壳聚糖及其衍生物对油豆角保鲜效果的研究

分别用壳聚糖和羧甲基壳聚糖配制的涂膜液处理油豆角,比较不同处理组的生理指标及感官指标,确定保鲜效果较好的涂膜液。结果表明,涂膜处理的油豆角呼吸强度、多酚氧化酶和过氧化物酶活性及丙二醛含量与对照组相比都有所降低;用N,O羧甲基壳聚糖处理的油豆角保鲜效果较好。     

壳聚糖可食用膜对油豆角贮藏生理的影响

使用壳聚糖配制的涂膜液处理油豆角,通过测定涂膜的油豆角在贮藏期间呼吸强度、PPO、POD、MDA的变化,探讨油豆角在贮藏期间的生理变化规律.结果表明,涂膜处理后能推迟油豆角呼吸高峰的到来;同时,在贮藏期间,涂膜油豆角的呼吸强度、PPO、POD、MDA与对照组相比都有所降低.     

超声波和涂膜技术在豆角保鲜中的应用

阐述了超声波杀菌对豆角保鲜的影响,通过多次试验得出超声波处理豆角在20～40s之间,对豆角的杀菌作用比较好.在此基础上进行了不同浓度魔芋粉涂膜对豆角保鲜的影响,多次试验得出浓度在0.3%～0.5%之间,可将豆角的贮存期在同等条件下延长到10d以上.     

油炸涂膜薯片的吸油率和丙烯酰胺含量研究

将不同浓度的羧甲基纤维素钠(CMC)膜液、大豆分离蛋白(SPI)膜液和壳聚糖膜液分别涂覆于薯片表面,高温油炸后,以薯片的吸油率和含水量为评价指标,确定3种膜液的最宜浓度,并对比了3种膜液最佳浓度下油炸薯片的丙烯酰胺含量、色泽值及感官品质。在CMC、SPI和壳聚糖膜液浓度分别为1.5%、8%和1.5%时,与未涂膜薯片对比,油炸涂膜薯片的吸油率分别下降17.73%、22.94%和7.58%,丙烯酰胺含量分别下降21.5%、42.9%和53.3%。结果表明,SPI涂膜可更大程度降低油炸薯片的吸油率,而壳聚糖涂膜可显著减少其丙烯酰胺含量,并具有较好的感官品质。     

臭氧在鲜切西洋芹保鲜中应用的研究

臭氧的杀菌能力是氯的3倍、杀菌速度较氯快300～600倍,且无残留,是极具潜力的食品“冷杀菌”技术,非常适合鲜切菜的杀菌、保鲜。通过对鲜切西洋芹的臭氧处理,结果表明,用0.3mg/L的臭氧水处理鲜切西洋芹10min可以使鲜切菜表面的微生物降低二个数量级,酶的活性降低50%,呼吸强度降低80%,对VC无破坏作用,感官品质优良,在4℃条件下最长时间可以保存20d。     

O_3水漂洗辅助海藻酸钠涂膜对冬枣品质的影响

为了保持常温贮藏冬枣的品质,该文研究了臭氧水漂洗辅助海藻酸钠涂膜处理对常温贮藏冬枣品质的影响。试验分2个阶段进行,第1阶段是将冬枣分别浸渍于浓度为0.3、0.5、0.7、0.9 mg/L的臭氧水中漂洗5 min,或者将冬枣采用0.5%、1.0%、1.5%和2.0%的海藻酸钠涂膜。第2阶段是将冬枣先浸渍于0.5 mg/L的臭氧水中漂洗5 min,然后用1.0%海藻酸钠涂膜处理。结果表明,组合处理可以降低常温贮藏冬枣的腐烂率。在第8天,组合处理冬枣的腐烂率仅为对照组的2.5%;其感官评价得分为7.16分,基本保持了冬枣色泽和风味品质。同时,组合处理能显著延缓冬枣硬度、可滴定酸、Vc、多酚和总叶绿素含量的降低,并能抑制可溶性固形物、失重率、丙二醛含量和电导率的升高。因此,采用0.5 mg/L臭氧水漂洗冬枣5 min,结合1.0%海藻酸钠涂膜可以提高常温贮藏冬枣的品质,为冬枣的常温保鲜提供参考。     

羧甲基壳聚糖可食用膜在油豆角保鲜中的应用

采用三因素三水平正交实验,来确定NO-羧甲基壳聚糖涂膜保鲜油豆角的保鲜液的最佳配比。结果表明,2.0%壳聚糖、25μg/mL6-BA及0.1g/kg脱氢醋酸钠混合制成的保鲜液,可有效地保持油豆角良好的感官品质。     

不同清洗方式对鲜切鸡毛菜保鲜效果的影响

实验采用臭氧水、电解水、次氯酸钠、超声波对鲜切鸡毛菜进行清洗,自来水清洗作为对照。通过测定贮藏期间叶绿素、VC、亚硝酸盐、细菌总数、感官品质等来比较清洗效果。实验结果表明,臭氧水和超声波处理的样品在杀菌、保持营养物质及感官上的效果相对其他处理的样品要好,贮藏至14d仍有商品价值和食用价值,可作为鲜切鸡毛菜加工过程中的处理方式。     

油豆角真空包装保鲜技术的研究

采用抽真空护绿和保脆工艺,经微波漂烫、真空包装及杀菌制成的油豆角产品,可在超市反季节上市或跨地区供应。在实验中,分别运用色差计和质构测定仪(TA-XTZiTextureAnalyser)对油豆角的色泽和脆度进行评价,避免了感官判断的误差,确保了实验数据的可靠性。     

羧甲基壳聚糖可食用膜对保鲜油豆角化学成分的影响

研究利用羧甲基壳聚糖涂膜液对油豆角进行保鲜,并测定涂膜油豆角在贮藏期间的各项化学成分。结果表明,随着贮藏时间的延长,水分、Vc及还原糖的含量不断下降;而叶绿素的变化趋势与前者不同,呈现出先降低后升高,最后又降低的趋势。     

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.