黄曲霉毒素去毒转化研究进展

该文综述黄曲霉毒素的物理化学去毒、生物化学解毒等方面研究成果,并提出磁性纳米微粒吸 附去除花生油中黄曲霉毒素新思路。     

黄曲霉毒素生物脱毒法研究进展

黄曲霉毒素是现今发现的毒性和致癌性最强的天然污染物,不仅对人类和动物的健康造成极大的危害,而且还带来巨大的经济损失,如何去除黄曲霉毒素是当前研究的热点。对黄曲霉毒素的生物脱毒方法进行综述,主要包括生物吸附法,生物酶解法和生物提取物抑制法。期望能将黄曲霉毒素生物脱毒方法应用到工业化生产中,更好地发挥出实际应用价值。     

蒙脱石对黄曲霉毒素B1的脱毒研究

通过雏鸭急性毒性、肉仔鸡饲养试验研究了蒙脱石在动物体内对黄曲霉毒素B1(AFB1)的脱毒效果和对动物健康与生产性能的影响。结果表明，每只雏鸭一次摄入16μg及以上AFB1时可出现急性中毒死亡。肉仔鸡摄入含AFB1 80μg／kg的饲料，1周后饲料报酬降低，但肝脏中无AFB1残留。蒙脱石能对抗AFB1对动物的急慢性毒性作用，减少动物急性中毒死亡率，恢复动物生产性能。在肉鸡日粮中添加0．5％的蒙脱石对鸡骨骼强度无不良影响．对鸡骨骼钙、磷、铜、铁、锌沉积无影响：使骨骼铅、氟沉积减少，骨骼锰含量降低。     

黄曲霉素的毒害及防除

真菌在新陈代谢过程中会产生大量化学结构各异的活性物质，这些物质被称为真菌毒素，其中许多对人和动物有害。黄曲霉毒素，简称黄曲霉素，就是由黄曲霉和寄生曲霉两种真菌菌株产生的真菌毒素，具有强烈的毒性和致癌、致畸、致突变性。本文介绍了黄曲霉素的危害及防除措施。     

酿酒酵母抗氧化相关基因突变体对黄曲霉毒素B_1的清除作用

黄曲霉毒素(AF)是粮食作物和饲料原料中容易污染的一种强毒性和强致癌性物质,酿酒酵母具有毒素清除功能。利用HPLC分析了酿酒酵母野生菌BY4742及三株关键的抗氧化相关基因缺失菌zwf1Δ、sod2Δ、glr1Δ对黄曲霉毒素B1的清除能力。结果表明,在PBS缓冲液中存活和死亡的细胞对AFB1的清除率分别为74%～76%和71%～73%,说明酵母细胞对AFB1的清除以生物吸附作用为主。在培养基中,3种突变菌活细胞对AFB1的清除率发生不同程度的降低,其中glr1Δ的AFB1清除能力下降最明显,其次是sod2Δ,而zwf1Δ下降最少,说明这些关键的抗氧化基因的缺失会影响细胞在生长状态下对AFB1的清除作用。     

黄曲霉毒素B1的分子致毒机理及其微生物脱毒研究进展

黄曲霉毒素B1（aflatoxin B1,AFB1）对人类和动物健康构成威胁。微生物脱毒方法安全、高效,已成为目前研究的热点,但仍然存在着作用周期长、脱毒功能不稳定、分离纯化难等瓶颈。因此,找到有效脱除AFB1的方法和应对措施对保障食品安全至关重要。本文概述了AFB1的分子致毒机理,包括其在基因和蛋白质层面的作用机理以及毒性位点研究概况;重点阐述了微生物脱毒进展中吸附和降解两种机制的解毒方法,以及细菌、真菌微生物本身及其代谢物的脱毒研究、脱毒酶的发现及机理研究,并对高效、无污染的AFB1脱毒技术的前景进行展望。     

基于强酸性氧化离子水技术的大米黄曲霉毒素降解机理的研究

针对连续煮饭机开发的需要 ,对污染了黄曲霉毒素B1的大米用强酸性氧化离子水进行降解、脱毒试验 ,经强酸性氧化离子水洗涤后的大米能有效地降解黄曲霉毒素B1,同时经过对强酸性氧化离子水洗涤后的大米进行氧化还原处理后 ,大米的构质不会受到太大的影响。在试验的基础上 ,对强酸性氧化离子水降解黄曲霉毒素B1的机理进行了初步的探讨。     

Detoxification of Aflatoxin B1 and M1 by Lactobacillus acidophilus and prebiotics in whole cow's milk

The detoxification ability of Lactobacillus acidophilus and prebiotics was evaluated by a Plackett‐Burman Design to examine the reduction of concentration and bioaccessibility of aflatoxin B₁ (AFB₁) and M₁ (AFM₁) in artificially contaminated whole cow's milk. Six variables were evaluated: AFB₁ (3.25–6.0 μg L^?1) or AFM₁ (1.0–2.0 μg L^?1) concentration; incubation time (0–6 h); and inulin, oligofructose, β‐glucan, and polydextrose concentrations (each between 0.00 and 0.75%). All runs achieved reductions of AFB₁ (13.53–35.53%) and AFM₁ (17.65–71.52%). Comparing with the positive control, the AFB₁ bioaccessibility ranged from 23.68 to 72.67% and for AFM₁ was 0%. The probiotic, isolated or combined with prebiotics, was efficient in mycotoxin reduction, while the combination of the two reduced the mycotoxin bioaccessibility. The best experimental condition was the highest concentration of AFB₁ (6.5 μg L^?1) and AFM₁ (2.0 μg L^?1), incubation time of 0 h and the addition of probiotic and inulin (0.75%).     

Biotransformation of Aflatoxin

Food grade fungi were screened for their capacity to degrade aflatoxin B₁ (AFB₁) in order to develop a biological detoxification process for contaminated feeds. An agar technique based on defluorescence of AFB₁ was used for this purpose. Good correlations were observed between defluorescent capacity, AFB₁ elimination and reduction of mutagenicity. Although not identified in these food grade fungi as yet, enzymatic studies performed separately with Aspergillus flavus indicated the possible involvement of monooxygenase enzyme systems in AFB₁ degradation.     

Effects of Processing on Aflatoxin Levels and on Mutagenic Potential of Tortillas made from Naturally Contaminated Corn

Naturally contaminated corn containing 127 μ total aflatoxin per kg was divided into kg samples and treated with Ca(OH)2 for making tortillas. The treatments varied in % Ca(OH)2, boiling time, and holding time. Samples were taken after each processing step. Afla-toxin levels and mutagenic activity of acetone extractions of alka-line and reacidified products were measured. All treatments caused a decrease of aflatoxin (up to 46%); however, acidifying products prior to analysis caused reformation of much of the original aflatoxin. All treatments also effected a decrease in the mutagenic potential of the products, except for that of the acidified tortillas which was higher than that of the control corn. The tortilla manufacturing process may not be as effective in aflatoxin destruction as originally surmised.     

Regulation of Aflatoxin Biosynthesis: Induction of Aflatoxin Production by Various Carbohydrates

The ability of various compounds to induce aflatoxin biosynthesis by Aspergillus parasiticus was investigated by initially culturing the organism in a peptone basal medium that does not support aflatoxin production, and then transferring the organism to a replacement medium containing the test compound. Ribose, xylose, glucose, fructose, sorbose, mannose, galactose, maltose, sucrose, raffinose, and glycerol induced aflatoxin production. This induction of aflatoxin production was blocked when cycloheximide was incorporated into the replacement medium. Aflatoxin biosynthesis was not induced by lactose, lactic acid, sodium pyruvate, oleic acid, citric acid, sodium acetate, α-methyl-D-glucoside, 3-0-methyl-D-glucoside, cAMP, or cGMP. The results suggest that the synthesis of one or more of the enzymes responsible for aflatoxin formation is regulated by the availability of specific readily-metabolizable carbon sources.     

天然食材解体毒

俗话说：“药食同源”,说的是生活中很多随处可见的食材都可入药．并且有一定的防病治病效果。 人体中的毒质包括外来的和内生的,外来之毒如大气污染、农药化肥．食物添加剂等,内生之毒如正常新陈代谢废物、代谢紊乱中产生的废物毒等。根据病症寻找一味天然的解毒药,可以让你拥有一份简单又自然的健康。     

Fluorescence and Aflatoxin Content of Individual Almond Kernels Naturally Contaminated with Aflatoxin

An effort was made to relate the aflatoxin content of individual almond kernels to their fluorescent color. The fluorescence of individual blanched almonds and defective almonds, most of which lack an intact pellicle, was described by means of Methuen color charts before each kernel was analyzed for aflatoxin. Almonds that fluoresced violet-purple under long-wave UV light were found to contain high levels of aflatoxins B₁ and B₂ but, with perhaps one exception, no measurable amounts of aflatoxins G₁ and G₂. Some diced almonds with blue fluorescence had all four aflatoxins present but at much lower levels than in the violet-purple kernels. Aflatoxin ranged from 1.0 × 10⁵ to 2.5 × 10⁶ ppb in the violet-purple kernels. These values agree with previous estimates of aflatoxin concentration per contaminated nut. Almond kernels with violet-purple fluorescence should be culled.     

亚麻籽脱毒的研究进展

亚麻籽是世界十大油料作物之一,有较高的利用价值,但因生氰糖苷的存在和毒性,限制了亚麻籽的使用和用量。本文详细介绍了亚麻籽生氰糖苷的组成、含量、致毒机理和脱毒方法等方面的国内外研究进展。     

黄曲霉毒素与食品污染

食品污染包括很多,黄曲霉毒素的污染是其中比较突出的一种。就黄曲霉毒素在中国食品的污染和监测情况,及有关黄曲霉毒素预防控制措施进行简要评述。     

Chemical Detoxification of Aflatoxin-containing Copra

Aflatoxin-containing copra at moisture contents of 24% and 7% was effectively detoxified by ammonium hydroxide (> 97% and 89% reduction, respectively). Detoxification was accomplished in 5 days using 1.5% ammonium hydroxide (ammonia/copra); in 10 days using 1.0% and in 15 days using 0.5%. The initial aflatoxin B₁ concentration of 500 ppb (9% moisture) was reduced to ≤ 20 ppb. Detoxification trials using a screw expeller showed 67% reduction in aflatoxin content of the oil with 1.0% ammonia.     

黄曲霉毒素与食品安全

食品安全是人们都极其关注的，尤其是绿色食品和有机食品概念的提出更加增加人们时食品安全的关注。时食品安全的影响因素很多，主要是：生物性危害、化学性危害和物理性危害。而黄曲霉毒素的危害是其中比较突出的一个问题。