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1.
丁琦  孙汉巨  赵红  朱兆娜  陈哲  石娟 《食品科学》2011,32(23):197-200
将鸭蛋蛋液用动物蛋白水解酶酶解后,添加黄豆、面粉制作鸭蛋酱,并通过正交试验对鸭蛋酱制曲的条件进行优化。采用米曲霉与黑曲霉混合菌种制曲,并通过对制曲过程中蛋白酶活力变化的分析,确定混合菌种发酵鸭蛋酱的最佳制曲温度、制曲时间、鸭蛋添加量及米曲霉与黑曲霉的配比。结果表明:最佳制曲条件是制曲温度30℃,鸭蛋添加量30%,米曲霉与黑曲霉的质量比为3:1,制曲时间48h,在此条件下,蛋白酶的活力最高,达到1465.81U/g。  相似文献   

2.
通过对米曲霉和黑曲霉在不同作用条件下混合制曲的曲料蛋白酶活力和曲酶孢子数的变化分析,探讨了制曲温度、制曲时间和曲霉的不同配比对米、黑曲霉混合制曲效果的影响。结果表明,制曲温度为30℃、制曲时间为35h、米曲霉和黑曲霉配比为3∶1时作用效果最佳,此时,曲料的曲酶孢子数为8.66×109cfu/g,蛋白酶活力可达2588U/g。  相似文献   

3.
以黄豆和面粉为主要原料,采用混合菌种制曲,以蛋白酶、淀粉酶的活性为评价指标,利用Box-Behnken响应面试验考察不同工艺条件对豆酱曲酶活的影响。试验结果表明,采用添加熟面粉的方式,湿豆与面粉质量比10∶4、接种量0.07%、制曲时间48 h,在此最佳制曲工艺条件下,蛋白酶酶活为1 049.83 U/g,淀粉酶酶活为781.29 U/g。  相似文献   

4.
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   

5.
以南瓜籽粕为氮源,麸皮为碳源,用6种米曲霉进行单菌和混菌制曲,以成曲的中性蛋白酶、酸性蛋白酶、糖化酶活力、氨基态氮的含量和发酵液的感观评定为指标,筛选出制曲所用的菌种.结果表明,当以沪酿As3.042、宇佐美曲霉为菌种、比例为3:1混菌制曲时,成曲的中性蛋白酶活力为5859.78U/g(干基),酸性蛋白酶活力为481.5U/g(干基),糖化酶活力为496U/g,氨基酸态氮的含量为0.685g/100g,且发酵液的风味最佳.  相似文献   

6.
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   

7.
以花生粕、小麦麸皮为原料制备花生酱油成曲,研究花生粕与小麦麸皮质量比、米曲霉(Aspergillus oryzae)As3.042接种量、制曲温度和制曲时间4个因素对花生粕酱油成曲中性蛋白酶酶活的影响,并通过单因素试验和响应面试验优化制曲工艺。结果表明,对中性蛋白酶活影响程度从大到小依次为制曲温度>接种量>原料质量比>制曲时间。花生酱油成曲的最佳制曲工艺条件为:花生粕与小麦麸皮质量比8∶2,米曲霉接种量0.65%,制曲温度32 ℃、制曲时间24 h。在此优化条件下,成曲中性蛋白酶活为(2 493.67±7.70) U/g,酸性蛋白酶活为(596.84±23.12) U/g、糖化酶活为(29.91±2.63) U/g、淀粉酶活为(882.85±32.63) U/g、纤维素酶活为(11.72±3.69) U/g。  相似文献   

8.
文章以鱿鱼内脏为原料,添加麸皮和面粉,接种米曲霉制曲酿造鱿酱油.以成曲蛋白酶活力为评价指标,研究了蒸料时间、制曲温度、面粉添加量、原料配比、接种量、制曲时间等因素对制曲效果的影响,并在此基础上进行正交试验,结果表明,最佳制曲工艺条件为:鱿鱼内脏与麸皮的质量比为1:2,面粉添加量2%,接种量1.5%,制曲时间120 h.优化后制得的成曲的蛋白酶活力为308.59 U/g.  相似文献   

9.
研究以豆粕和面粉的挤出物为原料,以中性蛋白酶活力、碱性蛋白酶活力为考察指标,以制曲温度、麸皮比例、润水量和制曲时间为制曲参数,采用四个因素进行五水平二次旋转正交实验,使用SAS 9.1软件进行试验数据处理,得出最佳制曲工艺参数:制曲温度30℃,麸皮比例30%,润水量100%,制曲时间60h。在此条件下豆粕和面粉挤压膨化物种曲的中性蛋白酶活力1920U/g,碱性蛋白酶活力786U/g。  相似文献   

10.
以豆酱制曲工艺和成品宝泉豆酱为研究对象,采用对比试验方法,分别对工厂化制曲阶段酱曲中性蛋白酶的活性、温度以及成品豆酱的食盐、水分、氨基酸态氮和总酸含量等指标进行品质分析,以期调控企业生产效率和提高产品质量。结果表明,在随机选择的3号和4号制曲池中,3号曲池酱曲蛋白酶活性最高值为1 876.9 U/g,4号制曲池酱曲蛋白酶活性最高值为1 763.2 U/g,4号曲池制曲温度总体低于企业制定的生产标准(Q/BJY 001);测定4个月的成品豆酱各指标显示,其食盐、水分、氨基酸态氮和总酸等含量的平均值分别为10.59%,59.58%,0.75%和1.65%,均符合企业生产标准。因此,在现行的宝泉豆酱生产过程中,适当地提高制曲温度适于增加豆酱曲中的蛋白酶活性,而豆酱的各项指标则符合质量要求。  相似文献   

11.
Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.  相似文献   

12.
An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.  相似文献   

13.
The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.  相似文献   

14.
The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.  相似文献   

15.
BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H2O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.  相似文献   

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17.
A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.  相似文献   

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This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.  相似文献   

20.
<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the  相似文献   

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