胡萝卜汁中白色沉淀主要成分的分析和鉴定

胡萝卜汁在贮藏过程中,瓶底会出现白色沉淀,本文对其主要成分进行了分析和鉴定。首先通过离子色谱法（IC）测定得到白色沉淀中含有少量无机阴离子,再通过高效液相色谱法（HPLC）对白色沉淀中的草酸根（C2O24-）、苹果酸根（C4H4O25-）和柠檬酸根（C6H5O37-）进行测定,得到其含量分别为59.67%、9.83%和4.53%;用电感耦合等离子体-原子发射光谱法（ICP-AES）测定得到Ca2+、Mg2+、Ba2+和Fe2+的含量分别为26.56%、0.017%、0.015%和0.0059%,这些数据表明,白色沉淀的主要成分为草酸钙。      

白酒中白色沉淀的成分分析研究

近年来白酒出现白色沉淀的现象呈上升趋势,在实际生产过程中人为的因素或者非人为因素都会给白酒质量带来一定影响。文中对出现问题的酒样和模拟液进行低温处理,使用气相色谱仪、离子色谱仪和红外色谱仪进行相应分析,找出了沉淀产生的原因,并确定了白色沉淀的主要成分为油酸酰胺,是瓶盖内塞生产工艺中添加的一种爽滑剂。     

瓶装矿泉水棕色沉淀及白色絮状物成因分析

对瓶装矿泉水常见的两类感官质量问题进行分析,提出了预防措施.     

黄酒中的另一种沉淀——草酸钙沉淀

以往的研究认为黄酒沉淀主要由蛋白质、多酚、糖类、铁、焦糖色等引起,通过研究发现黄酒中的另一种沉淀———草酸钙沉淀,并对草酸钙沉淀的形成与防止措施进行了探讨。     

白酒中白色絮状悬浮沉淀产生原因及处理方法

白酒在货架期产生的白色沉淀主要是无机沉淀和有机沉淀。以产生白色沉淀的贵州珍酒酒样为研究对象,对其产生沉淀的原因进行分析,并提出了解决措施。     

啤酒中的草酸及草酸钙沉淀

本文主要介绍了啤酒中草酸的来源，啤酒中草酸钙沉淀的分析方法，抗氧化剂异抗坏血酸钠的使用对啤酒中草酸含量的影响，以及生产过程中如何防止啤酒发生草酸钙沉淀。     

草酸钙沉淀的试验分析

啤酒中草酸钙沉淀现象主要表现为：成品酒在保存1～2个月后．在瓶底出现白色的沉淀，将瓶倒置后，沉淀象烟一样分散到酒体中，静置后又重新形成。此沉淀在低温下易形成，经膜过滤镜检视野内为方形或棱形晶体。     

浅析白酒在贮存中发生混浊、沉淀现象的成因及防治

白酒的色泽应为无色透明，但在生产、加浆、贮存过程中，有时会出现混浊沉淀现象，形成感官质量事故，从而影响到企业的质量信誉和经济效益。常见的有以下几种情况。     

46度优质酒出现发黄和白色晶状沉淀物的原因探析

４６度优质酒出现发黄和白色晶状沉淀物的原因探析曹建伟，王传荣，沈洪涛江苏淮阴酒厂（２２３３００）关键词蒸馏酒，白酒，成品，黄色，白色晶状沉淀物１９９５年６月２２日，我厂灌装一批４６度成品优酒，经检测，品尝合格入库后，却于１９９５年８月２３日发现这批优...     

Effect of hydrocolloids on pulp sediment, white sediment, turbidity and viscosity of reconstituted carrot juice

The effect of hydrocolloids such as guar (GU), xanthan (XA), sodium carboxymethylcellulose (CMC), gellan (GE) and a mixture of GE and XA (GX) on pulp sediment (PS), white sediment (WS), turbidity and viscosity of reconstituted carrot juice (RCJ) is investigated in this paper. The respective addition of 0.200 g/100 ml GU, 0.200 g/100 ml XA, 0.300 g/100 ml CMC and a mixture of 0.015 g GE + 0.100 g XA/100 ml into RCJ could decrease the amount of PS and WS, but could not prevent the occurrence of PS and WS after 60 d storage. However, PS and WS were not observed due to a smaller quantity in GE (0.020) sample, indicating that 0.020 g/100 ml GE could prevent the occurrence of PS and WS effectively. The prevention of PS and WS in GE (0.020) sample may be caused by a combined effect of the electrostatic repulsion between the GE molecules, viscosity and networks of GE. GE with a concentration of 0.020 g/100 ml had a least effect on the turbidity and viscosity of RCJ as compared to other hydrocolloids. Thus, GE was more suitable as a stabilizer in the application of RCJ.     

胡萝卜汁中胡萝卜素的快速测定

胡萝卜汁中由于含有较多的果胶，在进行胡萝卜素测定时，很难将胡萝卜素提取完全，造成较大的测定误差。本法采用了提取胡萝卜素时先加入无水Ｎａ２ＳＯ４洗涤净化，然后直接比色测定胡萝卜汁中的胡萝卜素，并进行了精密度、回收率试验，同时用ＧＢ１２３８９—９０纸层析法进行了显著性差异检验，得到了较满意结果。此方法可专用于胡萝卜汁中的胡萝卜素含量的快速测定。     

胡萝卜汁中胡萝卜素的快速测定

胡萝卜汁中由于含有较多的果胶，在测定胡萝卜素时，很难将胡萝卜素提取完全，本法采用了提取胡萝卜素对先加入无水Ｎａ２ＳＯ４洗涤净化，然后直接比色测定汁中的胡萝卜素，并进行了糖密度、回收率试验和ＧＢ１２３８９－９０纸层析法进行了显著性差异检验，结果满意，此方法可专用于胡萝卜汁中的胡萝卜素含量的快速测定。     

Antimicrobial properties of pepsin-digested lactoferrin added to carrot juice and filtrates of carrot juice

The objective of this study was to determine the antimicrobial activity of pepsin-digested lactoferrin added to carrot juice and filtrates prepared from carrot juice. Lactoferrin isolated from raw skim milk was digested by pepsin for 4 h at pH 3. The digest of lactoferrin was lyophilized, and the antimicrobial activity of the digests was determined in peptone-yeast-glucose broth, carrot juice, permeate from carrot juice, and the dialysate of carrot juice permeate using Escherichia coli (American Type Culture Collection strain 35343) as the test organism. Growth of E. coli and the inhibitory effect of the peptide were greater in peptone-yeast-glucose broth at pH 7 than at pH 4. The peptic digest of lactoferrin did not have antimicrobial properties in carrot juice at concentrations of less than 10 mg/ml of juice. Carrot juice was filtered through a membrane with a molecular weight rejection of 10,000 or 500 Da, and the permeate was dialyzed against distilled water. Growth of E. coli was delayed in the filtrate by 5 mg but not by 1 mg of the peptic digest of lactoferrin per ml of filtrate. Bacterial counts of the control and experimental samples were not significantly different after 24 h of incubation. The peptic digest of lactoferrin at a concentration of 5 mg of digest per ml of dialysate was bacteriostatic toward E. coli after 24 h of incubation at 23 degrees C. Dialysis of permeate caused a percentage reduction in cation concentration in the permeate ranging from 69.23% (Co) to 99.32% (Na). The antimicrobial activity of lactoferrin added to carrot juice was probably inhibited by cations.     

胡萝卜浓缩汁中耐热菌的分离及特性研究

对胀袋胡萝卜浓缩汁中的耐热菌进行了分离,通过形态观察和ITS rDNA基因序列分析方法鉴定耐热菌,通过碳源利用试验考查菌株的部分生理生化特性,通过热和酸碱处理考察菌株的热稳定性和酸碱稳定性,利用超声波破壁技术考察细胞中多糖、还原糖和色素情况。结果表明:胀袋胡萝卜浓缩汁中分离得到一株耐热菌SR-1,经形态学和分子生物学技术鉴定为肉色掷孢酵母,该菌经80℃热处理5~30min,生长良好;经90℃热处理15 min仍能生长,处理20 min后不能生长;在pH 6.0~8.0环境中生长良好,pH 3.0以下不能生长。超声波破壁后上清液还原糖含量为6.02~7.86mg/mL,多糖含量为32.93~41.78 mg/mL,菌体色素在414,539,634nm处有吸收峰。     

山楂胡萝卜汁饮料的研制

主要叙述了山楂胡萝卜汁生产工艺，确定了山楂胡萝卜汁最佳配比、澄清剂的最佳运用条件及最佳杀菌条件等。     

苹果浓缩汁加工中香气回收成分分析

以同一苹果浓缩汁生产线上收集的300倍回收香精、预浓缩回收液水和浓缩回收液水为实验材料,分析了三个样品中香气物质成分,旨在确定苹果浓缩汁加工过程中香气物质的变化特性和浓缩回收冷凝水中香气物质的主要成分。顶空固相微萃取结合气质联用测定各样品香气成分的差异,共检测出47种香气成分。结果表明:a.300倍回收香精中富含酯类、醛类、醇类香气物质,苹果浓缩汁预浓缩过程中,香精回收工艺收集了主要的芳香酯类(乙酸-2-甲基-1-丁酯、乙酸-2-苯基乙酯、乙酸乙酯等)和醛类[(E)-2-己烯醛、苯甲醛等]香气物质,芳香醇类香气物质相对较少。b.苹果汁预浓缩回收液水中苹果的典型醇类(1-己醇41.70%)香气物质含量高且丰富,同时预浓缩回收液水含有较高相对含量枯焦气息的苯酚类化合物(2,5-二叔丁基-对甲基苯酚13.26%、2,4-二叔丁基苯酚11.16%)。c.苹果汁浓缩回收液水富含苹果典型酯类香气物质(乙酸-2-甲基-1-丁酯、乙酸丁酯、乙酸甲酯等)和醇类香气物质(2-甲基-1-丁醇等),由加工过程中苹果汁中香气物质进一步逸散产生。     

Optimisation of electroplasmolysis application for increased juice yield in carrot juice production

Electroplasmolysis (EP) which is among electrical methods and helps to increase cell permeability was used in this study as a pretreatment on carrot juice production for improving yield. A voltage range of 20–60 V and an application time of 30–90 s were studied using the electroplasmolyzator. Response surface methodology (RSM) was used for determining the appropriate voltage gradient and time that are effective on breakage of vegetable tissues. After the conditions were optimised, carrot juice was produced and compared with untreated control juices on the aspect of yield and some quality characteristics. As a result, yield was increased 10.49% by EP application. Relative to control samples total pectin (14.78%) and total phenolic content (4.73%) have significant increase. In addition by the effect of electrical pretreatment there was an improvement in soluble solid, pulp content and acidity of juices. The results suggested that juice yield and functional properties were improved by EP application.     

萱藻中主要类胡萝卜素的分析与鉴定

采用有机溶剂浸提法从萱藻中提取类胡萝卜素,利用柱层析与薄层层析对萱藻主要类胡萝卜素组分进行了分离纯化。利用可见吸收光谱、红外光谱与高效液相-质谱联用等检测手段对萱藻中主要类胡萝卜素组分进行了分析鉴定,并通过高效液相法对萱藻中类胡萝卜素含量进行了测定。结果表明,萱藻中主要类胡萝卜素为β-胡萝卜素和岩藻黄素,其含量分别为124.55、2862.20μg/g（dw）。      

新鲜荔枝汁营养成分分析

对新鲜荔枝汁主要营养成分进行分析,发现荔枝汁含糖量161.4g/L,其中98%为还原糖,所含的有机酸主要是柠檬酸、酒石酸、苹果酸、乙酸等,氨基酸含量136.44mg/100mL,共含有17种氨基酸,其中7种为人体必需氨基酸,营养价值高。