真菌发酵胞外多糖的研究进展

真菌胞外多糖具有高黏性、抗氧化、抗病毒和抗肿瘤等多种生物学活性,在食品和医药工业等领域应用广泛。本文结合国内外最新研究成果,综述了近年来有关产胞外多糖的真菌、影响真菌胞外多糖产量的因素、产胞外多糖的菌株的选育策略以及真菌胞外多糖的功能研究,以期为真菌发酵胞外多糖的研究和应用提供参考。     

茯苓多糖的研究进展

多糖具有多种生物活性,其中,药食两用真菌多糖已成为食品、医药和生物领域的研究热点。近年来,有关真菌多糖治疗与保健功能的报道越来越多,茯苓多糖是从茯苓菌分离提取出来的真菌多糖,具有显著的抗肿瘤功能。本文对茯苓多糖的成分、性质、发酵制备和功能用途等进行比较全面的阐述,旨在为进一步研究与开发茯苓多糖,保护药食用真菌资源提供参考。     

食用真菌多糖提取、纯化及结构表征研究进展

食用真菌因其味道鲜美被广泛食用,并具有较高的营养价值和药用价值。多糖是食用真菌中最重要的活性成分之一。大量研究表明,食用真菌多糖具有抗氧化、抗肿瘤、抗炎和降血糖等功效。食用真菌多糖在医疗、食品和化妆品等领域被广泛应用。近年来,关于食用真菌多糖的提取、分离纯化及结构表征的相关研究越来越受重视。但提取和纯化方式不同将会导致多糖的生物学活性存在很大的差异。该文对食用真菌多糖的提取方法、纯化方法和结构特征进行整理、归纳和阐述,以期为食用真菌多糖的进一步研究提供理论参考。     

一种真菌复合多糖提取及体外抗氧化活性的研究

研究了一种从保健口服液中提取并纯化后的真菌复合多糖的体外抗氧化活性(还原力、对羟自由基和DPPH自由基的清除能力),并与复合多糖单一成分进行比较。结果表明:在实验浓度范围内,各真菌多糖抗氧化活性均随着多糖质量浓度增加显示出稳定增长。相同质量浓度下,真菌复合多糖的抗氧化活性高于竹荪多糖及虫草多糖,但较香菇多糖的活性低或相当。表明在考虑药效和经济成本平衡的前提下,真菌复合多糖具有更高的体外抗氧化活性。     

食源性真菌多糖在功能性食品中的应用

正有些发达国家在进行食源性真菌多糖研究的过程中,由于其研究时间较早,这也使其处于该领域研究的重要地位,而我国对于这类研究的起步较晚,因此需要在未来不断深入对于食源性真菌多糖方面的研究,并扩大其在功能性食品中的应用效果。食源性真菌多糖的类型当下功能性食品中使用的食源性真菌多糖主要来源于香菇、灵芝、银耳、黑木耳等食用菌种,一些真菌中提取出来的多糖由于其来源较为广泛而受到了更多研究人员的关注。真菌多糖主要分为霉菌多糖、酵母多糖、大型真菌     

真菌多糖及其生理功能

真菌多糖具有抗病毒、抗凝血、降血脂、抗肿瘤、免疫调节、延缓衰老等多种生物活性,已被开发成多种药物和功能性食品添加剂。该文综述了真菌多糖的种类和生理功能,并对真菌多糖的应用与开发前景作了概述。     

真菌多糖的研究进展

近年来,真菌多糖的研究已成为糖生物学研究的一个热点。真菌多糖是目前最有开发前途的保健食品和药品新资源之一,其生物活性也是保健食品功能因子的研究热点。本文综述了真菌多糖的化学结构、构效关系、多糖的提纯方法以及药理功能等方面的研究现状。     

复合真菌多糖调节免疫活性研究

真菌多糖具有多方面的生物活性。本文选取多种食用真菌,提取复合真菌多糖溶液,测定其多糖含量及免疫调节活性。结果表明:溶液中多糖含量为4.82%,中剂量组、高剂量组能显著提高免疫低下小鼠的机体免疫功能,具有免疫调节功效。     

食(药)用真菌多糖的研究

药用真菌和食用真菌多糖具有重要的经济和医药价值。本文探讨了食（药）用真菌多糖的化学特性、结构与功能的关系及其开发利用前景。     

食(药)用真菌多糖的研究进展

食(药)用真菌是一大类有大型子实体的高等真菌,俗称蘑菇或蕈,含有人体所需要的多种营养成分,如:真菌多糖、腺苷、黄酮、牛磺酸、有机酸等。20世纪70年代,日本学者率先证实了香菇多糖的抗肿瘤活性,从此食(药)用真菌多糖引起了生物学、医学、药物学、食品科学等领域的广泛关注,被称为"生物反应调节剂"。食(药)用真菌多糖由于其独特的生理活性,目前正成为国内国际众多学科领域研究的热点之一。本文综述了食(药)用真菌多糖的生物活性、构效关系、应用与开发前景等方面的内容,旨在为真菌多糖的深入研究和开发利用提供参考。     

Bioaccessibility of Se, Cu, Zn, Mn and Fe, and heme iron content in unaged and aged meat of Hereford and Braford steers fed pasture

The content and the bioaccessibility of Se, Cu, Zn, Mn, and Fe were determined in unaged and aged meat (14days) from the Psoas major (PM), Gluteus medius (GM) and Longissimus dorsi (LD) muscles of Hereford (H) and Braford breed (B) steers fed pasture. Furthermore, the content of heme-Fe was determined in the same muscles. The H had a lower content of Cu and a higher content of Fe. Also, H had more heme-Fe than B. The bioaccessibility in unaged meat for Se, Cu, Zn, Mn and Fe ranged between 75 and 91%, 30 and 45%, 40 and 68%, 55 and 95%, and 60 and 70%, respectively. After aging, the bioaccessibility for the same minerals ranged between 58 and 80%, 30 and 48%, 40 and 58%, 75 and 95%, and 59 and 70%, respectively. Aging affected negatively the Se content and its bioaccessibility, in the two breeds. Also, the heme-Fe content was negatively affected by aging in all muscles and breeds.     

Bioactivation of Phytoestrogens: Intestinal Bacteria and Health

Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors. Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc. They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins, and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects. Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans. However, isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria to produce equol, urolithins, and enterolignans, respectively. Equol, urolithin, and enterolignans are more bioavailable, and have more estrogenic/antiestrogenic and antioxidant activity than their precursors. Moreover, equol, urolithins and enterolignans have anti-inflammatory effects and induce antiproliferative and apoptosis-inducing activities. The transformation of isoflavones, ellagitanins, and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis, and menopausal symptoms. Bioavailability, bioactivity, and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.     

虾、蟹壳利用的研究进展

虾、蟹壳是虾、蟹加工过程中产生的主要废弃物,含有较大量的蛋白质、灰分和甲壳素,以及少量的脂肪、游离氨基酸和虾青素等。近年来,随着我国养殖、捕捞技术的进步以及伏季休渔制度的实施,虾、蟹产量逐年上升。因此,有效利用虾、蟹壳副产物,开发基于虾、蟹壳废弃物的利用途径和产品类型,以提高产品附加值,减少环境污染,对于虾、蟹产业的健康发展具有重要意义。目前,采用酸碱法制备甲壳素是虾、蟹壳利用的主要方法,该方法易于操作,但能耗高且污染严重,近年来研究人员对传统的酸碱法制备甲壳素的工艺进行了优化,并积极探索酶法和发酵法等新型提取工艺。此外,虾、蟹壳中其他可利用成分(蛋白质、脂肪、钙质和虾青素)的提取和利用也获得了许多研究成果。本文主要综述了虾、蟹壳的组成成分,虾、蟹壳整体利用途径以及虾、蟹壳中甲壳素、蛋白质、脂肪、钙质、虾青素等成分的提取和利用途径的研究进展,以期为虾、蟹壳的高效、低成本、无污染和高附加值利用提供借鉴。     

Religious slaughter: Evaluation of current practices in selected countries

As part of the project “Religious slaughter (DIALREL): improving knowledge and expertise through dialogue and debate on issues of welfare, legislation and socio-economic aspects”, this paper discusses an evaluation of current practices during Halal and Shechita slaughter in cattle, sheep, goats and poultry. During religious slaughter, animals are killed with and without stunning by a transverse incision across the neck that is cutting the skin, muscles (brachiocephalic, sternocephalic, sternohyoid, and sternothyroid), trachea, esophagus, carotid arteries, jugular veins and the major, superficial and deep nerves of the cervical plexus. In this report, the restraint methods, stunning, neck cutting, exsanguination, slaughter techniques and postcut handling in the abattoir were assessed for religious slaughter. Information about the procedures used during religious slaughter in Belgium, Germany, Italy, the Netherlands, Spain, the UK, Turkey and Australia was collected by means of spot visits to abattoirs. To standardize the information gathered during the spot visits three guidelines were designed, one for each species, and translated into the national languages of the countries involved. The document included questions on the handling and restraint methods (stunning, neck cutting/exsanguination/slaughter techniques and postcut handling performed under religious practices) and for pain and distress of the animal during the restraint, neck cutting and induction to death in each abattoir. Results showed differences in the time from restraining to stun and to cut in the neck cutting procedures and in the time from cut to death.     

毕节地区植烟土壤有效态微量元素含量评价

对毕节地区298个植烟土壤样品的有效态微量元素Cu、Zn、Fe、Mn、B和Mo的含量及丰缺特性进行了分析,以期为毕节烟区平衡施肥及提高烟叶品质提供依据。试验结果表明,毕节地区植烟土壤中有效态Cu、Fe、Mn含量极丰富,Zn含量丰富,有效硼和有效钼的含量比较缺乏,超过1/2的土壤缺硼,超过2/5的土壤缺钼。土壤中有效态Zn、Fe和Mn的含量与pH呈显著性负相关,有效钼含量与pH呈显著性正相关。土壤中有效Fe、Zn、Mn和B的含量与有机质含量呈显著性正相关。综上所述,毕节烟区要适当补充B肥和Mo肥,对Cu、Zn、Fe和Mn等元素要通过控制施入量或土壤改良来降低其有效含量,防止土壤重金属污染。     

Mycotoxins in botanicals and dried fruits: A review

Botanicals are used in many countries for medicinal and general health-promoting purposes. Numerous natural occurrences of mycotoxins in botanicals and dried fruits have been reported. Aflatoxins or ochratoxin A (OTA) have been found in botanicals such as ginseng, ginger, liquorice, turmeric, and kava-kava in the USA, Spain, Argentina, India, and some other countries, while fumonisins have been found in medicinal wild plants in South Africa and in herbal tea and medicinal plants in Turkey. Zearalenone was identified in ginseng root. Dried fruits can be contaminated with aflatoxins, OTA, kojic acid, and, occasionally, with patulin or zearalenone. One main area of concern is aflatoxins in dried figs; bright greenish yellow fluorescence under ultraviolet light is associated with aflatoxin contamination. OTA in dried vine fruits (raisins, sultanas, and currants) is another concern. There are also reports of aflatoxins in raisins and OTA in dried figs, apricots, dried plums (prunes), dates, and quince. Maximum permitted levels in the European Union include 4 µg kg^-1 for total aflatoxins in dried fruit intended for direct consumption and 10 µg kg^-1 for OTA in dried vine fruit. This review discusses the occurrence of mycotoxins in botanicals and dried fruits and analytical issues such as sampling, sample preparation, and methods for analysis. Fungal contamination of these products, the influence of sorting, storage, and processing, and prevention are also considered.     

Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses,exposure, and controversy

Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.     

Acrylamide–Sepiolite Based Composite Hydrogels for Immobilization of Invertase

ABSTRACT:  Novel composite hydrogels, poly(acrylamide)–sepiolite (PAS), poly(acrylamide/acrylic acid)–sepiolite (PAAS), and poly(acrylamide/itaconic acid)–sepiolite (PAIS) were prepared and used for the immobilization of invertase. The parameters of equilibrium swelling, diffusional exponent, and diffusion coefficient of these hydrogels were calculated from swelling experiments. Invertase was immobilized onto PAS, PAAS, and PAIS and immobilized invertases (PASI, PAASI, and PAISI) were prepared. Optimum pH values for free invertase, PASI, PAASI, and PAISI are found to be 5, 5.5, 4.5, and 6, respectively, and the optimum temperatures were 30, 50, 50, and 35 °C for free invertase PASI, PAASI, and PAISI. It was found that  K_m  values of free invertase, PASI, PAASI, and PAISI were 11.3, 41.0, 94.5, and 56.0 mM, respectively.  V _max values were 2 μmol/min for free invertase, 8.10 μmol/min for PASI, 1.30 μmol/min for PAASI, and 0.42 μmol/min for PAISI, respectively. The invertase immobilized hydrogels showed excellent, temperature, storage, and operational stability.     

Food oral processing—A review

Food oral processing is an essential procedure not only for the consumption and digestion of foods but also for the appreciation and pleasure of food texture and food flavour. The consumption of a food inside mouth involves various oral operations, including first bite, chewing and mastication, transportation, bolus formation, swallowing, etc. Exact mechanisms and governing principles of these oral operations are still not fully understood, despite of continuous efforts made by scientists from food, psychology, physiology, dental and clinical studies, and other disciplines. This article reviews recent progresses and literature findings about food processing and transformation in mouth, with particular attention on the physiology and rheology aspects of oral operations. The physiological behaviour of human's oral device is discussed in terms of biting capability, tongue movement, saliva production and incorporation, and swallowing. The complexity of oral processing is analysed in relation to the rheology and mechanical properties of foods. The swallowing and oral clearing process is also examined for its criteria, triggering mechanism, bolus deformation, and the rheology of swallowing.     

大豆油精炼过程中多环芳烃的迁移规律

明确大豆油精炼过程多环芳烃（polycyclic aromatic hydrocarbons,PAHs）风险成分的迁移规律,以便于食品中PAHs的风险防范和控制。通过对大豆油精炼生产中脱胶油、脱酸油、脱色油、脱臭油和对应加工助剂磷酸、烧碱、活性白土以及精炼副产物油脚、皂脚、废白土、脱臭馏出物样品中PAHs组分含量的检测,分析PAHs在大豆油精炼生产中的迁移规律。结果显示：大豆油精炼用加工助剂中均含有PAHs,磷酸、烧碱和活性白土中苯并[a]芘（benzo[a]pyrene,BaP）含量分别为0.95、1.84?μg/kg和0.71?μg/kg,欧盟限量控制的4?种PAHs（PAH4）（苯并[a]蒽、?、苯并[b]荧蒽和BaP）含量为2.81、16.81?μg/kg和8.85?μg/kg,美国优先控制的16?种PAHs（PAH16）含量为26.18、112.61?μg/kg和111.85?μg/kg;在大豆油水化脱胶、碱炼脱酸、蒸馏脱臭过程BaP的脱除率分别为7.57%、23.57%、91.65%,水化脱胶、碱炼脱酸、吸附脱色、蒸馏脱臭过程PAH4的脱除率分别为15.93%、10.41%、19.31%、50.91%,PAH16的脱除率分别为15.45%、11.59%、6.66%、52.99%;大豆油精炼副产物油脚、皂脚、废白土、脱臭馏出物中BaP含量分别为0.45、0.90、0.52、12.49?μg/kg,PAH4含量分别为10.14、7.39、9.69、300.50?μg/kg,PAH16含量分别为261.60、434.49、156.29、2?775.15?μg/kg。