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。     

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.     

果蔬汁中棒曲霉素的来源及检测

棒曲霉素是青霉属、曲霉属、裸囊菌属等多种真菌的次生代谢产物,在果品、蔬菜、果蔬汁、果酒［１－１７］、谷物、糕点以及香肠等食品中都发现了棒曲霉素,由于棒曲霉素在动物实验中,能引起动物的致畸性［１８］、致突变性［１９］和致癌性,所以,引起了世界各国卫生、...     

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℃。     

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。      

采用ICS3000型离子色谱法对苹果汁中棒曲霉素含量的测定

采用离子色谱法对苹果汁中棒曲霉素含量的测定,棒曲霉素主要来源于青霉病,此病危害成熟或接近成熟的果实,病斑黄白色,近圆形,果肉腐烂呈锥状湿腐,当条件适宜时,使全果腐烂,产生强烈的霉味同类标准执行的是苹果汁中的棒曲霉素最大限量50μg/L。美国戴安公司生产ICS300离子色谱,Ultimate 3000 varible waveleng detector紫外检测器。旋转蒸发仪、一次性滤膜0.45μm、1～5、5～10mL加样枪,色谱柱Diamonsil 5uc18 250×4.6mm,美国密理博公司生产的Direct-Q3超纯水机。     

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.     

REDUCTION OF PATULIN IN APPLE JUICE CONCENTRATES DURING STORAGE

In this study, the reduction of patulin content in apple juice concentrates during 6 months of storage at 22 and 30C was investigated. Results demonstrated that reduction in patulin content was dependent on the storage temperature and time. Patulin reductions after 1 month of storage at 22 and 30C were in the ranges of 45–64% and 66–86%, respectively. Levels of patulin were below detectable limits after 4 months of storage at 22 and 30C.     

INFLUENCE OF APPLE JUICE TREATMENTS ON THE CIDER MAKING PROCESS

This study was conducted to examine the influence of the following apple juice treatments on different parameters of cidermaking process: sulphiting (50 mg/L of total S0₂), clarification with pectolytic enzymes (Ultrazym 100 G, 3g/hL), and bentonite fining (lOOg/hL). The different treatments slowed down alcoholic fermentation, the greatest effect being found for the combination of the three treatments. With respect to malolactic fermentation, must sulphiting, with or without the other two treatments, delayed this process, which took place after alcoholic fermentation. The low levels of lactic acid bacteria during this period can explain this delay. The only treatment that had any significant influence on volatile acidity was sulphiting, either on its own or in combination with the other treatments. Thus lower acetic acid levels were detected in ciders treated with SO₂ .     

CONTAMINATION OF PATULIN IN CLEAR APPLE JUICE IN MASHHAD, IRAN

Patulin is a frequent contaminant of moldy and rotten apples and apple products. The aim of this study was to evaluate patulin contamination in 58 apple juices collected from a retail market in Mashhad during winter and spring of 2006.
Samples were assayed for patulin by high-performance liquid chromatography. Fifty-four samples were positive for patulin at levels that ranged from 10.5 to 121.8 µg/L, and six samples had patulin levels higher than 50 µg/L. The overall mean of patulin concentration was 29.2  ±  19.5 µg/L. Forty-eight samples had patulin concentration between 5 and 50 µg/L. Although the mean concentration of patulin samples was lower than Iranian maximum tolerated level of 50 µg/L, contamination of 10% of the samples at levels higher than 50 µg/L indicated the need for improving production techniques by the industry.

PRACTICAL APPLICATIONS

Studies have shown that the concentration of patulin may exceed the determined limits in apple juice and in other fruit products. Its presence can be a potential threat to the health of consumers, particularly children. The results may help us in understanding what should be the level of patulin in apple juice. The awareness of the apple industry of patulin contamination in fruit and the implementation of improved techniques for the production of apple products with reduced patulin concentrations have contributed to the quality of apple juice that are available on the Iranian market.     

EFFECT OF APPLE DECAY PROPORTION ON THE PATULIN, FUMARIC ACID, HMF AND OTHER APPLE JUICE PROPERTIES

Starking apples, classified by the decay proportion on the fruit surface as sound, 30, 60 or 100% decayed were used in the production of apple juice. Then patulin, fumaric acid, HMF, pH, brix and Hunter L, a and b values of apple juice samples were determined. Patulin and fumaric acid analysis were done with HPLC. The patulin concentration in juice samples produced with Starking apples that are sound, 30, 60 and 100% decayed ranged between 0.0–15.9 μg/kg, 47.1–500.3 μg/kg, 156.4–2257.5 μg/kg, 54.9–2508.6 μg/kg, respectively. The fumaric acid concentration in the same juice samples ranged between 0.00–0.20 mg/kg, 0.23–0.69 mg/kg, 0.41–2.08 mg/kg and 1.40–4.14 mg/kg. In general, the color values (L, a, b) of the samples produced from 100% decayed apples measured by reflectance with a Hunter colorimeter were low when compared with the others.     

石榴浓缩清汁产业化技术研究

介绍了石榴浓缩清汁产业化生产工艺、加工技术及相应的产品质量标准.选用目前国际先进设备,采用此项加工技术,可生产营养损失少、具有天然风味的石榴浓缩清汁.