淀粉酶在真假蜂蜜中的区别

针对蜂蜜掺假和造假的问题,文中对真、假蜂蜜中的蛋白质含量、淀粉酶活性及淀粉酶同工酶谱带差异进行测定分析。结果表明,天然蜂蜜在低温条件下可以在近1个月的时间内保持其蛋白质含量和酶值基本不变,但是在高温的条件下,随着贮存时间的延长,其蛋白质含量和酶值就会明显下降。而假蜂蜜其蛋白质含量和酶值均没有明显的变化。同工酶凝胶电泳结果也表明,真、假蜂蜜中淀粉酶同工酶谱带明显不同。因此,通过跟踪测定蜂蜜中蛋白质含量、淀粉酶值变化、淀粉同工酶谱带可以检测蜂蜜的真假及其质量变化。     

α-淀粉酶在检验真假蜂蜜中的应用

针对蜂蜜掺假和造假的问题,对真蜂蜜及耐高温α-淀粉酶中的蛋白质含量、淀粉酶活性进行测定分析.实验结果表明:天然蜂蜜在低温条件下可长期保持其酶值基本不变,但是在高温条件下,随着储存时间延长,其酶值就会明显下降.而耐高温α-淀粉酶酶值均没有发生明显变化.通过蜂蜜样品中的α-淀粉酶与耐高温α-淀粉酶酶学性质的比较为判别真蜂蜜与掺假蜂蜜提供依据.     

高科技鉴别真假蜂蜜

正蜂蜜是营养丰富的天然食品,目前市场上蜂蜜品类越来越多,售价也越来越高,难免会有掺假蜂蜜混杂其中,消费者也很难从表观上进行分辨。本文介绍三种最前沿的科学方法鉴别真假蜂蜜。酶活性检测法蜂蜜含有α-淀粉酶等内源性酶,可通过检测这些酶的含量、种类及活力来鉴别蜂蜜是否掺假。例如,不同植物来源蜂蜜中均有β-葡萄糖     

蜂蜜淀粉酶在鉴别蜂蜜掺假中的应用研究

针对蜂蜜掺假和造假的问题，本文通过测定蜂蜜粗蛋白、蛋白质含量和淀粉酶值，研究储存温度和时间对蜂蜜淀粉酶值和蛋白质含量的影响，寻找一种简单有效、客观公正的鉴别真假蜂蜜的方法。比较研究结果表明在高温(37℃、45℃)下贮存，天然蜂蜜的淀粉酶值和蛋白质的含量逐渐下降，而假蜂蜜中的淀粉酶值和蛋白质的含量基本不变。通过跟踪测定蜂蜜淀粉酶值和蛋白质含量的变化可以检测蜂蜜产品的质量，也可以鉴别真假蜂蜜。     

汾酒大曲酯酶和淀粉酶同工酶的分析

利用同工酶技术进行了清茬、后火和红心3种汾酒大曲酯酶和淀粉酶同工酶的比较研究。大曲电泳参数研究表明:酯酶和淀粉酶同工酶电泳分离胶浓度分别为12%和10%,上样蛋白浓度分别为5.5～11 mg/mL和0.34～0.69 mg/mL,连续抽提10批储存9 d,同工酶电泳图谱一致稳定。3种大曲同工酶酶谱分析表明:每种大曲都含有丰富的酯酶和淀粉酶同工酶酶带。3种大曲酯酶同工酶谱主带的数量和位置基本相同,曲皮、曲心和整曲也基本一致,仅在弱带区有所不同。3种大曲淀粉酶同工酶谱明显不同,后火曲有一条特征主带。曲心明显不同于曲皮和整曲,曲心的淀粉酶同工酶酶谱明显将3种大曲鉴别,其中有一条酶带可作为后火曲的同工酶标记。10批混合生产用曲的同工酶分析,酯酶和淀粉酶同工酶酶谱基本一致,淀粉酶同工酶谱分析混合曲中有后火曲存在。     

掺假蜂蜜和市售蜂蜜的检测分析

对纯正槐花蜜进行不同浓度蔗糖与淀粉的掺假处理,分析其对蜂蜜淀粉酶值(DN值)的影响,结果显示,掺假会使淀粉酶值(DN值)有不同程度的降低,且不同掺假物对蜂蜜的淀粉酶值(DN值)影响不同.同时对市售的3种瓶装蜂蜜各种质量指标进行了检测分析.     

真假蜂蜜理化指标的分析

针对蜂蜜掺假和造假问题,对所选蜂蜜的主要理化指标:还原糖含量、酸度、蔗糖含量、淀粉酶值、费氏反应等进行测定。同时研究储存温度(10、37、45℃)和时间(0、10、20、30d)对蜂蜜淀粉酶值和蛋白质含量的影响,比较真假蜂蜜的淀粉酶值和蛋白质含量的变化。并且对纯正蜂蜜进行不同浓度蔗糖与不同浓度淀粉的掺假处理,分析掺假对蜂蜜淀粉酶值的影响。从而为辨别蜂蜜掺假方法提供相关依据。     

UPLC-Q-Exactive四极杆-静电场轨道阱高分辨质谱联用鉴别掺假蜂蜜

为对掺假蜂蜜识别提供新思路和新方法,本研究应用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱联用的方法鉴定4种未掺假蜂蜜及2种掺假蜂蜜中肽类物质的组成和结构,并探讨未掺假蜂蜜和掺假蜂蜜多肽的差异。以20%的三氯乙酸溶液沉淀蜂蜜蛋白,所得蜂蜜蛋白以胰蛋白酶酶解,然后通过C₁₈固相萃取柱净化酶解肽段。采用0.1%甲酸和乙腈作为流动相进行梯度洗脱,以高分辨质谱(Q-Exactive)的Full MS/ddMS²模式对胰蛋白酶酶解后的蜂蜜多肽进行鉴定,MaxQuant软件分析质谱结果,分析所得肽段在Uniprot上进行Blast序列对比。结果显示,4种未掺假蜂蜜中均存在来自蜂王浆主要蛋白(MRJPs)的多肽,2种掺假蜂蜜中未检测出MRJPs,且4种未掺假蜂蜜中所鉴定出的多肽80%以上来自于蜜蜂(Apis cerana cerana、Apis cerana、Apis mellifera)。通过比对6种蜂蜜酶解肽段序列发现,肽段EYILVLSNK在4种未掺假蜂蜜中均有检测到,在2种掺假蜂蜜中未检出。因此,来自于Apis mellifera的MRJP1酶解产生的肽段EYILVLSNK或可作为辨别真伪蜂蜜的潜在肽段。     

基于糖类物质差异鉴别掺假蜂蜜技术研究进展

天然蜂蜜具有较高的营养价值,但目前市场上蜂蜜产品的质量却良莠不齐。随着蜂蜜掺假手段的提高,我国现行的国家检测标准已无法满足市场需求。近几年来,蜂蜜中最难检测的掺假手段就是在天然蜂蜜中掺入高果糖浆。高果糖浆与真蜂蜜中糖类物质的组成较为相似,检测蜂蜜中掺入高果糖浆一直是研究的难点,但是蜂蜜中的糖类物质的稳定性碳同位素比值、空间结构、热力学温度、寡糖组成等方面与掺假糖浆是有一定区别的。主要对基于糖类物质差异鉴别掺假蜂蜜的技术进行了综述,提出了今后掺假蜂蜜鉴别技术的发展方向,以期促进蜂蜜市场的规范化发展。     

百花蜜和八叶五加蜜中商品中温淀粉酶的pH值差异检测

目的:利用酶最适pH值的差异检测蜂蜜中人为掺入的商品淀粉酶。方法:以百花蜜和八叶五加蜜为对象,参照GB/T 18932.16-2003测定蜂蜜、中温淀粉酶以及蜂蜜和中温淀粉酶混合物的淀粉酶值。结果:百花蜜和八叶五加蜜淀粉酶的最适pH值为5,中温淀粉酶的最适pH值为7;八叶五加蜜和中温淀粉酶混合物的最适pH值处于5~7之间,其值随中温淀粉酶比例的增加逐渐向7偏移。在pH 7.0时蜂蜜样品淀粉酶值的比导数与商品淀粉酶占总酶值的百分比符合线性模型y=0.0036x-0.5383。4种八叶五加蜜和中温淀粉酶混合物的淀粉酶都大于8 mL/(g·h)。通过其比导数模型分析发现,它们当中天然蜂蜜淀粉酶值为分别为3.67,4.23,3.84 mL/(g·h)和1.63 mL/(g·h)。结论:通过测定蜂蜜样品淀粉酶的最适pH值,可以判断蜂蜜中是否掺入中温淀粉酶,并估算其中天然淀粉酶和商品中温淀粉酶的含量,从而评价蜂蜜的质量。     

Purification of Amylase from Honey

The major amylase in honey was concentrated by ultrafiltration, isolated by ultracentrifugation and gel filtration, and purified by ion‐exchange chromatography. The amylase activity was in the flow‐through fraction of the anion‐exchange column, suggesting a high isoelectric point (>7.4) for the enzyme. The enzyme fraction from the anion‐exchange chromatography was loaded onto a cation‐exchange column, and the amylase activity was eluted as a single band at 50 mM NaCl. The purification factor after this step was 531‐fold. The purified enzyme was an a‐amylase, as determined by thin‐layer chromatography, with a molecular weight of 57000 Da according to sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). The results supported the concept that amylase in honey had a high degree of similarity with bee amylase.     

Honey Amylase Activity and Food Starch Degradation

ABSTRACT: Honey amylase was evaluated for potential to degrade food starch and cause viscosity loss. Honey was assayed for amylase activity with diastase number (DN). A viscosity assay, developed with unmodified waxy maize starch, measured honey amylase rate of viscosity decrease (RVD). The relationship between DN and RVD was linear (R²= 0.98). Modified waxy maize starches showed resistance to honey amylase. Honey heat treatment at 85 °C reduced amylase activity 2 to 5 DN, but confirmed enzyme heat resistance. Optimum pH for honey amylase was confirmed at pH 5.3 to 5.6. RVD activity declined as pH decreased. Preventing food viscosity loss involved selecting honey with lowered DN and/or using modified starches. Complete control of activity was achieved in barbecue sauce at pH < 3.9.     

Characterization of honey amylase

ABSTRACT:  The major α-amylase in honey was characterized. The optimum pH range and temperature were determined for the enzyme as 4.6 to 5.3 and 55 °C, respectively. The enzyme was stable at pH values from 7 to 8. The half-lives of the purified enzyme at different temperatures were determined. The activation energy for heat inactivation of honey amylase was 114.6 kJ/mol. The enzyme exhibited Michaelis–Menten kinetics with soluble starch and gave K _M and V _max values of 0.72 mg/mL and 0.018 units/mL, respectively. The enzyme was inhibited by CuCl (34.3%), MgCl₂ (22.4%), and HgCl₂ (13.4%), while CaCl₂, MnCl₂, and ZnSO₄ did not have any effect. Starch had a protective effect on thermal stability of honey amylase. Therefore, it might be critical to process or control the amylase in honey before incorporation into starch-containing foods to aid in the preservation of starch functionality. One step could involve heat treating honey with other ingredients, especially those that dilute and acidify the honey environment.     

Effect of honey types and concentration on starch gelatinization

The complex and variable composition of honey, depending on source, season and processing, means different honey samples could cause variation in the characteristics of the finished product. The objective of this study was to determine how the minor components present in honey affect starch gelatinization. A Rapid Visco Analyser was used to measure changes in viscosity when unmodified maize starch was gelatinized in a honey or model sugar solution. When honey was compared to equivalent blends of sugars, there was an increase in starch viscosity with increasing levels of addition. However, at the same level, honey gave a lower viscosity than the blends of sugars. Honeys from different sources (differing in pH and amylase activity) show a varied effect on starch gelatinization, with starch viscosity increasing with addition level for six of the honeys, but decreasing with increasing addition level for two honey samples. Varying the pH also produced variation in starch gelatinization patterns between honey types. Between pH 3.0 and 4.0, starch viscosity was similar for all four honey types studied, while above this pH there were differences between all honey types. As expected, starch viscosity decreased as the solution pH neared the optimum for honey amylase activity (pH 5.3-5.6), though it did not increase as the pH moved away from the honey amylase activity optimum. Differences between honey samples, and between honey and a model sugar mixture, in their effect on starch gelatinization was attributed to honey amylase activity and the composition and concentration of minor organic compounds present.     

Proteine des Bienenhonigs

Zusammenfassung Die Amylase aus Tannenhonig wurde durch hydrophobe Wechselwirkungs-Chromatographie isoliert. Sie ließ sich diskelektrophoretisch in 7 Komponenten auftrennen; eine eindeutige Festlegung ihrer Amylaseaktivität gelang nicht.Dagegen lieferte die isoelektrische Fokussierung analytisch 11 Komponenten, präparativ 13 Komponenten. Diese waren sämtlich amylaseaktiv; die Hauptaktivität verteilte sich auf 4 Banden. Die Komponenten der Honigamylase fokussierten bei niedrigeren pI-Werten, als in der Literatur für Amylasen anderer Herkunft angegeben wird.Die starke Aufspaltung macht es wahrscheinlich, daß Tannenhonigamylase neben Komponenten, die von der Biene stammen, weitere anderer Herkunft enthält.Die gute Reproduzierbarkeit des Fokussierungsmusters spricht dafür, daß einerseits bei der Aufarbeitung und Fokussierung keine unkontrollierten Verluste oder Veränderungen am Amylaseprotein erfolgen, und daß es andererseits aussichtsreich ist, die Herkunft der Komponenten durch Vergleich mit anderen Honigen, insbesondere mit reinen Zuckerfütterungshonigen, zu klären.

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The proteins of honeyIV. Fractionation and characterisation of honey amylase by electrophoresis and Isoelectric focusing

Summary The amylase of a pine honey (fromabies sp.) was isolated by hydrophobic interaction chromatography. Seven components were separated by means of disc-electrophoresis; their amylase activity was not exactly determinable. In contrast, analytical and preparative isoelectric focusing furnished 11 respectively 13 components; all these components were active, the main activity being restricted to 4 bands. Compared to amylases of other origin, the honey amylase focused only in the acidic region.The split into so clearly distinct bands indicates that in all probability the amylase not only originates from bees, but also from other sources.The same focusing pattern appears in all successive runs; this indicates: 1. that the preparation and focusing do not cause any uncontrolled loss or change in the protein, and 2. that it is now possible to determine the origin of the components by comparison with other honeys, especially with honey obtained from sucrose fed, confined bees.

     

糖源蜜、花源蜜和市售蜂蜜品质的比较研究

该文对糖源蜜、花源蜜以及市售蜂蜜(黑蜂雪蜜、洋槐蜂蜜、天然蜂蜜、紫云英蜂蜜)的水分含量、电导率值、色度、果糖、葡萄糖、蔗糖、pH值、游离酸、总酸和蛋白质含量等基本理化成分以及矿物质含量、淀粉酶活性、总酚酸含量、总黄酮含量等活性成分进行测定.结果表明:糖源蜜、花源蜜以及市售4种蜂蜜的基本理化成分含量均符合我国国家标准,表...     

新疆薰衣草蜜活性成分的分析

以薰衣草蜜、洋槐蜜和椴树蜜3种蜂蜜为材料,对蜂蜜中的还原糖含量、淀粉酶值、蛋白质含量、总酚酸含量和它们清除DPPH自由基的能力进行分析。结果表明:薰衣草蜜中的淀粉酶值、总酚酸含量、蛋白质的含量分别为14.8mL/g·h、(200.8±6.9)μg/g和(25.35±2.74)mg/100g,均高于其他2种蜜,但还原糖含量比其他2种蜂蜜略低,为74%。3种蜂蜜均具有抗氧化的作用,薰衣草蜜与椴树蜜对DPPH自由基的清除能力相当,均高于洋槐蜜。总酚酸含量与抗氧化能力之间无明显相关性,说明蜂蜜中还含有其他的抗氧化活性成分。     

Hydroxymethylfurfuraldehyde and amylase contents in Australian honey

The quality of Australian honey samples (processed and unprocessed) was assessed using HPLC techniques. 5-Hydroxymethylfurfuraldehyde (HMF) was used as the main quality indicator. Sampling included four commercially-processed honeys (Australian rainforest, Beechworth, Homebrand and Leabrook) and three unprocessed (Banksia, Grey box and Mallee). All honey samples, except Leabrook and Beechworth, showed an initial HMF content less than the Codex Alimentarius and International Honey Commission standard (40 mg/kg). HMF contents in Leabrook and Beechworth were 50.8 ± 1.34 and 74.9 ± 2.34 mg/kg, respectively. Heating unprocessed honey at 85 °C for 2 min caused significant (p ? 0.05) increment in HMF contents. The amounts of HMF in Mallee samples increased from 34.0 ± 0.31 to 42.3 ± 0.37 mg/kg after 2 min at 85 °C. All honey samples showed amylase activity above the minimum limit (8 Gothes). The physiochemical properties of honey showed significant variations among samples. The results revealed also that heating was not the only factor influencing HMF formation in honey, but also honey composition, pH value and floral source can contribute to these variations. Consequently, the amount of HMF may be an insufficient sole indicator of honey quality.     

Proteins of bee honey. VI. Isoelectric focusing of amylase in various kinds of honey

The isolated honey amylase was characterized by preparative and analytical isoelectric focusing. An interesting aspect of the preparative isoelectric focusing was the reduction of iodine by Ampholines which were used for building up a pH-gradient, giving a false increase in apparent amylase activity as determined by the iodine/starch reaction. Dextran gels were not suited for the matrix, because interactions with the enzyme disturb the focusing. From the analytical isoelectric focusing of isolated honey amylase in ultrathin layer Polyacrylamide gels 10 protein bands resulted. A newly developed zymogram technique was positive for amylase activity in all 10 protein bands.