响应面优化复配型面包改良剂工艺研究

以面包的比容、硬度和弹性为指标,以面包专用粉为原料,分别采用正交设计试验和响应面设计试验优化复配型面包改良剂的配方.实验结果表明复配型面包改良剂的最适配比:复配胶添加量0.28 g/100 g面粉,复配酶添加量41.33 mg/kg面粉,抗坏血酸添加量42.96 mg/kg面粉,预测的面包比容达到7.23.面包中复配型改良剂的最适添加量为0.21 g/100 g面粉,添加复配型改良剂面包的老化速率明显下降,且抗老化的效果好于市售改良剂.     

面包复合改良剂的研究

在面包的生产加工过程中,改良剂的使用是最有效的提升面团加工特性的方法之一。该文以开发一种适用于改良面包品质的复合改良剂为目标,分别对卵磷脂、阿拉伯胶及α-淀粉酶进行单因素试验,并利用响应面法研究由以上3种添加剂复合形成的改良剂对面包品质的影响。单因素试验表明:卵磷脂、阿拉伯胶、α-淀粉酶的最适添加量分别为0.45%、1%、8 mg/kg;响应面优化试验表明:最适复合改良剂的配方为阿拉伯胶添加量1.01%,卵磷脂添加量0.44%,α-淀粉酶添加量7.96 mg/kg。最适改良剂的应用使面团的产气量从对照的603 m L/100 g增加至1 641 mL/100 g,面包的比容由2.64 mL/g增加至3.70 mL/g,面包的感官品质评分由72分提高至88分。     

响应曲面法优化面包预混粉配方研究

该文以面包比容为指标,利用响应面法对面包预混粉配方进行优化,将此面包预混粉(BPF)与市售面包粉(CBF)、添加市售改良剂面包基础粉(FCIA)流变学特性及面包加工品质进行对比,并对面包预混粉进行不同温度条件下的储藏试验。结果表明,BPF的最佳配方:木聚糖酶添加量5.34 mg/kg、谷朊粉添加量10.26%、淀粉酶添加量56.14 mg/kg,根据该配方制得面包比容为6.05 cm3/g,与CBF、FCIA相比,BPF面团弹性最好、筋力中等,BPF制作面包品质最好,BPF最佳储藏温度为4℃。     

天然复配改良剂对绿茶吐司品质的影响

目的 探讨天然复配改良剂对绿茶吐司品质的影响。 方法 以绿茶吐司为研究对象,采用单因素试验分别分析α-淀粉酶、海藻酸钠、大豆卵磷脂这3种天然改良剂对绿茶吐司品质的影响。再通过响应面试验,选择对感官评分影响最大的质构指标——硬度为响应值,确定3种复配改良剂的最优组合,最后进行验证试验。 结果 复配改良剂的最优组合为：α-淀粉酶添加量0.069 g/kg,海藻酸钠添加量1.925 g/kg,大豆卵磷脂添加量1.426 g/kg。按此组合制作的绿茶吐司,与不加改良剂的吐司相比,在感官评分、硬度、弹性、胶着性、咀嚼性和抗老化指标上具有明显的优势,产品的理化指标符合GB/T 20981-2021,微生物指标均符合GB 7099-2015 。结论 天然复配改良剂能显著改善绿茶吐司的品质,这为复配改良剂在绿茶吐司中的应用提供参考。     

复合品质改良剂对冷冻面团面包品质影响的研究

为了明确不同的品质改良剂对冷冻面团面包品质的影响,在实验前期研究结果的基础上,选择了包括卵磷脂、硬脂酰乳酸钠(SSL)、阿拉伯胶、酪蛋白酸钠、木聚糖酶和脂肪酶等品质改良剂采用正交实验设计进行复配,考察复合添加剂对面包体积、质构及感官品质的影响。结果显示:卵磷脂、阿拉伯胶和脂肪酶对冷冻面团面包品质的改善效果,分别优于同种类另一品种。同时,阿拉伯胶几乎对冻藏0天的样品没有影响。当添加了0.45%卵磷脂、1%阿拉伯胶和25 mg/kg脂肪酶时,冷冻面团面包具有最大的比容、最低的硬度和胶黏性以及最优的感官品质。     

杂粮面包预拌粉的烘焙品质改良

目的:改良杂粮面包预拌粉的烘焙品质。方法:在前期研究以燕麦粉、鹰嘴豆粉和小麦粉为主要原料制备的低血糖指数杂粮面包预拌粉的基础上,通过单因素和响应面法优化杂粮面包预拌粉的配方。结果:黄原胶添加量0.78 g/100 g、谷朊粉添加量3.42 g/100 g、麦芽糖淀粉酶添加量200.00 mg/kg,抗坏血酸添加量171.70 mg/kg时,所制得的面包比容为(2.26±0.16) mL/g,面包的实际硬度为(15.97±0.69) N,与纯小麦粉面包接近;感官评定结果显示,杂粮预拌粉面包的气味、内部结构、口感和整体接受度均优于纯小麦粉面包。结论:研究优化的杂粮面包预拌粉的改良剂配方可用于实际操作中。     

复配型面包品质改良剂在板栗面包中的应用

首次利用面包品质改良剂对板栗面包的焙烤品质及延缓老化的作用效果进行了研究。依据各种改良剂对面包防老化效果的不同,确定出试验用改良剂为黄原胶、α-淀粉酶、单甘酯。分别以三种面包品质改良剂做单因素实验,实验结果表明:当黄原胶以板栗粉与面包粉总重量的0.5%、1%、1.5%、2%的比例添加到板栗面包中时,对板栗面包的感官品质及老化指标均产生了显著影响,当添加量为1%时,不但板栗面包具有良好的焙烤品质而且延缓了面包的老化;当α-淀粉酶按不同的比例添加时,在添加量为0.01%或0.005%时,板栗面包的抗老化效果及焙烤性能均较对照组好,但当添加量为0.03%、0.06%时,致使板栗面包芯发粘,面包醒发性能受阻;在单甘酯的单因素实验中,不同添加量的单甘酯对板栗面包的老化均有延缓作用,但对面包的焙烤品质均产生负面影响。选择几种改良剂的较优添加量做正交实验,实验结果表明:在板栗面包制作过程中按板栗粉及面包粉总重用量添加1.5%黄原胶、0%α-淀粉酶、0.3%单甘酯时,板栗面包具有良好的焙烤品质,且在贮存7d后,面包芯硬度比对照组下降44%,延缓了面包老化,延长了其货架期。     

酶制剂对面团流变学特性和面包品质的影响

探讨不同添加量的酶制剂对面团流变学特性和面包品质的影响。结果表明:真菌淀粉酶和木聚糖酶可弱化面团的流变学特性,葡萄糖氧化酶、谷氨酰胺转氨酶和脂肪酶可不同程度地改善面团的流变学特性;真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶能有效改善面包焙烤品质,增大面包的比容,改善面包的硬度和弹性,而谷氨酰胺转氨酶对面包品质的影响不明显。真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶的最适添加量分别是5μL/kg、20mg/kg、30μL/kg、50mg/kg。     

响应面法优化青麦仁冷冻面团面包复配改良剂的研究

为改善青麦仁冷冻面团面包品质,在单因素试验基础上,以面包的比容、质构、感官评分为考察指标,并应用响应面分析法对复配改良剂配方进行优化,得到复配改良剂的最佳配方为:硬脂酰乳酸钠添加量0.3%、海藻糖添加量4.14%、抗坏血酸添加量0.005%、葡萄糖氧化酶添加量0.003%,此条件下制作的面包,实测比容为4.2 mL/g、硬度为14.5 N、弹性为4.35 mm,感官评分为94分,与预测值(94.6分)基本一致。     

复合添加剂对面包烘焙品质的影响

以面包粉为主要原料,添加不同比例的葡萄糖氧化酶、真菌α－淀粉酶、脂肪酶、单硬脂酸甘油酯4种添加剂于面包配方中,用直接发酵法制作面包,研究不同的添加剂配比及含量对面包品质的影响．通过感官评价,同时利用质构仪对面包芯硬度进行测定,结果表明,1 kg面包粉中添加葡萄糖氧化酶30 mg,真菌α－淀粉酶2 mg,脂肪酶40 mg,单硬脂酸甘油酯1．5 g时,面包的烘焙品质得分最高,口感最好．     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

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.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

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.     

European priorities for research to support legislation in the area of food contact materials and articles

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.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.