonation on the adhesion-to-fibers and film properties of starch for improving its end-use ability in warp sizing. A series of hydroxypropylsulfonated corn starch (HPSS) with different degrees of substitution (DS) were synthesized by the reaction of granular corn starch with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) in an alkaline aqueous medium. The adhesion was accessed by determining the tensile force of starch to cotton fibers according to a standard method (FZ/T 15001-2008), while film properties were estimated in terms of breaking elongation, tensile strength, degree of crystallinity, and moisture regain. In addition, desizability of HPSS was also evaluated by measuring the time interval required to break the film in water. The estimation was undertaken through the comparison of HPSS with ACS. Compared with ACS, HPSS exhibited stronger tensile force, higher breaking elongation and moisture regain of the film, and lower tensile strength, degree of crystallinity and time required to break the film in water. Therefore, hydroxypropylsulfonation was able to improve the adhesion, reduce film brittleness, and enhance the desizability. The increase in the hydroxypropylsulfonation level favored the increase in adhesion, reduction of film brittleness, and enhancement in desizability. Based on the results, HPSS prepared with a DS range of 0.03?~?0.041 showed the potential for the application of sizing cotton warp yarns. 相似文献
17.
从河北省玉米主栽品种中选取15个玉米品种作为供试材料,对玉米粉的白度、色差、蛋白质含量、脂肪含量、淀粉含量及玉米淀粉透明度、持水率、溶解度与膨胀势、冻融稳定性、凝沉性、糊化特性、凝胶质构以及微观结构进行系统研究。结果表明,不同玉米品种理化性质及淀粉品质间差异显著,并对淀粉品质测定结果进行分析,将所选的15种玉米根据类别分为糯玉米和普通玉米两大类,然后对普通玉米品种进行聚类分析,在平方Euclidean距离为10处,可将14种普通玉米根据淀粉性质分为3类,因此可根据不同加工目的选择不同类型的玉米品种。 相似文献
18.
19.
20.
Physical properties and chemical forces of extruded corn starch fortified with soy protein isolate
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Biying Chen Chen Yu Junfei Liu Yuling Yang Xinchun Shen Shaowei Liu Xiaozhi Tang 《International Journal of Food Science & Technology》2017,52(12):2604-2613
The effect of soy protein addition on physical properties of extruded corn starch was studied. The correlations between the chemical bonds in proteins and the physical properties of extrudates were analysed. Increasing soy protein isolate content resulted in higher expansion ratio (ER) but lower bulk density (BD), hardness, water solubility index (WSI), degree of starch gelatinisation (DSG), content of sulphydryl (SH) groups and protein solubility in phosphate buffer. In the other hand, increasing the processing temperature resulted in higher ER, water absorption index, DSG, contents of the SH group and disulphide (SS) bond but in lower specific mechanical energy, BD, hardness and WSI. The results indicated that changes in the chemical bonds in proteins had a significant effect on the apparent physical properties of extrudates. More protein–protein and protein–starch cross‐linking reactions occurred through new chemical linkages, such as the nondisulphide covalent bonds and hydrogen bonds, which are beneficial to the expansion of starch‐based products. 相似文献