Determination of luteolin and apigenin in celery using ultrasonic-assisted extraction based on aqueous solution of ionic liquid coupled with HPLC quantification

BACKGROUND: Ionic liquids are a class of organic salts with melting points equal to or below 100 °C, and their use in sample preparation has shown its promise, for example, in alleviation of environmental pollution and improvement of selectivity and extraction of certain interesting compounds. RESULTS: Optimal conditions were obtained by using 1.0 mol L^?1 1‐butyl‐3‐methylimidazolium methylsulfate ([Bmim][MS]) aqueous solution at pH 1.0 as the extraction solvent. An ultrasonic power of 200 W was chosen to ensure complete dispersion of [Bmim][MS] into celery in 90 min and the solid:liquid ratio was 1:10. CONCLUSION: The proposed ultrasonic assistant extraction approach, based on ionic liquid aqueous solution, exhibited satisfactory results, with recovery values ranging from 72.7% to 89.5%. Under optimal conditions, compared with conventional solvent extraction amounts of luteolin and apigenin were more than doubled. Copyright © 2011 Society of Chemical Industry     

Shelf life study of fresh celery (Apium graveolens L.) grown under different nitrogen fertilization treatments

Nitrogen fertilization is useful for obtaining higher growth and quality of productions, and the use of nitrogen fertilization is widespread. To evaluate the influence of nitrogen-rich fertilizers on quality characteristics of celery, shelf life tests of celery grown with 2 levels of nitrogen and 2 different nitrogen fertilizers were performed. The treatments of the celery samples were identified as follows: T1, mineral nitrogen (80 kg ha(-1)); T2, mineral nitrogen (120 kg ha(-1)); T3, organic nitrogen (80 kg ha(-1)); T4, organic nitrogen (120 kg ha(-1)); R4, residual organic nitrogen (120 kg ha(-1)); and C, untreated control. Celery plants were selected and packaged in either of the following 2 plastic films: antifog polyolefin (AFP) film or microperforated polypropylene (MPP) film. The nitrate contents, weight loss, hardness, changes in color parameters, and total phenols were studied for both packaging types during storage. The results demonstrated that celery fertilized with organic nitrogen and packaged in AFP film reached a shelf life of 37 d. The control sample packaged in MPP film was not marketable after 20 d, but the same untreated sample packaged in AFP film reached a shelf life of 30 d.     

灵芝发酵生产芹菜全营养产品

蔬菜汁生产过程中产生大量的蔬菜渣,具有蔬菜中绝大部分的膳食纤维有效物质。采用榨汁工艺对芹菜进行榨汁,利用灵芝对芹菜渣进行生物降解与转化,得到高含量灵芝有效物质及可溶性膳食纤维的发酵液,将发酵液与蔬菜汁进行勾兑获取全营养产品,产品中可溶性膳食纤维含量≥30g/L、总糖≥35g/L、可溶性固形物≥45g/L,可以作为所有人群,尤其是对高血压病人进行芹菜营养的补充。     

不同真空预冷处理条件对鲜切芹菜品质的影响

为完善对蔬菜真空预冷机理的研究,试验选取典型叶菜类柱状蔬菜——芹菜为研究对象,研究了在相同贮藏条件下,不同真空预冷处理条件对芹菜品质的影响。选择1、3、5、7℃4种预冷终温进行比较,得出了真空预冷过程中芹菜温度、真空室压力随时间的变化规律以及贮藏过程中芹菜品质的变化规律,并探讨了不同预冷终温对于芹菜质量、质构和过氧化物酶活性的影响。结果表明,与对照组相比,真空预冷能够很好地起到保鲜芹菜的作用。     

Identification and characterisation of allergens related to Bet v I,the major birch pollen allergen,in apple,cherry, celery and carrot by two-dimensional immunoblotting and N-terminal microsequencing

Low temperature extracts taken from Granny Smith and Braeburn apples, cherries, celery and carrots were separated by two-dimensional electrophoresis. Bet v I, the major birch pollen allergen, related allergens in apple, cherry, celery and carrot extracts were detected by means of two-dimensional immunoblotting with patients' sera containing IgE antibodies specific to Bet v I, a rabbit polyclonal antiserum raised against Bet v I , and two Bet v I specific mouse monoclonal antibodies. The major cross-reacting allergen spots were observed with molecular weights/isoelectric points of 18.0 kDa/pI 5.5 for apple (Granny Smith and Braeburn) and 18.0 kDa/pI 5.8 for cherry, 15.5 kDa/pI 4.4–4.6 for celery and 16.0 kDa/pI 4.4 for carrot extract. Additional antibody reactivities with certain isoprotein spots were observed, which may indicate the presence of Bet v I-related epitopes on these proteins. Based on the first 15 N-terminal amino acid residues, the major allergen spots revealed 53% sequence identity between Bet v I and the Granny Smith apple allergen, 50% between Braeburn apple allergen and Bet v I , 67% between Bet v I and the cherry allergen, and 40 and 28% for celery and carrot, respectively. Furthermore, the N-terminal sequences showed identities ranging from 40% (apple/cherry) to 66% (celery) with PcPR l-l, a pathogenesis-related protein in parsley.     

芹菜粉中总膳食纤维标准物质的研制

目的 使用芹菜粉研制天然食品中总膳食纤维标注物质。方法 经冷冻干燥、混匀、分装制备了芹菜粉中总膳食纤维标准物质。采F-检验评价标准物质的均匀性, 采用T检验(t-test)评价标准物质的长期和短期稳定性, 6家实验室统一采用酶重量对芹菜粉中总膳食纤维进行定值, 并对定值结果进行了不确定度评估。结果 芹菜粉标准物质均匀性、稳定性均符合标准物质定值技术要求。芹菜粉中总膳食纤维标准物质定值结果为 (29.9±2.3) g/100g, k=2。结论 该标准物质可用于天然食品中总膳食纤维的日常检测的质量控制。     

芹菜多酚的抗氧化性及其稳定性研究

以芹菜多酚为研究对象,采用DPPH自由基清除率法和铁离子还原能力(FRAP)法对其抗氧化性进行评价,并分析温度、光照、pH值、Na_2SO_3、H_2O_2、山梨酸钾等对其稳定性的影响。结果表明:pH值在2~6范围时DPPH自由基清除率从92.99%到84.88%;100℃,在40~60 min范围时清除率从91.32%降低到87.5%;Na_2SO_3浓度大于0.2%时,DPPH自由基清除率低于10.04%;防腐剂浓度与芹菜多酚DPPH自由基清除率呈负相关;光照和氧化剂对芹菜多酚的稳定性影响较小。研究认为芹菜多酚具有较好的抗氧化性,但需注意控制外界环境对其的影响,增强使用效果。     

北京地区主要芹菜品种贮藏性的比较分析

以北京地区11个芹菜品种为试验材料,测定其在贮藏过程中含水量、叶绿素含量、呼吸强度、相对电导率、纤维素含量和木质素含量的变化,并对其感观品质进行评价。结果表明:贮藏期内,日本小香芹和白芹的水分含量下降最快;马家沟、帝王、玉皇芹菜的叶绿素含量均保持在较高水平,而紫芹和白芹较低,但玉皇和白芹下降程度最大;白芹在贮藏第1天出现呼吸峰值开始进入衰老阶段;贮藏期内白芹和紫芹的相对电导率上升幅度较大;白芹在贮藏第4天时失去商品性;白芹木质素含量增加幅度最大,而斯地德木质素含量增加最少。综合各项指标分析,北京地区主要芹菜中贮藏性较好的品种为斯地德,贮藏性较差的品种为白芹。