白首乌酵素发酵工艺的优化

为了开发一款白首乌酵素产品,本文以白首乌为原料,采用乳酸菌和酵母菌复合发酵制备酵素,对乳酸菌和酵母菌的单因素实验条件进行优化,并确定两菌种复合发酵时的接种顺序和发酵时间。结果表明:采用先接种酵母菌后接种乳酸菌发酵的方式最优,该接种顺序下的最佳复合发酵工艺条件为:梅山酵母菌(S4)在初始pH5.0、装瓶量30 mL(250 mL)、蛋白胨添加量1.2%、接种量0.2%、发酵温度30 ℃的条件下,发酵24 h,酵母菌发酵结束后,接种3%的复合乳酸菌(嗜酸乳杆菌(LA)和植物乳杆菌(LP)以1:1混合(v:v)),37 ℃静置发酵36 h,然后在4~8 ℃下后发酵12 h,使发酵液产香。在此条件下,白首乌酵素中乳酸菌活菌为2.61×10⁸ CFU/mL,酵母菌活菌数为7.9×10⁷ CFU/mL,超氧化物歧化酶(superoxide dismutase,SOD)活力为4.23×10⁴ U/L。采用发酵的方法制备白首乌产品,为白首乌资源的开发利用提供了新的思路,对促进白首乌产业的发展具有重要意义。     

桂圆红枣复合发酵果酱的工艺优化

为研制风味独特、营养丰富的复合发酵型果酱,文章以桂圆干为原料,添加红枣片和红曲,结合乳酸发酵,采用单因素和正交设计试验对工艺进行优化。结果表明桂圆红枣果酱最佳发酵工艺为:桂圆和红枣的质量比为80:20,发酵时间为19 h,红曲添加量为0.5%,保加利亚乳酸杆菌液添加量为4%。通过此工艺发酵得出的果酱具有桂圆和红枣的香气滋味,甜香可口,口感层次丰富。     

麦苗酵素发酵工艺的优化及其抗氧化功能

以大麦幼苗为原料,采用酵母菌进行发酵,得到了麦苗酵素产品。以超氧化物歧化酶(SOD)活力为指标,通过单因素实验得到一条麦苗酵素的最佳发酵工艺参数:发酵温度32℃,酵母接种体积分数0.67%,蔗糖添加质量分数5.3%,发酵12 h。对该产品的抗氧化功能进行了初步研究,其结果表明该产品具有较好的抗氧化功能。     

山荷复合酵素发酵工艺优化

目的：对山荷复合酵素(山楂、山药、茯苓、荷叶、甘草)的发酵工艺进行优化,以期提高复合酵素中降血脂活性成分含量。方法：以双歧杆菌为发酵菌种,以复合酵素中降血脂成分(荷叶碱、熊果酸、金丝桃苷)含量为评价指标,通过正交试验优化发酵工艺参数;采用高效液相色谱法测定复合酵素发酵前后降血脂成分含量,采用95%可信区间重叠法统计分析。结果：复合酵素的最佳发酵工艺：接种量为发酵液体积的5%、发酵温度为31℃、发酵时间72 h。在此工艺参数条件下发酵得到的复合酵素中荷叶碱含量为0.045 1%,是发酵前含量(0.022 2%)的2.032倍,熊果酸含量为3.631%,是发酵前含量(1.157%)的3.137倍,金丝桃苷含量为0.042 3%,是发酵前含量(0.021 0%)的2.014倍。结论：在此发酵条件下复合酵素中降血脂成分(荷叶碱、熊果酸、金丝桃苷)含量显著增加。     

芸豆酵素复合发酵工艺优化

利用乳酸菌和酵母菌复合菌系制备酵素,通过多菌种单因素试验优化发酵菌种条件并确定复合发酵接种顺序及发酵时间。结果表明:最优发酵方式为先接种酵母菌预发酵后再接种乳酸菌,最佳复合发酵条件为装瓶量30mL(250mL)、pH 5.0、接种0.20%酵母菌、30℃振荡培养24h;再接种3.0%复合乳酸菌(植物乳杆菌嗜酸乳杆菌为11),37℃培养24h;4℃低温静置发酵24h,酵素产香。该条件得到的芸豆酵素上清液色泽通透呈黄色,气味清冽,活菌数显著增加,超氧化物歧化酶活力(SOD)达224.09U/mL。     

蓝莓酵素发酵工艺优化

以新鲜蓝莓为原料,植物乳杆菌（Lactobacillus plantarum）和酵母菌作为发酵菌种,以蛋白酶活力及超氧化物歧化酶（SOD）活力为评价指标,通过单因素试验和正交试验优化最佳发酵工艺条件。结果表明,植物乳杆菌（Lactobacillus plantarum）单独发酵蓝莓酵素时,发酵工艺条件为植物乳杆菌接种量为4%,39 ℃条件下发酵1 d。在此条件下蛋白酶活力及SOD酶活力分别为39.44 U/mL和84.17 U/g。植物乳杆菌（Lactobacillus plantarum）和酵母菌复合菌种发酵工艺条件为同时接入4%植物乳杆菌与0.15%的酵母菌,34 ℃条件下培养4 d,蛋白酶活力及SOD酶活力分别达到了55.76 U/mL和81.27 U/g,该方式是最佳的蓝莓酵素制备工艺。     

莲蓬酵素的发酵工艺研究

目的 优化莲蓬酵素的发酵条件, 获得品质最佳的莲蓬酵素。方法 经单因素试验分析发酵原料、发酵菌种类别、加糖量和发酵时间4个主要因素对莲蓬酵素的影响, 而后设计4因素3水平正交试验, 以蛋白酶活力、超氧化物歧化酶(superoxide dismutase, SOD)活力、多酚氧化酶(polyphenol oxidase, PPO)活力、总黄酮含量、Vc含量以及单宁含量为主要考察指标, 以取得最佳的莲蓬酵素。结果 通过4因素3水平正交试验确定莲蓬酵素发酵的最佳工艺条件为: 使用未过滤的莲蓬打浆液、菌种选用江大益生菌、加糖量为10%、发酵时间30 d。结论 使用未过滤的莲蓬打浆液发酵, 发酵的菌种选用江大益生菌, 发酵时加入10%的蔗糖, 发酵30 d后, 得到酵素的品质是最佳的。     

糙米酵素发酵工艺的研究

含胚米糠富含多种生理活性物质，经发酵后又增添多种酶，可制成糙米酵素，作为功能性食品的基料，为人类提供新的营养途径。为探讨糙米酵素合适的发酵工艺条件，以保鲜米糠添加少量蜂蜜为底物，采用活性面包干酵母进行发酵试验。以还原糖消耗量作为试验指标，设计了包含酵母活化时间、发酵时间和接种量三个因素及三水平的正交试验，对发酵工艺条件进行了优化。试验结果表明：优化的工艺条件为酵母活化时间取1h，发酵时间为11h，接种量为1．2g酵母，20g米糠。每8g发酵样品中消耗的还原糖达13．682mg。     

蓝莓果渣酵素发酵工艺优化

以蓝莓果渣为主要原料,优化最佳发酵工艺条件,提高酵素产品质量。选取工艺参数为酵母菌和干酪乳酸菌的最佳接种量、发酵温度、初始pH值、发酵时间,分析其对酵母菌的蛋白酶活力和浓度及对干酪乳酸菌浓度的影响。按照单因素试验和正交试验法设计上述工艺参数的优化试验。确定最佳酵母菌发酵工艺条件为：发酵液初始pH 3.5、发酵温度30 ℃、接种量0.15%、发酵时间16 h。酵母菌发酵16 h后在37 ℃条件下,发酵液pH 4.0,干酪乳杆菌接种量0.50%,静置发酵24 h,温度保持在18～20 ℃左右,静置进行24 h的后发酵,使发酵液产香,品质优良,将浓缩后的发酵液通过真空冷冻干燥,制成蓝莓果渣酵素粉状产品。     

苹果酵素自然发酵工艺优化及品质分析

为了优化苹果酵素自然发酵工艺,通过Box-Behnken试验设计,研究初始pH值、糖添加量、苹果片质量浓度对苹果酵素感官评分和超氧化物歧化酶（SOD）活性的影响,并采用超高效液相色谱（UPLC）及液相色谱-质谱联用技术（LC-MS）分析了酚类物质的组成和含量。结果表明,优化出自然发酵工艺条件为初始pH值4.6,糖添加量15%,苹果片含量200 g/L。在此优化条件下,苹果酵素感官评分为（8.45±0.24）分、SOD活性为（40.26±1.03） U/mL。苹果酵素共检测出15种酚类物质,其中绿原酸含量最高,原花青素B2、表儿茶素、原花青素B1、槲皮素-半乳糖苷、儿茶素以及根皮苷次之。     

芸豆酵素复合发酵工艺优化及功能性分析

以紫花芸豆为实验原料,利用酵母菌、复合乳酸菌协同发酵并优化芸豆酵素工艺参数,采用扩散法考察其抑菌活性并分析体外抗氧化能力。结果表明：芸豆酵素最佳发酵工艺条件为糖添加量6%、初始pH=4.0、接种量3%、发酵温度32 ℃,此条件下发酵液超氧化物歧化酶（SOD）活力为215.12 U/mL。抗氧化试验表明芸豆酵素DPPH自由基清除率及羟自由基清除率随着发酵时间延长呈持续增长趋势,至发酵结束其清除率分别为90.57%和88.06%。高浓度芸豆酵素（320 mg/mL）对四种致病菌均有显著抑制效果,且对革兰氏阳性菌（金黄色葡萄球菌）抑菌作用强于革兰氏阴性菌（沙门氏菌、志贺氏菌、大肠杆菌）。经此工艺条件制得的芸豆酵素色泽通透,具有较强抗氧化活性及抑菌能力。     

板栗龙眼糯米黄酒发酵工艺优化

为提高板栗和龙眼的资源利用率并开发一种高多糖含量的新型黄酒,以板栗和龙眼为辅料,糯米为主料,小曲和红曲为发酵剂,以感官评分和多糖含量为评价指标,采用单因素结合正交试验优化板栗龙眼糯米黄酒发酵工艺。结果表明,板栗龙眼糯米黄酒的最佳酿造工艺条件为：板栗添加量20%,龙眼添加量5%,小曲添加量0.9%,红曲添加量13%,主发酵时间8 d,主发酵温21 ℃。在此优化工艺条件下,板栗龙眼糯米黄酒的各项理化指标符合相关国标要求,感官评分为95.8分,多糖含量为7.93 g/L,是传统黄酒多糖含量的1.67倍。     

龙眼果酒发酵工艺优化、抗氧化活性研究及品质分析

以龙眼为主要原料酿造龙眼果酒,以酒精度、感官评分为评价指标,经单因素试验和正交试验确定龙眼果酒的最佳发酵工艺,并对龙眼果酒的品质及抗氧化活性进行研究。结果表明,龙眼果酒的最佳发酵工艺条件为初始糖度24%、酵母接种量0.25 g/L、初始pH值 6.6、发酵温度23 ℃。在此优化条件下,龙眼果酒酒体澄清透亮,无浑浊状,果香纯正,口感柔顺,酒精度为11.5%vol,感官评分89分,总糖、总酸、多酚及维生素C含量分别为3.6%、6.4%、114.52 mg/L、100.05 μg/L。发酵型龙眼果酒的超氧阴离子自由基清除率为64.97%、1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除率为93.75%、羟基自由基清除率为69.17%。发酵型龙眼果酒共检出27种挥发性香气物质,其中醇类6种、酯类7种、有机酸类5种、酮类2种,杂环类2种,烯烃类1种。     

高效液相色谱法同时测定沙枣果实中5种酚类化合物

建立了高效液相色谱法检测沙枣果实中绿原酸、咖啡酸、香豆酸、肉桂酸和阿魏酸等5种酚类物质的方法。样品用乙腈超声提取,色谱柱为HypersilODS100mm×4.6mm（i.d）,5μm柱;流动相为乙腈和磷酸缓冲液（0.6%）,梯度洗脱;流速为1mL/min;检测波长为323nm和280nm;进样量为10μL。5种组分在一定范围内有良好的线性关系,相关系数为0.991～0.997,平均回收率为93.3%～98.1%,相对标准偏差为3.1%～7.4%（n=6）。结果表明：沙枣果实中绿原酸、咖啡酸、香豆酸、阿魏酸和肉桂酸的含量分别为0.472、0.373、0.425、0.529、0.381mg/kg。     

Bioactive phenolic compounds of cowpeas (Vigna sinensis L). Modifications by fermentation with natural microflora and with Lactobacillus plantarum ATCC 14917

In this work we have determined the phenolic composition of raw cowpeas (Vigna sinensis L) of the variety Carilla by HPLC/PAD/MS and have studied the effect of fermentation, both spontaneous and with Lactobacillus plantarum ATCC 14917, on the phenolic compounds. This variety contains mainly ferulic and p‐coumaric acids esterified with aldaric acids, together with the cis and trans isomers of the corresponding free acids. Hydroxybenzoic acids such as gallic, vanillic, p‐hydroxybenzoic and protocatechuic were also found, along with flavonols such as a myricetin glucoside, mono‐ and diglycosides of quercetin and a quercetin diglycoside acylated with ferulic acid. Fermentation, both spontaneous and inoculated, modifies the content of phenolic compounds, but differently in each case. The antioxidant activity as free radical‐scavenging activity has also been evaluated. Fermentation followed by heating has been shown to be a very effective process to increase the functionality of this variety of V sinensis. For this reason, this cowpea variety could be used as an ingredient to obtain high value‐added flours. Copyright © 2004 Society of Chemical Industry     

A kinetic study on extraction and transformation phenomena of phenolic compounds during red wine fermentation

The aim of this work was both to model the kinetics of the extraction and transformation of phenolic compounds during fermentation and to propose an index to compare fermentation procedures. Six lots of Sangiovese grapes from five vineyards were used for red wine fermentation tests on lab and industrial scale during 2005 and 2006 vintages. Total phenol index, colour parameters, anthocyanin and pigmented polymer contents were measured during fermentations as variables related to phenolics. Microvinifications performed during vintage 2005 were used to model the evolution of total phenol index at 280 nm, malvidine content, colour parameter a* and pigmented polymer content during fermentation. Vinifications performed during vintage 2006 were used to validate the models. A specific adimensional number, called equivalent index, was set up to specify the operating conditions of red wine fermentation being a function of the extraction and transformation phenomena of phenolic compounds.     

蓝莓果汁发酵工艺优化及挥发性风味物质分析

为改善蓝莓果汁的风味,采用酿酒酵母（Saccharomyces cerevisiae）和乳酸菌分阶段发酵工艺制备发酵蓝莓果汁。通过单因素试验与正交试验优化发酵蓝莓果汁发酵工艺条件,并利用顶空固相微萃取结合气相色谱-质谱联用（HS-SPME-GC-MS）技术对发酵前后蓝莓果汁挥发性风味物质进行分析。结果表明,最佳发酵条件为酿酒酵母接种量2‰,植物乳杆菌（Lactobacillus plantarum）与干酪乳杆菌（Lactobacillus casei）比例为3∶1,接种量为1.5‰,发酵时间18 h,发酵温度34 ℃。在此优化条件下,发酵蓝莓果汁总酯含量为101.3 mg/L。GC-MS结果表明,发酵后蓝莓果汁共检出19种挥发性香气成分,其中酯类8种,醇类6种、醛类3种,酚类1种及烯烃类1种。与未发酵蓝莓果汁比较,发酵后的蓝莓果汁挥发性风味物质增加10种,其中酯类、醇类物质分别增加7种、3种,含量是未发酵蓝莓果汁的44.6倍、12.8倍。因此,发酵后蓝莓果汁风味物质更加丰富。     

Optimisation of the microwave‐assisted extraction process for six phenolic compounds in Agaricus blazei murrill

An efficient microwave‐assisted extraction (MAE) technique was employed in the extraction of phenolic compounds from Agaricus blazei murrill, and phenolic compounds were quantified by High‐performance liquid chromatography (HPLC). The MAE procedure was optimised, validated and compared with other conventional extraction techniques. MAE gave the best result because of the highest extraction efficiency within the shortest extraction time. The optimal conditions of MAE were 60% ethanol, ratio of solid/liquid 1:30, temperature 110 °C, irradiation power 500 W and three extraction cycles, each 5 min. This is the first report on combining MAE with HPLC for the extraction and quantification of phenolic compounds in A. blazei murrill. The developed MAE method provided a good alternative for the extraction of phenolic compounds in A. blazei murrill as well as other materials.     

腌渍芥菜二次发酵工艺优化及其挥发性成分分析

为了改善腌渍芥菜的风味,采用单因素和正交试验优化了腌渍芥菜人工接种二次发酵工艺。结果表明,腌渍芥菜多菌种人工接种二次发酵的优化工艺是：在室温条件下,分别接种植物乳杆菌（Lactobacillus plantarum）和短乳杆菌（Lactobacillus brevis）各4%,发酵时间6 d,产品的综合感官品质最好,为32.5分。利用气质联用（GC-MS）对腌渍芥菜、自然二次发酵和人工接种二次发酵芥菜的挥发性成分进行了分析,腌渍芥菜共检测出89种物质,总含量71.81%,自然二次发酵芥菜共检测出95种物质,总含量69.26%,优化工艺人工接种二次发酵芥菜共检测出93种物质,总含量79.45%,挥发性物质种类在经人工接种二次发酵后略有增加,并且总含量最高。     

Bioavailability of phenolic compounds

Phenolic compounds in foods originate from one of the main classes of secondary metabolites in plants. They are essential for the growth and reproduction of plants, and are produced as a response for defending injured plants against pathogens. In recent years, there is a growing interest in phenolic compounds and their presumed role in the prevention of various degenerative diseases, such as cancer and cardiovascular diseases. The importance of antioxidant activities of phenolic compounds and their possible usage in processed foods as a natural antioxidant have reached a new high in recent years. The absorption and bioavailability of phenolics in humans are also controversial. Data on these aspects of phenolics are scarce and merely highlight the need for extensive investigations of the handling of phenolics by the gastrointestinal tract and their subsequent absorption and metabolism. In this article, absorption, metabolism, and the bioavailability of pheniolic compounds are reviewed.