高压脉冲电场非热杀菌技术研究进展

高压脉冲电场杀菌能保持食品的原有风味、具有处理时间短、能耗低。本文介绍了高压脉冲电场杀菌的原理、工艺流程、影响因素、处理效果及其研究现状和进展。该项技术有望部分取代现有的食品热杀菌技术。     

高压脉冲电场对食品中生物大分子的影响

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。着重就高压脉冲电场对食品中的一些生物大分子如酶类、蛋白质等的影响进行综述。     

高压脉冲电场技术对液体食品品质的影响研究进展

高压脉冲电场技术是国际上最为先进的食品非热加工技术之一,具有效率高、处理温度低、对食品的色泽,风味和营养成分保存效果好、能耗低等一系列优点。文章介绍高压脉冲电场技术的杀菌机理,影响其杀菌效果的主要因素,对液体食品品质的影响以及对高压脉冲电场技术应用前景的展望。     

高压脉冲电场杀菌系统的研究进展

杀菌是食品加工处理过程中的一个重要工序。杀菌效果的好坏直接影响食品的安全与卫生,传统的杀菌技术会对食品的营养价值和风味产生一定的副作用。高压脉冲电场(PEF)杀菌技术因其杀菌效果好、快速、低耗、安全等优点而被广泛地用于食品杀菌中。文章介绍国内外高压脉冲电场杀菌技术对高压脉冲发生器、处理室、杀菌系统的影响,并综述对其应用的研究。     

国内外高压脉冲电场食品杀菌关键技术概况

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,高压脉冲发生器是产生高压脉冲电场的主要仪器。综述脉冲电场杀菌机理,高压脉冲发生器的设计原理,并分析国内外各种高压脉冲发生器及其处理室设计的优缺点。     

食品非热力杀菌新技术

综述了国内外食品非热力杀菌的新技术 ,特别介绍了微生物抑制剂、等离子体杀菌、高压脉冲电场杀菌、超高压灭菌技术对杀菌效果的影响因素。这些技术有望部分取代现有的食品热杀菌技术。     

食品物理冷杀菌技术研究进展

物理冷杀菌技术是一种新技术,既能杀灭食品中微生物、又能最大限度保持食品色泽、香味及营养成分。该文着重介绍超高压杀菌、高压脉冲电场杀菌、脉冲非热等离子体杀菌、脉冲强光杀菌、磁力杀菌、膜分离除菌、紫外线杀菌、辐照杀菌、微波杀菌、超声波杀菌、电阻杀菌、半导体光催化杀菌等技术的杀菌原理及其在食品中应用。     

高压脉冲电场杀菌技术在紫菜食品加工中的应用

高压脉冲电场(PEF)用于食品杀菌具有时间短、能耗低、能有效保存食品营养成分和天然色、香、味特征,非常具有工业化前途。本文是高压脉冲电场(PEF)在食品杀菌中的实践及它在工业生产加工中的应用。鲜紫菜加工厂应用PFE杀菌的技术工艺过程,设备的选型,参数设计。以往高压脉冲电场(PEF)技术多数停留在实验研究阶段,实际生产中的应用不多,此项目是对高压脉冲电场(PEF)杀菌技术的集成实施,从生产反馈中获得优化数据,有较好的推广前景。     

高压脉冲电场在食品灭菌方面的研究现状及展望

高压脉冲电场杀菌能保持食品的原有风味和营养成分,具有处理时间短、能耗低的特点.介绍了高压脉冲电场的杀菌机理、处理系统、影响因素、处理效果及其经济性这五个方面,并展望其在食品灭菌方面的应用前景.     

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。     

脉冲电场在固体食品加工中的应用

脉冲电场(pulsed electric field, PEF)技术被视为21世纪食品非热加工技术发展史上的里程碑之一。迄今为止, PEF已广泛应用于果汁、牛奶和液态蛋等液体食品的杀菌和钝酶,并朝着商业化道路前进。然而,与PEF在液体食品中的应用相比,其在固体食品中的应用还处于起步阶段。固体食品的表面虽然也富含微生物,但PEF处理这类食品对微生物的影响较小,因此不能将其应用于固体食品的杀菌保鲜。仅管如此, PEF诱导的细胞电穿孔使其可作为一种预处理方法 ,通过增加质量和能量传递效率的方式来进行辅助固体食品的干燥、冻融、烹饪等。因此,本文重点介绍基于PEF细胞响应的高品质食品加工应用,总结PEF处理室的特点及PEF预处理固体食品的相关机制。最后,本文探讨了PEF在固体食品加工中的主要障碍和前景,为PEF未来在食品行业的发展拓宽研究方向。     

A review of kinetic models for inactivating microorganisms and enzymes by pulsed electric field processing

As a non-thermal technology, pulsed electric field (PEF) treatment can be utilized in food processing and bioengineering for the inactivation of microorganisms and quality-degrading enzymes, as well as the retention of health-related compounds and the extension of shelf-life. Development of kinetic models that fit the degree of microbial inactivation and the loss of food quality is important to improve the efficiency of PEF treatment. The current review aims to provide an overview of the kinetic models used by PEF for microbial inactivation in liquid foods. Kinetics modeling for the destruction of microorganisms, inactivation of enzymes, retention of health-related compounds, and extension of shelf-life are discussed. Additionally, the fitting accuracy of several models, as well as issues that need further investigation, are discussed to promote further understanding and the deployment of PEF technology.     

脉冲电场对食品中酶的影响

综述了高强脉冲电场的产生,对酶作用的潜在优势以及操作参数、酶的种类、含酶介质对PEF作用酶的效果影响.列举了PEF对碱性磷酸酶、蛋白酶、多酚氧化酶、脂酶等食品中几种重要酶的作用效果,并探讨了其对酶作用的几种机理.最后对PEF钝酶的工业利用进行了展望.     

Nonthermal pasteurization of liquid foods using high‐intensity pulsed electric fields

Processing foods with high‐intensity pulsed electric fields (PEF) is a new technology to inactivate microorganisms and enzymes with only a small increase in food temperature. The appearance and quality of fresh foods are not altered by the application of PEF, while microbial inactivation is caused by irreversible pore formation and destruction of the semipermeable barrier of the cell membrane. High‐intensity PEF provides an excellent alternative to conventional thermal methods, where the inactivation of the microorganisms implies the loss of valuable nutrients and sensory attributes. This article presents recent advances in the PEF technology, including microbial and enzyme inactivation, generation of pulsed high voltage, processing chambers, and batch and continuous systems, as well as the theory and its application to food pasteurization. PEF technology has the potential to improve economical and efficient use of energy, as well as provide consumers with minimally processed, microbiologically safe, nutritious and freshlike food products.     

Pulsed electric field-assisted glycation of bovine serum albumin/starch conjugates improved their emulsifying properties

In this study, pulsed electric field (PEF, at electric field strengths from 3.5 to 8.1 kV/cm, pulse duration (τ) = 50 μs) was used to assist the glycation between soluble potato starch and bovine serum albumin (BSA). Moreover, the physicochemical and stability of BSA/starch conjugates emulsions were characterized. Spectroscopic investigations (A₄₂₀ and UV–Vis spectra) proved that PEF treatment (3.5–5.7 kV/cm) facilitated Maillard reaction between BSA and soluble starch. Moreover, the grafting degree (%) and the protein solubility of BSA/starch conjugates increased after PEF treatment but declined at higher electric field strengths. PEF treatment (at 3.5–5.7 kV/cm) decreased the particle sizes, surface hydrophobicity and fluorescence emission intensity of BSA/starch conjugates. Furthermore, emulsions stabilized by PEF-treated conjugates (at electric field strengths 3.5–5.7 kV/cm) exhibited smaller droplet sizes and higher adsorbed protein (AP%), indicating improved emulsion stability. Similarly, emulsions stabilized by PEF-induced conjugates (at electric field strengths 3.5–5.7 kV/cm) had better stability at pH = 4.6 and against different ionic strengths (150-300 mM NaCl). Differential scanning calorimetry (DSC) patterns showed that emulsions stabilized by PEF-treated conjugates had better freeze-thaw stability. In conclusion, PEF as a green technology could assist glycation and enhance the emulsifying properties of protein-polysaccharides conjugates.Industrial relevanceApplying green technologies in the food industry is critical for sustainable food production. As an eco-friendly food processing approach, PEF has been utilized in food industries to inactivate enzymes and microorganisms without affecting the nutritional quality of treated foodstuffs. Moreover, emulsions are widely applied in the food, drug delivery, and pharmaceutical industries. In our research, PEF could facilitate the Maillard reaction between soluble starch and BSA and improve the emulsifying properties of BSA/soluble starch conjugates. The results of this work could provide fundamental information on the mechanism of PEF-induced Maillard reaction and how PEF can improve the emulsifying properties of the conjugates. Thus, this work could help for increasing PEF applications in the food industries.     

Pulsed electric field and mild heating for milk processing: a review on recent advances

Pulsed electric field (PEF) treatment consists of exposing food to electrical fields between electrodes within a treatment chamber, which can improve the preservation of fresh-like products such as milk. Although several studies support the use of PEF technology to process milk at low temperature, these studies reported microbial reductions of around 3 log₁₀ cycles and also indicated a limited impact of PEF on some endogenous and microbial enzymes. This scenario indicates that increasing the impact of PEF on both enzymes and microorganisms remains a major challenge for this technology in milk processing. More recently, combining PEF with mild heating (below pasteurization condition) has been explored as an alternative processing technology to enhance the safety and to preserve the quality of fresh milk and milk products. Mild heating with PEF enhanced the safety of milk and derived products (3 log₁₀–6 log₁₀ cycles reduction on microbial load and drastic impact on the activity enzymes related to quality decay). Moreover, with this approach, there was minimal impact on enzymes of technological and safety relevance, proteins, milk fat globules, and nutrients (particularly for vitamins) and improvements in the shelf-life of milk and selected derived products were obtained. Finally, further experiments should consider the use of milk processed by PEF with mild heating on cheese-making. The combined approach of PEF with mild heating to process milk and derived products is very promising. The characteristics of current PEF systems (which is being used at an industrial level in several countries) and their use in the liquid food industry, particularly for milk and some milk products, could advance towards this strategy. © 2019 Society of Chemical Industry     

Inactivating effect of pulsed electric field on lipase in brown rice

Pulsed electric field (PEF) treatment was applied to brown rice grains in a treatment chamber which was surrounded by organic glass as walls around a pair of horizontally paralleled plate electrodes to investigate the feasibility of PEF on low moisture food materials. Based on a monolayer of brown rice grains the results showed that the lipase activity could be significantly inactivated by PEF. Among the PEF parameters, the voltage was the most important to the inactivating efficiency, followed by frequency and pulse width; while the time was less dominant. The interactions between voltage and pulse width and between frequency and pulse width also contributed to the lipase inactivation significantly. By using Box–Behnken design, response surface methodology was applied to optimize the process and a well fitting model was obtained with PEF parameters, voltage, frequency, pulse width, and residence time.Industrial relevancePulsed electric field (PEF) is a low temperature and environment friendly technology in food processing. It is promising and has received considerable attention over the years in the past. PEF has been applied to inactivate microorganisms or enzymes. However, research work regarding PEF focused almost only on liquid food processing so far. There has been no report of PEF on solid food materials. Rice bran is abundant and nutritious, but it could not be stored for a long time because enzymolysis takes place soon after it is scraped off from rice grains. If the PEF could be used for lipase inactivation in brown rice grains, the stabilized rice bran should be obtained after milling during the material convey. It would be another effective and in-line rice bran stabilization technique potential in the rice industry. Furthermore, the application scope of PEF in food industry could be widened.     

Behavior of the surviving population of Lactobacillus plantarum 564 upon the application of pulsed electric fields

The behavior of the surviving population of Lactobacillus plantarum 564 growing in MRS broth after pulsed electric field (PEF) treatments of different intensities was monitored by isothermal calorimetry, optical density and plate counts. Bacterial cells were treated with monopolar square pulses at varying nominal electric field strengths and number of pulses, corresponding to applied energies of 34.6, 65.8 and 658.1 J/cm³. After the PEF treatment, samples were inoculated into the MRS broth and incubated at 37 °C. The presented results show that surviving bacterial cells resume growth after a treatment-dependent delay. Both the untreated and treated cultures had similar growth rates, but the latter showed a higher growth rate during the late-growth phase, and the growth rate increased with the intensity of applied electric field. After the PEF treatment, the surviving population of bacteria was less susceptible to killing by further PEF application, showing that this subpopulation was less sensitive to the PEF treatment and could grow again.Industrial relevanceThe application of pulsed electric field (PEF) technology as a non-thermal alternative to traditional pasteurization of liquid foods has received considerable attention during the last years. Effective inactivation for most of the spoilage and pathogenic microorganisms has been shown in fruit and vegetable juices and milk with little or no impact on nutritional and sensorial properties of the food. However, very little is known about the growth abilities of the surviving population. Ensuring food safety requires a better understanding of the behavior of the surviving populations of microorganisms which may be recovering from sub lethal injury, such as PEF-induced stress. This paper reveals that the surviving population of the bacteria subjected to the PEF treatment could grow again, showing higher growth rates as the intensity of the PEF treatment increased. Also, the new bacterial population showed higher resistance to further PEF treatment. Therefore, for industrial application of the PEF technology, an in-depth characterization of surviving microorganisms in the treated product is required. Moreover, the evidence of bacterial persistence indicates that the PEF technology, as a non-thermal alternative to traditional pasteurization, could not completely replace thermal treatment, but can be applied as a supplement treatment.     

高压脉冲电场技术在热带果汁加工中的应用前景

高压脉冲电场杀菌技术(简称PEF)是一项新兴的食品非热加工技术,在果蔬汁的加工中已显示出优越性.对国内外近年来关于PEF对果蔬汁中酶的影响、灭菌的效果及对其品质的影响等方面进行综述,分析热带果汁加工中存在的主要问题及PEF技术在热带果汁加工中的应用前景.     

A Comparison of Pulsed Electric Field Resistance for Three Microorganisms with Different Biological Factors in Grape Juice via Numerical Simulation

Pulsed electric field (PEF) is a promising nonthermal food preservation technology that is based on the use of electric field to eradicate spoilage and pathogenic microorganisms in food products. The effect of various biological factors on the transmembrane potential of different microorganisms (Staphyloccocus aureus, Escherichia coli DH5α, and Saccharomyces cerevisiae) was investigated by means of both numerical simulation and experimental method. The PEF resistance of different microorganisms in grape juice was compared by applying field strength of 12–24 kV/cm, treatment time of 30–180 μs, and an initial temperature of 30?ºC. The results showed that S. cerevisiae exhibited the least resistance to PEF treatment, E. coli DH5α the second, and S. aureus the third. The simulation results indicated that larger cells like S. cerevisiae presented the higher values of transmembrane potential and induced field strength around the cells compared to E. coli DH5α and S. aureus, which led to a less resistance to PEF treatment. The effect of cell orientation on the induced transmembrane potential was very slight (1.67 % for E. coli DH5α and 3.43 % for S. cerevisiae). The thicker cell membrane caused concentrated electric field in the cell membrane, which enhanced the sensitivity of microorganism to PEF treatment. However, both transmembrane potential and electric field strength decreased with the thickness of cell wall increasing. According to both experimental and simulation results, it was evident that there was significant difference in the inactivation rate between different microorganisms, which could be largely attributed to the biological factors of different microorganisms.