柑橘酒的发酵工艺优化研究

以柑橘为原料,筛选出适合柑橘酒发酵的前处理方式及发酵菌种,采用单因素试验和正交试验研究初始糖度、酵母接种量、发酵温度以及主发酵时间对柑橘酒发酵的影响,并对发酵工艺条件进行优化。结果表明,柑橘酒的最佳发酵条件为：采用柑橘浊汁,接种SC果酒酵母,初始糖度24%,酵母接种量0.04%,发酵温度26 ℃,主发酵6 d,在此条件下,所得柑橘酒的酒精度12.4%vol,感官得分为83分,可为柑橘酒工业生产提供参考。 关键词：中图分类号：TS262.7 文章编号：0254-5071（20１6）10-0179-05 doi：     

柑橘红茶菌饮料发酵工艺的优化

为了确定柑橘红茶菌饮料的最佳发酵工艺参数。该研究以新会柑橘、英德红茶为主要原料,通过接种红茶菌发酵生产柑橘红茶菌饮料,在单因素实验的基础上,采用Box-Behnken响应面法设计试验,运用4因素3水平,以pH值为响应指标,探究乳酸菌粉添加量、蔗糖添加量、发酵时间和发酵温度四种因素对柑橘红茶饮料品质的影响,并确定柑橘红茶菌饮料发酵的最佳工艺条件参数。结果表明,柑橘红茶菌饮料发酵的最佳工艺条件参数为：乳酸菌添加量0.40%、蔗糖添加量15%、发酵温度32 ℃、发酵时间为4 d。在此条件下,此时pH值为3.14,感官评价分值为93.1分,可溶性固形物消耗量为12.30%,与3次验证试验的结果接近,说明回归模型拟合程度高,因此响应面法优化柑橘红茶菌饮料的发酵工艺具有可靠性,可为柑橘红茶菌饮料研发提供一定的科学依据。     

四种不同发酵基质柑橘果醋挥发性成分分析

为了研究四种不同发酵基质柑橘果醋挥发性成分的差异,分别以食用酒精发酵柑橘果醋（EACV）、酒醋连续发酵柑橘果醋（WVCV）、酒汁混合发酵柑橘果醋（WJCV）和酒水混合发酵柑橘果醋（WWCV）四种不同发酵基质的柑橘果醋为研究对象,利用电子鼻和顶空-固相微萃取气质联用技术（HS-SPME-GC-MS）,分析不同发酵基质的柑橘果醋挥发性成分的种类和含量。结果表明,四种柑橘果醋中共检测出138种挥发性成分,包括酯类物质34种、醇类物质37种、酸类物质20种、醛类物质8种、酚酮类物质13种、烃类物质10种和其他类物质16种。挥发性成分总含量高低依次为：WVCV＞WWCV＞WJCV＞EACV,其中EACV保留了更多柑橘果汁的气味,其他三种果醋风味更加浓郁。     

浓香型白酒窖泥中乳酸菌的分离鉴定及其在柑橘酒中的应用

在对浓香型白酒窖泥中乳酸菌进行分离鉴定的基础上,分别将其与酿酒酵母联合发酵进行柑橘酒制备,同时采用电子舌对 柑橘酒滋味品质进行了评价,探讨了乳酸菌在柑橘酒中应用的可行性。 结果表明,从窖泥中分离的15株菌均被鉴定为副干酪乳杆菌（Lactobacillus paracasei）,柑橘酒中的有机酸主要为乳酸、柠檬酸和琥珀酸,酸味是15株乳酸菌发酵而成的柑橘酒样品间差异最大的 滋味指标。 L. paracasei JNB1-3可明显降低柑橘酒的酸味和苦味强度,在后续柑橘酒发酵中可能具有一定的应用潜力。     

两种发酵方式柑橘果醋品质特性的比较

以柑橘为原料,在单因素试验的基础上通过正交试验对柑橘果醋一次发酵法发酵条件进行优化,并对一次发酵法与二次发酵法制备的柑橘果醋的品质特性进行比较。结果表明,柑橘果醋一次发酵法最优发酵条件为酒精度6.0%vol、柑橘果汁含量为50%、发酵温度34 ℃,在此优化条件下,柑橘果醋中总酸含量为6.0%,酒精转化率为96.31%,分别比优化前提高了0.27%、5.24%。一次发酵法和二次发酵法制备的柑橘果醋中最高总酸含量无显著差异（P＞0.05）,但一次发酵法的启动时间比二次发酵法延迟48 h,整个发酵时间延迟了24 h。以柑橘果汁为参比,一次发酵法与二次发酵法制备的柑橘果醋相比,黄色度（b*值）、透光率、嗅觉成分、味觉中的鲜味和丰富度更相近于柑橘果汁。     

柑橘精油风味发酵乳的开发与评价

为开发一种新型果味发酵乳,将柑橘精油作为天然香味剂应用于发酵乳,并力求降低柑橘精油的抑菌作用。首先通过抑菌实验寻找适宜的柑橘精油添加浓度,保加利亚乳杆菌和嗜热链球菌生长的适宜精油稀释浓度为10-3;进而在发酵乳的发酵液中添加0、450、700、950、1 200μL/L柑橘精油,发现精油对发酵乳的发酵时间、p H值、酸度、乳杆菌和嗜热链球菌的数量没有明显影响,而感官评分显示,精油添加量为450~950μL/L时,发酵乳的气味和口感得到显著提升,其中700μL/L的效果最好。结果表明,发酵液中添加450~950μL/L的柑橘精油可改善发酵乳气味和口感,提升发酵乳的感官品质,并扩大柑橘精油的用途。     

柑橘酒发酵条件研究

四川是柑橘大省,有着丰富的柑橘资源,本试验对柑橘酒发酵条件进行了研究。采用单因素试验找出发酵pH、接种量和温度的最佳条件,再用正交试验进行进一步的优化。结果表明:在pH 3.8,接种量12%,温度25℃的条件下发酵5d,酒精度达到11.24%。     

柑橘酒发酵过程中总黄酮、柠檬苦素和诺米林含量变化

以实验室酿制的柑橘酒为试验材料,采用分光光度法对柑橘酒发酵过程中的总黄酮含量进行检测;利用高效液相色谱(HPLC)法对柑橘酒发酵过程中苦味物质(柠檬苦素和诺米林)的含量进行检测。结果表明,柑橘酒在酿造过程中,柑橘原汁中总黄酮含量为1 747 mg/kg,主发酵结束后下降到566.3 mg/kg,之后变化趋于稳定。柑橘原汁中柠檬苦素含量为2.21 mg/L,诺米林未检出;在起酵时期,柠檬苦素和诺米林含量分别上升为15.65 mg/L和3.37 mg/L,主发酵结束后分别降至10.87 mg/L和2.20 mg/L,之后变化趋于稳定。     

柑橘皮发酵汁抗氧化活性和挥发性风味物质分析

以新鲜柑橘皮为原料并辅以面粉,分别采用米曲霉和黑曲霉两种曲霉制曲后用盐水发酵制备出柑橘发酵汁。分析了柑橘皮发酵汁的总黄酮含量、总多酚含量、DPPH·清除能力、FRAP活性和挥发性风味物质。研究发现,接种黑曲霉的柑橘发酵汁总黄酮含量最高,达74.43μgRE/mL,总多酚含量为2.80mgGAE/mL,且比柑橘皮增加了20种挥发性风味物质。接种米曲霉的柑橘皮发酵汁中总黄酮含量为62.83μgRE/mL,总多酚含量为5.94mgGAE/mL,增加了15种挥发性风味物质。接种米曲霉的发酵汁DPPH·清除能力、FRAP活性高于黑曲霉发酵,分别为6.26μmolTE/mL、12.02μmolFE/mL。橘皮中特征性风味物质在柑橘皮发酵汁中D-柠檬烯得到很好保留,相对含量达60%以上。     

柑橘皮渣发酵饲料研究

柑橘皮渣是柑橘加工业的主要副产物,约占鲜重的45%～60%,通过发酵处理可以成为优良的动物饲料,本文主要研究了柑橘皮渣发酵的最佳条件.     

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.     

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.     

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.     

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.