电导仪在啤酒糖化CIP生产中的应用

在CIP自动清洗系统中正确使用JUMOCT1920型电导仪．可保证糖化所有设备CIP的正常清洗、自动配浓、在线检测电导率、及时补充清洗过程中的酸碱消耗及清洗液的浓度．方便了操作,保证了产品的质量。     

关于电导率仪测试结果稳定性的影响因素分析

从校对、试样处理、仪器稳定性方面分析对电导率测定的影响,得出结论:校准液的类型及校准方式对电导率测试结果影响较大,可采用"84μS/cm标准液单点校准"作为电导率仪最佳校准模式;纸浆经过过滤处理后电导率呈规律降低,但测试数据的波动性并未减小,因此可采用直接测试分散后浆料的试样处理方式进行测试;使用0.001mol/L KCl溶液作为监控样对电导率仪进行监控可更好地控制电导率仪的自身稳定性。     

多参数精确测量——Seven Excellence~(TM)系列仪表全新上市

<正>梅特勒-托利多新一代Seven ExcellenceTM系列模块组合式多参数测试仪于2012年10月正式上市。Seven ExcellenceTM系列产品包含pH/mV测量仪、电导率仪、pH/离子浓度测量仪和双通道pH/电导率测量仪:Seven ExcellenceTMpH/mV测量仪(S400)—可测量pH、ORP、ISFET(离子场效应);Seven ExcellenceTM电导率仪(S700)—可测量电导率、盐度、TDS、电阻率、电导灰分;Seven     

淀粉糖生产过程相关因素影响灰分变化的研究

测定了果葡糖浆和葡萄糖浆生产过程中原料、中间物料和产品的灰分、电导率、p H、钠离子浓度等指标。结果表明,果葡糖浆和葡萄糖浆生产过程中,灰分的变化与电导率、p H、钠离子浓度的变化具有相关性,为进一步研究淀粉糖生产在线监控灰分含量提供了基础数据和技术参考。     

无机电解质对浆料Zeta电位的影响

通过改变浆料中无机电解质/阳离子聚酰胺-环氧氯丙烷树脂(PAE)的浓度,采用德国Mütek公司SZP-10型Zeta电位仪测量对比浆料Zeta电位及电导率的变化,研究无机电解质对含PAE浆料Zeta电位及电导率的影响。实验表明:随着Na+/Ca2+/Mg2+浓度的增加,浆料Zeta电位绝对值逐渐下降;随着导电离子浓度的增多,浆料电导率逐渐升高。随着PAE用量的增加,浆料的Zeta电位逐渐增加,当用量达到一定值后,Zeta电位的电性发生反转,由负变正,再继续增加PAE用量后,浆料Zeta电位继续升高。PAE用量固定在1%时,随着Na+/Ca2+/Mg2+浓度的增加,浆料的Zeta电位逐渐降低,电导率逐渐升高。     

颜料颗粒与溶剂型UV油墨连结料二元系电导率研究

通过选用不同浓度的颜料颗粒,用溶剂型UV油墨连结料配置二元系系统,测量该体系的电导率,分析不同颜料颗粒以及不同浓度对系统电导率的影响。结果表明,这种系统的电导率是由3个部分共同贡献的,即油墨连结料的电导率、微细颗粒溶解产生的电导率和颗粒对电流的阻隔作用产生的电导率。要精确了解电导率与系统中颗粒浓度的关系,还需要进一步研究微细颗粒溶解产生的电导率和颗粒对电流的阻隔作用产生的电导率对所测量电导率的影响。     

卤料盐度检测方法比较研究

用盐度计、电导率仪和硝酸银滴定三种盐度测定方法,监测传统禽肉卤制工艺下,不同批次卤料中盐度变化规律。分析三种盐度测定方法间相关性,探讨在工业生产中实施卤料盐度快速检测的可行性。结果表明,盐度计、电导率仪法均具有简便、快速、准确等优势,可作为生产中卤料盐度监测方法应用。     

卤料盐度检测方法比较研究

用盐度计、电导率仪和硝酸银滴定三种盐度测定方法,监测传统禽肉卤制工艺下,不同批次卤料中盐度变化规律。分析三种盐度测定方法间相关性,探讨在工业生产中实施卤料盐度快速检测的可行性。结果表明,盐度计、电导率仪法均具有简便、快速、准确等优势,可作为生产中卤料盐度监测方法应用。      

卤料盐度检测方法比较研究

用盐度计、电导率仪和硝酸银滴定三种盐度测定方法，监测传统禽肉卤制工艺下不同批次卤料中盐度变化规律。分析三种盐度测定方法间的相关性，探讨在工业生产中实施卤料盐度快速检测的可行性。结果表明，盐度计、电导率仪法均具有简便、快速、准确等优势，可作为生产中卤料盐度监测方法应用。     

温度和淀粉对果葡糖浆及蜂蜜电导率的影响

通过电导率仪检测温度和淀粉对果葡糖浆及蜂蜜电导率的变化情况。结果表明:不同品种蜂蜜的电导率不一样,但均随着温度的升高而增大,其变化趋势符合指数曲线;果葡糖浆的电导率随着温度升高和淀粉添加量增大而升高;向蜂蜜中添加淀粉后,其电导率也随着温度升高增加。掺入不同量淀粉后果葡糖浆和蜂蜜的电导率随温度变化也符合指数曲线关系。     

Ascorbic acid losses during processing of French fries and potato chips

The fate of ascorbic acid during processing of French fries and potato chips was observed. Both products still contained a remarkable amount of ascorbic acid despite of losses during processing. A variety dependency was given. Main reduction was after blanching (French fries) and washing (potato chips). Especially in potato chips a high concentration of dehydroascorbic acid was detected.     

On-line monitoring of fat,dry matter and acrylamide contents in potato chips using near infrared interactance and visual reflectance imaging

The contents of dry matter, oil and acrylamide are some of the most relevant parameters in the quality control of potato chips. Near infrared spectroscopy (NIR) is a common technique for routine analysis of bulk chemistry in different raw materials and products because it allows a fast and non-destructive analysis of samples. The objective of this research was to investigate the possibilities of using on-line NIR monitoring of acrylamide, moisture and oil content in potato chips. Sixty samples of potato chips from individual frying runs were measured on-line using a VIS/NIR interactance line scanner. The same samples were analysed in the laboratory to determine their corresponding moisture, acrylamide and oil contents. The mean VIS and NIR spectra for the 60 samples were modelled against the reference values for acrylamide, fat and dry matter using partial least squares regression (PLSR), and the regression models were validated using full cross-validation. On-line NIR interactance was found to predict fat and dry matter of potato chips with high accuracy, i.e. prediction errors of 0.99 and 0.86% (w/w), respectively. The corresponding correlations between predicted values and reference values were 0.99 and 0.97 for fat and dry matter. For acrylamide an average prediction error of 266 μg/kg was achieved using NIR and VIS signals in combination. The correlation between predicted values and reference values was 0.83 for this model. The system may be used to separate samples with very high acrylamide contents from samples with average to low contents.     

微波生产低油马铃薯片的工艺条件的探讨

通过单因素试验,对利用微波生产低油马铃薯片工艺中影响产品脆度、色泽和含油量的一些因素进行了探讨。结果表明:利用微波生产马铃薯片可以降低薯片含油量到20%以下;干燥前食盐水溶液浸泡处理(1.5%～2.0%食盐水溶液浸泡5min)和涂油前用豆奶粉裹衣处理,均能降低产品的含油量,提高马铃薯片的脆度;同时,适量的豆奶粉裹衣处理,能赋予产品良好的色泽,豆奶粉的用量6%比较适宜;冷冻处理能加深产品的色泽,但是对产品的脆度和含油量的影响不大。     

前处理对甘薯变温压差膨化效果影响

研究不同切片厚度、热烫、冷冻和浸渍等4个因素对甘薯变温压差膨化干燥产品含水率、硬度、色泽和复水比的影响。结果表明:甘薯切片的最佳厚度为2 mm,物料经浸渍处理所得产品品质较优;糖液浸渍预处理使物料加速失水,对物料色泽和外形的保持有显著的作用;在果葡糖浆、麦芽糖浆、麦芽糖醇中,选用麦芽糖浆作为预处理的浸渍溶液,且浓度为15%,浸渍时间为8 h产品质量较好。     

Modeling of acrylamide formation and browning ratio in potato chips by artificial neural network

The artificial neural network (ANN) modeling approach was used to predict acrylamide formation and browning ratio (%) in potato chips as influenced by time x temperature covariants. A series of feed-forward type network models with back-propagation training algorithm were developed. Among various network configurations, 4-5-3-2 configuration was found as the best performing network topology. Four neurons in the input layer were reflecting the asparagine concentration, glucose concentration, frying temperature, and frying time. The output layer had two neurons representing acrylamide concentration and browning ratio of potato chips. The ANN modeling approach was shown to successfully predict acrylamide concentration (R = 0.992) and browning ratio (R = 0.997) of potato chips during frying at different temperatures in time-dependent manner for potatoes having different concentrations of asparagine and glucose. It was concluded that ANN modeling is a useful predictive tool which considers only the input and output variables rather than the complex chemistry.     

Reduction of acrylamide formation by selected agents in fried potato crisps on industrial scale

Great interest and rapid research efforts on acrylamide in foods followed an announcement in April 2002 by the Swedish National Food Authority and the University of Stockholm. Reduction of acrylamide in high-temperature processing foods, including selection of the raw material and variation of processing parameters, etc. were extensive reported. In this research, effect of some agents on acrylamide formation was investigated. A glucose-asparagines reaction model system was used to test the effect of ferulic acid, catechin, CaCl₂, NaHSO₃, and l-cysteine on inhibition of acrylamide formation and three efficient inhibitors, NaHSO₃, CaCl₂ and l-cysteine were screened. The results showed that immersing of the fresh potato chips using different concentration of the agents greatly inhibited acrylamide formation in fried potato crisps, and the efficiency increased as their concentrations increased; among them, l-cysteine is the most efficient agent but CaCl₂ is most potential. Effects of these food additives on the texture of fried potato crisps were also studied. It was found that l-cysteine showed little effect on the texture of the crisps and CaCl₂ is regarded as the suitable choice because of its low price and the acceptable mouth feel of fried crisps treated by CaCl₂, although it increased the brittleness. Moreover, the application of CaCl₂ in industrial production of fried potato crisps was also studied. In the blanching process (deactivation process of enzymes at 85 °C), a computerized electrical conductivity detector was used to keep the concentration of CaCl₂ at constant and the result showed that immersion of potato slices in CaCl₂ solution at 5 g/L reduced acrylamide formation by more than 85% in fried crisps.Industrial relevanceThis research presents a technology to inhibit acrylamide formation in fried potato chips by immersion of fresh potato chips with some food additives. The approach suggested that cysteine and calcium chloride significantly decreased the content of acrylamide in fried potato chips and their concentrations could be kept constant by using a conductor as a detector.     

Influence of raw material on storage behaviour of potato chips (author's transl)

The influence of storage duration on the lipid and fatty acid content of potato tubers and on the concentration of volatile aroma substances in potato chips were studied. An increase in the unsaturated fatty acids of potato tubers was found during the first months of storage. The higher lipid content of early maturing varieties as compared with late maturing ones may be explained by decreased physiological maturity of these potatoes. Among the aroma substances the constituents hexanal, pentanal, and pentane are possible important indicators for the rancidity of potato chips. Relationships between differing storage conditions of chips and their reeping quality were indicated by volatile aroma substances, especially hexanal.     

马铃薯片常压油炸工艺优化研究

对影响常压油炸马铃薯片品质的工艺参数进行了优化研究。结果表明,在柠檬酸溶液浓度为0.10%～0.25%、预干燥时间为10～40min和油炸温度为170～200℃的范围内,以薯片的丙烯酰胺含量、含油量和脆度为指标,常压油炸薯片的最佳工艺条件为:薯片切片采用柠檬酸溶液浓度为0.20%的柠檬酸水溶液浸泡后,于85℃预干燥30min,最后用180℃恒温油炸至熟。     

Antioxidant capacity of potato chips and snapshot trends in acrylamide content in potato chips and cereals on the Canadian market

The concentration of acrylamide was measured in selected varieties of five brands of potato chips and breakfast cereals over a 5-year period. Most of the products were purchased in one locality in Canada. Samples were analysed by an isotope dilution (¹³C₃) acrylamide method. They were extracted with water, partitioned with dichloromethane, filtered through a 5 kDa centrifuge filter, cleaned-up on HLB Oasis polymeric and Accucat mixed mode anion and cation exchange SPE columns, and analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The acrylamide concentration in potato chips varied from 106 to 4630 ng g^?1, while values in cereals varied from 50 to 347 ng g^?1. Wide variations were observed between brands, within brands over time, and between lots of the same brand. A subset of potato chip samples was analysed for in vitro antioxidant activity. No relationship was found between antioxidative capacity of potato chips and their acrylamide content.     

The fluidization characteristics of potato chips

The fluidization characteristics of potato chips and potato cuboids have been investigated and the results compared with correlations obtained for the fluidization of plastic cuboids.
It was found that potato chips and cuboids behaved in a similar manner to the plastic cuboids and that the plastic cuboid correlations may be used to predict the performance of potato chips and cuboids.
Certain fluidization parameters may be used to predict the minimum transportation velocity of potato chips in vertical pipelines.