提高冻干香葱品质的工艺研究

为保持真空冷冻干燥香葱的鲜绿、天然的葱香味及品质,采用漂烫和护色剂对香葱进行浸泡护色处理,固相微萃取气质联用(SPME-GC-MS)测定香葱的挥发性成分,并确定真空冷冻干燥香葱气味最浓郁时的干燥时间、温度和真空度。实验表明:SPME-GC-MS分析确定以硫代亚磺酸酯的含量来衡量干燥后香葱气味的浓郁程度。干燥香葱颜色最鲜亮时的条件为:100℃水中烫漂30s,0.3%碳酸钠碱液中浸泡10min,0.03%氯化锌和0.2%氯化钙护绿液中护色30min。满足香葱香味最浓郁及水分要求的条件为:0℃下升华干燥6h,25℃下解析干燥2h,真空度60Pa。     

鱼香肉丝真空冷冻干燥工艺的研究

通过正交试验得出真空冷冻干燥鱼香肉丝的最佳工艺:鱼香肉丝厚度5mm、升华干燥时真空度140Pa、解析干燥时真空度30Pa、解析时加热板温度20℃,影响工艺的主要因素次序为加热板温度、厚度、升华压力和解析压力;以及复水量在原含水量Aw的140%～150%、复水温度65～85℃、复水时间20～30min最好;最后建立数学模型验证干燥时间。     

篌竹笋真空冷冻干燥工艺研究

采用正交试验、均匀设计试验和对比试验,对篌竹笋护色、预处理、真空冷冻干燥条件和不同干燥方法的干燥效果等进行探讨。采用0.2%抗坏血酸、0.1%柠檬酸和0.5%氯化钠溶液烫漂篌竹笋4min,进行护色处理,然后在43℃、2%蔗糖和8%麦芽糊精混合溶液中浸泡26min,进行预处理,可以明显提高篌竹笋冻干产品的复水比和感官品质。预处理篌竹笋的共晶点为-25℃,真空冷冻干燥条件为：物料预冻温度-35℃,预冻时间3h-4h,冷阱温度-55℃左右,干燥室真空度7Pa-9Pa,解吸阶段搁板加热温度40℃,物料冻干所需时间12h。真空冷冻干燥所得产品的质量明显优于热风干燥和真空干燥。     

典型中华菜肴的真空冷冻干燥工艺研究

以鱼香肉丝这一典型的中华菜肴为对象，研究其真空冷冻干燥工艺，进而开发中华菜肴式航天食品。通过正交实验求出了鱼香肉丝菜肴的最佳真空冷冻干燥工艺参数，即物料铺放厚度5mm、升华干燥的真空度140Pa、解析干燥的真空度50Pa、解析时加热板温度20℃。在此基础上求出的影响冷冻干燥工艺的主要因素的影响次序为：加热板温度、物料铺放厚度、升华压力和解析压力。同时还求出了其复水工艺参数，即，复水量为干制品的含水率的140％～150％，复水温度65～85℃，复水时间在20～50min左右最好。并通过本研究所建立的数学模型对鱼香肉丝的真空冷冻干燥时间进行了验证。     

菠萝蜜真空冷冻干燥机理及工艺研究

本文对菠萝蜜进行了真空冷冻干燥研究,通过DSC差示扫描热量法,测定共晶点和共融点分别为-20.33℃和-9.87℃。分析了升华干燥温度,升华干燥时间与解析干燥温度对菠萝蜜品质及营养成分的影响,通过正交实验,确定了菠萝蜜真空冷冻干燥的最佳工艺参数。结果表明:在菠萝蜜尺寸为30mm×15mm×3mm,升华干燥温度为-10℃,真空度为200Pa,升华干燥时间为8h,解析干燥为35℃,解析干燥时间为2h,真空压力为1000Pa时,冻干后维生素C保留含量达71.26%,感官品质最佳。     

真空冷冻干燥香芋脆片生产工艺研究

以槟榔香芋为原料,研究了冻干香芋脆片的生产工艺。结果表明:采用0.2%柠檬酸做护色,3min微波熟化的真空冷冻干燥香芋片,可以保持原有的色、香、味、形。香芋片的共晶点为-13～17℃,共融点为-11～15℃;预冻温度应低于-22℃,冻干过程为60℃加热升华285min,然后升温至75℃,在此温度下解析105min;冻干过程真空度恒定为60Pa,冷阱表面温度设置为-40～-45℃,热水罐温度高于加热板温度5～10℃。     

冻干光皮木瓜超微粉的加工工艺

联合使用真空冷冻干燥技术和超微粉碎技术制得冻干木瓜超微粉,并介绍了其工艺流程和技术要点。木瓜真空冷冻干燥时的物料粒度0.95cm3,物料厚度15～20mm;最佳升华干燥条件：真空度40Pa,加热板温度60℃,物料温度－ 40℃,冷凝温度－ 35℃;最佳解析干燥条件：真空度20Pa,加热板温度85℃,物料温度40℃,冷凝温度－ 35℃。先用植物粉碎机将冻干木瓜粗粉碎至60～80 目;再在压力大于12MPa、温度小于35℃的条件下,用气流磨机粉碎到1000 目以上,即得成品。本工艺生产的光皮木瓜冻干超微粉,具有良好的复水性、溶解性、活性,完整的保留了木瓜原有的色、香、味和其营养成分,可作为进一步深加工的主要原材料。     

响应面法优化虾仁的真空冷冻干燥工艺

以红虾虾仁为研究对象,以干燥虾仁的复水比、复水前后体表彩度c1、c2和复水后硬度、弹性、咀嚼性为基础的综合值作为产品的工艺指标,研究红虾虾仁的真空冷冻干燥工艺。在单因素的基础上,选取真空冷冻干燥时加热板温度、真空度和烫漂时间为自变量,综合值为响应值,利用Box-Benhnken中心组合设计原理和响应面分析法研究自变量及其交互作用对红虾虾仁干燥产品综合值的影响,模拟得到二次多项式回归方程的预测模型,确定最佳干燥工艺条件为加热板温度31.25℃、真空度22.81 Pa、烫漂时间1.43 min。在此条件下,红虾虾仁干燥产品的综合值为57.43分,与理论预测值58.136 8分相比,其相对误差约为1.2%,说明通过响应面优化后得到的方程具有实践指导意义。     

真空冷冻干燥红枣粉加工技术研究

红枣具有丰富的营养价值和保健功能,是一种药食同源的果品。以新鲜冬枣为试验材料,利用真空冷冻干燥技术制取红枣粉。冷冻干燥涉及3个主要的工艺参数,分别是真空度、升华干燥温度和解析干燥温度。在单因素基础上利用响应面法对试验进行设计和优化,确定最佳的真空冷冻干燥工艺条件为真空度74 Pa,升华加热温度41℃,解析加热温度72℃,综合评价值为70.42。     

真空冷冻干燥法制备草莓粉工艺研究

对真空冷冻干燥草莓粉的制备工艺进行研究。采用正交试验,对护色工艺进行考察,确定较优的护色条件为:L-谷氨酸浓度为30mg/L,pH值为2.0,NaCl为0.2%。以干燥速率、Vc含量和水分含量三者按权重综合评价为指标,对真空干燥工艺采用单因素和正交试验进行了优化,得到最佳工艺为解析温度60℃,真空度65Pa,升华温度55℃,在此条件下,综合评分值为8.88。同时对草莓粉的抗结性进行研究,确定了磷酸三钙添加量为4g/kg,可以使草莓粉具有良好的的拮抗性和流动性。     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.