浓缩苹果汁加工链中棒曲霉素的动态分析研究

研究了浓缩苹果汁加工过程中各工序对棒曲霉素含量的影响。结果表明,喷淋、拣选、清洗是去除棒曲霉素的关键步骤,去除率为60.18％;吸附树脂对棒曲霉素去除效果显著。此外,研究了加工季节中棒曲霉素的变化规律,为果汁加工厂家建立科学完善的HACCP管理体系提供了理论依据。      

浓缩苹果汁中棒曲霉素的来源及检测

棒曲霉素是由苹果腐烂部位的真菌类产生的次生代谢产物。由于棒曲霉素的致突变性和致畸性并可能对消费者的健康产生危害，许多国家都已经制定了相关标准以尽可能降低苹果制品中棒曲霉素的含量。本文简要介绍了近年来浓缩苹果汁中棒曲霉素常用的分析检测方法。     

基于SPE-HPLC的浓缩苹果汁中棒曲霉素检测方法的研究

棒曲霉素是真菌代谢所产生的一类有毒化合物,多存在于霉烂的苹果中。最常用的检测方法是利用各种液液萃取分离步骤来提取苹果汁中的棒曲霉素。在本研究中,两种固相萃取柱:C18-SPE和亲油亲水平衡大孔聚合吸附柱(HLB),被用来萃取分离浓缩苹果汁中的棒曲霉素。高效液相色谱(HPLC)检测用反相C18色谱柱,紫外检测器,检测波长276nm。在加标10～100μg/L的水平下测得棒曲霉素回收率分别为C18-SPE 87.56%～88.4%、HLB-SPE 85.45%～88.76%、LLE 79.47%～80.1%,变异系数分别为3.28%～4.47%、4.32%～7.15%、6.28%～7.67%。     

臭氧对苹果汁中棒曲霉素的降解效果研究

主要研究臭氧对苹果汁中棒曲霉素(Pat)的降解效果及对果汁品质的影响。研究采用臭氧对水和苹果汁中500、250、200、100、50μg/LPat浓度进行5、10、15、20、30min的降解处理。结果表明,臭氧处理对各浓度的Pat都有降解作用,浓度越低,降解效果越好。随着处理时间延长降解效果越好,15min以后降解率不再增加。臭氧处理15min,50μg/L的Pat降解效率最佳,在该条件下,臭氧对苹果汁的pH、VC含量、可溶性固形物和色值均没有明显的影响,因此,臭氧处理是高效、安全、低廉的Pat降解方法。      

氰基柱SPE-HPLC检测浓缩苹果汁中棒曲霉素的研究

借建立了SPE-HPLC检测浓缩苹果汁中棒曲霉素残留的方法.采用氰基柱固相萃取浓缩苹果汁中的棒曲霉素,经HPLC测定,样品的回收率为95.16%～120.89%,变异系数≤3.98%,最低检出浓度为0.003mg/kg.该方法较传统的LLE法简便、快速、准确,是处理浓缩苹果汁中棒曲霉素较理想的方法.     

苹果汁中棒曲霉素的吸附动力学研究

研究了苹果汁中棒曲霉素在八种大孔吸附树脂上的吸附行为,并筛选出最佳吸附树脂;研究了棒曲霉素在LSA-800B大孔吸附树脂上的静态动力学、吸附等温线和动态动力学曲线以及影响动态动力学曲线的因素,并确定了LSA-800B树脂吸附棒曲霉素的最适操作条件,结果表明:在实验条件LSA-800B树脂对棒曲霉素的静态吸附平衡时间为3h;20℃时LSA-800B树脂的吸附过程可用佛伦德列希(Freundlich)吸附等温式来描述,方程为:q=0.0539C1.0278(r2=0.9907);流速、果汁中棒曲霉素的浓度、操作温度对LSA-800B树脂的动态动力学曲线都有影响。树脂柱操作的最适条件为:流速4BV/h,温度50℃。     

高新技术在浓缩苹果汁加工中应用进展

综述了酶技术、膜技术、树脂吸附技术、壳聚糖和纳米技术等在浓缩苹果汁加工中的应用状况及研究进展,旨在为浓缩苹果汁的加工技术研究提供参考。     

辉光放电等离子体对苹果汁中棒曲霉素降解作用及对苹果汁品质的影响

为了寻求一种能最大限度保持苹果汁品质又能有效降解其中棒曲霉素(Pat)的技术方法,本文采用辉光放电等离子体技术,研究了其对苹果汁中棒曲霉素的降解效果及对果汁品质的影响。结果表明,当直流电压为550 V,电流范围为145~155 m A时,辉光放电等离子体可在5 min内有效降解苹果汁中的棒曲霉素,降解效果显著(p<0.05),降解率达到96.63%。在0~30 min处理时间范围内,苹果汁中的可溶性固形物无变化,苹果汁的色值和透光率提高。10 min内苹果汁总酸度变化不大,p H稍微降低,粘度、电导率、A660和A420无显著变化。综合分析,10 min的处理时间已完全使苹果汁中的棒曲霉素降低到一个很低的水平,又不会对苹果汁的主要理化指标造成影响。      

大孔吸附树脂吸附浓缩苹果汁中棒曲霉素的研究

研究DB101 B、DM-130、AB-8、HPD-850、HPD-200L、ATF.3树脂对棒曲霉素的吸附性能及对果汁主要理化性质的影响.比较6种树脂对棒曲霉素的吸附作用,筛选出最适吸附树脂,对其进行静态和动态吸附试验,研究其吸附性能.结标明,ATF-31型树脂对棒曲霉素的吸附率为60.41%,果汁的透光率和色值分别提高4.4%和88.3%,吸附最佳操作条件为:pH 4.2,吸附流速为10 mL/min,棒曲霉素初始浓度为35.20μg/L.ATF-31型树脂是棒曲霉素的良好吸附材料,并能较好的提高浓缩苹果汁的色值与透光率.     

Quantitative analysis of patulin in apple juice by thin-layer chromatography using a charge coupled device detector

A method was developed and validated in-house for the detection and quantification of patulin in apple juice concentrate using a charge coupled device (CCD) on thin-layer chromatography (TLC) plates. Samples were extracted with ethyl acetate and then cleaned-up by extraction with a sodium carbonate solution. The method showed a mean recovery of 95%. The quantification and detection limit were 14 µg l^?1 and 0.005 µg per spot, respectively. The CCD camera is sufficiently sensitive to detect changes in spot fluorescence intensity caused by small differences in mycotoxin concentration under homogeneous illumination from a UV light source. The results of validation confirmed the efficiency of the method, which is sensitive enough to be used to quantify patulin in apple juice by producers or for government monitoring/survey programs. The method was applied to the analysis of 16 apple juice concentrate samples and patulin levels ranged from 15 to 46 µg l^?1. This study demonstrated the applicability of the TLC–CCD technique as a tool for monitoring patulin in apple juice.     

Rapid determination of picogram levels of patulin in apple juice using a flow injection chemiluminescence procedure

BACKGROUND: A sensitive, rapid and simple chemiluminescence procedure, based on the enhancing effect of patulin on the chemiluminescence (CL) reaction between luminol and hydrogen peroxide in a flow injection (FI) system, has been proposed for the determination of patulin. RESULT: The increment of CL intensity was linear over the concentration of patulin ranging from 0.05 to 80 ng mL^?1, with a detection limit (3S/N) of 0.01 ng mL^?1. At a flow rate of 2.0 mL min^?1, a complete analysis could be performed in 25 s with a relative standard deviation of less than 4.0%. CONCLUSION: The proposed method was successfully applied to the measurement of apple juice samples obtained from the Shaanxi Entry–Exit Inspection and Quarantine Bureau. The recoveries were between 93.4 and 107.9% Copyright © 2008 Society of Chemical Industry     

苹果浓缩汁加工中热灭酶工艺研究

通过在不同温度和时间下热处理苹果汁,研究了使果汁中多酚氧化酶(PPO)部分或完全失活的条件,并考察了与果汁自然pH值相近的模拟体系对处理后的果汁酶活的抑制情况。表明:75℃、30s虽不能完全灭活PPO,但对其活性破坏较大,处理后的PPO酶活可以较好地被接近果汁自身pH值的低pH(3.8)所抑制,为最佳处理条件。     

Effect of heat treatment and evaporation on patulin and some other properties of apple juice

Patulin, hydroxymethylfurfural (HMF), colour and clarity values of 20 apple juice samples with different Brix contents were determined after heat treatment (90 and 100 °C for 5, 10, 15 and 20 min under atmospheric pressure) and evaporation (70 and 80 °C for 5, 10, 15 and 20 min) processes. As the heating and evaporation times increased, the concentration of patulin in the apple juice samples decreased. The 90 and 100 °C heat treatments resulted in reductions in patulin concentration of 18.81 and 25.99% respectively after 20 min; the corresponding values were 9.40 and 14.06% for 70 and 80 °C evaporation respectively. The increase in HMF was higher with heat treatment than with evaporation. Evaporation decreased the colour values of the samples, whereas heat treatment increased them. © 2003 Society of Chemical Industry     

Free and bound patulin in cloudy apple juice

During validation of an HPLC-UV method for patulin analysis, a time and concentration dependent recovery of patulin was observed. Spiked cloudy apple juice was analysed on successive days, which resulted in recoveries on day 3 which were up to 20% lower than on day 1. This reduction was caused by an interaction between patulin and the solid parts of cloudy apple juice. Since these solid parts are richer in proteins compared to the liquid phase of cloudy apple juice, and the binding of patulin to proteins has been described in the literature, patulin will most probably interact with the proteins in the solid parts. As a consequence, up to 20% of the present patulin is bound and not detected during HPLC-UV analysis, which can lead to an underestimation on toxicological level.     

The effects of processing technology on the patulin content of juice during commercial apple juice concentrate production

 The effects of different treatments on the patulin content of apple juice during the production of industrial apple juice concentrate were investigated. Conventional clarification using a rotary vacuum precoat filter was found to be more effective than using ultrafiltration for the removal of patulin from apple juice. The average losses of patulin were 39% and 25% for conventional clarification and filtration, and ultrafiltration, respectively. Washing and handling appeared to be the most critical steps in removing patulin from apples since up to 54% could be removed using high-pressure water spraying. Received: 22 January 1998 / Revised version: 21 April 1998