山葵风味物质-异硫氰酸酯

综述了山葵研究现状和应用前景及其风味物质异硫氰酸酯的特性、测定、提取、功能特性。     

Extension of Shelf Life by Treatment with Allyl Isothiocyanate in Combination with Acetic Acid on Cooked Rice

ABSTRACT: In order to extend the shelf life of cooked rice, allyl isothiocyanate (AIT) and acetic acid were applied, and both microbiological evaluations and sensory evaluations were performed during storage at various temperatures. The residual AIT concentration in the headspace of a cooked rice pack was also quantified. Total aerobic populations at various storage temperatures were lower where acetic acid alone or in combination with AIT were used. A sensory evaluation showed that the acceptability of cooked rice was influenced by the type of treatment. The antimicrobial effect of acetic acid in combination with AIT was excellent, so it seemed to have potential as an agent to extend the shelf life of cooked rice.     

反相高效液相色谱法测定白屈菜种子中挥发油 成分分析及氨基酸含量

目的研究白屈菜种子中挥发油的化学成分并建立一种反相高效液相色谱法对白屈菜种子中游离氨基酸和水解氨基酸含量进行测定。方法采用气质联用的方法对白屈菜种子中的挥发油成分进行分析,采用反相高效液相色谱法,以异硫氰酸苯酯为衍生试剂进行柱前衍生,采用梯度洗脱的方法,检测白屈菜种子中游离氨基酸和水解氨基酸含量。结果挥发油中共鉴定出化学成分27个,其中亚油酸的含量最高可达到65%左右。氨基酸的检测浓度线性范围为0.0020~0.2700 mmol/L,r均≥0.9991。21种游离氨基酸的平均加样回收率在87.88%~100.10%之间,RSD在0.62%~2.58%之间(n=6);水解氨基酸的平均加样回收率在91.79%~100.03%之间,RSD在0.48%~1.97%之间(n=6)。结论白屈菜种子种中挥发油的主要成分为不饱和脂肪酸,本文建立的氨基酸测定方法经方法学验证适合白屈菜种子中游离氨基酸和水解氨基酸的含量测定。     

Active Packaging of Fresh Chicken Breast,with Allyl Isothiocyanate (AITC) in Combination with Modified Atmosphere Packaging (MAP) to Control the Growth of Pathogens

ABSTRACT: Listeria monocytogenes and Salmonella typhimurium are major bacterial pathogens associated with poultry products. Ally isothiocyanate (AITC), a natural antimicrobial compound, is reportedly effective against these pathogenic organisms. A device was designed for the controlled release of AITC with modified atmosphere packaging (MAP), and then evaluated for its ability to control the growth of L. monocytogenes and S. typhimurium on raw chicken breast during refrigerated storage. In order to obtain controlled release during the test period, a glass vial was filled with AITC and triglyceride. It was then sealed using high-density polyethylene film. The release of AITC was controlled by the concentration (mole fraction) of AITC in the triglyceride and by the AITC vapor permeability through the film. The fresh chicken samples were inoculated with one or the other of the pathogens at 10⁴ CFU/g, and the packages (with and without AITC-controlled release device) were flushed with ambient air or 30% CO₂/70% N₂ before sealing, and then stored at 4 °C for up to 21 d. The maximum reduction in MAP plus AITC (compared to MAP alone) was 0.77 log CFU/g for L. monocytogenes and 1.3 log CFU/g for S. typhimurium. The color of the chicken breast meat was affected by the concentration of AITC. Overall, a release rate of 0.6 μg/h of AITC was found to not affect the color, whereas at 1.2 μg/h of AITC the surface of the chicken was discolored.     

Evaluation of antibacterial activity of 3-butenyl, 4-pentenyl, 2-phenylethyl, and benzyl isothiocyanate in Brassica vegetables

This study investigated antibacterial activities of 4 isothiocyanates (3-butenyl, 4-phentenyl, 2-phenylethyl, and benzyl isothiocyanate) against 4 Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus) and 7 Gram-negative bacteria (Aeromonas hydrophila, Pseudomonas aeruginosa, Salmonella choleaesuis, Salmonella enterica, Serratia marcescens, Shigella sonnei, and Vibrio parahaemolyticus) by an agar disc diffusion assay. Benzyl isothiocyanate (> 90.00 mm inhibition zone diameter at 0.1 μL/mL) and 2-phenylethyl isothiocyanate (58.33 mm at 0.2 μL/mL) showed large inhibition zones especially against B. cereus. Also, 3-butenyl isothiocyanate (21.67 mm at 1.0 μL/mL) and 4-pentenyl isothiocyanate (19.67 mm at 1.0 μL/mL) displayed potent antibacterial activity against A. hydrophila. Benzyl and 2-phenylethyl isothiocyanate indicated higher activity against most of the pathogenic bacteria than 3-butenyl and 4-pentenyl isothiocyanate, and were more effective against Gram-positive bacteria than Gram-negative bacteria.     

Supercritical Fluid Chromatography of Myrosinase Reaction Products in Ground Yellow Mustard Seed Oil

ABSTRACT: Escherichia coli O157:H7 can survive the dry fermented sausage manufacturing process. Compounds generated by enzymatic hydrolysis of glucosinolates present in ground mustard have shown potential antibacterial properties against E. coli O157:H7. In the present study, supercritical fluid chromatography (SFC) was used to investigate degradation products of 4-hydroxybenzyl glucosinolate (sinalbin), the major glucosinolate present in yellow mustard seed. Using SFC the concentration of the reactive component, 4-hydroxybenzyl isothiocyanate (PHBITC) was measured during the hydrolysis of sinalbin with myrosinase while imposing the temperature and pH regimen used for the fermentation phase of dry fermented sausage production. The PHBITC concentration grew to a maximum after 7 h and decreased rapidly. The concentration of 4-hydroxybenzyl alcohol increased rapidly to reach a maximum at 31 h and stayed at that level. The concentration of 4-hydroxybenzyl cyanate increased up to 24 h, then decreased to 65% of its maximum, and stayed constant. The stability of 4-hydroxybenzyl isothiocyanate in the presence of maltodextrin in this system was investigated. It was concluded that the major PHBITC loss in the mixture of the oil with maltodextrin occurred within the first 4 d of its storage. Practical Application: During the work 4-hydroxybenzyl isothiocyanate (PHBITC) was measured during the hydrolysis of sinalbin with myrosinase while imposing the temperature and pH regimen used for the fermentation phase of dry fermented sausage production. The results on PHBITC stability in maltodextrin presented provide precautionary information on the limited ability of this material to afford stability of PHBITC expected.     

番木瓜籽中异硫氰酸苄酯抗癌抑菌功能研究进展

番木瓜(Carica Papaya)是一种极具营养价值而被广泛种植的热带水果,其籽中含有苄基硫代葡萄糖苷(Glucosinolate,GS),约占番木瓜重量7%,是果肉加工的废弃物。GS主要存在于细胞空泡,当其接触到芥子酶就会被水解,生成异硫氰酸酯类(Isothiocyanates,ITCs)。ITCs是十字花科植物的次生代谢产物,是一类重要的有机合成中间体,公认具有防癌抗癌功效以及抑菌作用,异硫氰酸苄酯(Benzyl isothiocyanate,BITC)是ITCs中生物学效果最为明显的一种。BITC对许多癌症有明显的抑制作用,可以阻断癌细胞增殖分化;BITC对致病菌有抑制甚至杀死作用,这种抑菌活性可以作用于细菌和霉菌。本文结合国内外相关研究现状,综述BITC在防癌抗癌及抑菌方面的研究进展,为番木瓜籽副产物BITC更深一步的加工以及番木瓜综合利用率的提升提供一定的理论依据。     

红色LED光照下上海青采后硫代葡萄糖苷代谢的变化

为研究发光二极管（Light-Emitting Diodes，LED）处理对上海青采后硫代葡萄糖苷（简称硫苷）代谢的作用机理，该研究首先采用不同颜色和光密度的光照处理上海青，得出6.5 μmol/(m2•s)的红色LED光照处理可显著抑制上海青中叶绿素降解，延缓其黄化。在此基础上，研究了6.5 μmol/(m2•s)红色LED光照处理对贮藏期间上海青中硫苷代谢相关物质及基因表达水平的影响。结果表明，上海青叶柄中总硫苷和异硫氰酸酯含量分别为叶片的2.72倍和1.32倍；红色LED光照处理可显著上调上海青叶柄中脂肪族合成关键基因MYB28、CYP83A1、GSTF11等的表达水平，从而促进叶柄中主要硫苷物质3-丁烯基硫苷等的合成；由此，上海青叶柄中总硫苷含量在贮藏4~8 d期间为对照组的1.62~1.99倍；同时，该处理提升了上海青叶柄的黑芥子酶活性，从而促进了总异硫氰酸酯的积累，且在贮藏4~8 d期间，对照组上海青叶柄的总异硫氰酸酯含量为红光处理组的77.43%~91.98%。综上，红色LED光照处理通过调控硫苷合成关键基因和黑芥子酶活性来延缓上海青中硫苷物质和异硫氰酸酯的流失。     

Synthesis and Evaluation of Functionalized Aryl and Biaryl Isothiocyanates against Human MCF-7 Cells

Organic isothiocyanates (ITCs) are a class of anticancer agents which naturally result from the enzymatic degradation of glucosinolates produced by Brassica vegetables. Previous studies have demonstrated that the structure of an ITC impacts its potency and mode(s) of anticancer properties, opening the way to preparation and evaluation of synthetic, non-natural ITC analogues. This study describes the preparation of a library of 79 non-natural ITC analogues intended to probe further structure-activity relationships for aryl ITCs and second-generation, functionalized biaryl ITC variants. ITC candidates were subjected to bifurcated evaluation of antiproliferative and antioxidant response element (ARE)-induction capacity against human MCF-7 cells. The results of this study led to the identification of (1) several key structure-activity relationships and (2) lead ITCs demonstrating potent antiproliferative properties.