一种新型复合天然抗氧化剂的研究

研究了一种由甘草提取物、陈皮提取物、卵磷脂、抗坏血酸和柠檬酸组成的复合天然抗氧化剂。通过响应面分析法得到了的具有最佳抗氧化性的复合天然抗氧化剂,其各成分比例为30∶60∶20∶1∶2。在添加量相同的情况下,复合天然抗氧化剂的抗氧化性高于BHT和茶多酚,但比TBHQ低。     

肉桂醛-羟丙基-β-环糊精包合物的喷雾干燥法制备及表征

为了提高肉桂醛的稳定性,采用喷雾干燥法制备羟丙基-β-环糊精-肉桂醛包合物,并对包合物的结构、热稳定性及缓释特性进行研究。结果表明,当肉桂醛和羟丙基-β-环糊精质量比为1:2、进料速度20 mL/min、进风温度180℃时包合率达到77.6%。红外光谱、差示扫描量热、热重以及扫描电镜分析,证实了肉桂醛包合物的形成,被包埋后肉桂醛的热稳定性得到显著提高。释放特性表明,肉桂醛包合物在模拟海水中的释放率显著低于在纯水中的释放率,有望应用于海产品保鲜领域。     

Study of the refirming effect of a plant complex

Loss of skin elasticity is one of the main problems of ageing. This is a mechanical property influenced by elastin, a protein in the dermis which, together with collagen and glycosaminoglycans, makes up the connective tissue. This tissue is affected by a large number of events (such as cutaneous ageing, pregnancy, slimming processes and cellulitis) which eventually cause it to change. At the same time, the metabolism of the proteins of the connective tissue decreases and there is an ever greater presence of enzymes, principally elastases and collagenases, which are responsible for breaking down the elastin and the collagen. One way to prevent such a loss of elasticity is to use active ingredients that are able to inhibit elastase enzymes. A plant complex was prepared using the following plants: lady's thistle (Silybum marianum GAERTN), alchemilla or yarrow (Alchemilla vulgaris L.), horsetail (Equisetum arvense L.) as well as germinated seeds (Glycine soja Siebold and Zucc., Triticum vulgare Vilars, Medicago sativa L., Raphanus sativus L.). The complex was standardized to give the corresponding active principles, silybin, tannins, silicon and peptides, respectively, and in vitro enzymatic tests were carried out to establish its ability to inhibit elastase. The study of enzymatic inhibition was carried out using two enzymes: (1) porcine pancreatic elastase (PPE), and (2) human leukocyte elastase (HLE). The results showed that the plant complex presents non-competitive inhibition in the order of 41.0% against PPE and 50.0% against HLE. An in vivo test was made alongside the in vitro test using an SEM 474 Cutometer (Courage & Khazaka) to study the elasticity of the skin, and positive effects were obtained when applying a cosmetic formulation containing 5% of the plant complex. Image analysis of duplicates of the cutaneous surface, before and after treatment began with a product containing 5% of plant complex and showed that wrinkles were decreased by 36.7%.     

黄芪多糖铬络合物的合成及其降血糖活性的初步研究

从黄芪药材中提取了黄芪多糖,制备黄芪多糖的铬络合物,并研究了黄芪多糖及其铬络合物对链脲佐菌素致高血糖小鼠模型的降糖作用。提取的黄芪多糖经过纯化后,在碱性条件下与三价铬离子络合,用IR、UV手段初步表征了络合物的形成。用链脲佐菌素致高血糖小鼠,药物分低、中、高三个剂量组给药,黄芪多糖铬络合物低、中、高三个剂量组与给药前相比都能显著降低高血糖小鼠的血糖（p〈0.05）,而黄芪多糖仅低剂量组与给药前相比有降糖效果（p〈0.05）。因而黄芪多糖铬络合物具有比黄芪多糖更强的降糖效果,有一定的开发前景。     

槲皮素-锌(Ⅱ)配合物清除自由基的活性研究

为改善槲皮素的水溶性,将其制成锌(Ⅱ)配合物,测定了槲皮素-锌(Ⅱ)配合物对四种自由基——DPPH·、·OH自由基、O-2·自由基以及烷基自由基的清除能力,并同VC、BHT进行了比较。并通过体内实验,测定其在小鼠体内的总抗氧化能力。结果表明:在实验质量浓度范围内(0.05～1.2mg/mL),槲皮素-锌(Ⅱ)配合物对DPPH·、·OH自由基、O-2·自由基的清除率可达90.51%、85.65%和79.81%;其对烷基自由基的抑制率为82.67%,且其抗氧化活性强于VC和BHT。小鼠体内的总抗氧化能力的测定结果显示,槲皮素-锌(Ⅱ)配合物在高剂量时具有最大抗氧化力,为12.7980±0.9131单位/mL血清。结果表明,槲皮素-锌(Ⅱ)配合物是一种有效的自由基清除剂。     

复合L-氨基酸镁络合物合成的研究

以豆粕为原料,利用酶水解工艺制备复合L-氨基酸,将氯化镁与复合L-氨基酸螯合制备复合L-氨基酸镁。结果表明:豆粕酶水解最佳工艺条件为:固液比1∶25、pH8.5、加10%胰蛋白酶与8%植物蛋白酶、酶解时间4h,所得豆粕水解度为37.80%。复合氨基酸与氯化镁螯合的最佳工艺条件为:配位摩尔比3∶1、pH8.0、温度80℃、时间50min,此条件下螯合率为45.82%。经红外光谱分析,复合L-氨基酸与氯化镁之间存在螯合作用。     

Overview of the potent cyanobacterial neurotoxin β-methylamino-L-alanine (BMAA) and its analytical determination

Blue-green algae are responsible for the production of different types of toxins which can be neurotoxic, hepatotoxic, cytotoxic and dermatotoxic and that can affect both aquatic and terrestrial life. Since its discovery the neurotoxin β-methylamino-L-alanine (BMAA) has been a cause for concern, being associated with the neurodegenerative disease amyotrophic lateral sclerosis/Parkinsonism–dementia complex (ALS/PDC). The initial focus was on Guam where it was observed that a high number of people were affected by the ALS/PDC complex. Subsequently, researchers were surprised to find levels of BMAA in post mortem brains from Canadian patients who also suffered from ALS/PDC. Recent research demonstrates that BMAA has been found at different levels in the aquatic food web in the brackish waters of the Baltic Sea. There is emerging evidence to suggest that sand-borne algae from Qatar can also contain BMAA. Furthermore, there is now concern because BMAA has been found not only in warmer regions of the world but also in temperate regions like Europe. The aim of this review is to focus on the methods of extraction and analysis of the neurotoxic non-protein amino acid BMAA. We also consider the neurotoxicity, aetiology, and diverse sources and routes of exposure to BMAA. In recent years, different methods have been developed for the analysis of BMAA. Some of these use HPLC-FD, UPLC-UV, UPLC-MS and LC-MS/MS using samples that have been derivatised or underivatised. To date the LC-MS/MS approach is the most widely used analytical technique as it is the most selective and sensitive method for BMAA determination.     

固定化复合酵母生产黍米黄酒的新工艺

以黍米为原料 ,采用固定化复合酵母细胞技术发酵生产黄酒 ,确定了最佳工艺条件 :固定化复合酵母细胞接种配比为酿酒酵母∶产酯酵母 =3∶2 ;固定化复合酵母载体填充率 8% ;发酵温度2 0℃ ;发酵时间 96h ;起始 pH4 0。在该条件下发酵生产的黄酒 ,口感风味较好 ,在缩短了发酵时间的同时总氨基氮和总酯含量较传统工艺都有了较大的提高。     

In vitro and in vivo inhibition of Hass avocado polyphenol oxidase enzymatic browning by paeonol, β-cyclodextrin,and paeonol:β-cyclodextrin inclusion complex

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复合改良剂在面制品中的应用

复合改良剂以其良好的性能在食品加工中应用广泛，现对其在面制品中的应用作一综述。