共查询到20条相似文献,搜索用时 62 毫秒
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本研究以红曲霉、米曲霉、黑曲霉为菌种,以米渣、麸皮为原料,进行混合制曲,通过对制曲过程中糖化酶和酸、中性蛋白酶活力的变化分析,确定了混合菌种发酵米渣的最佳菌种配比、接种量及制曲时间,得出:米渣接入红曲霉培养4d后,最佳接种量及菌种配比为5%米曲霉+5%黑曲霉混合菌种,制曲时间为2d。并通过四因素三水平正交设计方法确定了最佳pH、初始水分含量、原料配比、温度等制曲条件,其结果是:温度为31℃;米渣:麸皮=6:4;初始水分含量为35%及pH为5,在此条件下,糖化酶为4212U/g干曲,酸、中性蛋白酶活力分别为2130U/g干曲及2521U/g干曲。 相似文献
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该文考察了米曲霉和黑曲霉在单独制曲及混合制曲条件下,成曲的中性蛋白酶、酸性蛋白酶、糖化酶及孢子数,探讨了酱油多菌种制曲的可行性.实验以豆粕、麸皮为原料,以AS3.042米曲霉、AS3.350黑曲霉为菌种,探讨了2种制曲方式及不同配比制曲效果的影响.结果表明,米、黑曲霉分开制曲比混合接种制曲所得成曲效果好,米、黑曲霉分别以33℃制曲42h、48h得成品曲,再以2∶1混合所得成曲可获得较佳的酶活力,曲料总蛋白酶活力2748U/g与对照值相当,而酸性蛋白酶及糖化酶活力分别达712U/g、1090U/g,较对照分别提高55.8%、25.4%. 相似文献
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酱油多菌种制曲工艺条件研究 总被引:4,自引:1,他引:4
研究不同条件对黑曲霉制曲效果的影响,确定黑曲霉制曲的最适条件,以利于与米曲霉分别制曲后混合发酵,提高曲料蛋白酶活力。结果显示:黑曲霉制曲的最适原料配比为膨化大豆粉67%,小麦粉26%,麸皮7%,膨化大豆:水=1:1.3;采用固态培养法,接种黑曲霉量为0.3%,制曲温度控制在30℃~33℃,培养36h出曲。 相似文献
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《中国调味品》2017,(6)
以花生高温榨油产生的下脚料花生饼为原料,分别接种黑曲霉及米曲霉制备花生酱成曲。以成曲的糖化酶活力和氨基态氮含量为依据,考察了花生饼用量、制曲时间及孢子接种量对成曲制备效果的影响,并通过正交试验优化了两种霉菌制曲的最佳工艺条件。结果表明:米曲霉单独制曲的最佳条件为制曲时间44h、接种孢子数4.40×108个/g、花生饼用量比例为80%,此条件下得到的成曲糖化酶活力为905U/g,氨基态氮含量为0.434g/dL;黑曲霉单独制曲的最佳条件为制曲时间26h、接种孢子数8.03×109个/g、花生饼比例90%,此条件下得到的成曲糖化酶活力为926U/g,氨基态氮含量为0.450g/dL。研究结果为后续深入研究以高温花生饼制备花生酱奠定了基础。 相似文献
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Study of ochratoxin A-producing strains in coffee processing 总被引:1,自引:0,他引:1
Mirna Suárez-Quiroz Oscar González-Rios Michel Barel Bernard Guyot Sabine Schorr-Galindo & Joseph-Pierre Guiraud 《International Journal of Food Science & Technology》2004,39(5):501-507
Ochratoxin A (OTA) is the main mycotoxin that has been detected in coffee. The occurrence of OTA in coffee beans can be because of environmental conditions and/or processing conditions. Three coffee processes were evaluated (wet, mechanical and dry processes), at different stages from harvesting to storage, and fungi producing OTA were enumerated and identified. The frequency of potential OTA‐producing fungi and their ability to produce OTA was also studied. By direct plating, the levels of contamination found in the coffee processes were 80, 72 and 92%, respectively, for parchment and dry cherry coffee and 20, 34 and 15% for green coffee. Aspergillus ochraceus isolated from the three processes accounted for 6.6, 8.3 and 3.3%, and Aspergillus niger for 15, 13 and 25% of the strains isolated, respectively. The toxigenic potential of five A. ochraceus and two A. niger strains was tested in FDA medium and coffee medium using the HPLC technique. There was no difference between the processes studied in terms of isolation and occurrence of ochratoxigenic fungi. 相似文献
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选择产生淀粉糖化酶较多的3种黑曲霉菌株H303-4-3、AS.3324和CICC2137,对3株菌株产酶条件进行优化使菌株的产糖化酶能力得到提高,经优化后H303-4-3菌株的糖化酶活力最高.在麸皮与豆粕的比例为4:1,麸皮与水分的比例为15:10,pH值5,装瓶量为15g的条件下,接种培养4d的菌株,30℃培养4d,H303-4-3的糖化酶活力达2783.63U/g. 相似文献
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本研究从发霉粮食中分离出数株黄曲霉菌菌株,并进行了形态学和分子生物学鉴定。为了探究分离菌株与黄曲霉标准菌株之间产毒能力的差异,通过对分离菌株和黄曲霉标准菌株进行发酵培养和HPLC测定,分析确定产毒能力。结果表明黄曲霉菌株之间产毒能力差异巨大:黄曲霉菌株3.4408产毒量很高,黄曲霉菌株HDWH产毒量很低,黄曲霉菌株3.2572甚至不产生黄曲霉毒素;产生黄曲霉毒素菌株中部分黄曲霉菌株产生四种黄曲霉毒素AFB1、AFB2、AFG1、AFG2,黄曲霉菌株HDWS只产生黄曲霉毒素AFB1、AFB2。 相似文献
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酒曲源曲霉的分离及其产蛋白酶条件优化 总被引:1,自引:0,他引:1
利用稀释平板法从曲样中分离获得4株曲霉1#、2#、3#和4#,将各菌株分别制米曲后测定酶活力,并通过正交实验及单因素实验确定蛋白酶发酵的培养基和最佳工艺条件。在优化的发酵培养基和发酵条件下(温度、培养时间、培养基起始pH、接种量),产蛋白酶活力分别达到:1#菌11545.7U/g,2#菌8240.4U/g,3#菌9146.0U/g,4#菌4527.7U/g。最后,将活力比较高的三株菌进行Biolog微生物系统鉴定,分别为栖土曲霉(Aspergillus terricola Marchal),寄生曲霉(Aspergillus parasiticus Speare)和杂色曲霉(Aspergillus versicolor)。 相似文献
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研究对比了两株米曲霉的形态特征以及成曲的蛋白酶酶学性质。结果显示,两株米曲霉的形态差异明显:米曲霉1号菌落较大、发芽和产孢子较快,种曲及成曲颜色偏黄,菌丝较短,孢子较多;而米曲霉2号菌落较小,孢子发芽时间及产孢子时间比1号晚,成曲孢子较1号少,但菌丝长且粗壮,种曲颜色偏绿,成曲颜色偏白,米曲霉2号的产酶能力强。蛋白酶性质的研究结果显示,两株米曲霉成曲的蛋白酶性质有差异,1号和2号的最适反应温度分别为45℃和50℃,最适反应pH分别为6.0和9.0。此外,两株米曲霉的成曲蛋白酶的耐盐性相当,随着盐浓度的增大,酶活力均逐渐降低,在20%氯化钠条件下,酶活力均降至无盐条件下的20%~30%。 相似文献
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《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(11):1709-1721
ABSTRACTFood decay by spoilage fungi leads to significant economic losses and hazards to consumers’ health due to the potential of mycotoxin occurrence. Ochratoxin A (OTA) is a mycotoxin known as nephrotoxic and carcinogenic to humans. Natural capsaicin was evaluated for its effectiveness against the growth of five Aspergillus section Nigri strains and accumulation of OTA in inoculated black grapes. Results showed that capsaicin was effective in inhibiting fungal growth and OTA production by new four Aspergillus section Nigri strains (ATHUM 6997, 6998, 6999, 7000) and by Aspergillus carbonarius as well. Moreover, capsaicin addition exhibited maximum inhibition of OTA produced by ATHUM 6997, 6998, 6999, and 7000 in black grapes at 28.9%, 8.6%, 68.4%, and 78.1%, respectively. Inhibition percentage of OTA production by A. carbonarius in grapes treated with capsaicin was estimated at 61.5%. These results suggest that capsaicin influences the OTA biosynthesis pathway of all Aspergillus section Nigri strains and therefore could be used as an effective natural preservative against OTA contamination of vineyards. Risk assessment revealed that when grapes are treated with capsaicin, consumers are less exposed to OTA. 相似文献