海藻酸钠凝胶特性的研究

研究了海藻酸钠的浓度、氯化钙浓度、凝胶温度及增塑剂对海藻酸钠凝胶强度、持水性、弹性以及外观特性的影响,采用L9(34)正交实验优选出最佳凝胶条件.实验结果表明:海藻酸钠凝胶特性与凝胶体内的钠钙比率有密切关系;凝胶的温度及增塑剂对凝胶特性也有影响.通过正交实验得到最优实验方案:3%的海藻酸钠溶液与5%的氯化钙在60℃下胶化成形,所形成的凝胶性能最好.     

羧甲基淀粉钠与凝胶性多糖的应用及发展

分别介绍了羧甲基淀粉钠和魔芋胶、海藻酸钠与卡拉胶等三种凝胶性多糖的结构性质及其在食品等工业中的应用.羧甲基淀粉具有好的分散力和结合力、吸湿性、乳化性,稳定性好,透明度好等特点.作为食品的乳化剂、稳定剂及增稠剂,使组织细腻且可口性好,可显著提高食品品质及风味.海藻酸钠在水中具有良好的溶解特性、凝胶特性、生物相容性、成膜性、稳定性和螯合性,用作食品添加剂、澄清剂和增稠剂.魔芋胶具有良好的成膜性和凝胶性,具有流变性、增稠性、增效性、黏结性、吸水性、成膜性、衍生性等性质.卡拉胶具有形成亲水胶体、凝胶、增稠、乳化、成膜、稳定分散等特性,在食品工业中的作用主要表现在具有凝胶、增稠和蛋白反应性三个方面.同时对羧甲基淀粉钠和一种凝胶性多糖共混的一些研究作了简要阐述,并根据各自的特性展望了它们的发展方向.     

海藻酸钙凝胶特性影响因素的探讨

实验研究了海藻酸钠浓度、pH、温度、溶涨时间、凝固剂、金属离子、乙醇以及海藻酸钠以其它食用胶的协同作用对海藻酸钙凝胶拉伸强度、弹性、脱水性等特性的影响。实验结果表明形成的海藻酸钙凝胶特性较好的条件是:海藻酸钠浓度为1.5％、pH为4—5,温度为50℃-60℃,溶胀时间为45min,采用乳酸钙、加入硫酸铝;另外,海藻酸钠与瓜尔豆胶、明胶、β-环状糊精、EDTA的协同增效作用有利于海藻酸钙凝胶的形成。     

海藻酸钠-高甲氧基果胶复合体系凝胶特性的研究--蔗糖、Ca2+、葡萄糖酸-δ-内酯对复合体系凝胶特性的影响

研究了蔗糖、Ca2+、葡萄糖酸-δ-内酯对海藻酸钠-高甲氧基果胶复合体系凝胶特性的影响.结果表明蔗糖、Ca2+对该体系的凝胶特性影响很大,适量蔗糖的添加不仅可增加体系的凝胶强度和持水性,还可增加凝胶的融点;Ca2+的添加可使体系的凝胶类型从热可逆变成热不可逆,且对体系凝胶强度的影响与其对海藻酸钠的影响类似;在海藻酸钠、高甲氧基果胶单独不能形成凝胶的条件下,葡萄糖酸-δ-内酯的添加可诱导两种胶的混合物形成凝胶,且该复合物的凝胶强度与葡萄糖酸-δ-内酯的浓度、胶体总浓度有关.     

海藻酸钙凝胶特性影响因素的探讨

实验研究了海藻酸钠浓度、pH、温度、溶涨时间、凝固剂、金属离子、乙醇以及海藻酸钠以其它食用胶的协同作用对海藻酸钙凝胶拉伸强度、弹性、脱水性等特性的影响。实验结果表明形成的海藻酸钙凝胶特性较好的条件是：海藻酸钠浓度为1．5％、pH为4－5,温度为50℃－60℃，溶胀时间为45min，采用乳酸钙、加入硫酸铝；另外，海藻酸钠与瓜尔豆胶、明胶、β－环状糊精、EDTA的协同增效作用有利于海藻酸钙凝胶的形成。     

复配海藻酸盐凝胶作为传递体系的研究进展

海藻酸钠是传递体系中应用最广泛的聚合物多糖之一,以其为原料制备的凝胶常被用作生物活性化合物和药物等物质的运输载体,在食品和药品领域具有较大的应用潜力.目前复配凝胶法已被用于改善单一海藻酸盐凝胶的机械性能和应用缺陷,并且应用形式多样.本文综述了海藻酸钠的结构与基本性质,重点介绍了近年来海藻酸钠复配凝胶的研究状况,包括与多...     

米蛋白-海藻酸钠互穿网络水凝胶的制备及性能表征

为满足食品领域目前对于高机械强度水凝胶的需求,本研究以碎米蛋白和海藻酸钠为主要原料,通过热处理和离子交联法制备一种高力学性能的食品级碎米蛋白（RP）-海藻酸钠(SA)互穿聚合物网络（IPN）水凝胶。通过改变米蛋白与海藻酸钠凝胶体系中米蛋白的浓度（80、100、120、140、160 mg/mL）调节IPN水凝胶的力学性能,混合液加热及钙离子交联形成水凝胶后,测定其质构性能、流变性能、白度、溶胀性、含水量等性质。结果表明:随着凝胶体系中碎米蛋白浓度的增大,RP-SA IPN水凝胶的储存模量G'、损耗模量G"和凝胶硬度均增加,当碎米蛋白浓度达到为140 mg/mL时,凝胶硬度增加幅度变小。水凝胶溶胀性先降低后趋于平缓,但水分分布更为均匀。因此,适量的碎米蛋白能对RP-SA IPN水凝胶网络有很好的填充效果,并对水凝胶的形态没有太大的改变,同时可通过调节蛋白的添加量来调节水凝胶的力学性能,该研究为米蛋白在食品领域的应用提供了理论基础。     

蛋清蛋白质凝胶质构特性的研究

蛋清蛋白质因具有良好的凝胶性能在肉制品、方便面等食品中有很好的应用,研究其凝胶质构特性可以为蛋清粉在这些食品中的应用提供重要的理论参考。本研究以蛋清粉为原料,通过旋转正交实验设计,研究蛋白质浓度、蛋清溶液的pH、加热温度、加热时间对凝胶形成的影响,采用物性仪对凝胶的质构特性如凝胶硬度和弹性进行了测定。结果表明,形成凝胶硬度最大的制备条件为:蛋白质浓度19%、蛋清溶液的pH5.5、温度85℃、加热时间55min;形成凝胶弹性最大的制备条件为:蛋白质浓度19%、蛋清溶液的pH6.0、温度78℃、加热时间40min。     

乳清蛋白与海藻酸钠复合物凝胶特性的影响因素

海藻酸钠与乳清蛋白复合物凝胶具有较好的包埋性,可用于活性物质的微胶囊化,具有广泛的应用价值。本研究采用热处理方式对乳清蛋白与海藻酸钠进行交联,并对影响乳清蛋白与多糖凝胶特性的因素进行研究,结果表明:在10%乳清蛋白溶液中添加2.0%的海藻酸钠,80℃加热30 min,乳清蛋白与海藻酸钠复合物凝胶质构特性较好;当海藻酸钠添加量为1.5%时持水性较好。复合物凝胶特性明显优于乳清蛋白凝胶和海藻酸钠凝胶,说明二者结合能够提高凝胶的性状,达到改性的目的。p H值越高质构特性和持水性越差。添加甘油使凝胶质构特性显著下降,其持水性虽很高,但甘油对海藻酸钠与乳清蛋白的交联阻碍很大。当K+浓度在50~200 mmol/L之间时,凝胶的硬度和黏度随K+浓度的增大而增大,而凝聚性和粘性指数在100 mmol/L达到最大值。     

海藻酸钠-高甲氧基果胶复合体系凝胶特性的研究--蔗糖、Ca2+、葡萄糖酸-δ-内酯对复合体系凝胶特性的影响

研究了蔗糖、Ca2+、葡萄糖酸-d-内酯对海藻酸钠—高甲氧基果胶复合体系凝胶特性的影响。结果表明:蔗糖、Ca2+对该体系的凝胶特性影响很大,适量蔗糖的添加不仅可增加体系的凝胶强度和持水性,还可增加凝胶的融点;Ca2+的添加可使体系的凝胶类型从热可逆变成热不可逆,且对体系凝胶强度的影响与其对海藻酸钠的影响类似;在海藻酸钠、高甲氧基果胶单独不能形成凝胶的条件下,葡萄糖酸-d-内酯的添加可诱导两种胶的混合物形成凝胶,且该复合物的凝胶强度与葡萄糖酸-d-内酯的浓度、胶体总浓度有关。     

Optimization of Instrumental Texture of Carrot and Meat Alginate Simulated Particles for Use in Thermal Processing Biological Validation Studies

Alginate-based simulated particles with spores of heat resistant microorganisms distributed in them are used in the biological validation studies, and the process lethality is usually calculated using initial and final counts. Such particles should be hard enough to save their integrity till the end of the thermal process. Also, they should not adhere to each other inside the can or to the can's inner wall. In this study, a response surface methodology was used to determine the optimum conditions that give maximum hardness and minimum adhesiveness of meat and carrot alginate fabricated particles. Sodium alginate concentration (1.5–6.5%), calcium chloride concentration (1.0–3.0%), and immersion time in the calcium chloride solution (4–44 h) were employed as factors at five levels, and the instrumental textural properties were assessed using the texture profile analysis. For each response (hardness and adhesiveness), a second-order polynomial model was developed using multiple linear regression analysis. Hardness of the fabricated particles was found to significantly increase (p < 0.05) with increasing sodium alginate concentration and immersion time in the calcium chloride solution, while calcium chloride concentration had no significant effect. On the other hand, adhesiveness (in absolute values) of the reconstituted particles increased significantly (p < 0.05) with increasing sodium alginate while the other two parameters had no significant effect. Applying the desirability function method, optimum conditions were found to be sodium alginate concentration of 4.7%, calcium chloride concentration of 2.6%, and immersion time of 32.0 and 30.8 h for carrot alginate and meat alginate fabricated particles, respectively. Fabricated particles using the optimum conditions did not show any variability in hardness values, unlike real food particles, when subjected to thermal processing. This investigation could help food processors using continuous agitation processing to fabricate firm and thermally stable reconstituted particles to be used in the biological validation studies.     

Using RGB Image Processing for Designing an Alginate Edible Film

The use of edible films to coat food products is a technique that allows for an extended shelf-life. One of the most widely used polymers is calcium alginate. However, this polymer can modify the original food color and the perception by consumers. The objective was to design an alginate film based principally on color changes using a RGB color model. Edible films were prepared with sodium alginate and glycerol as plasticizer, cross-linking the polymer with calcium. Dry and hydrated states of the edible films were studied. Film thickness was directly proportional to surface concentration and increased with hydration. There is a zone in which the color does not change with alginate surface concentration and another where the color is directly proportional to it. This latter scenario is not a consequence of structural changes or the degree of hydration. Results showed a range where the color was not modified by the alginate concentration; hence, an optimal surface concentration was determined as a design parameter. Edible films made using the optimal surface concentration would not mask microbial contamination and have good physical properties (water vapor transmission and swelling) compared with other surface concentrations. In addition, it was possible to model alginate surface concentration as a function of surface color using mathematical tools (clustering, linear regression, and support vector machine), allowing one to study the optimal use of the edible films.     

Encapsulation characteristics of protein hydrolysate extracted from Ziziphus jujube seed

Food protein hydrolysates and peptides are known as a promising functional food ingredient. Encapsulation can be used for improving the bioavailability and organoleptic properties of peptides. In the present study, good entrapment efficiency was obtained when 2.5% sodium alginate, 3% protein concentration, and 2% calcium chloride. Fourier transform infra-red analysis (FTIR) and scanning electron microscope presented that papain hydrolysate was cross-linked in calcium alginate beads. The peptide showed high antioxidant activity, metal ion chelation activity, and reducing power as compared to encapsulated peptide.     

钙类食品添加剂滴定检测方法研究进展

钙类食品添加剂(碳酸钙、磷酸钙、乳酸钙、糖精钙、山梨酸钙、海藻酸钙等)一般广泛用于食品膳食补充剂、甜味剂、防腐剂、增稠剂。不合格的钙类添加剂添加到食品中会直接影响了食品的品质, 影响人民群众的身体健康, 由此引起的安全问题也成为公众广泛关注的焦点。由于钙类食品添加剂种类繁多, 钙离子的结合方式不同, 不同添加剂的基质也各不相同, 因此不同的钙类食品添加剂其化学性质和应用领域、检测方法均不一样。本文对钙类食品添加剂的标准检测方法及其他常用滴定检测方法和检测过程中的注意事项进行了综述, 并探讨了各种方法的适用范围, 以期为钙类食品添加剂的检测提供参考和借鉴。     

Crosslinking Kinetics of Thermally Preset Alginate Gels

The Sharp-Interface model was used to describe the crosslinking kinetics of thermally preset calcium alginate gel at constant temperature. The model assumes diffusion of calcium ions through a preformed gel of sodium alginate and a selected carrier, and an instantaneous reaction between the calcium and sodium alginate. The proposed model was experimentally verified using two different carriers at the following concentrations: agar 0.6(g/100 mL)-0.8(g/100 mL), and gelatine 4(g/100 mL); sodium alginate concentrations were 1(g/100 mL) and 1.5(g/100 mL), while a 2(g/100 mL) calcium lactate solution was used as calcium ion source. The diffusion coefficient of calcium ion was determined using a cell diffusion model. The model can be used to predict processing effects on food gels.     

海藻酸钠的复合特性及其在肉制品中的应用研究进展

海藻酸钠是从褐藻中提取的一种多糖类碳水化合物,不仅是一种安全的食品添加剂,而且可作为仿生食品或疗效食品的基材,在食品工业中被广泛用作稳定剂、增稠剂、粘结剂、分散剂和凝固剂等。海藻酸钠与大多数阳离子反应会形成交联,本文主要介绍了海藻酸钠与钙离子交联形成网状结构,并应用于肉制品中作粘结剂和保水剂,以控制水分子的流动性,能增加肉制品的粘着性、持水性和柔嫩性,减少营养成分损失,提高了产品质量。另外,海藻酸钠也能与其他亲水性胶体如卡拉胶、果胶、结冷胶等产生交联作用,本文简介了海藻酸钠与一些亲水性胶体复合特性的最新研究进展。     

响应面法优化桑葚酵素食用凝胶的制备工艺

以海藻酸钠、壳聚糖、桑葚酵素为原料,氯化钙为离子交联剂,制备酵素食用凝胶。通过单因素实验和Box-Behnken响应面法,研究海藻酸钠与壳聚糖质量比、交联时间、氯化钙浓度对酵素凝胶硬度、胶着性、咀嚼性等质构指标的影响。结果表明,酵素凝胶最佳的制备工艺为:海藻酸钠与壳聚糖质量比5:2.82、交联时间131 min、氯化钙浓度17.9 mg/mL。在此优化工艺条件下,测得酵素凝胶硬度为7.19 N、胶着性为6.60 N、咀嚼性为0.70 kgf。优化所得结果准确可靠,可为酵素功能性食品的进一步开发与利用提供理论依据和技术参考。     

交联体系对海藻酸钠/印度树胶复合膜性能的影响

为探究交联体系对海藻酸钠/印度树胶复合膜性能的影响,本文选取氯化钙-柠檬酸、氯化钙-乳酸、氯化钙-苹果酸三种不同的Ca2+-H+交联体系,以力学性能、水蒸气透过率及水溶性为指标进行评价;同时,利用傅里叶红外光谱(FTIR)、扫描电子显微镜技术(SEM)进行微观结构表征。结果表明,选用氯化钙-柠檬酸交联体系,Ca2+浓度为1.5%,H+浓度为1.0%,交联时间为5 min时,拉伸强度为34.11 MPa,断裂伸长率为15.27%,水蒸气透过率为6.99×10-11 g/(m·s·Pa),水溶性为6.41%,海藻酸钠/印度树胶复合膜综合性能最佳。此外,傅里叶红外光谱和扫描电子显微镜也表明氯化钙-柠檬酸交联体系形成的交联膜微观结构紧密、均匀、交联度高。本研究成功制备了一种新型复合膜,为其在食品包装领域的应用提供理论依据。     

Measurement and targeting of thermophysical properties of carrot and meat based alginate particles for thermal processing applications

The objective of the study was to investigate the thermo-physical properties of meat and carrot based alginate particles as influenced by the formulation variables. A response surface methodology (RSM) was used to study the effect of sodium alginate concentration, calcium chloride concentration and dipping time in the calcium chloride solution, at five levels each, on the thermo-physical properties of the fabricated particles (9 mm in diameter and 9 mm in height). Density was similar for all conditions. Increasing sodium alginate concentration resulted in a significant decrease in the heat capacity and thermal conductivity values. These changes were primarily attributed to the lowering of moisture content of the particles resulting from the treatment. Using RSM, optimum conditions for fabricating particles having similar thermo-physical properties to real foods were obtained as 5.3% and 4.9% sodium alginate, 2.2% calcium chloride and 14.2 and 36.0 h immersion in the calcium chloride solution for meat and carrot alginate particles, respectively.     

Gelation behaviour of gelatin and alginate mixtures

Mixtures of alginate and gelatin were studied by rheology as a function of different parameters, such as temperature, biopolymer concentrations, calcium concentration and ionic strength. In particular conditions, the formation of a mixed gel of alginate and gelatin is obtained. A slow release of calcium ions leads first to an irreversible alginate gel and cooling results in a reversible gelatin gel. Depending on experimental conditions, non-linear behaviours upon gelation of alginate occur and a collapse of alginate gel is directly observable by rheology. These trends are favoured between 35 and 45 °C, by a high total biopolymer concentration or a high calcium concentration and ionic strength. Different mechanisms could be responsible for this collapse, such as a competition between alginate gelation and phase separation in the biopolymer mixture or an over-association of alginate chains at high Ca²⁺ concentration, favoured by the presence of gelatin.