苹果浓缩汁生产工艺对酚类物质影响的研究

为了提高苹果浓缩汁的色值指标,采用HPLC法,对苹果浓缩汁生产单元操作中酚类物质的含量进行检测。实验结果表明:杀菌、酶解、吸附这三步操作同时影响果汁中的酚类物质含量。选择性地去除有颜色的多酚氧化产物,是理想的苹果浓缩汁加工工艺。     

Evaluation of the sensory properties of irradiated apple juice concentrate

Summary Apple juice concentrate with or without addition of aroma essence was irradiated with doses of 0.5–2.0 kGy. The irradiated samples and nonirradiated control were evaluated for colour, clarity, odour and taste. The trained eight-member panel of judges examined the concentrate using a 10-cm long unstructured graphical scale method. In addition, the intensity of some odour and sensory profiles were obtained. Slight sensory differences could be noticed between the irradiated and nonirradiated samples, these differences were more pronounced in the concentrate irradiated with the dose of 2.0 kGy. Sensory evaluation of the colour confirmed the brightening of the irradiated samples which was also observed by spectrophotometric measurements. The clarity of the concentrate was not influenced by irradiation.

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Bestimmung der sensorischen Eigenschaften des bestrahlten Apfelsaftkonzentrates

Zusammenfassung Das Apfelsaftkonzentrat mit oder ohne Zugabe von Aromaessenz wurde mit Dosen von 0,5 bis 2,0 kGy bestrahlt. Die bestrahlten Proben und die nicht bestrahlte Kontrollprobe wurden auf Färbung, Klarheit, Geruch und Geschmack untersucht. Das Apfelsaftkonzentrat wurde durch acht erfahrene Personen unter Verwendung einer 10 cm langen graphischen Skala geprüft. Zusätzlich wurde die Intensität der Geruchsund Geschmacksprofile geschätzt. Es wurden geringfügige sensorische Unterschiede zwischen bestrahlten und nicht bestrahlten Proben gefunden. Die Unterschiede waren stärker wahrnehmbar nach der Bestrahlung mit 2,0 kGy. Sensorische Untersuchung der Färbung bestätigte die Aufhellung der bestrahlten Proben, die ebenfalls bei den spektrophotometrischen Messungen beobachtet wurde. Die Bestrahlung hatte keine Wirkung auf die Klarheit des Konzentrates.

     

高色值脱农残浓缩苹果汁的生产工艺

以自行研制的冷破碎设备为基础,研究了榨前分离工艺对提高浓缩苹果汁品质的影响;通过试验对比分析了新工艺前后苹果汁的色值、农残、多酚、果胶等各项指标的变化情况。试验结果表明:冷破碎榨前分离工艺使苹果汁的色值升高了97.41%;果胶含量降低34.78%,多酚含量降低3.42%;农药残留敌百虫含量降低61.67%,敌敌畏含量降低了86.94%。冷破碎榨前分离技术能明显提高果汁的品质,是高色值脱农残浓缩苹果汁生产的良好工艺,更是果汁加工技术的发展趋势,值得应用推广。     

Evaluation of 18 apple varieties for their suitability for juice production

Eighteen apple varieties have been evaluated both organoleptically and chemically for their suitability as raw material for apple juicep reduction. Fruits, for the main part, were evaluated in 1977 and 1978, and the few varieties showing significant differences were re-evaluated in 1979. Large differences in aroma and taste were observed between the various varieties. On a 0-10 scale, the best varieties had scores of 7-8, while the poorest scored 2-4. Evaluation of the overall taste was strongly correlated with ‘fruit aroma’. Sugar, acid and polyphenol contents also played a role in taste. The sugar: acid ratio, rather than total acid or total sugar content, was very important in determining whether a juice was evaluated as very sour or very sweet. A sugar:acid ratio of 15-16 was judged to give the optimal balance of sweetness-sourness in the juice.     

鲜榨苹果汁与浓缩苹果汁酿酒特性的比较

以苹果鲜榨汁和浓缩汁为原料,分别通过添加蔗糖和稀释的方式使发酵起始糖度为200g/L进行酒精发酵。对发酵产品的常规理化指标和总酚,总类黄酮以及黄烷醇含量进行测定,并对发酵产品进行感官鉴评。实验结果表明:稀释浓缩汁和鲜榨果汁酒样总酸含量分别为2.6g/L和3.2g/L。鲜榨果汁酒样总酚含量、总类黄酮以及黄烷醇含量均高于稀释浓缩汁酒样。两种酒各具特色,鲜榨汁酒样果香浓郁,稀释浓缩汁酒样酒香醇厚。      

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     

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     

清洁生产在浓缩苹果汁加工厂节水减污中的应用

通过对浓缩苹果汁加工厂用水量及排水水质的监测，确定重点节水减污单元。在清洁生产思想的指导下改进重点节水减污单元生产工艺并加强管理，达到了节水减污的目的。     

清洁生产在浓缩苹果汁加工厂节水减污中的应用

通过对浓缩苹果汁加工厂用水量及排水水质的监测,确定重点节水减污单元。在清洁生产思想的指导下改进重点节水减污单元生产工艺并加强管理,达到了节水减污的目的。     

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。     

考马斯亮兰G-250法测定苹果浓缩汁生产中的蛋白含量

考马斯亮兰G-250法(Bradford法)是目前灵敏度最高的蛋白质测定法。将其用于检测果汁中的蛋白．研究发现，苹果汁中的几种主要成分，如；果糖、葡萄糖、蔗糖和苹果酸等不会对测定造成干扰，其最大吸收波长不变，标准曲线的线性较好，并对苹果浓缩汁生产中不同工序物料中的蛋白含量进行测定，测定结果的精密度较好，加标回收率在97．76％～103．20％之间。     

Patulin reduction in apple juice from concentrate by UV radiation and comparison of kinetic degradation models between apple juice and apple cider

Patulin, a mycotoxin produced by several genera of fungi, including Byssochlamys, Aspergillus, and Penicillium, has been an important concern in apple cider and apple juice due to its toxicity and health consequences. In this study, the effects of UV on the patulin level, physical and chemical properties, and sensory attributes in apple juice from concentrate were investigated. Kinetic modeling of patulin reduction by UV radiation in apple juice from concentrate was calculated and compared with the degradation rate observed previously in apple cider. From an initial patulin contamination of approximately 1,000 ppb (μg/liter), the UV exposure, ranging from 14.2 mJ/cm(2) (one pass) to 99.4 mJ/cm(2) (seven passes), was successful in reducing patulin levels by 72.57% ± 2.76% to 5.14% ± 0.70%, respectively. Patulin reduction by UV radiation followed first-order kinetic modeling in a fashion similar to first-order microbial inactivation. An exponential correlation between UV exposure and the percentage of patulin remaining was observed, giving an r(2) value of 0.9950. Apple juice was repeatedly exposed to 14.2 mJ/cm(2) for each treatment, and patulin levels were significantly decreased when compared with the level obtained with the previous UV exposure treatment. While there were no significant differences in the percentages of titratable acidity and ascorbic acid (P > 0.05), there were minor yet random sampling differences in pH and degrees Brix (1 °Brix is 1 g of sucrose in 100 g of solution; the °Brix represents the soluble solids content of the solution as percentage by weight [%, wt/wt]) (P ≤ 0.05). A significant difference (P ≤ 0.05) in sensory perception for the finished apple juice was detected between the control and the full seven-pass UV radiation treatment using an experienced consumer panel and a triangle test. Patulin reduction by UV radiation from both the current study and a previous study involving apple cider was compared, which showed that both matrices strongly fit a first-order kinetic degradation model. However, the kinetic constant for degradation in apple juice was approximately 5.5 times greater than that observed in an apple cider matrix.     

苹果浓缩汁后混浊的研究进展

综述了苹果浓缩汁后混浊的反应机理、影响因素及抑制方法。     

Simulation modelling and optimal operation of an apple juice concentrate plant

It is possible to operate apple juice concentrate plants to maximize profits. To do this a mathematical model of the plant is made and solved by linear programming. To this end an actual plant was selected and all the relevant variables were measured. An optimal operation pattern was found. The analysis allowed identification of operating bottlenecks in the clarification and concentration sections. The response of the plant to prevention of milling waste and juice dilution, as well as to debottlenecking, was quantified. It was shown that the selection of apple varieties has a significant effect on profit. In situations of scarcity or surplus of raw material, the optimal operation and corresponding profit can be found in each case.     

苹果浓缩汁后混浊的形成机理及控制

概述了引起苹果浓缩汁后混浊的因素(酚类、蛋白质、高价阳离子、阿拉伯聚糖、果胶、淀粉、微生物、明胶残留)、形成机理以及综合调控的方法。     

苹果浓缩汁加工中香气回收成分分析

以同一苹果浓缩汁生产线上收集的300倍回收香精、预浓缩回收液水和浓缩回收液水为实验材料,分析了三个样品中香气物质成分,旨在确定苹果浓缩汁加工过程中香气物质的变化特性和浓缩回收冷凝水中香气物质的主要成分。顶空固相微萃取结合气质联用测定各样品香气成分的差异,共检测出47种香气成分。结果表明:a.300倍回收香精中富含酯类、醛类、醇类香气物质,苹果浓缩汁预浓缩过程中,香精回收工艺收集了主要的芳香酯类(乙酸-2-甲基-1-丁酯、乙酸-2-苯基乙酯、乙酸乙酯等)和醛类[(E)-2-己烯醛、苯甲醛等]香气物质,芳香醇类香气物质相对较少。b.苹果汁预浓缩回收液水中苹果的典型醇类(1-己醇41.70%)香气物质含量高且丰富,同时预浓缩回收液水含有较高相对含量枯焦气息的苯酚类化合物(2,5-二叔丁基-对甲基苯酚13.26%、2,4-二叔丁基苯酚11.16%)。c.苹果汁浓缩回收液水富含苹果典型酯类香气物质(乙酸-2-甲基-1-丁酯、乙酸丁酯、乙酸甲酯等)和醇类香气物质(2-甲基-1-丁醇等),由加工过程中苹果汁中香气物质进一步逸散产生。     

Modeling flux behavior for membrane filtration of apple juice

The flux behavior of ceramic membranes with different pore sizes (0.2, 0.1 and 0.02 μm) was examined during dead-end membrane filtration of depectinized control (CTJ) and ascorbic acid treated (AAJ) apple juices. A new model based on an expanded exponential relationship was developed. The model represented the flux with precision over the entire filtration process for both juice types and all membrane pore sizes. Two parameters, A and B, provided a measure of the rate of flux decline. The same approach was used to model the permeate flux of CTJ for various 0.2 μm pore size polymeric membrane materials operated in a dead-end mode, and for tubular ultrafiltration membranes of different pore sizes (9, 20 and 100 kDa) operated in crossflow mode.     

Reuse,treatment, and discharge of the concentrate of pressure-driven membrane processes

Application of pressure-driven membrane processes (microfiltration, ultrafiltration, nanofiltration, and reverse osmosis) results in the generation of a large concentrated waste stream, the concentrate fraction, as a byproduct of the purification process. Treatment of the concentrate is a major hurdle for the implementation of pressure-driven membrane processes since the concentrate is usually unusable and has to be discharged or further treated. This paper reviews possibilities to treat or discharge the concentrate: (i) reuse, (ii) removal of contaminants, (iii) incineration, (iv) direct or indirect discharge in surface water, (v) direct or indirect discharge in groundwater, and (vi) discharge on a landfill. General guidelines are given for the choice of a proper method as a function of the origin and composition of the water treated. Next, the further treatment of the concentrates in four application areas of pressure-driven membrane processes (drinking water industry, leather industry, and membrane treatment of landfill leachates and of textile process waters) is discussed.     

影响浓缩苹果汁中富马酸因素的研究

采用高效液相色谱法测定不同质量的苹果原料中富马酸含量，获得了不同加工工艺条件下富马酸变化趋势，提出了控制富马酸超标的方法。     

Application of biosensors in early detection of contamination with lactic acid bacteria during apple juice and concentrate production

The aim of Collective Research Project QUALI-JUICE (COLL-CT-2005, Co Nr 012461) was to introduce the biosensors in control of microbiologically pure apple juice production. Three commercial lactate biosensors were used and compared with enzyme kits assays. Parallel the microbiological analysis of the production process at one juice producing enterprise was done. The results of lactic acid assay with biosensors were in good correlation with those obtained by enzyme kits. The main benefit of biosensor use was shortening of measurement time as compared with assay by enzyme kit and possibility to measure at line. The concentration of l-lactic acid in apple pulp could be correlated with the number of lactic acid bacteria. Pasteurization process was eliminating lactic acid bacteria and the concentration of lactic acid was at this stage not exceeding 0.1 g L⁻¹. The final product (apple concentrate) contained in some cases very high amounts of lactic acid indicating secondary microbiological contamination after pasteurization step. Parallel microbiological analysis of production process and lactate assay indicated that the critical point during production was prolonged vacuum filtration after pasteurization.