高压脉冲电场杀菌技术在食品工业中的应用

食品杀菌是食品处理过程中的一个重要环节。高压脉冲电场杀菌因其杀菌时间短、效率高、能耗少等特点在食品灭菌中发挥着越来越重要的作用,综述了高压脉冲电场杀菌机理、特点、杀菌效果和在食品工业中不同方面的应用。并对此技术的发展前景提出了展望。     

Food Processing by Pulsed Electric Fields: Treatment Delivery, Inactivation Level, and Regulatory Aspects

Industrial implementation of pulsed electric field electro-technology (PEF) for food preservation has been rather slow, despite its potential to produce safe, nutritious and high-quality products. Several research groups around the world are in a race to validate and optimize the operation of PEF systems. Insufficient kinetic studies and inaccurate treatment delivery assessment are some of the main obstacles to the implementation of this technology. Equivalency among PEF systems, treatment delivery and control variables need to be clearly defined before actual industrial implementation takes place. Limited commercial availability of PEF systems, mainly due to the complexity and high cost of pulsers, and to technical and economical limitations of the scaling-up process, reflects into high initial investment and operation costs. This paper reviews the state of the art on the above-mentioned issues, and also discusses engineering, biological, and regulatory aspects that should be considered for optimization and commercial implementation of PEF as a food preservation technology.     

Inactivation of Peach Polyphenoloxidase by Exposure to Pulsed Electric Fields

The effect of exponential decay pulsed electric fields on peach (var. Miraflores) polyphenoloxidase (PPO) was evaluated. Electric field intensities ranged from 2.18 to 24.30 kV/cm. Pulses of 0.02 and 0.08 ms width were applied in mono‐ and bipolar mode. A 70% maximum reduction in enzymatic activity was achieved after 5 ms using 0.02 ms width pulses in bipolar mode at 24.30 kV/cm. Peach PPO activity decreased following an exponential decay kinetic model. Rate constants ranged from 9.0 to 138 μS^‐1 in monopolar mode, and from 8.7 to 235 μS^‐1 in bipolar mode. An exponential decay model may describe the relationship between residual PPO and input electric energy.     

Review: Potential of High Hydrostatic Pressure and Pulsed Electric Fields for Energy Efficient and Environmentally Friendly Food Processing

The application of emerging, novel processing techniques such as high hydrostatic pressure or pulsed electric fields can be utilized to replace, enhance or modify conventional techniques of food production. In addition to quality improvements and consumer benefits by gentle microbial inactivation and improvement of mass transfer processes, their potential to improve energy efficiency and sustainability of food production will be discussed within this review.     

Review: Potential of High Hydrostatic Pressure and Pulsed Electric Fields for Energy Efficient and Environmentally Friendly Food Processing

The application of emerging, novel processing techniques such as high hydrostatic pressure or pulsed electric fields can be utilized to replace, enhance or modify conventional techniques of food production. In addition to quality improvements and consumer benefits by gentle microbial inactivation and improvement of mass transfer processes, their potential to improve energy efficiency and sustainability of food production will be discussed within this review.     

高压脉冲电场(PEF)非热处理的加工原理与安全控制

高压脉冲电场非热处理技术因处理时间短,温升小,能耗低和杀菌效果明显等成为目前杀菌工艺中研究最为活跃的技术之一,而且在功能物质提取与保持物质活性等方面也展现了较好的应用前景。本文着重对该技术在食品加工中的作用原理、工艺过程和加工中的安全质量控制等方面进行阐述。     

高压电场技术在食品加工中的应用研究进展

高压电场技术是一种重要的非热处理技术,由于其效率高、能耗小、无污染、对食品品质几乎无影响,因此在食品加工领域具有广阔的应用前景。目前,该技术主要应用于食品杀菌、食品物料干燥、辅助食品冷冻解冻以及提取食品生物活性物质等方面。本文概述了高压电场技术的基本原理,分析了高压电场对食品中组分的影响,综述了其在食品加工中的应用研究进展及作用机制,并对其应用前景进行了展望,以期为高压电场技术在食品加工中的应用提供理论参考。     

Apricot Nectar Processing by Pulsed Electric Fields

Application of pulsed electric fields to process apricot nectar by determining the pH, °Brix, total acidity, conductivity, color, non-enzymatic browning index, concentration of mineral ions, and retention of ascorbic acid and beta carotene as well as inactivation of Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Pseudomonas syringae subs. syringae, Erwinia carotowora, Penicillum expansum, and Botrytis cinerea was explored in this study. Processing of apricot nectar did not cause a significant difference in measured attributes (p > 0.05). However, inactivation of all microorganisms was significantly increased with increased electric field strength and treatment time (p ≤ 0.05). Microbial inactivation data fit both the Weibull distribution and log-logistic model.     

高压脉冲电场作用下蛋清蛋白功能性质和结构的变化

研究高压脉冲电场(PEF)作用下蛋清蛋白功能性质与结构的变化。结果表明：25～35kV/cm PEF处理100～800μs可引起蛋清蛋白结构改变,蛋白质分子展开,疏水基团和巯基外露,蛋清蛋白的起泡和乳化功能提高,当PEF处理强度(电场强度和处理时间)增加时,蛋白质结构改变程度增加,蛋白质表面疏水基团和巯基增多,则会发生疏水作用和二硫键交联作用,SDS-PAGE电泳显示蛋清蛋白形成蛋白质聚集体,溶解度下降,蛋清蛋白起泡和乳化功能下降。     

高压脉冲电场(PEF)对蛋清蛋白功能特性的影响

蛋清蛋白不仅具有重要的营养价值,而且还具有重要的功能特性如乳化性、起泡性等,作为一种重要的蛋白原料,本实验研究了高压脉冲电场对蛋清蛋白功能性质的影响。结果表明:蛋清蛋白的溶解度在脉冲电场强度大于35kV/cm时下降;蛋清蛋白的乳化性、起泡能力、泡沫稳定性及疏水性先随脉冲电场强度增加而增大,但当脉冲电场强度大于30kV/cm后,蛋清蛋白的乳化性、起泡能力、泡沫稳定性及疏水性下降;随着脉冲电场数的增加,蛋清蛋白的溶解度、乳化性、起泡能力、泡沫稳定性及疏水性变化不显著。     

Kinetics of Peroxidase Inactivation in Carrot Juice Treated with Pulsed Electric Fields

Peroxidase activity accounts for quality losses in many plant‐based foods. The paper provides insight into the inactivation kinetics of peroxidase (POD) in carrot juice treated with pulsed electric fields (PEF). Juice samples were subjected to electric field intensities of 20 to 35 kV/cm for 300 to 2000 μs. Up to 93% of the initial activity was inactivated after treating at 35 kV/cm for 1500 μs. POD activity inactivation correlated well with the increase in energy density input. A first‐order fractional conversion model best fitted the experimental results. Other kinetic approaches such as the Fermi's model can be used to estimate residual POD activity values in treated juices as a function of electric field strength. Practical Application : Pulsed electric fields (PEF) are a processing technology that can be used for the pasteurization of liquid food products. Peroxidase activity inhibition is required in carrot juices to prevent undesirable quality losses, such as discoloration, flavor changes, and loss of nutrients. The most significant processing parameters ruling POD inactivation in PEF‐treated carrot juice are identified and mathematical modeling of experimental data is conducted.     

高压脉冲电场对大豆分离蛋白结构特征的影响

本文研究了高压脉冲电场对大豆分离蛋白结构特征的影响。结果表明：在其它脉冲条件一定时，脉冲处理时间在0-288us范围，大豆分离蛋白的分子量、粒径及二级结构改变较小或几乎没有改变。当脉冲处理时间大于432us时，由于蛋白质分子变性、亚基的解离以及通过非共价键相互作用重新聚集，大豆分离蛋白的分子量、粒径发生了变化，形成了大分子的聚集体，但二级结构变化较小。     

高压脉冲电场杀菌电力系统的研究

高压脉冲电场用于液态食品杀菌 ,具有时间短、能耗低 ,能有效保存食品营养成份和天然色、香、味特征 ,非常具有工业化应用前途。本文重点介绍高压脉冲电场杀菌电力系统的结构特点和应用。     

脉冲电场和热处理对鲜榨苹果汁贮藏期品质的影响

研究高压脉冲电场处理 (PEF)和热处理对鲜榨苹果汁贮藏期的品质影响。研究发现 ,4℃贮藏 3 0d ,PEF( 2 5kV/cm ,1 0 3 5个脉冲 )和热处理 ( 72℃、1 5s和 90℃、60s)可以降低果汁中微生物数量 ,而且对苹果汁的电导率、Brix和 pH值的影响不显著 (P >0 0 5 )。但是热处理对果汁的浊度有显著影响 (P <0 0 5 ) ,而PEF处理差异不显著 (P >0 0 5 )。PEF处理苹果汁的L值和色值均优于热处理 ,感官评价中风味和色泽比热处理的苹果汁更接近对照的风味和色泽。     

Pulsed Electric Field Processing of Beer: Microbial, Sensory, and Quality Analyses

ABSTRACT: In this study, pulsed electric field (PEF) treatment of beer, effectiveness of PEF treatment on microbial inactivation, effects of PEF treatment on sensory properties, and detection of electrode material migration were explored. Beer samples were treated by PEF for the inactivation of natural flora and inoculated cultures of Saccaromyces uvarum, Rhodotorula rubra, Lactobacillus plantarum, Pediococcus damnosus , and Bacillus subtilis . Inactivation induced by the PEF treatment was 0.5, 4.1, 4.3, 4.7, 5.8, and 4.8 log₁₀ colony-forming units/mL in the above microorganisms, respectively ( P < 0.05). There was a significant increase in the amount of Cr, Zn, Fe, and Mn ions in the beer samples after PEF treatment ( P < 0.05) leading to a statistically significant degradation in flavor and mouth feel. Further studies are needed to optimize electrode materials and PEF treatment to minimize or eliminate this degradation.     

脉冲电场协同酶法制备淀粉锌络合物及其显微结构的研究

以普通南方大米淀粉为原料,采用α-淀粉酶和糖苷酶协同制备多孔大米淀粉,研究了酶含量、酶配比和时间等因素对多孔淀粉水解率和吸油率的影响,得出制备多孔大米淀粉的最佳条件为:酶含量1.0%(以淀粉干基计),酶配比(α-淀粉酶:葡萄糖苷酶)1:12,处理时间12 h,所得多孔淀粉的水解率为50%,吸油率为96.3%。在此基础上,分别选择原淀粉和多孔大米淀粉(水解率分别为30%、40%和50%)与0.1 mol/L的乙酸锌水溶液进行脉冲电场处理协同强化锌络合,脉冲电场处理条件为电压20 V、频率1 k Hz、流速24 m L/min,有效处理时间分别为2.88×10~3μs、8.64×10~3μs和14.4×10~3μs;借助扫描电子显微镜(SEM)及红外光谱(FT-IR)对淀粉络合物的显微结构进行研究,并通过原子吸收测定淀粉络合锌的含量,最终得出:水解率40%的多孔大米淀粉经脉冲电场(2.88×103μs)处理后的锌络合含量最高,为352.85 mg/100 g。     

Application of High-Intensity Pulsed Electrical Fields in Food Processing

High-intensity pulsed electric fields (HIPEF) treatment is gaining popularity as a nonthermal processing technology due to its instant penetration characteristics and short processing time. It is evolving as a potential alternative to other thermal and chemical unit operations in food processing. In recent years, numerous research groups have demonstrated the possibility of inactivation of a range of microorganisms and food quality-related enzymes. This article focuses on the potential to use the HIPEF treatment as a preservation technology and as an adjunct to other processing steps, such as extraction, osmotic dehydration, air dehydration, and rehydration.     

Application of High-Intensity Pulsed Electrical Fields in Food Processing

High-intensity pulsed electric fields (HIPEF) treatment is gaining popularity as a nonthermal processing technology due to its instant penetration characteristics and short processing time. It is evolving as a potential alternative to other thermal and chemical unit operations in food processing. In recent years, numerous research groups have demonstrated the possibility of inactivation of a range of microorganisms and food quality-related enzymes. This article focuses on the potential to use the HIPEF treatment as a preservation technology and as an adjunct to other processing steps, such as extraction, osmotic dehydration, air dehydration, and rehydration.     

Effects of Pulsed Electric Fields on the Activities of Microorganisms and Pectin Methyl Esterase in Orange Juice

Orange juice was treated with pulsed electric fields (PEF) in a pilot‐plant system to optimize PEF‐processing conditions for maximum microbial inactivation and to investigate the effects of PEF on pectin methyl esterase (PME) activity. Electric‐field strengths of 20,25,30, and 35 kV/cm and total treatment times of 39, 49, and 59 μs were used. Higher electric‐field strengths and longer total treatment times were more effective to inactivate microorganisms and PME (p < 0.05). PEF treatment of orange juice at 35 kV/cm for 59 μs caused 7–log reductions in total aerobic plate count and yeast and mold counts. About 90% of PME activity was inactivated by PEF treatment at 35 kV/cm for 59 μs. PEF‐treated orange juice at 35 kV/cm for 59 ms did not allow growth of microorganisms and recovery of PME at 4, 22, and 37 °C for 112 d.     

肉类保藏技术(八) 高压脉冲在食品保藏中的应用

高压脉冲电场是近年发展起来的一项食品保藏新技术。其具有处理时间短、能量使用率高、能保持食品原有风味和营养成分等特点,能避免食品因加热处理带来的不良影响。本文介绍了高压脉冲电场的基本装置、杀菌效果及机理、在食品保藏中的应用、对食品质量的影响以及其发展前景与展望。