菲订生产中中和条件的选定

研究了中和剂，州值及温度对菲汀得率和质量的影响，得出在较高温度下以Ca（OH）2和NaOH分两步中和至pH6．8为较佳的中和条件。     

鲤鱼鱼鳞中甲壳素的提取

以鲤鱼鱼鳞为原料提取甲壳素。通过盐酸和氢氧化钠溶液将鱼鳞中矿物质和蛋白质等去除,从而提取鱼鳞中的甲壳素,加热脱去乙酰基得到壳聚糖。通过4个不同的单因素确定最佳的提取工艺,HCl溶液浓度为1 mol/L,HCl溶液浸泡时间为30 min,Na OH溶液浓度为1 mol/L,Na OH溶液处理时间为8 min,得到甲壳素的最大提取率为11.72%。将提取出来的甲壳素加入到Na OH溶液中,水浴(T=80~℃,t=10 min)加热,水洗,并用酸度计调节至中性,干燥得到黄色的壳聚糖。     

葵花籽粕酶解制备低钠盐ACEI抑制肽

为制备低钠盐含量的葵花籽粕蛋白血管紧张素转换酶抑制肽(ACEI抑制肽),建立了以Ca(OH)2溶液调节酶解反应pH值的制备工艺并进行了工艺参数优化。以蛋白水解度、产物ACE抑制率和苦味值为评价指标通过选酶试验从6种商业蛋白酶中确定胰蛋白酶为水解用酶。通过对葵花籽粕蛋白酶解试验,发现在其他酶解条件相同情况下,以Ca(OH)2调节酶解pH值的葵花籽粕水解多肽的ACE抑制率和水解度优于NaOH调节的,而苦味值相近。通过对底物浓度、加酶量、pH、温度和时间进行单因素试验和对时间、温度、pH等因素进行的正交优化试验,确定用Ca(OH)2调节酶解pH值的制备葵花籽粕蛋白ACEI抑制肽工艺参数为:底物的质量浓度为3.5%,加酶量2.85%(E/S),pH7.5、温度45℃和酶解时间5min,所得ACEI抑制肽产品的IC50值为6.06mg/mL。     

国外不锈钢酸洗技术

介绍国外不锈钢酸洗技术。国外不锈钢酸洗一般采用隧道式全封闭自动化酸洗生产线,酸洗工艺大多采用还原型碱浸与预酸洗和混酸洗,成品采用硝酸钝化和石灰中和处理。还原型碱浸是由质量分数0.16%～0.30%的NaH加NaOH组成;预酸洗液由质量浓度为180～220 g/L的H2SO4组成;混酸是由质量浓度为20～55 g/L的HF和质量浓度为120～220 g/L的HNO3组成;钝化液由质量浓度为180～250 g/L的HNO3组成;中和液是质量分数为10%～15%的Ca(OH)2溶液。     

响应面法优化酪蛋白酸钙生产工艺

以食品级干酪素为原料,以制备的酪蛋白酸钙中钙含量为指标,采用单因素实验、中心组合(Box-Benhnken)试验设计与响应曲面分析法,研究了酪蛋白酸钙的生产工艺。在单因素实验的基础上采用3因素3水平的响应曲面分析法,以酪蛋白酸钙中钙含量为指标,考察溶液pH、溶液浓度与Ca(OH)2添加量对酪蛋白酸钙制备的影响,建立了酪蛋白酸钙制备中钙含量与各影响因子的回归方程,确定了最佳工艺条件。结果表明:最佳制备工艺为溶液pH值为7.16、料液浓度为5.97%、Ca(OH)2添加量为1.716%,在此条件下制备的酪蛋白酸钙中钙含量为1.639%,与预测值1.642%相差不显著。该工艺酪蛋白酸钙得率高,所得产品含钙量较高,产品具有较好的品质。     

微波技术提取砂糖橘皮中的橙皮甙

以饱和Ca(OH)2为提取溶液,采用碱提酸沉微波辅助提取技术,通过单因素试验和正交试验研究了从砂糖橘皮中提取橙皮甙的工艺.结果表明,在料液比1:10(g/mL)、提取温度60℃、提取时间4 min、酸沉淀pH 4.0的条件下,砂糖橘皮中橙皮甙的提取率为1.93%,纯度为94.45%.     

出口袋装四季豆加工过程中的护绿研究

对四季豆在加工过程中所采用的护绿措施以及护绿效果进行了研究 ,探讨护绿方法和工艺条件。结果表明 ,经过挑选分级的四季豆于 95～ 10 0℃水中烫漂 1 5min左右 ,充分快速冷却后置于 pH 1 5柠檬酸溶液中 ,室温褪色 2 5h ,流动水浸泡去除多余的酸后 ,于 85℃、30 0mg/LCuSO4 溶液中浸泡 2 5min ,流动水冷却清洗 2h至水无色 ,随后放入质量分数为0 6 %CaCl2 溶液中浸泡 10～ 15min ,捞起后放到 pH 4 2柠檬酸溶液中以四季豆占 6 0 % ,柠檬酸溶液占 4 0 % ,包装封口 ,于 85～ 90℃水浴杀菌 2 0～ 30min。所得产品质地良好 ,色泽理想。     

适合荷叶贮藏的最佳加工技术参数研究

试验对新鲜荷叶进行杀菌,经CaCl2溶液或植酸溶液浸泡后,在不同干燥条件(温度、时间)进行干燥处理,然后放在常温下贮藏。结果表明:(1)Ca2 在荷叶干燥中有抑制自由水分散失和增强荷叶的拉伸性能的双重作用;(2)植酸除具有很强的杀菌防腐效果外,还具有很强的保水性,增加荷叶的柔韧度;(3)最佳干燥技术参数为5?2 浸泡15min、0.1%植酸浸泡10min、60℃干燥50min或5?2 浸泡15min、1%植酸浸泡10min、70℃干燥30min。     

NaOH、Ca（OH）2和Mg（OH）2水解牛毛的差异性研究

用正交试验优化NaOH碱水解牛毛的条件,得出最佳条件为NaOH碱用量6%、水解时间8h、水解温度100℃。再分别用Ca(OH)2和Mg(OH)2两种碱以相同的碱用量在此条件下水解牛毛,比较三种水解液的氨基酸浓度、含氮量、黏度以及相对分子质量的不同,研究它们水解牛毛的差异性。     

杏仁罐头生产过程中脱皮和脱苦方法的研究

本文对杏仁罐头生产过程中的脱皮和脱苦问题进行了探讨。试验表明采用5％Na_2CO_3+5％Ca(OH)_2为脱皮剂、温度90℃、脱皮时间1分钟效果最好;采用0.2％HCl溶液、温度60℃、浸泡12小时可脱苦除去HCN,该方法大大缩短了脱苦时间。     

Optimization of Processing Parameters for the Preparation of Flounder Frame Protein Product

Flounder frame was used as a raw material for the preparation of protein product. Processing parameters were evaluated using both fresh and frozen ground frames. The results indicate the following optima: (1) pH of extraction medium, ii; (2) extraction time, 60 min; (3) volume to weight ratio, 10: 1; (4) extraction temperature, 23°C. Isoelectric precipitation was conducted at pH 5 using KCI or H₃PO₄. Results indicate that NaOH was more effective than Ca(OH)₂ in solubilizing frame protein at pH 11. Ground frozen flounder frames gave a 10% decrease in protein extractability when compared to fresh frames using NaOH as the extractant and a 22% decrease when Ca(OH)₂ was employed as the extractant. Approximately 70% of the protein is recovered using the NaOH-HCI system.     

AN IMPROVED PROCESS FOR ISOLATION OF GLANDLESS COTTONSEED PROTEIN USING INDUSTRIAL MEMBRANE SYSTEMS

An improved process employing a combination of isoelectric precipitation and ultrafiltration to isolate glandless cottonseed protein was developed. The effectiveness of Ca(OH)₂, NaOH, and KOH in extracting storage protein (SP) was compared at pH 10, 9.5 and 9.0. KOH and NaOH each solubilized ca 88% of the flour nitrogen at pH 10, 87% at pH 9.5, and 85% at pH 9.0. Ca(OH), proved less effective, solubilizing about one-fifth as much as the other two hydroxides. Nonstorage protein (NSP) extract was separated by acid precipitation into curd and whey: The lysine-rich NSP whey was then added to SP extract and the mixture ultrafiltered to obtain a higher yield of SP isolate having a lighter color and increased lysine content.     

Pilot-scale waste activated sludge alkaline fermentation, fermentation liquid separation, and application of fermentation liquid to improve biological nutrient removal

The use of sludge fermentative short-chain fatty acids (SCFA) as an additional carbon source of biological nutrient removal (BNR) has drawn much attention recently as it can reuse sludge organics, reduce waste activated sludge production, and improve BNR performance. Our previous laboratory study had shown that the SCFA production was significantly enhanced by controlling sludge fermentation at pH 10 with NaOH. This paper focused on a pilot-scale study of alkaline fermentation of waste activated sludge, separation of the fermentation liquid from the alkaline fermentation system, and application of the fermentation liquid to improve municipal biological nitrogen and phosphorus removal. NaOH and Ca(OH)(2) were used respectively to adjust the alkaline fermentation pH, and their effects on sludge fermentation and fermentation liquid separation were compared. The results showed that the use of Ca(OH)(2) had almost the same effect on SCFA production improvement and sludge volatile suspended solids reduction as that of NaOH, but it exhibited better sludge dewatering, lower chemical costs, and higher fermentation liquid recovery efficiency. When the fermentation liquids, adjusted with Ca(OH)(2) and NaOH respectively, were added continuously to an anaerobic-anoxic-aerobic municipal wastewater BNR system, both the nitrogen and phosphorus removals, compared with the control, were improved to the same levels. This was attributed to the increase of not only influent COD but also denitrifying phosphorus removal capability. It seems that the use of Ca(OH)(2) to control sludge fermentation at pH 10 for efficiently producing a carbon source for BNR is feasible.     

改性大豆蛋白的粘度及其在代木材料中的应用

利用NaOH、Ca(OH)_2、脲(NH_2CONH_2)、SDBS对SPI溶液改性,并通过对粘度随改性剂种类、浓度、改性时间的变化分析SPI分子的化学变化及适宜的改性条件。提出复合改性的方法,并通过制备轻质代木包装材料进一步分析改性剂对材料性能的影响,利用单因素及正交试验确定当Na OH、Ca(OH)_2、脲、SDBS、SPI∶水的质量比为0.01∶0.01∶1.2∶0.1∶1∶10,改性温度40℃,复合改性时间3h时制备的SPI胶粘剂,为制备轻质代木包装材料的最佳方案。     

Influence of technological variables on the functionality of the cell‐free fraction of fermented buttermilk

Buttermilk is a suitable substrate for fermentation with proteolytic strains of Lactobacillus in order to release peptide fractions able to enhance the gut mucosal immune system. We aimed to determine the influence of the degree of proteolysis of buttermilk proteins on their functionality. Animals received for seven consecutive days the cell‐free fraction of 10 or 20% (w/v) buttermilk fermented with Lactobacillus delbrueckii subsp. lactis 210 at pH 6. The pH was controlled either with NaOH or Ca(OH)₂. No significant differences in the number of IgA‐producing cells in the small intestine of mice were found. The functional capacity of the product under study was not affected by the technological variables considered.     

Effect of Dilute Alkaline Steeping on the Microbial Contamination,Toxicity and Diastatic Power of Sorghum Malt

Steeping in dilute alkali was investigated with the primary aim of reducing the moulds, coliforms, and preventing toxicity of sorghum malt. Red tannin‐free sorghum cultivars NK 283 and PAN 8546 were steeped in 0.1, 0.2 and 0.3% NaOH and 0.1, 0.3 and 0.5% Ca(OH)₂. The effects of these solutions on aerobic plate count, lactic acid bacteria, yeasts, moulds, coliforms, the presence of some mycotoxins (aflatoxins, fumonisins, deoxynivalenol and zearalenone), the cytotoxicity and diastatic power (DP) of sorghum malt was evaluated. Steeping NK 283 in 0.1% Ca(OH)₂ increased the DP from 10.5 to 16 Sorghum Diastatic Units (SDU)/g. However, it did not reduce the general levels of malt microflora. Steeping in dilute NaOH reduced the microflora on the malt. Steeping both grain cultivars with 0.2% NaOH resulted in malts with the moulds and coliforms reduced to approximately 3.5 and 2.0 log colony forming units/g, respectively and the percentages of some mould species to very low or undetectable levels. The DP of the 0.2% NaOH steeped malts increased to 16.2 and 26.9 SDU/g in the NK 283 and PAN 8546, respectively. There were no detectable amounts of mycotoxins and no indication of cytotoxicity in the 0.2% NaOH steeped samples. Steeping sorghum grains in food‐grade 0.2% NaOH is recommended as a method for the control of bacterial and fungal contamination during sorghum malting.     

化学发光法测定风干肠中的亚硝酸盐

利用亚硝酸根对鲁米诺-溴酸钾化学发光体系具有显著增强作用的特点测定风干肠中的亚硝酸盐。讨论酸度、反应物浓度、干扰离子因素等对测定结果的影响,确定化学发光测定的最佳反应条件为硫酸浓度0.05mol/L、溴酸钾浓度0.06mol/L、鲁米诺浓度1.50×10-4mol/L、NaOH浓度0.25mol/L,此时方法的线性范围为0.001～10mg/L,检出限为8×10-5mg/L(3σ)。样品平行测定(n=11)结果显示：其相对标准偏差为3.55%,加标回收率为99.70%,可见,方法具有较高的灵敏度和选择性,与传统方法相比快速、简便,易于操作。     

凝结芽孢杆菌混合碳源乳酸发酵研究

为了更好的研究工业乳酸发酵中的分解代谢物阻遏效应,在实验室规模反应器对凝结芽孢杆菌混合碳源乳酸发酵进行不同通气量、p H、中和剂等条件的发酵特性研究,并研究了不同金属离子、渗透压等条件对饥饿状态下凝结芽孢杆菌自溶的影响。结果表明：凝结芽孢杆菌葡萄糖+海藻糖混合碳源乳酸发酵呈现明显的分解代谢物阻遏效应,且发酵可分为葡萄糖消耗阶段、有机酸消耗阶段和海藻糖消耗阶段。不同发酵条件在葡萄糖消耗阶段对菌体生长和乳酸生成影响较小,但对发酵后期海藻糖利用阶段菌体生长和乳酸合成有明显影响。在海藻糖消耗阶段,通气量为7.2 L/h时有较高的底物消耗速率和产酸速率;用NaOH作为中和剂在p H6.5时海藻糖消耗速率和乳酸生成速率均高于pH6.0,而p H5.5时不利用海藻糖且不生产乳酸;与NaOH作为中和剂相比,在p H6.5条件下Ca(OH)₂作为中和剂使海藻糖消耗速率和乳酸生成速率分别提高21.0%和28.3%。发现Ca₂₊、Mg₂₊等二价离子确实对菌体自溶有一定的缓解作用,且Na₊能在饥饿状态下维持菌体的活性,为研...     

Activity of trisodium phosphate compared with sodium hydroxide wash solutions against Listeria monocytogenes attached to chicken skin during refrigerated storage

The potential of using trisodium phosphate (TSP) and sodium hydroxide (NaOH) to reduce Listeria monocytogenes populations in chicken skin was studied. Raw chicken legs inoculated with L. monocytogenes were dipped in water (control), in 8% (pH=12·59), 10% (pH=12·68) and 12% (pH=12·75) (w/v) TSP solutions, or in NaOH solutions of equal pH values to those of TSP: 0·175%, 0·200% and 0·220% (w/v). Surface pH values and L. monocytogenes counts of chicken skin were determined immediately after treatment (day 0) and after 1, 3 and 5 days of storage at 2°C. Compared with water dipping, TSP and NaOH treatments significantly (P<0·05) reduce Listeria populations at days 0, 1, 3 and 5 of refrigerated storage. Bacterial reductions varied between 1·12 and 3·34 log₁₀ cycles for TSP-treated samples and between 1·80 and 3·28 log₁₀ cycles for NaOH treated samples. The observed reductions in all treated samples were significantly (P<0·05) greater following storage. The concentration of the TSP solution was a significant factor in reducing the populations of L. monocytogenes. However, bacterial reductions were similar in samples treated with different concentrations of NaOH. The TSP or NaOH treatments resulted in relatively high residual surface pH values (8–9) initially and throughout storage. The pH values were significantly higher in the samples treated with TSP than in those treated with NaOH.     

POTASSIUM HYDROXIDE REPLACEMENT FOR LYE (SODIUM HYDROXIDE) IN TOMATO PEELING

Lye (sodium hydroxide [NaOH]) peeling is the most common method for peeling tomatoes in the Midwest U.S. With the rise in the cost of NaOH and the associated disposal problems, alternative methods for peeling need to be examined. Solutions of NaOH, potassium hydoxide (KOH) and calcium hydroxide (Ca[OH] ₂ ) at different concentrations were compared to determine their efficacy as peeling agents. Ca(OH) ₂ was ineffective as a peeling agent because of its low solubility. KOH produced peeling equivalent to NaOH, but at half the normality. A lower normality is needed because of the increased reactivity of KOH compared to NaOH. This is further demonstrated by the addition of salts to the solution. The use of KOH instead of NaOH may result in cost savings and decreased waste disposal problems.