新资源短梗五加及其同属植物根皮中抗疲劳因子的HPLC定量研究

目的：测定新资源短梗五加及糙叶藤五加、红毛五加、刺五加、白毛五加、韩五加、细柱五加、白簕五加等8 种五加属植物根皮中紫丁香苷的含量。方法：采用RP-HPLC 测定紫丁香苷的含量。色谱柱为ODS C18柱,流动相为20% 甲醇溶液,流速为1.0ml/min,检测波长为265nm,柱温35℃。采用正交试验法考察乙醇浓度、提取时间、溶剂用量对提取效果的影响。结果：紫丁香苷在0.0148～0.074mg/ml (r ＝ 0.9999)范围内,进样量与峰面积具有良好的线性关系,回归方程：Y ＝ 15234560X － 7881.767,R2 ＝ 0.9999,平均回收率为98.24%。8 种五加属植物中,糙叶藤五加紫丁香苷含量最高,短梗五加次之。最佳提取工艺为用水做提取剂,料液比1:15、煮沸提取3.5h。结论：本法简便,结果可靠,可用于新资源短梗五加及其同属植物的质量控制。     

高效液相法测定刺玫果中金丝桃苷的含量

目的：建立刺玫果中金丝桃苷含量测定的方法。方法：采用高效液相色谱法测定,色谱柱为Shim-packVP-ODS C18(4.6mm × 150mm,5μm);以甲醇(A)和0.2% 磷酸溶液(B)进行梯度洗脱,流速为1.0mL/min;进样量20μL;检测波长360nm;柱温40℃。结果：金丝桃苷进样质量浓度在4.76～76.16μg/mL 范围内呈良好的线性关系,r=0.9993。平均回收率为98.06%,RSD 为1.72%。结论：采用高效液相色谱法测定刺玫果中金丝桃苷的含量,方法简便、准确,可以用于刺玫果的质量控制。     

大叶白麻不同部位总黄酮和金丝桃苷含量研究

本研究采用高效液相色谱法(HPLC)测定了大叶白麻叶、花、根和茎四个部位的金丝桃苷含量;以NaAc-A1C13体系为显色剂,用分光光度法于400nm处测定了大叶白麻不同部位总黄酮的含量。结果表明：本研究采用的色谱条件可用来检测大叶白麻体内金丝桃苷。叶中的金丝桃苷含量较高,约为0.24%,花、茎和根中几乎检测不出;叶中的总黄酮含量亦较高,约为3.54%,花、茎和根中含量较低。     

新疆地产干果中苦杏仁苷含量的快速测定

研究利用高效液相色谱法快速分析新疆地产干果杏仁、苦杏仁和桃仁中苦杏仁苷的含量。采用Shim-packVP-ODS(150mm × 4.6mm,5μm)色谱柱,甲醇- 水(20:80,V/V)为流动相,进样量为2μL,流速为1mL/min,柱温为40℃,在波长215nm 处检测苦杏仁苷,并进行方法学考察。结果表明,利用此方法能有效分离并快速分析干果中苦杏仁苷含量,建立的回归方程为Y ＝ 4.86244 × 10-6X － 0.0129273,具有良好的线性和重复性,可作为在线检测干果中苦杏仁苷的定量手段。     

HPLC法测定野蔷薇中金丝桃苷的含量

建立一种简单、快速测定野蔷薇果中金丝桃苷含量的反相液相色谱方法。利用乙腈、0.05%磷酸溶液,以1 mL/min流速梯度洗脱,在361 nm波长下检测,金丝桃苷在3.38 min内即可达到基线分离。经与标准品对照,野蔷薇果中含有金丝桃苷,含量为8.12μg/g(以干重计)。经测定:此方法测定金丝桃苷回收率较好,为93.4%;相对标准偏差为1.23%,方法重复性较好,可用于野蔷薇果中金丝桃苷的快速分析检测。     

新疆产大叶白麻不同部位黄酮类成分含量分析

采用高效液相色谱法测定新疆产大叶白麻不同部位金丝桃苷、异槲皮苷、芦丁及总槲皮素的含量;以NaAc-A1C13体系为显色剂,用分光光度法于波长420 nm处测定大叶白麻不同部位总黄酮的含量。结果表明：大叶白麻叶、花、根和茎中的总黄酮含量分别为1.39%、0.89%、0.30%和0.13%。在所检测的3 个主要黄酮类成分中,异槲皮苷含量最高,除根外,在叶、花和茎中均可检测,含量分别为0.4%、0.15%和0.07%;芦丁和金丝桃苷含量较低。采用高效液相色谱法检测叶片和花中酸水解后总槲皮素含量,结果表明,叶和花中槲皮素含量分别为0.63%和0.34%。     

RP-HPLC法测定糙叶五加不同部位中五加酸和贝壳烯酸含量

为了建立反相高效液相色谱法(RP-HPLC)测定糙叶五加不同部位中五加酸和贝壳烯酸的定量分析方法,本研究采用RP-HPLC外标法测定了五加酸和贝壳烯酸含量。所用色谱柱:ODS-C18(250mm×4.6mm,5μm);流动相:乙腈-水(0～60min时乙腈含量为10%～100%,60～70min时乙腈含量为100%);检测波长207nm;柱温30℃;流速1.0mL/min。结果表明:在上述色谱条件下,五加酸和贝壳烯酸获得良好分离,线性范围分别为:0.1070～0.5351g/L(相关系数r=0.9999)和0.0930～0.4649g/L(r=0.9998),加样回收率分别为97.93%(标准偏差为1.33%)和98.12%(标准偏差为1.16%)。糙叶五加根、茎、叶中五加酸的平均含量(n=3)分别为:39.90、19.72、49.19μg/g;贝壳烯酸的平均含量(n=3)分别为:21.01、21.70、25.88μg/g。由此可知,该方法准确性高,重现性好,为糙叶五加的质量控制提供了可借鉴的定量分析方法。     

高效液相色谱法测定天山花楸中金丝桃苷的含量

目的：建立天山花楸枝叶中金丝桃苷的含量测定方法。方法：采用HPLC Shim-pack VP-ODS 柱(150mm× 4.6mm,5μm),流动相为乙腈- 水(25:75,V/V),流速为1.0ml/min,柱温为25℃,检测波长为360nm。结果：金丝桃苷在0.04～0.32mg/ml 之间线性关系良好,r ＝ 0.9992,平均回收率99.7%,RSD 为2.6%;结论：本法快速、灵敏、准确、可靠、重复性好,可用于天山花楸药材的质量控制。     

半制备高压液相色谱法制备罗汉果苷Ⅴ标准品

目的：通过半制备高压液相色谱分离技术,建立一种快速、稳定、高效制备高纯度罗汉果苷Ⅴ标准品的方法。方法：先采用树脂吸附脱色技术进行前处理,再通过半制备高压液相色谱分离制备罗汉果苷Ⅴ,色谱条件为Eclipse XDB-C18 色谱柱(9.4mm × 250mm,5μm) ,流动相为乙腈- 水,采用梯度洗脱,流速4mL/min,检测波长210nm,进样量36mg,柱温38℃。结果：分离得到的罗汉果苷Ⅴ的纯度为99.1%。结论：本方法具有操作简单、快速、稳定和产品纯度高等优点,可应用于实际样品的检测。     

HPLC法同时测定湘莲中芦丁、金丝桃苷及槲皮素含量

目的:建立高效液相色谱法同时测定湘莲中芦丁、金丝桃苷及槲皮素的含量。方法:采用Agilent ZORBAX SB-C₁₈色谱柱(4.6 mm×250 mm, 5μm),以甲醇—0.6%磷酸水溶液为流动相，梯度洗脱，流速1.0 mL/min,柱温30℃,检测波长255 nm。结果:20批湘莲样品中芦丁、金丝桃苷及槲皮素含量分别为1.32～2.06,1.36～2.43,1.41～3.26 mg/kg;芦丁、金丝桃苷和槲皮素检测质量浓度线性范围均为5～200μg/mL(R²=0.999 9),在相应的线性范围内，3种黄酮类物质线性关系好，灵敏度高，精密度、稳定性、重复性及回收率试验相对标准偏差(RSD)均小于4.0%;芦丁、金丝桃苷及槲皮素的平均加标回收率分别为96.6%,96.9%,97.4%。结论:该方法操作便捷且结果准确，可用于湘莲中黄酮类成分的含量测定和质量评价。     

酶钝化处理对菊苣茎PPO活性和绿原酸含量的影响

通过水浴、蒸汽、微波3 种烫漂方式处理新鲜菊苣茎,钝化多酚氧化酶（PPO）,为提高干燥菊苣茎中绿原酸含量提供依据。烫漂处理后立即测定菊苣茎PPO相对活性,同时测定经烫漂处理后再经空气干燥茎中绿原酸含量,分析二者之间的相关性;测定不进行烫漂处理直接进行空气干燥的菊苣茎在干燥过程中PPO相对活性和绿原酸含量的变化。结果表明：空气干燥过程中,PPO始终保持一定的相对活性（≥20.02%）;水浴、蒸汽和微波烫漂处理可有效抑制PPO相对活性,且在以上3 种处理方式中绿原酸含量与PPO相对活性均呈显著负相关（P＜0.05）;4 种方法处理后风干茎中绿原酸的含量依次为：直接空气干燥＜水浴烫漂后干燥＜蒸汽烫漂后干燥＜微波烫漂后干燥。在实验条件下,微波（600 W）烫漂鲜茎样品4.67 min时,风干菊苣茎中绿原酸含量（8.11 mg/g）最高,与鲜茎相比只降低16.82%,是直接空气干燥茎中绿原酸含量的2.17 倍。     

Effect of pretreatments and drying methods on physico‐chemical,sensory characteristics and nutritional value of oyster mushroom

This study was aimed to evaluate the effect of pretreatments and drying methods on the chemical, physico‐chemical, sensory characteristics and nutritional value of oyster mushroom. Chemical analysis of oyster mushroom (OM) showed that the values content were increased by many times when calculated on dry weight basis. Nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying, and sun drying). Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in 0.5% citric acid solution for 30 min).The results and statistical analysis revealed that, sun dried oyster mushroom samples (without pretreatments) were found to be the best. The DMP samples resulting of the sun drying had a highest physico‐chemical properties, sensory evaluation scores, and contents of the mineral elements and amino acids as compared to other pretreatments and drying methods.

Practical applications

Fresh mushrooms have high water content, high enzymatic activity and hence are highly perishable. Thus, in this study nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying and sun drying).Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in citric acid).The DMP samples (untreated) resulting of the sun drying were better than other pretreatments and drying methods regarding quality attributes.     

Air Drying Characteristics of Apricots

The optimization of the drying of apricots was studied using four treatments: (1) blanching and drying; (2) sulfiting-blanching and drying; (3) blanching-sulfiting and drying; and (4) sulfiting-drying to 50% moisture-blanching and finish drying. Levels of sulfiting were from 0–2000 ppm SO₂ and drying was done at 50° to 80°C. The quality of dried apricots was judged by extent of browning development and hardness determination. A surface response statistical design was applied to evaluate the optimum drying conditions. Sulfiting-drying, using 80–1000 ppm SO₂ at any temperature in the range 50–80°C, was found to be the best treatment. Thus, sulfite was the major factor in controlling dry apricot quality and would be hard to reduce. Drying time was reduced by 50% when apricots were dried at 80°C compared to 50°C, and blanching reduced the time by 10 to 20%. Loss of SO₂ was greater than 50% for all treatments.     

干制方式对藏香猪肉干食用品质的影响

目的:探究干制方式对藏香猪肉干食用品质的影响。方法:以藏香猪肉为原料,采用油炸、预煮—油炸、烘烤、预煮—烘烤4种干制方式对藏香猪肉干进行处理。结果:不同干制方式对藏香猪肉干色泽、质构、营养组分等品质均有显著影响。其中,油炸组感官评分最高、色泽均匀、肉香味浓郁、硬度适中、食用品质佳;烘烤组肉干硬度较大,咀嚼性较差;预煮处理后肉干色泽呈灰棕色,肉质变硬。此外,预煮还会导致大量脂肪酸损失,影响藏香猪肉干原有的营养价值。结论:油炸可作为一种生产藏香猪肉干的潜在干制方法。     

Effect of Infrared Blanching on Enzyme Activity and Retention of β‐Carotene and Vitamin C in Dried Mango

The objectives of this work were to evaluate infrared (IR) dry blanching in comparison with conventional water blanching prior to hot air drying of mango to inactivate polyphenol oxidase (PPO) and ascorbic acid oxidase (AAO) enzymes, and to study its effect on color change and retention of vitamin C and β‐carotene. Mango cylinders were blanched under similar temperature–time conditions either by IR heating or by immersion in a water bath during 2 min at 90 °C (high‐temperature‐short‐time—HTST) or for 10 min at 65 °C (low‐temperature‐long‐time—LTLT). After blanching mango was hot air dried at 70 °C. PPO was completely inactivated during the blanching treatments, but AAO had a moderate remaining activity after LTLT treatment (～30%) and a low remaining activity after HTST treatment (9% to 15%). A higher retention of vitamin C was observed in mango subjected to IR dry blanching, 88.3 ± 1.0% (HTST) and 69.2 ± 2.9% (LTLT), compared with water blanching, 61.4 ± 5.3% (HTST) and 50.7 ± 9.6% (LTLT). All‐trans‐β‐carotene retention was significantly higher in water blanched dried mango, 93.2 ± 5.2% (LTLT) and 91.4 ± 5.1% (HTST), compared with IR dry blanched, 73.6 ± 3.6% (LTLT) and 76.9 ± 2.9% (HTST). Increased levels of 13‐cis‐β‐carotene isomer were detected only in IR dry blanched mango, and the corresponding dried mango also had a slightly darker color. IR blanching of mango prior to drying can improve the retention of vitamin C, but not the retention of carotenoids, which showed to be more dependent on the temperature than the blanching process. A reduction of drying time was observed in LTLT IR‐blanching mango.     

Effect of preliminary processing, method of drying and storage temperature on the level of antioxidants in kale (Brassica oleracea L. var. acephala) leaves

The levels of vitamin C, polyphenol constituents and Trolox equivalent antioxidant activity (TEAC) were analyzed in raw kale leaves, blanched leaves and dried leaves obtained using air and freeze-drying methods. 100 g of raw kale leaves contained 683 mg vitamin C and 2236 mg polyphenols (identified using the HPLC method); the level of antioxidative activity was 71 μM Trolox/1 g dry matter. Compared with the raw material, blanching before drying brought about significant decreases of 15% in vitamin C, 32% in polyphenols and13% in TEAC. After 12-month storage, air-dried material retained 30-37% polyphenols; 43-57% vitamin C; and 41-50% of the initial TEAC level; the corresponding values for freeze-dried material were 40-47%; 50-65% and 54-66% depending on the type of sample. Freeze-dried kale leaves contained higher levels of antioxidants than air-dried material: polyphenols, vitamin C and TEAC were respectively 36%, 15%and 33% higher.