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.     

PHYSICAL PROPERTIES OF RECONSTITUTED CARROT/ALGINATE PARTICLES STABLE FOR ASEPTIC PROCESSING

Textural and thermophysical properties of reconstituted carrot/alginate particles, subjected to thermal and mechanical stresses during aseptic processing, were investigated. Four levels of sodium alginate (4, 6, 8 and 10%) and calcium chloride (0.2, 0.5, 1.0 and 1.5%) and three levels of water addition (50, 150 and 300 mL) were used for two types of alginate (high in guluronic acid, HGA and low in guluronic acid, LGA). Hardness, water content, density and thermal conductivity of reconstituted carrot/alginate particles were determined using an Instron, an oven drying technique, a pycnometer measurement and a line heat source method, respectively. Moreover, Bacillus subtilis was inoculated in carrot/alginate particles. Reconstituted particles, unlike carrot cubes and other vegetables, were thermally stable. The moisture content increased with a decrease in calcium chloride concentration and an increase in water addition. There was no significant effect of formulation on density and thermal conductivity measurements. Reconstituted carrot/alginate cubes were able to sustain successfully thermal and mechanical stresses encountered in a pilot scale aseptic processing system.     

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。     

Improvement in Texture of Pressure-Assisted Thermally Processed Carrots by Combined Pretreatment using Response Surface Methodology

The effect of pretreatment pressure (0.1 to 400 MPa), temperature (25 to 75 °C), and calcium chloride concentration (0 to 1.5%) and their complex interaction on hardness, residual pectinmethylesterase (PME) activity, and diffused calcium content of pressure-assisted thermal processed (PATP, 700 MPa, 105 °C for 15 min) carrot have been studied using response surface methodology. Predicted values of carrot hardness, calcium content, and residual PME activity were found to be in good agreement with experimental values as indicated by the high R ² values of 0.98, 0.96 and 0.96, respectively. The optimum processing conditions, namely, calcium chloride concentration 1.0%; pretreatment pressure ranging from 286 to 314 MPa; pretreatment temperature varying from 53.8 to 58.3 °C, fulfill the conditions to obtain the PATP carrot with hardness ≥145 N, calcium content ≥ 2.5 mg/g, and residual PME activity ≥ 70%. These conditions resulted in more than tenfold increase in the hardness of PATP carrot (14.08 to 145 N) as compared to PATP carrot without any pretreatment. The study demonstrated that response surface methodology can be used for modeling carrot quality parameters of PATP.     

Influence of Varying pH and Algin/Calcium Binders on Selected Physical and Sensory Characteristics of Structured Beef

Structured beef was prepared with eight combinations of the ingredients (sodium alginate, calcium carbonate, lactic acid/calcium lactate) used to bind meat with the algin/calcium gelation mechanism at nine pH values (4.1–6.4) in order to evaluate their influence on its physical and sensory characteristics. Products with alginate alone were similar to samples from the treatment without binders. The combination of alginate/calcium/lactate gave products of higher values (P>0.05) for parameters such as hardness in the raw state, bind and penetration than all other treatments. Decreasing pH values increased raw and cooked product hardness and penetration force. Products of pH values 5.7–5.8 were superior to other treatments in bind scores evaluated by a sensory panel.     

响应面法优化重组罗非鱼肉制备工艺

利用加工副产物开发重组罗非鱼肉制品,以罗非鱼碎肉为原料,制备重组罗非鱼肉制品,采用响应面试验优化重组罗非鱼肉制品的加工工艺。结果表明：重组罗非鱼肉制品的最佳制备工艺为NaCl添加量0.52%、谷氨酰胺转氨酶（transglutaminase,TG）添加量0.95 U/100 g、CaCl2添加量0.39%;影响重组罗非鱼肉硬度的大小顺序为TG添加量＞CaCl2添加量＞NaCl添加量。     

益生菌副干酪乳杆菌R8双层包埋工艺研究

目的:以益生菌副干酪乳杆菌R8为研究对象,进行双层包埋关键工艺参数的研究,以提高菌体的稳定性,并实现在肠道定向释放的目的。方法:筛选冻干保护剂、益生元;优化微胶囊包埋材料海藻酸钠和固化液中氯化钙浓度;检测和分析制得的微胶囊在人工胃液和人工肠液中的释放特性。结果:筛选出的最佳冻干保护剂为20%全蛋液;最佳益生元为菊粉;最佳包埋液配方为:5%益生菌、2%菊粉、20%全蛋液,1%海藻酸钠;最佳固化液配方为2.5%氯化钙。所得微囊颗粒可耐受胃液破坏,在模拟肠环境中45 min内释放完毕,人工肠液中活菌数为原微囊活菌数的65.6%。全蛋液在制备工艺过程起到保护作用,并提高在储存过程中的稳定性;将菌体/蛋白质/海藻酸钠微胶囊进一步用壳聚糖材料进行覆膜,可实现在肠道定向释放。     

THE EFFECT OF SOME MEAT PROTEINS ON THE RHEOLOGICAL PROPERTIES OF PECTATE AND ALGINATE GELS

The viscosity of 1% sodium alginate and 1% sodium pectate solutions containing low levels of calcium chloride were investigated using cone and plate viscometers. The level of calcium required to initiate partial gelation was significantly lower for pectate compared with alginate. With increasing calcium chloride concentration the solutions became more pseudoplastic and eventually showed thixotropy.
One percent bovine serum albumin or 1% myoglobin was incorporated into the polysaccharide solutions together with sufficient calcium to cause incipient gelation in the absence of the protein. Myoglobin inhibited the formation of an alginate gel, the effect being greatest at a pH of about 6.3. Bovine serum albumin also inhibited alginate formation, the effect increasing with increasing pH. In contrast the addition of both myoglobin and bovine serum albumin caused gel formation in the presence of pectate below pH 6.0.
The results are discussed in terms of the protein/polysaccharide interactions and the polymer/ion interactions that can take place in these systems. The relevance of this work to the use of these polysaccharides as thickeners and gelling agents in canned meat products is considered.     

利用固定化酵母进行黄酒主发酵的初步研究

该文以海藻酸钙凝胶为固定化载体,从酵母浓度、海藻酸钠浓度、氯化钙浓度3方面来探究黄酒主发酵阶段的最佳固定化条件,确定了酵母浓度为109个/mL,海藻酸钠浓度为2.0%,氯化钙浓度为4%。同时将其与传统游离酵母的发酵曲线进行对比,并且在实验室条件下连续进行了12次固定化酵母发酵,结果显示主发酵结束时酒样的酒精度在7.4%vol左右(与游离发酵结果类似),稳定性较为理想。     

氯化钙对超高压处理的鲜切马铃薯硬度改善效果的研究

超高压（Ultra-high pressure,HPP）会造成鲜切马铃薯硬度的下降,为探究氯化钙对HPP处理的鲜切马铃薯硬度的改善效果,以鲜切马铃薯为原料,在不同氯化钙处理浓度、时间和浸泡方式下对HPP处理的鲜切马铃薯硬度的变化进行研究。结果表明：氯化钙真空浸渍硬度改善效果优于普通浸泡;在此基础上,采用响应面试验对氯化钙的改善效果进行优化分析得出不同浓度氯化钙及不同真空浸渍时间与不同超高压压力、压力作用时间作用于鲜切马铃薯是交互影响的,且氯化钙溶液浓度对鲜切马铃薯的质地影响最大。在HPP压力为300 MPa,作用时间10 min结合1.0%CaCl2,真空浸渍10 min 的处理条件下,鲜切马铃薯硬度值最大,为3284.83g,与未处理的鲜切马铃薯硬度相当,钙离子含量最高,为3157.82 ug/g,显著高于未处理组钙离子含量。     

Quality Characteristics and Glass Transition Temperature of Hydrocolloid Pre-Treated Frozen Pre-Cut Carrot

The effect of hydrocolloid pre-treatment, i.e., pectin, carboxy methyl cellulose, xanthan gum and sodium alginate on textural properties, drip losses and sensory quality as well as on glass transition temperature (T_g′′′) of the frozen-thawed pre-cut carrots was studied. Untreated frozen samples showed detrimental effects in texture and also excessive drip losses while the carrot tissue integrity was well retained in the hydrocolloid pre-treated samples. As the concentration of the hydrocolloid increased, hardness and fracturability were also found to increase. However, adhesiveness was observed to follow a reverse trend. Xanthan gum (0.4%) resulted in higher texture retention than other hydrocolloids used as well as than the control samples. Hydrocolloids imparted lightness and higher red and yellowness to the carrot samples due to reduced solute mobility and moisture conditioning effects. Overall acceptability of the hydrocolloid pre-treated samples was found to be more than the experimental control samples. All the hydrocolloids were found to be effective in increasing the T_g′′′ to an extent, ?2.73 to ?0.28°C compared with T_g′′′ (?5.4°C) of untreated carrot samples. T_g′′′ increased to almost 74% in CMC (0.4%) pre-treated samples. The maximum enhancement was found in carboxy methyl cellulose followed by pectin, sodium alginate, and xanthan gum. The threshold concentrations in terms of sensory attributes were determined for optimal conditioning of the product prior to freezing.     

不同改良剂及醒发时间对马铃薯全粉面条品质特性的影响研究

采用不同改良剂和合适的醒发时间对马铃薯全粉面条品质进行改良,研究谷朊粉、海藻酸钠、食盐及不同醒发时间对面条感官品质、质构特性和蒸煮特性的影响。结果表明:加入改良剂并选取合适的醒发时间可以显著改善面条的品质,适量添加谷朊粉、氯化钠和海藻酸钠,合适的醒发时间可以提高面条的感官品质、硬度、弹性,并降低面条的蒸煮损失率。四种处理对面条感官品质影响顺序为醒发时间海藻酸钠谷朊粉食盐,对硬度的影响顺序为海藻酸钠醒发时间食盐谷朊粉,对蒸煮损失率的影响顺序为醒发时间食盐谷朊粉海藻酸钠。当醒发时间为15~60 min时,显著改善面条的感官品质、硬度、粘性及蒸煮损失率;当谷朊粉添加量为1%~3%时,显著改善面条的感官品质、硬度、内聚力、弹性和蒸煮损失率。由此可见,通过适度醒发和添加改良剂,可以显著改善马铃薯全粉面条的品质特性。     

固定化酵母在糯米稠酒中的应用

以海藻酸钠为载体，以CaCl2和ZnSO4为交联剂制作固定化酵母，并将其应用于糯米稠酒的连续发酵。研究结果表明，当海藻酸钠溶液浓度为2．5，以CaCl2溶液为交联剂制备的固定化酵母，应用于糯米稠酒生产的效果较好。连续发酵5批，所得糯米稠酒米香、醇香浓酸甜适中，酒体醇厚，无苦涩味。     

克雷伯氏菌固定化技术发酵生产1,3-丙二醇

通过对4种常见的包埋材料固定化克雷伯氏菌发酵生产1,3-丙二醇的研究发现,海藻酸钙固定化无论在制备难易还是在发酵强度上都有很大优势,并进一步确定了海藻酸钙固定化的最优条件:海藻酸钠质量浓度6%,CaCl2质量浓度4%,交联时间4 h。相对于游离发酵,固定化发酵1,3-丙二醇终浓度提高了7.4%,发酵强度达到了1.04 g/(L.h)。此外,固定化克雷伯氏菌还能用于1,3-丙二醇半连续发酵。     

肉制品复合保水剂的研制

肉制品的持水力是衡量肉制品品质的一个重要指标,因此提高肉制品的持水力具有重要的意义.本实验利用海藻酸钠与钙离子可形成凝胶这一特性,向肉制品中添加海藻酸钠和钙盐来提高肉制品的持水力,改善产品的质构.实验中,分别选择几种不同凝胶强度的海藻酸钠及钙盐对肉制品持水力及质构的影响进行研究,并采用当前世界最先进的TPA质构分析仪对产品的物性进行测定,实验结果表明:相同工艺条件下,不同凝胶强度的海藻酸钠、不同钙盐对肉制品持水力的影响有差别,通过复配实验分析得出复合保水剂的最佳配比为:300mPa     

Instrumental Textural Characteristics of Restructured Carrot Cubes

Studies were carried out on the instrumental textural evaluation of restructured carrot cubes. The experiment was conducted by incorporating different levels of alginate, glucono delta lactone (GDL), and calcium salt to the carrot pulp. Investigations showed that as pulp level increased from 0 to 90%, there was a corresponding decrease in failure stress, failure strain, and deformability modulus. Instrumental textural profile analysis (TPA) parameters viz. hardness, springiness, gumminess, cohesiveness, chewiness, and resilience also showed a similar trend. Effect of formulation variables, i.e., alginate, GDL, and calcium salt on hardness (response variable) were evaluated by the application of response surface methodology. All the three ingredients showed a significant (P < 0.05) influence on hardness of carrot gel. Heat treatment of restructured carrot samples resulted in an increased hardness, cohesiveness, gumminess, and chewiness while springiness, cohesiveness, and resilience decreased. The data indicated that the shrinkage during thermal treatment may be responsible for the change in textural attributes. The authors concluded that a thermally stable restructured product with appreciable textural integrity can be obtained from carrot pulp.     

Rheological properties of a calcium alginate-potato starch hydrolysate-water system]

The rheological properties of liquid solutions and gels of sodium alginate, calcium gluconate and gelling maltodextrin were investigated and compared with the behaviour of pastes and gels of non-degraded potato starch. The dependence of the rheological properties upon the calcium gluconate concentration is extreme. A marked increase in the viscosity of the liquid solutions and maximal values for the hardness and the breaking strength of the gels are obtained at a calcium gluconate/sodium alginate ratio of 0.3. As to breaking strength, elasticity and hardness, the maltodextrin-based gels are many times inferior to the potato starch-based gels. The breaking strength, hardness and elasticity of maltodextrin gels are increased by the addition of sodium alginate and calcium gluconate, which increases their effectiveness when used in foods.     

Quality Characteristics of Restructured Turkey Meat with Variable Alginate/Calcium-Lactate Ratios

Restructured ground turkey and turkey breast meat patties, formulated with combinations of 0–1.0% sodium alginate, 0–0.1875% calcium carbonate and 0–0.6% lactate, were compared to a no additive control. The ratio of sodium alginate to calcium carbonate was held constant at 5.3 to 1. Optimal sensory and instrumental raw and cooked product bind was achieved with combinations of 0.4–1.0% sodium alginate, 0.0750–0.1875% calcium carbonate and 0.6% lactate. All restructured products with the algin/calcium binder had higher (p<0.05) cook yields than the no additive control. Sensory aroma, flavor and juiciness of cooked products were not different (p>0.05) between treatments.     

海藻酸钠与氯化钙对大米淀粉回生影响机理的热力学分析

为探究海藻酸钠与氯化钙对大米淀粉回生的影响机理,采用差示扫描量热仪研究海藻酸钠与氯化钙对大米淀粉回生热力学特性的影响,采用Avrami模型分析大米淀粉的回生动力学参数,并用热重分析法验证影响结果。结果表明：3?mmol/L氯化钙组、质量分数0.9%海藻酸钠组及其混合物分别使大米淀粉的糊化峰值温度提高1.0%、1.1%和2.2%,使糊化焓提高4.7%、14.0%和21.4%;储藏21?d后,氯化钙对大米淀粉的回生没有显著性影响（P＜0.05）,质量分数0.6%的海藻酸钠及其与氯化钙混合物分别使大米淀粉的回生焓降低23.7%和27.6%,使回生率降低33.9%和36%;氯化钙、海藻酸钠（0.9%）及其混合物使大米淀粉的成核方式由瞬间成核转变成连续成核,并分别使大米淀粉的结晶速率常数降低73.0%、90.1%和95.3%;海藻酸钠（0.6%）与氯化钙混合物使回生大米淀粉的水分损失率减少87.1%,验证海藻酸钠与氯化钙混合物对大米淀粉回生的抑制作用。     

响应面法优化苹果多酚微胶囊工艺

为确定苹果多酚微胶囊的最佳工艺,提高苹果多酚对不利环境的抗性及缓释能力,利用响应面法采用海藻酸钠、壳聚糖和氯化钙为壁材,以包埋率为响应值进行苹果多酚微胶囊工艺优化,并将优化后的微胶囊在模拟人工胃液、肠液中进行耐受性分析。结果显示,海藻酸钠浓度、氯化钙浓度、pH、芯壁比对苹果多酚包埋率均有显著影响。海藻酸钠浓度0.020 g/mL,氯化钙浓度0.040 g/mL,pH7.0,芯壁比2:1时,苹果多酚微胶囊的包埋率达到85.13%。微胶囊产品能减少苹果多酚在胃肠道中受到的破坏,在模拟胃液和肠液环境中得到了很好的释放,肠液中的最大释放率为83.00%。实验结果显示,该方法简单可行,有效提高了苹果多酚微胶囊的包埋率及缓释能力。