双蛋白豆酸乳制作工艺优化及抗氧化作用研究

目的：优化双蛋白豆酸乳制作工艺，检测抗氧化活性。方法：以大豆和脱脂奶粉为基本原料，基于单因素试验，采用Box-Behnken响应面法优化工艺，通过DPPH自由基清除、超氧阴离子清除、羟自由基清除法检测双蛋白豆酸乳抗氧化活性。结果：优化工艺为干豆∶水=1∶10.25、脱脂奶粉添加量4.62%、发酵温度40.43℃、发酵时间8.68 h,该工艺感官评分89.91,与模型预测值89.85接近，发酵温度影响较为显著；抗氧化活性方面，DPPH自由基清除能力7.919 U/mL、超氧阴离子自由基清除能力10.448 U/mL、羟自由基清除能力3.573 U/mL,与自制酸牛奶相比分别提高13.31%、9.97%、2.61%。结论：单因素试验和响应面法优化后的双蛋白豆酸乳口感佳，与同型乳制品相比有更高的抗氧化活性。     

响应面法优化黄浆水发酵液制备工艺及其抗氧化活性研究

采用植物乳杆菌(Lactobacillus plantarum)、嗜酸乳杆菌(Lactobacillus acidophilus)和清酒乳杆菌(Lactobacillus sakei)3种乳酸菌对黄浆水进行组合发酵,以发酵液DPPH自由基清除率为评价指标,研究发酵温度、发酵时间、脱脂乳粉添加量、葡萄糖添加量和接种量对发酵液的影响。在单因素试验基础上,采用响应面法优化制备高抗氧化活性黄浆水发酵液的工艺条件。结果表明最佳发酵参数为:接种量1%、发酵温度37℃、发酵时间37.50 h、脱脂乳粉添加量8%、葡萄糖添加量5%。在此条件下制备的黄浆水发酵液DPPH自由基清除率为82.36%。抗氧化活性试验表明:黄浆水发酵液提取物抗氧化能力得到显著提升,其清除DPPH自由基、羟自由基和ABTS自由基的半抑制质量浓度(IC50)分别为2.03 mg/mL、1.12 mg/mL和0.30 mg/mL。     

超声波预处理芝麻粕制备芝麻多肽的研究

采用超声波对芝麻蛋白进行预处理,研究超声波条件对制备芝麻多肽抗氧化活性的影响。以DPPH自由基和羟自由基清除率为指标,对影响芝麻多肽抗氧化活性的超声时间、超声温度、超声功率进行单因素试验,并运用响应面法对超声波条件进行优化。结果表明:超声波预处理优化工艺条件为超声时间15 min、超声温度52℃、超声功率210 W;此时,芝麻多肽的DPPH自由基和羟自由基清除率分别为69.46%和60.54%,比未经超声波预处理的芝麻多肽的DPPH自由基和羟自由基清除率分别提高了15.33、13.30个百分点。说明超声波预处理能提高芝麻多肽的抗氧化活性。     

Box-Behnken模型优化油茶饼粕多酚提取工艺及抗氧化活性研究

以油茶饼粕为试验材料,通过单因素和响应面试验优化其微波辅助提取工艺,并初步研究其抗氧化活性。结果表明,最佳提取工艺条件为微波功率600 W、微波时间5.5 min、微波温度63℃、乙醇体积分数48%、液料比70∶1（mL/g）,此条件下,油茶饼粕多酚的实际提取量为42.29 mg/g。抗氧化试验结果表明,油茶饼粕多酚对DPPH自由基、超氧阴离子自由基、羟基自由基均具有一定的清除能力,在试验所选浓度范围内,最高清除率分别为83.76%、83.38%、34.96%,表明油茶饼粕多酚具有良好的抗氧化活性。     

响应面法优化艳山姜多糖提取工艺及抗氧化研究

以艳山姜为试验原料,采用响应面法优化艳山姜多糖提取工艺,并研究艳山姜多糖的抗氧化活性。建立以葡萄糖为对照品,紫外分光光度法测定多糖含量的定量分析方法。在单因素试验基础上,以提取时间、超声功率和液料比为自变量,多糖得率为因变量,运用Box-Behnken 设计-响应面优化艳山姜多糖的提取工艺。通过对DPPH 自由基、超氧阴离子自由基、羟基自由基清除作用研究艳山姜多糖的抗氧化活性。结果表明,艳山姜多糖最佳提取工艺条件为：提取时间35 min、超声功率70 W、液料比40∶1（mL/g）,在此条件下多糖得率为5.37%。艳山姜多糖对DPPH 自由基、超氧阴离子自由基和羟基自由基有较强的清除能力,多糖浓度越高,抗氧化活性越强。     

芝麻蛋白水解工艺优化及芝麻多肽组分抗氧化活性的研究

研究了芝麻多肽的水解工艺条件及其组分抗氧化活性.采用Box-Behnken试验设计,优化了芝麻蛋白水解条件,对芝麻多肽(SP)和不同分子质量的芝麻多肽(SP1、SP2和SP3)清除DPPH自由基活性、总抗氧化能力、抑制猪油和冷藏熟肉糜脂质氧化作用进行了研究.优化的水解条件为:6.91 g芝麻蛋白,0.082 g碱性蛋白酶,水解时间6.82 h,水解度为30.2%.芝麻多肽均有一定的抗氧化能力,SP3和SP的抗氧化活性明显高于芝麻蛋白.0.02%SP3和SP对DPPH自由基清除率分别为79.17%和52.54%,清除能力由高到低的顺序为SP3>SP>SP2>SP1.芝麻多肽的总抗氧化能力与清除DPPH自由基的活性一致.0.02%的芝麻多肽具有明显的抑制猪油氧化和冷藏熟肉糜脂质氧化的作用,可使猪油过氧化值从126.6 mmol/kg降低至45.4 mmol/kg,SP3和SP对冷藏熟肉糜脂质氧化的抑制率分别为74.68%和59.37%,抑制能力由强到弱的顺序为SP3>SP>SP2>SP1.     

响应面优化杨梅果酒发酵工艺及其抗氧化性

目的:优化杨梅果酒的发酵工艺。方法:以酒精含量为响应值,在单因素实验基础上,以含糖量、接种量、发酵时间、p H、发酵温度为实验因素,采用响应面法建立数学模型,筛选最佳发酵工艺条件;并通过杨梅酒对羟自由基、ABTS+自由基、DPPH自由基和超氧阴离子自由基的清除作用来研究其抗氧化活性。结果:通过二次回归模型响应面分析,确定杨梅酒发酵最佳工艺条件为:接种量0.03%,含糖量22%,发酵温度28℃,发酵时间7 d,p H3.5,此条件下杨梅酒酒精含量为10.87%,模型方程理论预测值为11.03%,两者相对误差小于2%。杨梅酒具有一定的抗氧化活性,对ABTS+自由基的清除率为55.47%,对羟基自由基清除率57.24%,超氧阴离子清除率48.15%,DPPH自由基抑制率达到88.65%。结论:采用响应面法优化得到了杨梅酒发酵的最佳工艺,该工艺方便可行。     

酱油曲霉发酵芝麻饼粕中抗氧化物质提取条件的优化

采用正交设计和响应面的试验方法,对酱油曲霉发酵芝麻饼粕中的抗氧化物质的提取工艺进行了优化。结果表明,正交优化试验中,影响提取发酵芝麻饼粕中抗氧化物质因素的主次顺序为:乙醇体积分数液料比提取时间提取次数。通过响应面试验再优化,得到影响提取抗氧化物质因素的二次多项式数学模型方程为:RSA=82.22+0.32A+1.88B+0.91C-0.21AB-0.78AC+0.45BC-4.71A2-4.066B2-3.16C2。优化的提取条件为:提取时间120.4 m in,液料比15.7 mL/g,乙醇体积分数61.3%,在此条件下,DPPH自由基清除率可达81.5%。该结果为下一步对提取的抗氧化物质的分离和发酵机制的研究奠定了基础。     

龙眼果酒发酵条件优化及其抗氧化活性

目的研究龙眼果酒发酵条件及其抗氧化特性。方法以龙眼干肉和活性干酵母为原料,探讨了发酵温度、初始可溶性固形物含量、接种量对龙眼酒酿造的影响,并以酒精度、残糖量和总酚转化量作为响应值,利用Box-Benhnken试验设计和响应面分析进行酿造工艺优化,并测定优化条件下其主发酵期的总酚含量、DPPH自由基清除能力及ABTS自由基清除能力。结果优化条件为:温度27℃,初始可溶性固形物含量26°Brix,接种量11%,发酵时间为7 d,得到果酒酒精度14.2%vol,残糖量20.71 g/L,总酚转化量为9.38 mg/100 m L。总酚含量与DPPH自由基清除能力及ABTS自由基清除能力具有相似的变化趋势。结论响应面分析优化的龙眼果酒发酵工艺条件,可为实际生产应用提供参考。     

灵芝多糖提取工艺优化及抗氧化活性的研究

目的研究灵芝多糖(Ganoderma lucidum polysaccharides,GLP)的最优提取工艺,并研究其抗氧化活性。方法通过单因素和响应面法优化提取工艺参数,获得GLP;将GLP进行乙醇分级得到GLP30、GLP60和GLP80 3个组分;采用还原力、DPPH自由基清除试验和羟自由基清除试验评估GLP及3个组分的抗氧化活性。结果灵芝多糖最优提取条件为:温度86°C,液料比50:1(mL/g),时间142min,实际提取得率为1.71%;抗氧化活性试验结果表明:GLP及GLP30、GLP60和GLP80均具有一定的抗氧化活性,均呈现浓度-活性依赖性,其中GLP80还原力最强,GLP清除DPPH自由基和羟自由基的能力最强。结论响应面法有效优化了GLP的提取,灵芝多糖具有较好的抗氧化活性,值得进一步研究及开发利用。     

灵芝发酵麸皮粗多糖的组成及抗氧化活性分析

为研究灵芝发酵麸皮粗多糖组成及抗氧化活性,对比分析了灵芝发酵前后麸皮粗多糖的体外抗氧化活性和组分,并通过高效液相色谱、傅里叶红外光谱初探灵芝发酵麸皮粗多糖的结构。结果表明:灵芝发酵麸皮粗多糖（GWBP）在4.0 g/L浓度下的DPPH、羟基自由基清除率和还原力分别为91.37%、95.74%和0.92,显著高于未发酵麸皮粗多糖（WBP）（P<0.05）。GWBP组分中黄酮、多酚、蛋白含量分别为5.41、12.74和206.41 mg/g,显著高于WBP（P<0.05）。GWBP是一种吡喃糖,主要由葡萄糖、木糖和核糖等组成,分子量为4.172×103 Da。灵芝液态发酵可以提高麸皮粗多糖的抗氧化活性,改变粗多糖的组成成分。本研究为灵芝发酵麸皮粗多糖天然抗氧化的开发提供参考。     

Antioxidant properties of various solvent extracts of potato peel,sugar beet pulp and sesame cake

BACKGROUND: Growing interest in the replacement of synthetic food antioxidants by natural ones has fostered research on vegetable sources and screening of raw materials to identify new antioxidants. The food‐processing industry generates substantial quantities of phenolic‐rich by‐products that could be valuable natural sources of antioxidants. In this study the antioxidant properties and total phenolic, flavonoid and flavonol contents of three industrial by‐products, sugar beet pulp, sesame cake and potato peel, extracted with various solvents were examined. Since different antioxidant compounds have different mechanisms of action, several methods were used to assess the antioxidant efficacy of extracts. RESULTS: Among the six solvents tested, methanol gave the highest extract yield of potato peel and sugar beet pulp, while diethyl ether gave the highest extract yield of sesame cake. Methanol exhibited the highest extraction ability for phenolic compounds, with total phenolics amounting to 2.91, 1.79 and 0.81 mg gallic acid equivalent g^?1 dry weight in potato peel, sugar beet pulp and sesame cake extracts respectively, and also showed the strongest antioxidant capacity in the three assays used. All three methods proved that potato peel extract had the highest antioxidant activity owing to its high content of phenolic compounds and flavonoids. CONCLUSION: On the basis of the results obtained, potato peel, sugar beet pulp and sesame cake extracts could serve as natural antioxidants owing to their significant antioxidant activity. Therefore they could be used as preservative ingredients in the food and/or pharmaceutical industries. Copyright © 2009 Society of Chemical Industry     

烟管菌漆酶合成的营养条件研究

对筛选到的漆酶高效产生菌烟管菌(Bjerkandera adusta)WZFF．W-Y11合成漆酶的营养条件进行了研究,发现该烟管菌漆酶属于一种组成型酶,酶活力高,产酶高峰到来早,酶的合成与菌体生长过程紧密相关。漆酶合成需要丰富的营养因子,麸皮水解液是重要的成分,葡萄糖-淀粉的复合碳源和氯化铵-豆饼粉的复合氮源以及适量的无机盐有利于漆酶的产生。虽然增加 Fe~(2+)的量明显抑制了漆酶的产生,但 Cu~(2+)却能有效地促进漆酶的合成。在经过优化的培养条件下,酶活力高达1 108 U/mL。     

利用酒糟深层发酵生产灵芝酸的培养基的优化

以利用酒糟为出发点,研究了营养性因子对灵芝酸深层发酵的影响,结果表明酒糟、葡萄糖、麸皮、豆饼粉、酵母膏、蛋白胨有利于灵芝酸的形成。碳氮源浓度实验表明,只有在一定的浓度范围内才能较好地形成灵芝酸。正交优化实验确定了灵芝酸深层发酵的最佳培养基组成。     

发酵麦麸及其面包面团中阿拉伯木聚糖溶解性与酚酸释放研究

将发酵麦麸作为功能配料用于高膳食纤维面包面团制作,采用化学分析、高效液相色谱及离子色谱法分析麦麸发酵、面包制作过程及面包中阿拉伯木聚糖溶解性和酚类化合物释放。结果表明：随着发酵时间延长,麦麸中水溶性阿拉伯木聚糖、游离酚及阿魏酸含量逐渐增加。发酵处理后,麦麸中游离阿拉伯糖、葡萄糖和果糖含量增加,水溶性阿拉伯木聚糖含量显著提高,分支度显著下降（P＜0.05）。面包搅拌、醒发及烘焙过程中,阿拉伯木聚糖不断溶解,酚类化合物持续释放;富含发酵麦麸的面包中水溶性阿拉伯木聚糖含量及分支度更高。模拟肠、胃消化后,富含发酵麦麸的面包中游离酚和阿魏酸含量更高,且吸收效果好。此外,发酵麦麸显著提高了面包的抗氧化活性。     

芝麻饼粕中抗氧化成分的提取及其活性研究

研究了芝麻木脂素的提取工艺及其抗氧化性能。以料液比、浸提时间、温度、提取次数为考察因素,采用单因素试验及正交试验对芝麻饼粕中木脂素进行了提取条件优化的试验。试验结果表明,料液比1:6,浸提时间10h,温度55℃及提取次数3次为最佳提取条件,芝麻木脂素粗品的提取率为2.62%。用分光光度法测定了芝麻饼粕提取物对DPPH·的清除作用和对小鼠离体组织匀浆脂质过氧化及Fe2+-VC体系诱导的脂质过氧化的抑制作用。结果发现芝麻饼粕提取物具有良好的抑制脂质过氧化的作用。     

利用廉价原料生产聚谷氨酸的研究

目的 降低聚谷氨酸的生产成本.方法 从聚谷氨酸发酵所需的氮源和碳源出发,分别研究了小麦水解蛋白、豆饼粉、豆粕粉、玉米蛋白、玉米浆等有机氮源和甘蔗糖蜜、甜菜糖蜜、葡萄糖蜜、玉米糖蜜等碳源对聚谷氨酸发酵产量的影响,在此基础上通过单因素实验优化了玉米浆、硫酸铵、甜菜蜜、谷氨酸钠的添加量,最后通过发酵罐发酵比较了优化后的工艺与...     

Effects of processing on the phenolic contents,antioxidant activity and volatile profile of wheat bran tea

Wheat bran is a major milling by-product with significant nutritional importance. This study investigated the influence of processing on the antioxidant activity and volatile profile of wheat bran tea. The processing protocol involved two different pretreatments: soaking and cellulase treatment, followed by steaming and roasting. The results indicated that total phenolic content and antioxidant activity were reduced post both pretreatments, but increased after steaming, and dramatically increased after roasting. The cellulase-roasted samples had significantly higher antioxidant activity compared to soak-roasted samples. A total of forty key volatile compounds were identified in the wheat bran tea. The total volatile compounds were significantly increased by both soaking and cellulase treatments and steaming, but reduced by roasting. Compared to soaking pretreatment, cellulase pretreated samples had significantly higher total volatile compounds at each processing step. This study offers a practical method in processing of wheat bran into novel grain tea products.     

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.     

Effect of thermal processing on antioxidant properties of purple wheat bran

Antioxidant activity of purple wheat bran, heat-treated purple wheat bran, and purple wheat bran muffins was evaluated to determine the impact of thermal processing on potential health benefits. The purple wheat bran and muffin samples were analyzed for total phenolic content, anthocyanin content and free radical scavenging activity using peroxyl (oxygen radical absorbance capacity assay) and 2,2-diphenyl-1-picrylhydrazyl (DPPH assay) radicals. Total phenolic content and oxygen radical absorbance capacity (ORAC) values of sample extracts were significantly affected by various extracting solvents. The conditions selected for heat treatment did not markedly change antioxidant activity of purple wheat bran. However, there was a significant reduction in total phenolic contents, ORAC values and total anthocyanins during processing of purple wheat bran- or heat-treated purple wheat bran-enriched muffins. On the contrary, muffin extracts still remained excellent in DPPH radical scavenging activity.