山楂糖球化糖影响因素的研究

测定10个品牌的糖球化糖时间,并对糖球化糖问题进行研究.结果表明:10个品牌的糖球化糖时间均不超过12 h.用海藻糖熬制的糖球化糖时间明显比用白砂糖熬制的糖球化糖时间长.当温度为160℃,糖球感官品质好,糖球化糖时间长.随着增稠剂比例的增加,CMC(羧甲基纤维素纳)延长糖球化糖时间的效果最明显,其次是明胶.阿拉伯胶对糖球化糖时间的影响为先延长后缩短.随着储存温度的升高和湿度的增加,糖球化糖时间逐渐缩短.     

菊糖衍生物的制备、表征、功能及应用研究进展

基于菊糖的高生物相容性、灵活性以及益生元等特点,制备菊糖的衍生物并拓展其应用范围一直是近年来的研究热点。本文主要综述了菊糖的衍生化方法、结构特征、生物活性和潜在的应用价值。目前,菊糖的衍生化方式可分为三种,即将功能基团、生物活性分子或生物大分子嫁接到菊糖上。衍生物的结构可以通过多种仪器分析方法来表征。衍生化能极大地改变菊糖的理化性质和生物活性。相比于天然菊糖,菊糖衍生物具有更高的抗氧化性、抗炎和抗癌等生物活性。此外,菊糖衍生物还可作为乳化剂、包埋材料、包衣材料以及荧光标记物载体,在众多领域具有良好的应用前景。     

气相色谱分析多糖衍生化方法的研究与比较

采用糖腈衍生化和糖醇衍生化两种方法分析多糖组分,找出线性关系,计算摩尔比,测定加样回收率、精密度、重复性等。糖醇衍生化中,果糖经过还原可得到山梨醇和甘露醇的混合物,测定结果容易导致色谱峰的混乱,不易定性分析,并且衍生化方法反应时间较长,操作比较麻烦。糖腈乙酸酯衍生物气相色谱法具有衍生物制备简便、试剂易得等优点,并且每种糖都能得到单一的色谱峰。通过对气相色谱糖腈衍生化法和糖醇衍生化法的研究和比较,表明糖腈衍生化方法是气相色谱研究食品多糖较为合适的衍生化方法。     

渗透脱水循环处理对糖液及桃片理化特性的影响

以白桃片为实验材料,追踪分析了单阶段(糖液浓度不变)和多阶段(糖液浓度逐渐增加)渗透脱水循环处理后糖液特性和桃片理化特性的变化。糖液循环利用5次,期间不做任何调整。结果表明:随着糖液循环利用次数的增加,单阶段渗透脱水处理过程中糖液黏度降低、稀化现象严重,导致渗透压力差减小,使桃片水分损失率和固形物增加率逐渐降低,同时桃片中可溶性物质的溶出致使糖液电导率、浊度、色差值显著增加;多阶段渗透脱水循环处理基于多浓度糖液组合利用,有效降低了循环利用过程中糖液稀化现象的发生,保持了较好的渗透压力差,进而有利于桃片更多固形物的获得和更多水分的散失,且糖液的电导率、浊度等特性得到了较好的保持,但是多阶段渗透脱水循环处理会使桃片与空气接触更多,不利于产品色泽的保持,且长时间的高渗透压导致桃片中可滴定酸含量显著改变。从糖液循环利用中桃片渗透脱水效率和糖液特性保留角度出发,多阶段渗透处理可在桃片渗透方式的选择上提供一种新颖的思路,具有良好的应用前景。     

色谱法分析果蔬中糖类

水果与蔬菜中糖的测定,以往采用测还原糖,再换算成蔗糖含数。本文采用高效液相色谱和气相色谱法分析了果蔬的果糖、葡萄糖和蔗糖。前者样品处理简便,后者样品经提取和硅烷化处理,两种方法均可得到良好的结果。 1 实验部分 1.1仪器与设备 美国waters 244 型高效液相色谱仪,     

不同方法对桑椹渗糖效果的研究

主要研究了不同渗糖方法的桑椹的渗糖速度和渗糖效率.常压下,温度对渗糖速度影响显著,100℃的渗糖速度约为室温条件的200倍;超声波和真空渗糖法对渗糖速度有影响,大大缩短了渗糖过程中达到平衡的时间,渗糖方法对渗糖效率影响不显著.     

菊芋菊糖的提取与纯化

重点研究了菊芋菊糖的提取与纯化。选择提取温度、提取时间、料液比、提取次数进行单因素实验,确定条件范围,再采用正交实验优化提取条件,得到菊芋菊糖提取最佳工艺条件为温度70℃、提取时间90min、料液比1∶15,菊糖提取率可达90.76%。提取液80℃保温1h菊糖保留率高达95.88%且除去60%以上蛋白质。经过D218离子交换树脂脱色处理,菊糖液色泽澄清,呈白色,蛋白质基本除去。最后冷冻干燥得产品,总糖含量达98%以上,其中菊糖含量为96.23%。     

淀粉糖浆中糖的分析方法研究

本文讨论了采用衍生化——萃取法处理含糖样品,毛细管气相色谱测定糖的方法。测定了淀粉浆中糖的含量。结果表明,方法简便、可靠。方法的相对标准偏差小于4%。     

HPLC分析来自糖胺聚糖的不饱和二糖

介绍一种快速、简单的HPLC分析透明质酸、硫酸软骨素、硫酸皮肤素、硫酸乙酰肝素以及肝素的酶解产物—不饱和二糖的方法,采用氨基键合硅胶柱,并用磷酸二氢钠线性梯度洗脱。对于硫酸软骨素类化合物和硫酸乙酰肝素类化合物,二糖随着盐浓度的增加以非硫酸化二糖、单硫酸化二糖、二硫酸化二糖、三硫酸化二糖的顺序依次洗脱。这种分析方法能够定量分离硫酸化糖胺聚糖中的大部分组成二糖,而有利于化合物在色谱柱上直接酶解,无需任何预处理,且经由单次色谱法即可得到多种二糖的良好分离。     

菊糖硫酸化改性研究

采用三氧化硫-吡啶法对菊糖进行硫酸化改性,以取代度为指标,对反应温度、反应时间、物料质量比以及反应溶剂量进行工艺优化,确定了适宜的修饰条件为:反应温度为95℃、反应时间为4h,菊糖与三氧化硫-吡啶的质量比为1:4,吡啶25mL,此时取代度为2.81。对改性菊糖的红外和紫外光谱分析表明,菊糖分子上引入了硫酸酯基团。     

Modeling temperature gradients in wine fermentation tanks

Extreme temperatures are common in large wine fermentation tanks. If not controlled properly, they can lead to problematic fermentations. Thus, efficient cooling and automatic control systems must be designed. However, it is rather difficult to design and implement effective cooling and control systems without adequate models able to reproduce the complex dynamic behavior observed in large fermentors. Therefore, we developed a compartmental dynamic mass-and-energy-balance model able to simulate temperature and concentration gradients in large wine fermentation tanks. This paper presents the model, along with all its parameters. It discusses simulations of temperature, alcohol content, density, biomass, and sugar concentrations. Finally, it presents a sensitivity analysis of the must temperature dynamics. The model reproduced reasonably well the values of the observed variables, including the most critical one: must temperature (with an absolute mean error of 1.4 °C). After proper calibration, it can be used to design control strategies for cooling in large wine fermentation tanks. Our research efforts will be directed in designing such control strategies.     

固定化酵母载体的装填使用方法

对固定化酵母的两种装填方式进行比较,一种是在发酵罐中装填,一种是在酵母罐中装填,实践表明,第二种装填方式各项消耗指标低,平均酒分高,残糖低,因酒母罐体积小,便于杀菌,从而保证了酒母质量。     

蔗糖形态对氢化棕榈仁油/可可脂混合体系结晶性质的影响

以氢化棕榈仁油/可可脂(质量比9∶1)混合体系为基料油,采用差示扫描量热仪(DSC)考察不同形态蔗糖(结晶糖、糖粉)和卵磷脂对熔化结晶性质的影响。结果表明:未添加卵磷脂时,蔗糖形态对基料油的熔化结晶性质影响不大;添加卵磷脂后,蔗糖颗粒越细,熔化和结晶温度越高;两种形态的蔗糖体系,添加卵磷脂均使结晶温度显著降低。     

Physical State Study of (Sugar Mixture)-Polymer Model Systems

The physical state of components in the unfrozen solute phase of frozen solutions was determined by using differential scanning calorimetry (DSC) for mixtures of lactose, sucrose, and trehalose with albumin, gelatine, or cornstarch. An equal weight ratio (1:1) of lactose-sucrose, lactose-trehalose and sucrose-trehalose mixtures with polymer systems (sugar mixture-albumen (1:1:1), gelatine (1:1:1), and cornstarch (1:1:1), as well as cornstarch-gelatine (1:1:1:1) was used. Mixed sugar mixture (lactose/sucrose)-polymer systems were further studied for maximum freeze-concentration in complex systems. A comparative thermal study between sugar-polymer and mixed sugar-polymer systems was conducted. The sugar-polymer and mixed sugar-polymer systems showed similarities and differences in thermal behaviour. The similarities included maximum freeze-concentration of a frozen system at an annealing temperature (T_m´-1) °C, constant initial concentration independent onset of glass transition T_g´, and onset of ice melting temperature T_m´, and increased in temperature difference between T_g´ and T_m´ or increase in broadness of transition with the addition of polymeric compound.     

全自动喷雾燃硫系统技术原理及应用

为提高糖厂生产的自动化程度和降低劳动强度,设计了第3代全自动喷雾燃硫系统,通过固态硫熔化、雾化喷出、高温燃烧、冷却等步骤,提供稳定的满足糖厂生产要求的SO2气体。硫熏强度稳定在±1.5 cc,共有8台设备在8个糖厂生产使用,在节省硫磺用量、提高白砂糖优一级品率方面效果显著。     

Subject: Transport and storage of milk and milk products

Reference is made to the anticipated completion of churn conversion by 31st July, 1979. The main designs of bulk milk tanks currently in use on farms in England and Wales and the milk cooling systems associated with them are illustrated and discussed. Cleaning systems for both refrigerated and non-refrigerated tanks are described and their relative effectiveness indicated. Methods intended to reduce energy requirements and costs in connection with milk cooling are discussed. The relative importance of bulk milk storage equipment and other sources of contamination on the hygienic quality of refrigerated bulk milk is considered.     

Bittersweet chocolates containing prebiotic and sweetened with stevia (Stevia rebaudiana Bertoni) with different Rebaudioside A contents: multiple time–intensity analysis and physicochemical characteristics

The objective of this study was to evaluate the time–intensity profile of the sensory attributes possibly affected in sugar‐free and low‐fat chocolates containing inulin and stevia with different rebaudioside A contents, such as sweetness, bitterness and melting rate. The bittersweet chocolates were analysed by the multiple time–intensity analysis. The time–intensity profile for the sweetness stimulus was similar for all chocolate samples. The differences between the contents of rebaudioside A were not perceived by the assessors. In relation to the bitterness stimulus, the low‐fat samples had a more accentuated perception of this attribute by the assessors, with significant differences for Imax and Area when compared to the sugar‐free samples. The stimulus melting in the mouth was more affected in the low‐fat samples. The sensory results obtained in this study are useful for food industry and researchers working with sweeteners and prebiotics in food, especially in chocolates.     

酵母形态指标百分数离散度与啤酒质量的关联性

通过跟踪不同发酵罐相同发酵时间的啤酒发酵液中的酵母形态指标百分数离散度,检测发酵结束后各发酵罐的啤酒的质量指标,得出啤酒酵母指标百分数离散度与啤酒质量的关联性,即酵母形态指标百分数离散度与酒精度、发酵度、总酸这三个啤酒质量指标成负相关,与原麦芽汁浓度、外观糖度、乙醛浓度、pH值、双乙酰这五个啤酒质量指标成正相关.     

Cooling and storage of milk on farms

In view of the growing concern about present energy use, current trends in milk cooling and storage on farms are considered, with particular reference to energy saving techniques and types of equipment that are currently available. The cost of the various systems including refrigerated bulk milk tanks, in-line coolers and heat recovery units are discussed. A brief mention is made of the problem of cleaning the larger milk storage tanks.