Accumulation of thiobarbituric acid‐reactive substances in cured pork sausages treated with propolis extracts

Propolis collected by bees has many components that possess antifungal, anticancer and antioxidant properties. Cured ground pork meat was treated separately with 0.4% w/w ethanol‐extracted propolis (EEP 0.4%), 0.6% w/w water‐extracted propolis (WEP 0.6%), 0.8% w/w dried residue of ethanol‐extracted propolis (DREEP 0.8%) and 0.1% w/w potassium sorbate (PS 0.1%) and made into sausages. Thiobarbituric acid‐reactive substances (TBARS) were measured in the sausages to assess the effects of storage at 5, 10 and 20 °C after 0, 2 and 4 weeks. After 4 weeks of storage at 5 °C the sausages treated with EEP 0.4%, DREEP 0.8%, WEP 0.6% and PS 0.1% yielded TBARS values which were 50, 59, 35 and 91% respectively of the control value. There was an increase of 0.33 mg MDA kg^?1, the lowest of all treatments, in TBARS for the 0.4% w/w EEP‐treated sausages. The curing process will control microbiological spoilage, as will potassium sorbate. © 2002 Society of Chemical Industry     

Hot-pressurized fluid extraction of flavonoids and phenolic acids from Brazilian propolis and their cytotoxic assay in vitro

This work has examined the hot-pressurized fluid extraction of seven flavonoids, caffeic acid phenethyl ester and four phenolic acids from Brazilian propolis lumps generating, during the process, fat- and water-soluble extracts. The solid content of water-soluble extract obtained by hot-pressurized water in the presence of 29% natural surfactant was 35.2 mg/mL and was 44% greater than that obtained without natural surfactant. Furthermore the amount of the seven flavonoids and caffeic acid phenethyl ester in the fat-soluble extract exceeded those in the water-soluble sample while, on the other hand, the amount of the four phenolic acids in the water-soluble extract was more than those in the fat-soluble extract. Our findings show that the total solid content and the amount of these 12 active compounds produced by the emulsified hot-pressurized water are 36% and 7% higher, respectively, than those produced by emulsified water at atmospheric pressure. The EC₅₀ value of the free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl of the emulsified hot-pressurized water extract was the lowest, and presented the strongest anti-oxidation ability among all the extracts. In vitro cytotoxicity indicated that the water-soluble extract strongly suppressed the growth of leukemia (HL-60, U937), lung cancer (A549, CH27) and liver cancer (Hep G2, Hep 3B) cells in a concentration-dependent behavior.     

蜂胶对牛乳保鲜作用的研究

以蜂胶对牛乳的保鲜作用为基础,探讨了蜂胶的添加方式和浓度对牛乳的酸度和细菌总数的作用效果．将0．2％的蜂胶添加到经巴氏灭菌（65℃,30min）后的牛乳中,牛乳酸度变化最慢,在保质期内可控制到17．5。T,细菌总数可以控制在8．5×10^8个cfu／mL．该研究为蜂胶保鲜剂在牛乳中的应用提供了理论参考．     

蜂胶对酸奶保鲜效果的研究

在乳制品中,酸奶的微生物污染常常被人们所忽视.作者研究了不同浓度的蜂胶水溶液对酸奶的保鲜效果.实验结果表明,蜂胶水溶液浓度越大,对酵母菌的抑制作用越强,即对酸奶的保鲜效果也越好.添加浓度为0.05%的蜂胶水溶液在延长酸奶保存期的同时,还能保证酸奶自身的品质,因此蜂胶可以作为天然的食品保鲜剂.该研究为蜂胶对各种乳制品的保鲜应用提供了参考.     

大鼠灌胃中国蜂胶醇提物后血浆中5种酚酸类成分的HPLC测定及其药代动力学

对大鼠灌胃蜂胶乙醇提取物（EEP）后,血浆中5种酚酸类成分的药代动力学特性进行研究.用HPLC-UV法测定血浆中咖啡酸、香豆酸、阿魏酸、异阿魏酸和3,4-二甲氧基肉桂酸的浓度.应用WinNonlin非典型房室模型计算软件计算相应的药代动力学参数.血浆中内源性物质和内标对酚酸类成分测定无干扰,回收率、准确度及日内、日间精密度均符合生物样品测定要求.结果表明,该方法简便、快速、重复性好,适用于咖啡酸等5种蜂胶中酚酸类成分的大鼠血药质量浓度测定及体内药动学研究.     

Antimicrobial and antioxidant activities of different propolis samples from north‐western Algeria

The aim of this study was the investigation of antimicrobial and antioxidant activities of different ethanolic extracts of propolis (EEP) collected from north‐western Algeria. Total polyphenols and flavonoids contents of extracts were measured. The UV absorption spectrum showed and confirmed their polyphenols constituents. All EEPs exerted antibacterial activity against Gram‐positive bacteria, but no effect on Gram‐negative bacteria. The minimum inhibitory concentration (MIC) of EEPs ranged from 0.01% to 2.6% v/v. The antioxidant activity was measured using ferric‐reducing power (FRAP), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical‐scavenging and ESR methods. Propolis TIA‐2 and MOH‐MAS samples showed the highest antioxidative capacity, after 35 min, while TIA‐1, NED‐TL and SFS‐SBA samples showed the highest antioxidative potential of measured EEPs, after 3 min. TIA‐2 sample showed the highest antibacterial, antioxidant activity and highest DPPH free radical‐scavenging activity as well as the highest polyphenols and flavonoids content, compared with other propolis samples.     

蜂胶抗氧化作用研究

研究蜂胶清除自由基和抗油脂氧化作用的能力。结果表明，蜂胶提取液清除·OH自由基的能力与总黄酮含量呈正相关；蜂胶具有良好的抗油脂氧化能力，其能力略高于同浓度的二丁基羟基甲苯（BHT）。     

Antioxidant activity and constituents of propolis collected in various areas of China

Propolis is a resinous substance collected by honeybees from various plant sources. The composition of propolis depends on time, vegetation, and the area of collection. This study examined the antioxidant activity of propolis from various areas of China: Heilongjiang, Neimongol, Hebei, Shandong, Shanxi, Gansu, Henan, Hubei, Sichuan, Hunan, Yunnan and Hainan. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant activities by β-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging, and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assays. Furthermore, the major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis with a photodiode array (PDA) and mass spectrometric (MS) detection, and each component was quantitatively analyzed. All propolis samples except that from Yunnan had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis with strong antioxidant activity contained large amounts of antioxidative compounds, such as caffeic acid, ferulic acid and caffeic acid phenethyl ester. On the other hand, propolis from Yunnan and Hainan had compounds not present in propolis from other areas.     

不同产地蜂胶中总黄酮的提取及含量测定

目的:测定不同产地蜂胶中总黄酮的含量,为蜂胶的质量控制提供更多依据。方法:通过正交设计试验,优选蜂胶中总黄酮的提取方法;以芦丁为对照品,用分光光度法测定不同产地蜂胶中总黄酮的含量。结果:国内主要产地的蜂胶中总黄酮含量均高于巴西蜂胶,且河南,山东产蜂胶中总黄酮含量大于20%。结论:该方法可靠,测定结果能反映客观实际,可作为蜂胶质量控制指标之一。