大孔树脂分离纯化柚皮黄酮的研究

该文以总黄酮含量和总黄酮回收率为考察指标，研究了大孔树脂分离纯化柚皮黄酮的工艺。结果表明：AB-8型树脂对柚皮总黄酮有较好的吸附分离性能，是分离纯化柚皮黄酮的适宜大孔树脂；AB-8型大孔树脂分离纯化柚皮黄酮的最佳工艺条件为：柱体积为160 mL，柚皮提取物上样量为62.5 mg/mL(以湿树脂体积计)，先用pH 4的水淋洗，再用30%的乙醇洗脱，洗脱剂用量为2.5～3倍湿树脂体积。AB-8大孔树脂按上述确定的吸附洗脱条件可重复使用3次。柚皮黄酮经上述工艺纯化后总黄酮含量达到39.67%，总黄酮回收率为62.48%。对经AB-8大孔树脂纯化后的柚皮黄酮进行高效液相色谱(HPLC)分析发现，柚皮黄酮主要为黄酮甙类。     

油梨皮黄酮提取及大孔树脂纯化

该文研究了油梨皮黄酮的提取及大孔树脂纯化条件.结果表明:油梨皮黄酮的最佳提取条件为乙醇浓度70%、提取温度70℃、提取时间1.5 h、料液比(m/V)1:20.乙醇浓度和提取温度对提取得率有显著性(P<0.05)影响.在此条件下,黄酮的提取得率为1.12%;AB-8型树脂对油梨皮黄酮有较好的吸附和洗脱效果,其纯化油梨皮黄酮的条件为柱体积250 mL,上样量2.03 g,水洗,接着用75%的乙醇洗脱(约500 mL),在此条件下AB-8型树脂可重复使用6次.经纯化后油梨皮黄酮相对纯度为82.37%,纯化后总黄酮回收率为71.65%.     

微波辅助萃取-大孔树脂分离纯化芳樟叶黄酮

为了综合利用芳樟叶精油提取过程中产生的大量残渣,该文利用微波辅助萃取和大孔树脂选择性吸附来分离纯化芳樟叶黄酮。采用L9(34)正交试验,考察了萃取剂、微波辐射功率、辐射时间及料液比对黄酮得率的影响,确定了微波辅助萃取的优化工艺条件:以60%乙醇做萃取剂,微波功率320W,间歇辐射2次,每次1min,料液质量体积比1:12,在此条件下,芳樟叶黄酮的提取得率为2.97%,与乙醇热回流提取方法相比,得率提高了6.83%,时间缩短了98.89%;为进一步纯化萃取所得的黄酮提取物,选择6种大孔吸附树脂,测定芳樟叶黄酮在树脂上的吸附量和解吸率,筛选出了吸附剂HPD-450,其对芳樟叶黄酮有较好的静态吸附和解吸效果。经装填有大孔树脂HPD-450的固定床纯化后黄酮纯度由22.49%提高到51.28%,纯化倍数2.3倍。     

鱼腥草叶总黄酮的提取分离

采用微波辅助提取鱼腥草叶总黄酮,并用正交试验进行工艺参数的优化。同时选择7种大孔树脂,比较其对鱼腥草叶总黄酮的吸附量和解吸率,筛选出较优的大孔树脂并对其动态吸附及解吸性能进行考察。结果表明:优化的工艺条件为乙醇浓度50%,固液比1∶50(w/v),预浸泡30 min,微波作用时间30 s,微波功率540 W;与传统乙醇提取法相比,微波法使每次提取时间由3 h减少为30.5 min,提取率从92.14%增加到95.93%。NKA-9型大孔树脂对鱼腥草叶总黄酮有较好的吸附和解吸效果;较优的吸附分离工艺参数为:样液pH值在3.00～3.50,上样液流速1 mL/min,上样液浓度2.21～3.10 mg/mL,用70%乙醇洗脱时,解吸率达97.8%,3BV洗脱液基本上能将鱼腥草叶总黄酮洗脱下来。     

树脂法精制沙棘籽原花色素的研究

为纯化沙棘原花色素,本文对16种不同类型树脂进行沙棘原花色素静态吸附试验、动态吸附和解吸性能的比较,筛选出对沙棘原花色素有较好分离纯化效果的4种树脂,比较不同洗脱级分中原花色素的含量,最后筛选出D3520大孔树脂为符合提纯要求的最适合的树脂;采用该树脂,用30%乙醇洗脱,原花色素产品纯度达96.5%,得率为30.4%。     

杜仲叶绿原酸和黄酮类化合物提取工艺研究

对杜仲叶中绿原酸和总黄酮的最佳提取工艺进行了研究,结果表明溶剂为60%乙醇;提取时间为2h;提取次数为3次;温度为80℃;料液比为116(W/V).其中浸提温度是首要影响因素,其次是时间和料液比.此工艺所得的杜仲浸膏,得率为31.67%,其中绿原酸含量为8.43%,提取率为90.21%;总黄酮含量为5.49%,提取率为93.32%.     

银杏黄酮苷提纯工艺研究

根据黄酮苷的物性选择丙酮，正丁醇，正丙醇，乙酸乙酯为萃取剂。单因素实验优选出正丙醇为萃取黄酮苷的主萃取剂。对其进行改性，通过单因素实验和正交实验优化出：水∶正丙醇=1∶25为萃取黄酮苷的较佳萃取剂。T=25℃，t=10 min，固液比=15∶1(g/100 mL)为其最佳萃取工艺参数。最后得到纯度＞50%，得率＞80%的总黄酮苷产品。为后续提纯分离打下较好的基础。     

芝麻叶中总黄酮的最佳提取工艺研究

该文测定了芝麻叶中总黄酮的含量，并对芝麻叶黄酮的提取工艺进行了研究。重点探讨了采用乙醇提取法和微波处理与乙醇提取相结合的方法提取芝麻叶黄酮类化合物的最佳工艺条件。试验结果表明：芝麻叶中总黄酮的含量为0.98%；乙醇提取法的最适工艺参数是浸提剂乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为2.5 h，如此条件可使黄酮提取率达95.6%；微波处理与乙醇提取相结合的方法的最适工艺参数是微波功率200 W、微波处理时间70s，乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为30 min，这种工艺可使黄酮提取率达95.8%。     

高含量大豆皂苷的制备工艺研究

为了得到高含量大豆皂苷，该文对6种大孔吸附树脂即AB-8，XAD-2，HPD-100，ADS-7，HPD-300，HPD-600进行优选，以上样量、洗脱率和产品纯度为指标，用柱层析法对低含量的大豆皂苷提取液进行初步分离，得到大豆皂苷粗品。然后通过结晶进一步提高其纯度。考察并优化了结晶时的溶剂、大豆皂苷的初始浓度、降温速率等工艺条件。结果表明：ADS-7树脂为合适的吸附剂；优化的柱层析条件为：上样和洗脱温度60℃，上样原料浓度6 mg/mL，上样和洗脱流量均为1.0 BV/h；优化的结晶工艺条件为：结晶溶剂30%～40%乙醇，大豆皂苷初始浓度165 mg/mL，降温速率3.2℃/h。在上述条件下，用柱层析法可使大豆皂苷的含量从原料中的3.0%提高至45%以上，大豆皂苷收率大于90%。再通过结晶可得含量大于96.0%的大豆皂苷，大豆皂苷收率大于50％。说明该文研究的制备工艺明显优于现有的萃取工艺，具有重要的工业应用价值。     

用离子交换法分离苹果汁中果酸的技术研究

为了分离苹果汁中的果酸，该文对离子交换法分离浓缩苹果汁中果酸的技术方法进行了系统研究，通过树脂分离果酸的静态和动态试验，对离子交换树脂进行了筛选优化，对树脂洗脱剂和洗脱条件进行了优选与优化，结果表明：D380树脂对果酸的交换吸附能力最强，其静态吸附量为30.73 mg/mL，动态吸附量可达60.24 mg/mL,静态交换吸附平衡时间为270 min,最佳吸附果汁浓度为11°Brix苹果汁；D380树脂对果酸的较佳动态吸附条件为：流速5 mL/min,温度20℃，果汁浓度11°Brix的苹果汁；较佳洗脱条件为：50%乙醇，温度25℃，流速6 mL/min，洗脱3次，洗脱剂与树脂比例2∶1(v/v)。     

Adsorption and desorption properties of macroporous resins for anthocyanins from the calyx extract of roselle (Hibiscus sabdariffa L.)

Adsorption of roselle anthocynins, a natural pigment, onto various macroporous resins was optimized to develop a simple and efficient process for industrial separation and purification of roselle anthocyanins. Nine different macroporous resins (AB-8, X-5, HPD-100, SP-207, XAD-4, LS-305A, DM-21, LS-610B, and LS-305) were evaluated for the adsorption properties of the anthocyanins extracted from the calyx extract of Hibiscus sabdariffa L. The influences of phase contact time, solution pH, initial anthocyanin concentration, and ethanol concentration with different citric acid amounts were studied by the static adsorption/desorption method. The adsorption isotherm data were fitted well to the Langmuir isotherm, and according to this model, LS-610B and LS-305 exhibited the highest monolayer sorption capacities of 31.95 and 38.16 mg/g, respectively. The kinetic data were modeled using pseudo-first-order, pseudo-second-order, and intraparticle diffusion equations. The experimental data were well described by the pseudo-second-order kinetic model. Continuous column adsorption-regeneration cycles indicated negligible capacity loss of LS-305 during operation. The overall yield of pigment product was 49.6 mg/g dried calyces. The content of roselle anthocynins in the pigment product was 4.85%.     

Activity and concentration of polyphenolic antioxidants in apple juice. 2. Effect of novel production methods

There is a great interest in food components that possess possible health-protecting properties, as is the case with flavonoids. Previous research showed that conventional apple juice processing resulted in juices poor in flavonoids and with a low antioxidant activity. This paper shows that it is possible to improve flavonoid content in juice and its antioxidant activity by applying an alcoholic extraction either on the pulp or on the pomace. The levels of flavonoids and chlorogenic acid in enriched juice were between 1.4 (chlorogenic acid) and 9 (quercetin glycosides) times higher than in conventional apple juice. In enriched juice the antioxidant activity was 5 times higher than in conventional apple juice, with 52% of the antioxidant activity of the originating fruits present. The novel processing method had similar effects for three apple cultivars tested (Elstar, Golden Delicious, and Jonagold). The taste and color of enriched juice were different from those of conventional juice.     

香蕉树中度荫蔽下充分灌水提高干热区咖啡产量及品质

为研究香蕉荫蔽栽培下灌溉对干热区小粒咖啡产量和品质的影响,以5 a生小粒咖啡为研究对象,通过大田试验,设3个灌水水平:充分灌水(FI)、轻度亏缺灌水(DIL:75%FI)和重度亏缺灌水(DIS:50%FI),4个荫蔽栽培模式:无荫蔽(S0:单作咖啡)、轻度荫蔽(SL:4行咖啡间作1行香蕉)、中度荫蔽(SM:3行咖啡间作1行香蕉)、重度荫蔽(SS:2行咖啡间作1行香蕉),并运用主成分分析和TOPSIS法对生豆营养品质(总糖、蛋白质、脂肪、咖啡因、绿原酸、粗纤维和水浸出物)进行综合评价。结果表明:小粒咖啡干豆产量受荫蔽栽培模式和灌水水平极显著的影响(P0.01),其中FISM处理的干豆产量最高(5 854.34 kg/hm2),且百粒干质量最大,而该处理的百粒体积和百粒鲜质量与各处理中的最大值相比差异不显著(P0.05)。小粒咖啡大多生豆营养品质在不同荫蔽栽培模式和灌水水平下差异显著(P0.05),蛋白质、脂肪、绿原酸和水浸出物含量间呈极显著正相关(P0.01)。主成分分析法和TOPSIS法均表明,FISS处理的综合品质最优,其次是FISM处理,而DISS0处理的最差。与FIS0相比,FISM处理的产量增加14.32%,而FISS处理减少15.69%。从小粒咖啡提质增产的综合效益考虑,建议干热区小粒咖啡灌水处理和香蕉荫蔽栽培模式的最佳组合选用中度荫蔽栽培下充分灌水,该结果可为干热区小粒咖啡水光管理提供理论依据和实践参考。     

Effect of postharvest storage and processing on the antioxidant constituents (flavonoids and vitamin C) of fresh-cut spinach

The effect of modified atmosphere packaging (MAP) and cooking on the flavonoids and vitamin C content (ascorbic + dehydroascorbic acid; AA + DHAA) of fresh-cut spinach was evaluated. The total flavonoid content (approximately 1000 mg kg(-)(1) f.w.) remained quite constant during storage in both air and MAP atmospheres, while vitamin C (750 mg kg(-)(1)f.w.) was better preserved in MAP-stored spinach. AA was transformed to DHAA during storage, and its concentration was higher in MAP-stored tissues. The free-radical scavenging activity of the isolated flavonoids was tested, and only those flavonoids with either a dihydroxyl grouping or acylated with ferulic acid showed significant activity. A decrease in the total antioxidant activity was observed during storage, particularly important in MAP-stored spinach. The higher content of DHAA and lower content of both AA and antioxidant flavonoids in the MAP-stored samples could explain this antioxidant activity decrease. Boiling extracted 50% of total flavonoids and 60% vitamin C in the cooking water. However, flavonoid glucuronides were extracted more in the cooking water than the other glycosides. The vitamin C content of the cooked tissue was higher in those samples stored in MAP.     

Major phenolics in apple and their contribution to the total antioxidant capacity

The contribution of each phytochemical to the total antioxidant capacity of apples was determined. Major phenolic phytochemicals of six apple cultivars were identified and quantified, and their contributions to total antioxidant activity of apples were determined using a 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and expressed as vitamin C equivalent antioxidant capacity (VCEAC). Average concentrations of major phenolics and vitamin C in six apple cultivars were as follows (mg/100 g of fresh weight of apples): quercetin glycosides, 13.20; procyanidin B(2), 9.35; chlorogenic acid, 9.02; epicatechin, 8.65; phloretin glycosides, 5.59; vitamin C, 12.80. A highly linear relationship (r (2) > 0.97) was attained between concentrations and total antioxidant capacity of phenolics and vitamin C. Relative VCEAC values of these compounds were in the order quercetin (3.06) > epicatechin (2.67) > procyanidin B(2) (2.36) > phloretin (1.63) > vitamin C (1.00) > chlorogenic acid (0.97). Therefore, the estimated contribution of major phenolics and vitamin C to the total antioxidant capacity of 100 g of fresh apples is as follows: quercetin (40.39 VCEAC) > epicatechin (23.10) > procyanidin B(2) (22.07) > vitamin C (12.80) > phloretin (9.11) > chlorogenic acid (8.75). These results indicate that flavonoids such as quercetin, epicatechin, and procyanidin B(2) rather than vitamin C contribute significantly to the total antioxidant activity of apples.     

亚麻籽双液相多级逆流萃取工艺模拟试验

为了考察双液相技术萃取亚麻籽的工业化效果,应用模拟试验探讨了多级逆流萃取工艺应用于正己烷-乙醇-水三元双液相亚麻籽萃油脱氰苷生产的可行性。结果表明,在料烷比1︰5 (m/V),料醇比1︰2 (m/V),温度55℃,时间 30 min,乙醇质量分数85% (m/m),NaOH添加量为乙醇相0.05% (m/V)的条件下,实验室串级模拟四级逆流萃取达到工艺要求,亚麻粕中残油量小于1%,氰苷残余小于0.7 mg/kg,多级逆流接触法萃取流程适宜于亚麻籽双液相萃油脱氰苷生产工艺。     

乙醇水溶液提取玉米胚芽油的工艺优化

为了解决水酶法提取玉米胚芽油生产成本高、提取时间长的缺点,该文采用乙醇水溶液作为提取剂提取玉米胚芽油。通过对粒径、料液比、温度、乙醇体积分数、p H值和时间等条件对油在油相、水相和渣相中分布的研究发现,物料粒径和乙醇体积分数对提高清油得率具有显著(P0.05)的影响,而提取时间对清油得率的影响最小(P0.05)。在单因素试验的基础上通过正交试验,得出乙醇水溶液提取玉米胚芽油的最佳工艺参数为:物料细粉4次(此时粒径为49.18μm)、料液比1∶7 g/m L、温度70℃、乙醇体积分数30%、p H值9.0、提取时间2 h。在该条件下,清油的得率为94.05%±0.32%,水相含油量为3.49%±0.77%,渣相含油量为2.55%±0.82%。分析乙醇水溶液提取的玉米胚芽毛油酸价、过氧化值和含水率等指标发现,该毛油的质量优于国标规定的玉米原油,并且和压榨一级成品油指标接近,只需要经过简单精炼就可以达到食用油要求。研究结果为乙醇水溶液工业化生产玉米胚芽油提供参考。     

氮肥用量对药用菊花生长及其药用品质的影响

本文采用盆栽试验研究了氮肥用量对药用菊花（药菊）生长及其药用品质的影响。结果表明,氮肥可促进植株生长、花芽分化和提前开花,提高菊花产量。当氮肥用量为0.5069 g/kg土时,药菊单株鲜花总产量最高,为542.01 g /株。菊花中绿原酸、总黄酮和可溶性糖的含量同氮肥用量成反比,高氮肥处理时上述成分最大下降幅度可分别达35.48%～45.26%、28.58%～35.58%和6.42%～9.51%。随着氮肥用量增加,药菊植株次生代谢关键酶苯丙氨酸解氨酶（PAL）活性和菊花中磷（P）、钾（K）、钙（Ca）元素含量大幅降低,而N/P、N/K和N/Ca比值和可溶性氨基酸含量升高。高氮处理因提高植株氮含量,降低PAL活性和可溶性糖含量,从而抑制植株绿原酸和黄酮等酚类物质合成而影响菊花的药用品质。试验还表明,当氮肥用量为0.4180～0.4598 g/kg土时,菊花中总黄酮和绿原酸的累积量最高。综合比较氮肥用量对菊花药材产量、外观品质、活性成分含量与累积量等因素的影响,建议菊花生育期内氮肥用量在0.30～0.40 g/kg土范围为适宜。     

Influence of extraction parameters on the phytochemical characteristics of extracts from buckwheat (Fagopyrum esculentum) herb

In recent years, the interest in herbal medicinal products, especially in the field of dermatology and cosmetics, has risen enormously. Many plant-derived substances show photoprotective properties in terms of absorption of UV radiation and preventing photodamage to molecular structures of human skin. Modern phytopharmaceutics as well as phytocosmetics require standardized, defined extracts from the herbal matrix. Buckwheat herb is rich in flavonoids, which have been identified as potent antioxidants. Up to now, there have been no systematic investigations available concerning the extraction conditions for phenolic substances from buckwheat herb. In this paper, we report the influence of three extraction parameters, ethanol concentration, temperature, and extraction time, on the response variables extractable matter, antioxidant activity, and content of fagopyrin, rutin, and chlorogenic acid. Our results suggest that an extract with good antioxidant activity, a high content of phenolics, and a low content of the phototoxic fagopyrin can be yielded by agitated maceration with 30% ethanol at 60 degrees C for 2 h. Furthermore, there is good correlation between the antioxidant activity and the rutin content, whereas the extractable matter is not an appropriate parameter for extract quality. Huge differences in the content of rutin and chlorogenic acid when using herbal drugs from different suppliers confirm the demand of standardized procedures for the production of herbal drugs.     

Preparative separation and purification of rebaudioside a from steviol glycosides using mixed-mode macroporous adsorption resins

Preparative separation and purification of rebaudioside A from steviol glycosides using mixed-mode macroporous adsorption resins (MARs) were systematically investigated. Mixed-mode MARs were prepared by a physical blending method. By evaluation of the adsorption/desorption ratio and adsorption/desorption capacity of mixed-mode MARs with different proportions toward RA and ST, the mixed-mode MAR 18 was chosen as the optimum strategy. On the basis of the static tests, it was found that the experimental data fitted best to the pseudosecond-order kinetics and Temkin-Pyzhev isotherm. Furthermore, the dynamic adsorption/desorption experiments were performed on the mini column packed with mixed-mode MAR 18. After one run treatment, the purity of rebaudioside A in purified product increased from 40.77 to 60.53%, with a yield rate of 38.73% (W/W), and that in residual product decreased from 40.77 to 36.17%, with a recovery yield of 57.61% (W/W). The total recovery yield reached 96.34% (W/W). The results showed that this method could be utilized in large-scale production of rebaudioside A from steviol glycosides in industry.