Fermentation and Properties of Calcium-fortified Soy Milk Yogurt

Calcium-fortified soy milk yogurt containing 190 mg calcium/100g was produced and evaluated for textural and microstructural properties. The soy milk base contained 10% full fat soy flour, 2.25% soy protein isolate, 2.75% high fructose corn syrup, 1.55% calcium lactogluconate, and 1.25% potassium citrate. The mixture was heated 5 min at 80°C, cooled to 42°C, and inoculated with yogurt cultures. Calcium-fortified soy milk required a higher rate of inoculation (5%) than non-fortified soy milk (2.5%) and had higher titratable acidity and more syneresis. Calciumfortified soy milk yogurts showed comparable gel strength with that of commercial regular yogurt. Gels from nonfortified soy milk yogurts were hard and brittle. Addition of calcium did not significantly affect microstructure of the yogurts.     

热处理对豆浆总酚含量及其抗氧化能力的影响

以绥农56大豆为原料,研究热处理对豆浆中总酚含量和体外抗氧化能力的影响.结果 表明:一定程度的热处理可适当提高豆浆中总酚含量.豆浆在100℃处理20 min时,总酚含量1.54mg/g,且脲酶呈阴性;豆浆热处理过程中,DPPH自由基清除能力先减弱后增强,从42.80％增加至50.46％;ABTS·+清除能力先增强后减弱...     

Impact of source and level of calcium fortification on the heat stability of reconstituted skim milk powder

Calcium enrichment of food and dairy products has gained interest with the increased awareness about the importance of higher calcium intake. Calcium plays many important roles in the human body. Dairy products are an excellent source of dietary calcium, which can be further fortified with calcium salts to achieve higher calcium intake per serving. However, the addition of calcium salts can destabilize food systems unless conditions are carefully controlled. The effect of calcium fortification on the heat stability of reconstituted skim milk was evaluated, using reconstituted skim milks with 2 protein levels: 1.75 and 3.5% (wt/wt) prepared using low and high heat powders. Calcium carbonate, phosphate, lactate, and citrate were used for fortification at 0.15, 0.18, and 0.24% (wt/wt). Each sample was analyzed for solubility, heat stability, and pH. The addition of phosphate and lactate salts lowered the pH of milk, citrate did not have any major effect, and carbonate for the 1.75% protein samples increased the pH. In general, changes in solubility and heat stability were associated with changes in pH. Calcium addition decreased the solubility and heat stability. However, interestingly, the presence of carbonate salt greatly increased the heat stability for 1.75% protein samples. This is due to the neutralizing effect of calcium carbonate when it goes into solution. The results suggested that the heat stability of milk can be affected by the type of calcium salt used. This may be applied to the development of milk-based calcium enriched beverages.     

高蛋白低脂肪豆奶的研制

以豆粕为主要原料生产豆奶,着重研究了豆粕与水的配比、乳化稳定剂的用量、均质的工艺条件以及杀菌温度等对豆奶稳定性的影响.实验结果表明,豆奶生产中,控制豆粕和水的配比为1:6.7,其它配科添加量的质量比分别为:白砂糖5.00%,六偏磷酸钠0.05%,糊精3.00%,KHN-9993复配乳化剂0.25%,大豆油0.50%;压强30 MPa下均质两次,均质温度83℃;杀菌温度为121℃,时间15min.此条件生产的豆奶成本低廉,工艺可行,稳定性高,质量优良.     

热处理对牛乳成分的变化影响及热损标识物的选择

牛乳是一种成分组成十分复杂的高级营养食品,热处理是乳品工业中不可或少的一个环节,通过杀灭微生物可以延长货架期或改变性状。但乳的加热处理会改变乳成分的物理化学状态,促使乳中一些热敏物质发生变化,尤其是乳蛋白（免疫球蛋白、酶、乳清蛋白）发生变性,造成牛乳营养成分损失,甚至产生可能有害的新物质。本文对牛乳热处理过程中发生的成分变化以及热损标识物的选择作了详细综述。     

Heat Stability of Oil-in-Water Emulsions Containing Milk Proteins: Effect of Ionic Strength and pH

Emulsions (20 wt% soybean oil; 2 wt% protein) made with caseinate at pH 7 and with whey protein isolate (WPI) at pH 7 and 3 were stable to heating at 90 and 121°C. WPI emulsions destabilized at pH values between 3.5 and 4.0. In the presence of KCI (12.5–200 mM), large particles were formed in WPI emulsions at pH 3 and the emulsions were viscous. At pH 7, moderate concentrations of KCI decreased the heat stability and gels were formed. KCI had less effect on WPI emulsions made at pH 3. Combining the emulsions with caseinate allowed some control of the heat-induced gelation.     

Heat Inactivation Kinetics of Trypsin Inhibitors During High Temperature-Short Time Processing of Soymilk

Heat treatment of soymilk was studied in the conventional batch boiling process and under High Temperature-Short Time (HTST) conditions. Reduction in total trypsin inhibitor was assayed enzymatically, and individual inhibitors, the Kunitz and the Bowman-Birk inhibitor, were assayed by ELISA technique. Standard first-order reaction kinetics and thermodynamics were applicable for inactivation, and results indicated that the mechanism was not protein unfolding, because entropy changes were zero or negative. The two inhibitors were inactivated at the same rate around 137°C. Therefore, a simple first-order kinetic model which gave a good, slightly conservative estimate of residual anti-trypsin activity under HTST conditions could be established.     

Heat Curing of Soy Protein Films at Selected Temperatures and Pressures

Vacuum and temperature effects on moisture content, water vapor permeability (WVP), color (L, a, b, and ΔE), tensile strength (TS), elongation (E), and total soluble matter (TSM) of soy protein isolate (SPI) films were examined. SPI films were cured at 60, 72.5, or 85 °C and at 101.3, 81.32, or 61.32 kPa for 24 h. As a result of heat-curing moisture content, WVP, E, and TSM decreased, and total color difference and TS increased. Pressure, individually and interactively with temperature, significantly affected film moisture content, TS, and TSM.     

海南椰奶清补凉饮料的生产工艺研究

海南椰奶清补凉是一款营养丰富的特色小吃,但其工业化生产工艺研究甚少.本文对椰奶清补凉辅料配方、乳化剂复配、均质和杀菌等方面进行研究,优化其工业化的生产配方、工艺和稳定性.结果表明:加糖量,椰果肉与水质量比,绿豆、西米和椰果的质量比分别为10%、1:3、1:2:3时综合感官评定分最高;单甘酯、Span-20、Tween-...     

Soluble and Lipid-Bound Calcium and Zinc During Processing of Infant Milk Formulas

Samples were withdrawn during the manufacture of infant formulas to determine steps which may affect soluble and lipid-bound Ca and Zn, which were estimated after centrifugal separation of in vitro digested samples. Pasteurization did not significantly reduce solubility of Ca and Zn. Blends forewarmed at low temperature contained a smaller proportion of soluble Ca than skim milk, but Zn was not affected. Forewarming at high temperature reduced solubility of Ca. The solubility of Ca and Zn was lower in sterilized and spray-dried formulas than in blends forewarmed at low temperature. Though initial Ca and Zn levels were greater in infant formulas than in human milk, percentages of soluble Ca and Zn were not higher.     

咖啡奶茶的研制及其稳定性研究

以奶粉、绿茶和咖啡粉等为主要原料,采用正交设计方法,进行了咖啡奶茶主要原料配比试验。并以稳定性作为主要评定指标,研究了乳化剂对咖啡奶茶油脂析出率、离心沉淀率等其稳定因素的影响,确定咖啡奶茶的最佳制作工艺条件。结果表明,在奶粉添加量为9．0％,茶水30．0％,咖啡0．30％,白砂糖3．0％,蔗糖酯0．08％,海藻酸钠0．02％,CMC-Na0．04％的条件下,所得咖啡奶茶在色泽、气味、组织状态和风味都比较好。     

食品热焓和比热容的经验计算公式

采用ORIGIN数据统计分析软件对常见19种食品的热焓-温度数据进行拟合,并对拟合公式求导数,给出食品热焓和比热容的经验计算公式。通过与文献数据比较,结果表明,经验计算公式具有较高的精度。     

Magnetic Treatment of Milk and Surface Treatment of Plate Heat Exchangers: Effects on Milk Fouling

After milk property effect was eliminated, relative fouling rates of electropolished stainless steel, 304 stainless steel, titanium, polysiloxane and Teflon were 0.99,1.00,1.01,1.14, and 1.20, respectively. No significant reduction of cleaning time was found on the Teflon-coated plate although Teflon had significantly larger contact angles in both surface-water-air and surface-water-octane than did stainless steel. Magnetic field treatment of milk and calcium phosphatase solution did not significantly affect fouling rates or type of calcium phosphate crystals in deposits.     

猕猴桃果奶生产工艺及稳定性研究

以"米良1号"猕猴桃为原料,对猕猴桃果奶的生产工艺及稳定性进行试验研究,重点探讨了原料配比、稳定剂复配及均质工艺。结果表明:猕猴桃果奶的原料配比采用猕猴桃汁20%、全脂奶粉6%、总酸0.3%、总糖13%,加入0.15%CMC-Na、0.10%PGA、0.06%GMS和0.10%STPP作为复合稳定剂,在23～27MPa、50～60℃下进行均质处理,风味、口感及稳定性较为理想。     

高抗性淀粉米乳饮料制作工艺

以含高抗性淀粉的宜糖米为原材料,采用酶解的方法,开发出了一种适合糖尿病人和肥胖人群饮用的抗性淀粉米乳饮料。研究了原料配比、烘焙条件、糊化时间、酶解条件等工艺,最大限度地提高了米乳饮料中抗性淀粉的含量,并且通过正交试验确定了米乳饮料的最佳配方。     

Heat Inactivation of Native Plasminogen Activators in Bovine Milk

Inactivation of plasminogen activators appeared to follow first-order kinetics in the temperature range tested. The Arrhenius plot was linear (correlation coefficient 0.990). The Arrhenius equation for heat inactivation was deduced, from which the rate of inactivation at any temperature in the range 60–140°C could be calculated. The decimal reduction time (D-value) was 109 min at 70°C and 32 set at 140°C. This indicated that native plasminogen activators in bovine milk are not affected by pasteurization, and to a large extent are not inactivated by UHT dairy processing conditions.     

巴氏杀菌乳生产工艺的研究

介绍了巴氏杀茵乳的生产工艺，针对乳制品中易出现蛋白质沉淀和脂肪上浮等现象，选择了合适的生产工艺及复合乳化稳定剂，以提高产品稳定性及产品档次。结果表明，当酪朊酸钠的用量为0．1％，CMC0.1％，PGA0．05％时，巴氏杀菌乳的稳定性最好；当杀菌温度为70℃，10min时，杀菌效果最为理想。     

Calcium Fortification of Rice: Distribution and Retention

A method of calcium fortification of milled rice was developed and tests conducted to investigate calcium distribution and retention. Milled rice (Karen variety) was soaked in 3.0% calcium lactate solution (CLS)(rice: CLS, 1.0:0.75 w/v) for 3 hr at room temperature followed by steaming 10 min at 0.68 atm, and drying to 10–11% moisture. Washing fortified rice resulted in calcium losses of ～5%. Calcium fortified rice flour samples after dialysis, retained ～60% of original calcium. Fortification process met U.S. standards for calcium-fortified rice (110–220 mg/100g rice) and resulted in minimal washing losses.     

不同热处理工艺对牛乳中热敏感成分的影响

热处理是保证乳制品质量稳定和卫生安全的重要手段之一,牛乳在热处理过程中会发生美拉德反应、乳糖异构化和蛋白质变性等多种化学变化,且反应程度与热处理强度密切相关。文中以纯鲜生乳为材料,经巴氏、超巴氏和超高温瞬时杀菌(UHT)等热处理后,分析检测牛乳中主要热敏感成分的变化。结果表明:随着热处理强度的提高,牛乳中的糠氨酸含量呈指数关系增加,纤溶酶活则逐渐下降;热处理强度不同导致乳清蛋白各组分的变性程度也不同,其中β-LgB和BSA对热最敏感,β-LgA其次,α-La的耐热性最强;热处理温度越高,时间越长,牛乳中VB1和VB6的损失率也就越高。根据牛乳中热敏感成分含量或活性在热处理过程中的的变化规律,可以将糠氨酸、α-乳白蛋白和纤溶酶活等作为牛奶受热程度的指示物,从而更好的指导实际生产和维护消费者权益。     

Chemical, Physical and Sensory Attributes of Noodles with Added Sweetpotato and Soy Flour

Noodles were prepared with sweetpotato flour or puree and defatted soy flour (DSF) added to all-purpose wheat flour. These ingredients provided β-carotene for vitamin A and protein. Test samples were compared with control noodles. Combinations of sweetpotato and DSF increased protein, ash and total dietary fiber and decreased fat and carbohydrates. Sweetpotato contributed orange color and β-carotene, while DSF reduced lightness and added no β-carotene. Both ingredients increased cooking loss—10.4% from sweetpotato to 12.0% from sweetpotato and DSF combinations. Sweetpotato increased color acceptability with no change in flavor or overall acceptabilities. Sweetpotato decreased stickiness and DSF had no effect on acceptability.