酶-碱法协同水解麦麸提取阿魏酸及功能性研究

探讨了酶-碱法协同处理麦麸制备阿魏酸的工艺,并对提取所得的阿魏酸通过抗氧化和抑菌实验来验证其功能性。研究结果表明,通过正交实验分别确定碱解、酶解麦麸提取阿魏酸的最佳工艺参数为:酶解pH5、温度55℃、麦麸含量8%、时间5h;碱解料液比1∶15、温度为60℃、时间6h、亚硫酸钠1.0%、氢氧化钠1.5%。这两种方法协同对麦麸进行处理能明显使阿魏酸产量增加。同时,该法提取的阿魏酸具有较好的抗油脂氧化能力和抑菌功能。      

碱解小麦麦麸制备阿魏酸的工艺条件研究

研究以小麦麸皮为原料碱解制备阿魏酸的工艺条件.用淀粉酶和蛋白酶酶解除去麦麸中的淀粉和蛋白质,氢氧化钠碱解制得阿魏酸,并以阿魏酸量为考察指标通过正交试验确定碱解麦麸制备阿魏酸的最佳工艺条件.试验结果表明:酶解50 g麦麸,两种酶的最佳用量分别为:耐高温α-淀粉酶0.45 g,中性蛋白酶0.5 g;碱解麦麸制备阿魏酸的最佳工艺条件:氢氧化钠浓度1%,碱解温度85℃,碱解时间4 h;在此条件下水解50 g麦麸可获得406.2 mg阿魏酸.此工艺条件可用于小麦麦麸制备阿魏酸.     

酶-碱法提取碎米蛋白工艺研究

以精米加工副产物的碎米为原料,采用酶法富集-碱法浸提工艺对碎米蛋白质进行提取。首先采用α-淀粉酶对碎米进行液化预处理,以利于碎米中蛋白质组分的富集。在酶解温度95℃、pH7.5、固液比1∶15、α-淀粉酶用量20U/g、水解时间150min条件下,碎米原料液化率达到61.4%,经离心分离后的沉淀作为下游碱法提取蛋白质的原料。在单因素实验基础上,以提取率为指标,设计正交实验对碱法提取工艺条件进行了优化。结果表明,最佳浸提工艺参数为:NaOH浓度0.06mol/L、料液比1∶5(w/v,g/mL)、提取时间5h、温度50℃,在此最佳条件下,碎米蛋白提取率达到86.26%。酶-碱复合法集酶法富集与碱法浸提为一体,为碎米蛋白的生产及碎米资源的高值化利用提供了相关依据。     

酶-碱法提取酵母β-1,3-葡聚糖的研究

采用酶-碱法从酵母自溶残渣中提取β-1,3-D-葡聚糖,通过正交试验得出最佳碱处理工艺条件为酶解后的沉淀物用60mL2%氢氧化钠溶液75℃处理6h,经冷冻干燥后,成品葡聚糖的得率为21.38%,其中多糖含量为92.17%,蛋白质含量为1.32%,水分含量为5.53%,酶-碱法处理工艺具有葡聚糖得率高、蛋白质含量低的特点。     

沙棘籽粕蛋白的碱酶两步法提取工艺及功能性研究

以沙棘籽粕为原料,采用碱提酸沉法提取沙棘籽粕蛋白,得到最佳提取工艺参数为:pH10、料液比1:12、温度60℃、时间60min。后用碱性蛋白酶对碱提残渣中的蛋白进行水解,最适提取条件为:pH8.5、碱性蛋白酶加酶量240U/g、料液比1:10、60℃、60min。通过碱提、酶法两步提取后,总提取率为67.24%。并对其乳化活力和乳化稳定性等功能性质进行了研究,表明性质受pH、温度、盐离子浓度等环境因素影响大,在等电点pH5.0附近时乳化活力和乳化稳定性的数据最低。      

醇-碱法提取啤酒糟中蛋白质的研究

以酒糟为原料,通过醇-碱法进行蛋白质提取的研究。对影响蛋白质提取的因素,如醇碱比的选择、提取温度、提取时间及提取料液比等条件进行了正交试验。确定了获得最大提取量的条件,即以醇．碱比为1：2作为提取剂,提取温度30℃,提取时间为70mm,提取料液比为1：30。     

自溶-酶-碱法提取啤酒酵母中β-1,3-葡聚糖的工艺研究

本文通过正交试验,对自溶-酶-碱法提取废啤酒酵母中β-1,3-葡聚糖的最佳工艺进行了研究.结果表明其最佳工艺条件为:啤酒酵母于50℃自溶6h后,添加100U/湿酵母木瓜蛋白酶,继续自溶18h后离心,沉淀用2%的NaOH溶液分散,于80℃水浴处理3h后离心,沉淀用蒸馏水清洗3～4次后进行真空冷冻干燥,粉碎得成品.成品得率10.80%,其中多糖含量87.70%、蛋白质含量0.45%、水分含量6.72%、灰分含量1.05%,具有得率高、纯度高、蛋白质含量低的特点.     

柿子红色素的微波-超声波法协同提取及其理化性质的研究

研究了微波和超声波对柿子红色素提取的影响,通过单因素分析和正交试验设计确定了最佳提取工艺条件,并对柿子红色素的理化性质进行了进一步研究。最佳提取工艺条件为微波功率624W,微波处理时间60s,超声波处理时间40s,料液比为1：6。该色素耐热性、耐光性、耐酸、耐糖、耐还原性较好;但耐氧化性较差,有较高的利用价值。     

响应面法对Neutrase蛋白酶酶解燕麦麸的优化研究

以燕麦麸皮为原料,采用Neutrase复合蛋白酶水解,并对水解工艺进行优化.以水解度(DH)及氮溶指数(NSI)为评价指标,在对加酶量、反应时间、料液比等单因素实验的基础上,采用BoxBenhnken响应面分析法,设计了3因素3水平实验,得到了燕麦麸蛋白酶解的最优条件.     

Composition and functionality of wheat bran and its application in some cereal food products

Production of wheat bran (WB) for human consumption is estimated to be about 90 million tonnes per year. WB is a cheap and abundant source of dietary fibre which has been linked to improved bowel health and possible prevention of some diseases such as colon cancer. It also contains minerals, vitamins and bioactive compounds such as phenolic acids, arabinoxylans, alkylresorcinol and phytosterols. These compounds have been suggested as an aid in prevention of noncommunicable diseases such as cardiovascular disease. This article discusses WB extraction, its nutritional properties, potential health benefits, effects on quality and sensory properties of some cereal foods, and its application in some baked products as well as in fried cereal snacks, as an additive for oil reduction and fibre enrichment.     

Ferulic acid and its position among the phenolic compounds of wheat

Ferulic acid (3-methoxy-4-hydroxycinnamic acid) is the main phenolic acid occurring in cell walls of monocotyledones. Due to its blue-and-white fluorescence it is easily identified and is located in the cereal grain morphological parts. Its 40-fold greater concentration was found in the cells walls of the seed coat and aleuronic layer than in the cells walls of endosperm. Most often, it is linked by ester bonds with hemicellulose chains, mainly with arabinose residues and it also polymerizes with lignin through ether bonds. However, ferulic acid in the pentosane molecules forms specific complexes with proteins through chemical bonds with amino acids. It is interesting to mention the theory of the pentosane gel formation in which a great role is assigned to ferulic acid. An oxidized form of ferulic acid-diferulic acid-produces gel formation by linking two pentosane or protein molecules. The blue-and-white fluorescence of ferulic acid can be applied to determine flour contamination with grain coat particles and its ability to form complexes with pentosanes and proteins is important in the formation of dough texture with its semi-elastic properties.     

麦麸中植酸的脱除工艺

目的 探究麦麸中植酸的脱除工艺.方法 以植酸脱除率为目标,参照国家标准方法测定植酸脱除前后麦麸中主要组分,对麦麸中植酸的脱除工艺进行了分析和优化.结果 植酸脱除的最佳工艺是:以0.5 mol/L盐酸溶液为植酸提取溶剂,料液比为1:10(g/mL),20℃下提取2 h,植酸脱除率可达到73.54％.升高提取温度不利于植酸...     

微波-酶法处理小麦麸皮制备低聚木糖的工艺研究

以小麦麸皮为原料制备低聚木糖,先微波消解,后加酶水解,研究微波酶法制备低聚木糖过程中微波功率、微波处理时间、液料比、加酶量和酶解时间5个因素对低聚木糖提取率的影响.经单因素和正交试验,确定最佳工艺条件为:微波功率600 W、微波处理时间7 min、加酶量2.5％和酶解时间8h,低聚木糖提取率为47.5％.该工艺成本较低,所得到的粗提取液颜色较浅,便于脱色,明显优于传统单一的微波消解法和酶解法.     

Phenolic acid profiles and antioxidant activities of wheat bran extracts and the effect of hydrolysis conditions

Four different types of wheat bran were extracted and analyzed for phenolic acids using the Folin–Ciocalteu method and HPLC. The extracts and their hydrolysis products were also evaluated for their antioxidant activities. The total phenolic content of the red wheat bran was higher than that of the white wheat. We found that the majority of the phenolic acids existed in a bound form in wheat bran. These phenolic acids can be released by hydrolyzing the bran under alkaline or acidic conditions; however, the former was more efficient in the release of free phenolic acids than the latter. Ferulic, vanillic, and syringic acids were the major individual phenolic acids in the studied wheat bran. The main portion of the total ferulic acid was from alkaline hydrolysis. The alkaline hydrolysable fractions had greater antioxidant activities, while the acid hydrolysable fractions showed lower activities in both the red and white bran. The antioxidant activity of bran extract was stronger than that of free phenolic acids.     

Extraction and purification of ferulic acid from flax shives,wheat and corn bran by alkaline hydrolysis and pressurised solvents

Extraction of ferulic acid and vanillin from flax shives, wheat bran and corn bran were carried out using two extraction methods, non-pressurised alkaline hydrolysis (0.5 M NaOH) and pressurised solvents (0.5 M NaOH, water, ethanol and ammonia). There were no differences in the content of products extracted with non-pressurised and pressurised 0.5 M NaOH solution yielding mostly ferulic acid, p-coumaric acid and small amounts of vanillin. Pressurised low-polarity water (PLPW), pressurised aqueous ethanol (PAE) and pressurised aqueous ammonia (PAA) were efficient in the one-step production of vanillin from ferulic acid in flax shives (guaiacyl-rich), wheat bran and corn bran (ferulic acid-rich). Vanillin was produced from the bound-ferulic acid via cleavage of the aliphatic double bond under the pressurised conditions. Higher content of ferulic acid in the corn bran yielded higher amounts of vanillin compared to wheat bran and flax shives. A simple and efficient purification procedure for ferulic acid from the alkaline extracts is presented. This procedure exploits the solubility of ferulic acid at different ethanol concentrations.     

玉米皮酸解提取L-阿拉伯糖的工艺研究

L-阿拉伯糖是一种没有热量的甜料,属于五碳醛糖.其最大功能是可以选择性对肠道内蔗糖酶的活性起非竞争性抑制作用,对蔗糖的代谢转化有显著阻断作用,抑制因摄入蔗糖而导致的血糖升高,从而具有降血糖和减肥的功效.摄入适量的L-阿拉伯糖还能促进双歧杆菌的增殖,调节人体肠道的菌群.美国医疗协会将L-阿拉伯糖列入抗肥胖剂的营养补充剂或非处方药.日本厚生省的特定保健用食品清单中将L-阿拉伯糖列入调节血糖的专用特殊保健食品添加剂.然而受限于其生产,目前国内外市场上的阿拉伯糖价格昂贵,因此本文采用正交方法研究了用草酸水解玉米皮生产L一阿拉伯糖的工艺条件,得出最佳工艺条件为:草酸浓度0.5%,酸解温度90℃,酸解时间2.5h,最佳条件下L-阿拉伯糖的收率为10.08%(干物质计).以期对稀有功能糖L-阿拉伯糖的开发提取提供一定的理论参考.     

Color of whole-wheat foods prepared from a bright-white hard winter wheat and the phenolic acids in its coarse bran

Abstract: The color of wheat kernels often impacts the color and thereby the value of wheat‐based foods. A line of hard white winter wheat (B‐W HW) with bright appearing kernels has been developed at the Kansas State Agricultural Research Center. The objective of this study was to compare the color of several foods made from the B‐W HW wheat with those of 2 hard white wheat cultivars, Trego and Lakin. The B‐W HW kernels showed higher lightness (L*, 57.6) than Trego (55.5) and Lakin (56.8), and the increased lightness was carried over to its bran and whole‐wheat flour. Alkaline noodle and bread crumb made from the B‐W HW whole‐wheat flour showed slightly higher lightness (L*) than those made from Trego and Lakin. The sum of soluble and bound phenolics extracted from the 3 wheat brans, which had not been preextracted to remove lipids, was found to be 17.22 to 18.98 mg/g. The soluble phenolic acids in the brans were principally vanillic, ferulic, and syringic. The bound phenolic acids in the brans were dominated by ferulic, which accounted for 50.1% to 82.2% of total identified bound phenolic acids. Other bound phenolic acids were protocatechuic, caffeic, syringic, trans‐cinnamic, p‐hydroxybenzoic, p‐coumaric, and vanillic. The lightness (L*) values of coarse wheat brans correlated positively with their levels of bound protocatechuic (r = 0.72, P < 0.01) and p‐hydroxybenzoic acids (r = 0.75, P < 0.01).     

复合风味蛋白酶酶解麦麸蛋白制备麦麸抗氧化肽的研究

以麦麸蛋白为原料,复合风味蛋白酶为水解酶,探讨麦麸蛋白水解度(DH)与麦麸肽抗氧化能力的关系,并以超氧阴离子自由基(O2-·)清除率为指标,采用正交试验设计优化制备麦麸抗氧化肽的工艺条件.试验结果表明,制备麦麸抗氧化肽的最佳酶解条件为pH 5.0,加酶量为6000U/g麦麸蛋白,底物浓度5%,温度55℃,酶解7.5h,在该条件下制得的麦麸抗氧化肽清除超氧阴离子自由基的清除率可达53.70%.