高压脉冲电场技术在食品质量与安全中的应用进展

高压脉冲电场技术作为国际上最先进的非热加工技术之一,以其良好的应用特性如能耗低、省时、处理温度低、效率高和对食品原有品质保存效果好等特点,吸引了国内外广大研究者的关注。与其它食品加工技术相比,高压脉冲电场技术不仅具有更好的杀菌、钝酶效果,还能有效降解残留农药,减少食品添加剂的使用,而且基本不影响食品的原有品质和营养特性。因此,将高压脉冲电场技术有效应用于食品工业中,可大大提高食品质量与食品安全性,为食品行业的发展开辟新途径。作者介绍了高压脉冲电场的处理装置、加工机理以及在食品质量与安全中的应用途径,并对高压脉冲电场技术的应用前景进行了展望。     

超高压灭菌技术在保障食品品质及安全性的 应用现状与展望

超高压灭菌技术能有效对食品进行杀菌和灭酶, 是食品加工业中的一种新型的非热力加工技术。本文综述了超高压灭菌原理、主要特点以及超高压处理对食品感官品质、酶活性、微生物、营养成分的影响, 并分析了超高压处理产品的安全性及其在食品加工业中的应用前景。     

高压对牛乳理化性质和成分的影响

高压食品加工是一种非热杀菌技术,是指在室温或低温下用100-800MPa高压处理食品。与传统的热杀菌比较,它具有很多优点,不仅能杀死微生物钝化酶类,而对食品的营养成分和感官品质改变较小。本文综述了高压处理对牛奶物理化学性质和成分的影响。     

超高压处理技术在水产品保鲜中的研究进展

超高压技术是指对食品施加100 MPa以上的压力,使其在常温或较低温度下达到杀菌效果的冷杀菌处理技术。文章系统阐述超高压处理技术对水产品中的微生物、酶、组织结构、色泽、风味与营养成分等方面的影响,并对超高压技术在水产品杀菌保鲜中的应用进行总结与展望。     

Effects of high electric field pulses on enzymes

The application of high electric field pulses (HELP) in food processing offers potential both as a preservation technology, and as an adjunct to other processes, such as drying, extraction. In respect of the use of pulsed electric fields as preservation technology, the impact of this technology on food quality degrading enzymes is of particular interest. This paper presents a detailed literature review on the effects of pulsed electric fields on enzymes, complemented with recent results on the impact of this HELP-technology on enzymes, obtained within EU project ‘High electric field pulses: food safety, quality and critical process parameters’ (contract FAIR-CT97-3044).     

Recent Advances in the Use of High Pressure as an Effective Processing Technique in the Food Industry

High pressure processing is a food processing method which has shown great potential in the food industry. Similar to heat treatment, high pressure processing inactivates microorganisms, denatures proteins and extends the shelf life of food products. But in the meantime, unlike heat treatments, high pressure treatment can also maintain the quality of fresh foods, with little effects on flavour and nutritional value. Furthermore, the technique is independent of the size, shape or composition of products. In this paper, many aspects associated with applying high pressure as a processing method in the food industry are reviewed, including operating principles, effects on food quality and safety and most recent commercial and research applications. It is hoped that this review will promote more widespread applications of the technology to the food industry.     

蒸汽爆破技术的应用现状与发展前景

蒸汽爆破技术是指将物料在高温高压的蒸汽下处理一段时间,然后在0.01 s内瞬时泄压实现“爆破”,热能转换为机械能做功,蒸汽以冲击波的形式作用于物料,改变其结构组成的一种物理化学处理技术。通过气相蒸煮过程的热化学作用以及蒸汽爆破阶段的物理做功,原料致密有序的结构被打破,酶及化学试剂的可及性增加,易于后续反应的进行。蒸汽爆破技术以其安全、高效、环保等特点,在食品领域有广阔的发展前景。该文介绍了蒸汽爆破技术的原理、优缺点及影响因素,概述了其发展历史,并分别总结了蒸汽爆破技术在植物性原料以及动物性原料中的应用现状,最后对其发展前景作出了展望,以期为蒸汽爆破技术在食品领域进行更广阔的应用提供一定的参考价值。     

Reaction Kinetics at High Pressure and Temperature: Effects on Milk Flavor Volatiles and on Chemical Compounds with Nutritional and Safety Importance in Several Foods

Consumers demand, in addition to excellent eating quality, high standards of safety and nutrition in ready-to-eat food. This requires a continuous improvement in conventional processing technologies and the development of new alternatives. Prevailing technologies such as thermal processing can cause extensive and undesirable chemical changes in food composition while minimal processing strategies cannot eliminate all microbial pathogens. This review focuses on pressure-assisted thermal processing, a new alternative for shelf-stable foods. Its implementation requires an analysis of reaction kinetics at high pressure and elevated temperature. Acceleration of the inactivation of bacterial spores by the synergistic effect of pressure and temperature is expected to allow processing at lower temperature, shorter process time, or a combination of both. Therefore, thermal degradation of quality is expected to be lower than that of conventional thermal processes. However, few studies have focused on the effect of the conditions required for the inactivation of bacterial spores on the kinetics of chemical reactions degrading food quality, particularly at the high temperatures required for the processing of low-acid foods.     

超声波灭酶机制及其在食品加工中的应用

超声波是一项新型食品加工技术,已被广泛用于食品加工中各个操作单元,如杀菌、灭酶、果汁脱气等。本文首先概括了超声波钝化食品内源酶的机理,随后分析了影响超声波灭酶效果的因素,最后介绍了超声场下酶失活动力学模型及该技术在食品加工中的应用现状,指出其中存在的问题,以期望为超声波灭酶技术在食品加工中的开发与利用提供理论支持。      

超高压升/卸压过程对杀菌效果的影响研究进展

相比传统食品热杀菌技术,超高压杀菌技术不仅能达到良好的杀菌效果,还能保持食品原有的颜色、风味、营养等品质。为了保证超高压杀菌的可靠性与安全性,就需要对影响超高压杀菌效果的因素进行研究。以往的研究主要集中在压力、保压时间及温度等方面等因素,然而,一系列研究表明,超高压升/卸压过程也会影响杀菌效果。本文介绍了影响超高压杀菌效果的主要因素,重点介绍升/卸压过程对杀菌的影响,以期推进超高压杀菌技术在我国食品加工领域的应用。     

The inactivation of Salmonella by cold atmospheric plasma treatment

The need to fulfill consumer demand for fresh products without compromising microbial food safety and quality has increased the interest of the food industry in low-temperature innovative processes for food preservation. Compared to thermal processing, these emerging technologies rely on physical processes, such as high hydrostatic pressure, ionizing radiation, ultrasonication, pulsed electric fields, ultraviolet radiation and cold plasmas that are able to inactivate microorganisms at ambient or sublethal temperatures. This latter treatment is one of the more promising food preservation technologies. In this review we survey the main factors affecting the sensitivity and resistance of Salmonella to cold atmospheric gas plasmas. A more complete understanding of the factors involved in inactivation by this emerging technology will enhance its implementation in food preservation.     

Quality-Related Enzymes in Plant-Based Products: Effects of Novel Food-Processing Technologies Part 3: Ultrasonic Processing

High-power ultrasound is a versatile technology which can potentially be used in many food processing applications including food preservation. This is part 2 of a series of review articles dealing with the effectiveness of nonthermal food processing technologies in food preservation focusing on their effect on enzymes. Typically, ultrasound treatment alone does not efficiently cause microbial or enzyme inactivation sufficient for food preservation. However, combined with mild heat with or without elevated pressure (P ≤ 500 kPa), ultrasound can effectively inactivate enzymes and microorganisms. Synergistic effects between ultrasound and mild heat have been reported for the inactivation of both enzymes and microorganisms. The application of ultrasound has been shown to enhance the rate of inactivation of quality degrading enzymes including pectin methylesterase (PME), polygalacturonase (PG), peroxidase (POD), polyphenol oxidase (PPO), and lipoxygenase (LOX) at mild temperature by up to 400 times. Moreover, ultrasound enables the inactivation of relatively heat-resistant enzymes such as tomato PG1 and thermostable orange PME at mild temperature conditions. The extent to which ultrasound enhances the inactivation rate depends on the type of enzyme, the medium in which the enzyme is suspended, and the processing condition including frequency, ultrasonic intensity, temperature, and pressure. The physical and chemical effects of cavitation are considered to be responsible for the ultrasound-induced inactivation of enzymes, although the dominant mechanism depends on the structure of the enzyme.     

New Insights into the High‐Pressure Processing of Meat and Meat Products

Abstract: For years, high‐pressure processing has been viewed as useful for pasteurizing food while maintaining the quality of fresh food. However, even at moderate pressure, this process is not without effects on food, especially on meat products. These effects are especially important because pressure greater than 400 MPa is generally necessary to achieve efficient microbial inactivation. In this review, recent advances in the understanding of the impacts of high pressure on the overall quality of raw and processed meat are discussed. Many factors, including meat product formulation and processing parameters, can influence the efficiency of high pressure in pasteurizing meat products. It appears that new strategies are applied either (i) to improve the microbial inactivation that results from high pressure while minimizing the adverse effects of high pressure on meat quality or (ii) to take advantage of changes in meat attributes under high pressure. Most of the time, multiple preservation factors or techniques are combined to produce safe, stable, and high‐quality food products. Among the new applications of high‐pressure techniques for meat and meat‐derivative products are their use in combination with temperature manipulation to texturize and pasteurize new meat products simultaneously.     

健康与方便的新概念

<正> “即饮”作为现代消费者对未来饮料的要求,呼声越来越高。这不仅体现在包装形式的量身订做上,更体现在饮料的内容上。毫无疑问,对于酒精饮料和非酒精饮料来说,已混合成型的产品更具优势,比如消费者更倾向于诸如雪碧、混合可乐或啤酒混合饮料这样方便又味美的产品。     

Impact of irradiation on the safety and quality of poultry and meat products: a review

For more than 100 years research on food irradiation has demonstrated that radiation will make food safer and improve the shelf life of irradiated foods. Using the current food safety technology, we may have reached the point of diminishing returns even though recent figures from the CDC show a significant drop in the number of foodborne illnesses. However, too many people continue to get sick and die from eating contaminated food. New and under utilized technologies such as food irradiation need to be re-examined to achieve new levels of safety for the food supply. Effects of irradiation on the safety and quality of meat and poultry are discussed. Irradiation control of the principle microbial pathogens including viruses, the differences among at-risk sub-populations, factors affecting the diminished rate of improvement in food safety and published D values for irradiating raw meat and poultry are presented. Currently permitted levels of irradiation are probably not sufficient to control pathogenic viruses. Typical gram-negative spoilage organisms are very sensitive to irradiation. Their destruction leads to a significant increase in the acceptable shelf life. In addition, the destruction of these normal spoilage organisms did not provide a competitive growth advantage for irradiation injured food pathogens. Another of the main focuses of this review is a detailed compilation of the effects of most of the food additives that have been proposed to minimize the negative quality effect of irradiation. Most of the antimicrobials and antioxidants used singly or in combination produced an increased lethality of irradiation and a decrease in oxidation by-products. Combinations of dosage, temperature, dietary and direct additives, storage temperature and packaging atmosphere can produce meats that the average consumer will find indistinguishable from non-irradiated meats. A discussion of the production of unique radiological by-products is also included.     

食品中酶的微波钝化技术研究进展

食品中的酶对食品质量具有正反两方面的影响,因此在食品加工过程中,有效控制食品中酶的活性显得尤为重要。传统热处理是钝化食品中酶的主要方式,而近年来一些新型的钝化酶技术已成为新的研究热点。文中就微波钝化酶技术的原理与微波钝化酶的影响因素进行了综述,同时概述了微波钝化酶技术在食品中的应用状况,最后对微波钝化酶技术发展趋势提出了展望。     

Enhancing Food Processing by Pulsed and High Voltage Electric Fields: Principles and Applications

ABSTRACT

Improvements in living standards result in a growing demand for food with high quality attributes including freshness, nutrition and safety. However, current industrial processing methods rely on traditional thermal and chemical methods, such as sterilization and solvent extraction, which could induce negative effects on food quality and safety. The electric fields (EFs) involving pulsed electric fields (PEFs) and high voltage electric fields (HVEFs) have been studied and developed for assisting and enhancing various food processes. In this review, the principles and applications of pulsed and high voltage electric fields are described in details for a range of food processes, including microbial inactivation, component extraction, and winemaking, thawing and drying, freezing and enzymatic inactivation. Moreover, the advantages and limitations of electric field related technologies are discussed to foresee future developments in the food industry.

This review demonstrates that electric field technology has a great potential to enhance food processing by supplementing or replacing the conventional methods employed in different food manufacturing processes. Successful industrial applications of electric field treatments have been achieved in some areas such as microbial inactivation and extraction. However, investigations of HVEFs are still in an early stage and translating the technology into industrial applications need further research efforts.     

Effect of material properties and processing conditions on the prediction accuracy of a CFD model for simulating high pressure thermal (HPT) processing

High pressure thermal (HPT) processing is a candidate technology for achieving commercial sterility of low acid shelf-stable and chilled food products. A major food safety challenge to the implementation of HPT lies in achieving temperature uniformity inside the vessel during processing. Computational Fluid Dynamics (CFD) modelling can be used to predict locally specified temperature profiles arising during HPT processing, but it is essential that such models are validated, and that predictions agree well with temperatures measured in actual processes. In this work, the effects of variations in inputs for compression fluid properties and process conditions (i.e., the applied pressure profiles) on the prediction accuracy of a CFD model for a Stansted 3.6 L Isolab HPTS system were studied. Good agreement was found between simulated and measured temperature distributions when accurate compression heating coefficients for the compressed materials and actual pressure profiles were used as inputs of the model. Inaccurate approximations of these values and conditions resulted in much less useful models, highlighting the importance of attention to detail in input data for CFD models of HPT processing, in these still early stages of development of the technology.     

Simultaneous microwave heating and three-dimensional MRI temperature mapping

In microwave processing a number of microwave specific factors cause non-uniform heating patterns with hot and cold spots. Hence, the quality and safety of food products can be compromised. Capabilities for creating three-dimensional temperature maps are therefore essential for control, optimisation and validation of microwave heating processes. This paper will discuss the advantages and shortcomings of different techniques for measuring temperatures in electromagnetic fields. The unique possibilities of applying non-invasive magnetic resonance imaging (MRI) for temperature mapping are demonstrated by experiments. In particular, in-situ measurements with three-dimensional isotropic resolution of 1 mm and a reasonable temporal resolution of 13 s are presented and compared with infrared thermography and fibre optic thermometry. Numerical simulations are employed to assess the extent of two kinds of systematic errors involved in the MRI experiment.

Industrial relevance

The presented approach for measuring temperatures volumetrically in-situ during a microwave heating process allows for the determination of three-dimensional temperature distributions; hence hot and cold spots in the products can be detected.Although the experiments in this study have been conducted in a high-resolution MRI tomograph with a small sample diameter, the same approach works in larger scale medical tomographs with bores up to 1 m diameter, making it also relevant for industrial scale applications.The costs of an MRI tomograph are still high; however, having premium products where quality would be adversely affected by overheating and safety compromised by under-processing, the application of such technology would be of great benefit for the food industry. Two approaches for applying this technology in industrial applications are possible:1. In-situ temperature measurement would allow for a feed-back control of the process, which is essential for microwave applications to be applied to processing of high quality products.2. The technology can be used for random tests, which in turn allows for evaluating temperature performance (level and uniformity), as well as fine-tuning of coupled electromagnetics/CFD models to simulate and optimise processing lines.No calibration of such system is needed and only a small amount of unbound water has to be present in the product for the methodology to be applied on or close to an industrial processing line.With a feed-back controlled microwave process, which can be simulations or real processes, the main advantage of such applications, the increase of process rates due to the volumetric heating can be utilised and at the same time the quality of the treated product can be optimised and product safety can be ensured by improving temperature uniformity. Furthermore, regulatory bodies can be satisfied.     

高静压与温度协同加工对食品微生物的影响

高静压协同温度处理的方法已成为高压食品加工研究的重要方向。本研究着重讨论高静压协同温度处理对微生物生命活动的影响、致死微生物的机理及其动力学等，由此建议该技术研究应在充分利用其它有利因素的前提下，力求降低工作压力；高静压协同中温与高静压协同低温加工的对象也应有所不同。