TRIAL METHOD FOR MEASURING THE EFFECT OF LIPIDS ON THE RHEOLOGICAL PROPERTIES OF STARCH PASTE DURING THE GELATION PROCESS

An attempt was made to measure the effect of lipid components on the viscosity and thixotropy of wheat starch paste in a short aging time after gelatinization. Viscometry was used to follow periodically the changes in apparent viscosity (at 76.8 s⁻¹) of the mixed paste of wheat starch and one of a series of lipids in a cone-plate viscometer for 210 min after gelatinization, i.e. a procedure of eight cycles of measurement with a sample. Each cycle of the measurement consisted of viscometry for 3 min and a rest period for 27 min at 30°C. The apparent viscosity of all the samples decreased greatly during the 3 min measurement due to thixotropic breakdown of the macroscopic structure in the samples. The results suggest that the presence of a small amount of free fatty acid and monoglyceride may play a role in reducing starch paste gelation.     

复合保鲜剂对菊花脑保鲜效果的影响

通过正交试验研究了以6-苄基腺嘌呤、赤霉素、水杨酸和欧威消毒剂组成的复合保鲜剂对菊花脑的保鲜效果.结果表明,复合保鲜剂处理的菊花脑,在10℃下贮藏12 d,以叶绿素含量作为评价指标.四因素6-苄基腺嘌呤、赤霉素、水杨酸和欧威保鲜消毒剂在减缓菊花脑黄化方面的作用大小依次为6-苄基腺嘌呤、水扬酸、欧威消毒剂和赤霉素;四因素的最佳复合组合是10mg/L6-苄基腺嘌呤 20mg/L赤霉素 14mg/L水杨酸 100mg/L欧威消毒剂,最佳组合可有效减缓叶绿素、蛋白质和可溶性固形物的损失,抑制菊花脑黄化、失重和纤维化.减少超氧阴离子和丙二醛含量,从而延缓了采后菊花脑的衰老.     

小麦淀粉磷酸酯取代度的测定

本实验采用总磷减去游离磷的方法求出结合磷,并对总磷及游离磷的测定条件进行摸索,从而得出一个新的方法,可以简捷快速、可靠的测定淀粉磷酸酯的取代度,为指导实验室研究工作及保证生产中产品质量稳定提供依据。     

水溶性大豆多糖对淀粉糊化特性的影响

利用快速粘度分析法(RVA)和差方扫描量热法(DSC)研究三种水溶性大豆多糖SSPS、SSPS-G1、SSPS-G2对淀粉糊化特性的影响.结果表明:它们均能显著影响淀粉的糊化特性,但作用效果不同,SSPS-G1与SSPS-G2对淀粉糊化特性的影响更显著.     

EFFECT OF SUGAR AND GUMS ON THE PASTING PROPERTIES OF CASSAVA STARCH

Pasting properties of cassava starch solutions were prepared with different types of sugars (glucose, sucrose and fructose) at different levels as 10.71, 19.35, 32.43% and gums (gum acacia, guar gum and gum tragacanth) at 0.1, 0.2, 0.3, 0.4% levels, respectively, were analyzed using the Rapid Visco Analyzer. The pasting temperature increased with increase in the sugar concentration in cassava starch–water system and the maximum 78.27C at 32.43% sucrose solution. The peak viscosity (PV) and breakdown viscosity (BD) decreased with increase in the sugar concentration. Hot paste viscosity and cold paste viscosity decreased progressively with increase in sugar concentration in fructose and glucose solution. The PV and BD increased with increase in guar gum concentration and was maximum 5,704 and 3,773 mPa·s at 0.4% concentration, respectively.

PRACTICAL APPLICATIONS

Cassava starch performs most of the functions where maize, rice and wheat starch are currently used. In food industry, cassava starch is used in extruded snacks for improved expansion, as a thickener in foods, in processed baby foods as a filler material and bonding agent in biscuit and confectionary, textile, pharmaceutical, paper and cosmetic industries. Cassava starch can be converted to maltotriose, maltose, and glucose as well as to other modified sugars and organic acids. Starch from cassava can be used to make gelatin capsules. Starches and gums are often used together in food systems to provide texture, control moisture, water mobility, improve overall product quality and stability, reduce cost and facilitate processing. Cassava starch, due to its high swelling power, is reported to yield better quality instant noodles.     

用紫外分光光度法对棉籽油中棉酚定量测定的研究

棉酚是一种毒性较强的化合物,且分布较广.本文研究了用60%的乙醇萃取棉籽油中的游离棉酚,然后用UV—240分光光度计在233nm波长下进行测定,所得结果相对误差小于6.25%.此法灵敏度高,重现性好,操作简便,理论检测下限为5ppm.     

富马酸酯类防腐剂改性方法研究现状

富马酸酯类具有良好的抗茵活性,广泛用做食品防腐剂.近年来人们通过对富马酸酯类进行结构改造,合成具有防腐及其它综合性能的新型食品添加荆.介绍富马酸单酯、溴代富马酸二甲酯、反丁烯二酸蔗糖甲酯等富马酸酯衍生物的改性方法及改性效果的研究现状.     

紫外分光光度法测定植物黄酮含量的方法

综述了紫外分光光度法测定植物中黄酮含量的方法。重点介绍了单波长法、差示法、双波长法、三波长法、导数法等紫外分光光度法测定黄酮类化合物含量的原理及分析特性。     

超声强化制备低取代度黄姜醋酸酯淀粉的工艺研究

在比较未施加超声场和超声强化制备相同取代度黄姜醋酸酯淀粉条件的基础上,以黄姜醋酸酯淀粉的取代度为指标,探讨用超声强化制备低取代度醋酸酯淀粉的工艺,并用扫描电镜（SEM）对产物的表面形貌进行分析。结果表明：超声强化可以促进淀粉的酯化反应,而且制备低取代度的醋酸酯淀粉的效果更为明显。超声强化制备低取代度醋酸酯淀粉过程中,超声作用时间影响显著,其最佳工艺条件为：超声作用时间为15min,超声温度为50℃～60℃,超声波功率为96W。由SEM分析结果可知,超声辅助法对所制备的相同取代度的黄姜醋酸酯淀粉的颗粒大小和表面形貌有一定的影响。     

荧光光谱标准加入法测定苯甲酸钠的含量

建立了荧光光谱标准加入法测定苯甲酸钠含量的方法，并测定了一种饮料中苯甲酸钠的含量。     

EFFECT OF KILNING ON MALT STARCH AND ON THE DEXTRIN CONTENT OF RESULTING WORTS AND BEERS

Examination of starches separated from green malt and from kilned malts of colour ranging between 3 and 23 shows that only small amounts of “new” carbohydrate linkages are formed in the starches during kilning, though the colour changes from white to buff and the amount of contaminating protein increases. Nevertheless, standard enzymic treatments show that the higher the colour value of the malt, the less susceptible it is to attack by amylases, and the larger is the content of non-fermentable, non-dialysable dextrin. Although the amount of non-dialysable dextrin rises as the colour value of the malt increases, dextrin content of the derived wort is not directly related to the enzymic activity of the malt. Thus, the non-fermentable dextrin of wort from malt of colour 3 is little higher than that of wort from green malt, despite the considerably higher diastatic power of the latter. Head retention values of draught and bottled beers from the green malt and kilned malts of colours 3, 6 and 13 show no correlation with dextrin content.     

醋酸、盐酸酸化对碘法滴定测定保险粉含量的影响

保险粉是一种重要的化工产品,大量用于印染行业,其含量的高低可反映质量的优劣。采用碘法滴定测量其含量,并探讨了醋酸酸化和盐酸酸化对测定的影响。结果表明用盐酸酸比用醋酸酸化测含量受时间和温度变化的影响小,测定结果更接近真实值。     

复合天然保鲜剂对低温酱鸭保鲜效果的研究

以低温酱鸭为原料，通过对6种天然保鲜剂进行筛选，选出4种抑菌效果较好的，进一步进行组合实验，根据抑菌率得出抑制酱鸭腐败菌的最佳组合为壳聚糖2．00％、乳酸链球菌素（Nisin）0．01％、茶多酚1．00％、桂皮2．40％。采用此最佳组合的复合天然保鲜剂对酱鸭进行保鲜实验，定期测定其微生物指标和理化指标，结果表明利用优选的组合保鲜剂保鲜，加上真空包装、低温水浴杀菌，可使酱鸭保质期冷藏达2-3个月。     

正交试验优化木薯微孔淀粉的工艺研究

利用α-淀粉酶制备木薯微孔淀粉。通过L9（3^4）正交试验，研究酶用量、pH值、反应温度和反应时间对微孔淀粉吸附性能的影响。实验证明：木薯微孔淀粉对柠檬黄色素、油脂的吸附性能好于木薯淀粉对柠檬黄色素、油脂的吸附性。并得出利用α-淀粉酶制备木薯微孔淀粉的最佳工艺条件是：酶用量为1．0％，pH值为4．67，温度为50℃，反应时间为16h。     

粗淀粉酶酸法生产液体葡萄糖新工艺的研究

以粗淀粉原料直接投料，用酶液化、离交酸化糖化工艺生产液体葡萄糖，比传统的酶酸法工艺生产的产品质量好，比常用的双酶法工艺生产过滤快，产量高，效益好。     

火锅底料食品中油脂酸价的测定

研究了国标测定火锅底料类油脂酸价时存在难以判断滴定终点的问题.在优化试验条件下,于火锅底料中加入适量中性饱和食盐水,改酚酞为百里酚蓝为指示剂进行滴定操作,可以清晰地观察到滴定终点,测定结果准确、精密度高.