食品的微波加工研究新进展

近年来,微波技术因其加热速度快、效率高等优势,在食品加工中得到了广泛的应用。本文从微波技术的原理着手,对微波技术在食品加热或烹饪、干燥、杀菌以及有效成分提取等方面的最新应用进展加以阐述,并探讨微波对食品颜色、质地、营养成分、生物化学成分、复水性、微观结构等食品品质的影响,以期为微波技术在食品领域的进一步开发及规模化应用提供参考,进而促进食品行业的发展。     

肉类保藏技术(五) 微波技术的应用

微波技术作为一种新兴技术,已广泛地应用于食品加工等领域。本文介绍了微波加热的原理、特点,介绍了近年来微波技术在肉制品、谷类和果蔬等食品原料中的应用技术研究,分析了微波技术的现状及存在的问题,提出了微波技术在食品工业中的应用研究前景。     

食品的介电性质

食品的电性质在一些食品加工中很重要,这些性质包括电阻率,传导率,以及介电性质。微波加热技术广泛应用于食品的加热、干燥、脱水、烹调、杀菌以及解冻等加工中,家庭微波炉也日益普遍。微波加热的     

微波加工对食品安全性的影响

<正>微波技术是近年来比较流行的一项物理应用技术,家庭中常用的微波炉就是运用微波技术加热、加工食品的最好应用。微波食品加工具有很多优势,如加热速度快、均匀性好、热效率高和易于控制与操作等特点。基于以上优点,在粮食和蔬菜等食品领域中具有较为广泛的应用。微波加工食品的逐渐普及,给人们生活带来了极大的便利。与此同时,对食品工业规模化生产和提高食品加工效率、产值和科技含量等方面都产生了积极的推动作用。然而     

有待开发的食品微波技术

微波技术最早应用于雷达上，二十世纪三四十年代人们对微波技术在工业上的应用开始关注和研究。最早把微波技术应用于食品上的是美国，并生产出了最早的微波炉，取得了微波应用于食品的第一个专利权。尔后，微波在食品工业中的应用更为广泛，除食品烹制外，还应用于冷冻食物解冻、食品杀菌、食品干燥、食品加工等。 微波炉的普及和微波食品的开发 自二十世纪九十年代以来，随着我国城乡人民生活水平提高，微波炉已走进普通百姓家的厨房。据统计全国１９９８年底城乡居民家庭微波炉拥有率达８．４％。微波炉热效高、加热快、且无油烟、干净卫…     

可微波预油炸食品的研究

微波食品是指应用现代加工技术,对食品原料采用科学的配比和组合,预先加工成适合微波炉加热或调制,便于食用的方便食品。微波食品加工简单化和方便化,适应现代人高效率、快节奏的生活方式。但是,由于微波加热本身所固有的缺点,使得速冻的预油炸食品在微波炉中复热时,产品表面"浸湿"、"浸油",失去了香酥松脆的良好口感。所以对可微波油炸食品的研制已成为传统食品工业化中的一个重要课题。     

微波加工过程中食品温度分布规律及其均匀性研究

微波加热因其加热速度快、操作简便等特点,已成为食品加工业的研究热点之一。虽然微波加热技术在过去几十年里发展快速,但加热不均匀仍是微波加工过程中存在的主要问题,许多学者对其温度分布规律、加热均匀性改善等方面做了大量研究。该文首先介绍了微波加热技术在食品行业中的发展过程及应用优势,并阐述了微波加热的基本原理、介电特性及穿透深度的含义,在此基础上按照食品种类,对微波加工过程中发现的温度分布不均的现象进行归纳,并对现有改善均匀性的方法进行总结,改善方法包括提高电场分布均匀性、改善食品组分及几何尺寸、优化环境媒介及包装形式,最后对改善食品微波加热的均匀性研究提出几点展望。     

射频加热技术在农产品和食品加工中的应用

射频加热技术是近年来广受关注的一种加热方式，因其具有加热迅速、均匀性好、节约能源、维护成本低等特点，被广泛应用于食品和农产品的加工之中。该文首先对射频加热技术的工作原理和特点进行探讨，提出可以通过使用COMSOL软件的模拟实现来改善射频加热的均匀性；然后，通过分析近年来射频加热技术的应用文献，综述了射频加热技术在解冻、干燥、灭菌和杀虫等领域的研究进展；最后，提出了射频加热技术尚存的问题，并对未来研究方向进行展望。     

微波在食品加工中应用的原理和特点

微波技术在食品加工中的应用作为一个新的技术领域日益受到重视。微波在食品加工中的应用主要是它的热效应。微波加热的原理与其他加热方法相比有很大的区别,因此,微波加热有许多特点。本文从微波加热的原理上论述了它的特点,以期促进微波在食品加工中的正确应用。     

微波技术在食品加工中的应用

随着社会的进步,生活水平的提高,人们对饮食提出了新的要求。追求方便、安全、营养、卫生无疑是一种趋势。微波技术作为一种现代高新技术,在食品加工中的应用越来越广泛,如食品的加热、焙烤、膨化、烹调、解冻、杀菌等。可以说,微波技术在很大程度上促进了食品工业的发展。尤其是对于价值高、质量要求严、热传导率低的产品,以及用传统工艺难以解决的物料,微波在加热、杀菌技术上发挥了重要作用。     

微波辐射对淀粉结构特性的影响及其在淀粉类食品加工中应用的研究进展

微波辐射加工技术是一门新兴技术,具有穿透性好、加热均匀和快速及营养损失少等特点,在食品工业和基础研究中广泛应用。本文介绍了微波辐射的基本原理,重点阐述了微波辐射过程中的淀粉介电特性和影响因素,以及微波辐射对淀粉颗粒形貌、晶体结构、化学结构和淀粉性质的影响。同时,概述了微波辐射在淀粉类食品加热、淀粉原料改性和淀粉类食品杀菌消毒中的应用情况。最后,对微波辐射与淀粉结构特性变化相关研究中存在的问题和不足之处进行了展望,以期为微波辐射影响淀粉结构特性的作用机理和淀粉类食品的深度加工提供参考和建议。     

Research progress in fluid and semifluid microwave heating technology in food processing

Microwave is a form of electromagnetic radiation that has high penetration and heating efficiency in food processing. Uneven heating is the main problem of microwave processing, especially in solid foods. Fluid and semifluid media, which are good carriers in microwave processing, have uniform dielectric properties and good material fluidity. Herein, we review the development, application prospects, and limitations of microwave in fluid and semifluid food processing and the research progress in microwave heating with steam as carrier. The mixture of generated steam and tiny micro droplets from food material under the action of microwave can absorb microwave and transfer heat evenly, which effectively improves the uniformity of microwave heating. Due to the relatively uniform dielectric properties and consistent texture of fluid and semifluid food materials, uneven heating phenomenon during their microwave processing can be significantly inhibited. Based on the development of microwave heating technology and equipment design, the microbial inactivation and enzyme inhibition in fluid and semifluid food were improved and food product with better retention of nutrients and sensory profile were produced. Also, microwave radiation can be used to prepare the printing material or process the printed product for 3D food printing, which enhances the added value of 3D printed products and the personalization of food manufacturing. In future research, intelligent control technology can be applied in the microwave processing of fluid and semifluid food materials for various applications. Therefore, the processing conditions can be adjusted automatically.     

Research progress and application of ultrasonic- and microwave-assisted food processing technology

Microwaves are electromagnetic waves of specific frequencies (300 MHz–3000 GHz), whereas ultrasonic is mechanical waves of specific frequencies. Microwave and ultrasonic technology as a new processing method has been widely used in food processing fields. Combined ultrasonic and microwave technology is exploited by researchers as an improvement technique and has been successfully applied in food processing such as thawing, drying, frying, extraction, and sterilization. This paper overviews the principle and characteristics of ultrasonic- and microwave-assisted food processing techniques, particularly their combinations, design of equipment, and their applications in the processing of agricultural products such as thawing, drying, frying, extraction, and sterilization. The combination of ultrasonic and microwave is applied in food processing, where microwave enhances the heating rate, and ultrasonic improves the efficiency of heat and mass transfer. The synergy of the heating effect of microwave and the cavitation effect of ultrasonic improves processing efficiency and damages the cell structure of the material. The degradation of nutrient composition and energy consumption due to the short processing time of combined ultrasonic and microwave technology is decreased. Ultrasonic technology, as an auxiliary means of efficient microwave heating, is pollution-free, highly efficient, and has a wide range of applications in food processing.     

食品膨化技术及其应用

膨化技术作为一种新型食品生产技术,正逐步在食品工业中得到广泛的应用。目前膨化食品的生产技术主要包括挤压膨化技术和高温膨化技术２种类型。本文主要介绍了挤压膨化技术和高温膨化技术的膨化机理、生产工艺和流程以及它们在膨化休闲小食品生产中的应用;并对膨化食品的研究开发和微波膨化、烘焙膨化、真空油炸等新型食品膨化技术及其发展趋向进行了讨论。     

Frequency Distribution in Domestic Microwave Ovens and Its Influence on Heating Pattern

In this study, snapshots of operating frequency profiles of domestic microwave ovens were collected to reveal the extent of microwave frequency variations under different operation conditions. A computer simulation model was developed based on the finite difference time domain method to analyze the influence of the shifting frequency on heating patterns of foods in a microwave oven. The results showed that the operating frequencies of empty and loaded domestic microwave ovens varied widely even among ovens of the same model purchased on the same date. Each microwave oven had its unique characteristic operating frequencies, which were also affected by the location and shape of the load. The simulated heating patterns of a gellan gel model food when heated on a rotary plate agreed well with the experimental results, which supported the reliability of the developed simulation model. Simulation indicated that the heating patterns of a stationary model food load changed with the varying operating frequency. However, the heating pattern of a rotary model food load was not sensitive to microwave frequencies due to the severe edge heating overshadowing the effects of the frequency variations.     

微波加热对食品中酚类物质的含量及抗氧化活性的影响

酚类物质具有预防疾病和抗氧化等功效,在食品中应用广泛,但是食品烹调手段可能会影响酚类物质的组成和特性,微波加热是新兴的食品烹调加工方法,本文对微波引起食品中酚类物质和食品抗氧化活性的影响进行了综述,展望了酚类提取物的应用情况。     

Recent developments in numerical modelling of heating and cooling processes in the food industry—a review

Numerical modelling technology offers an efficient and powerful tool for simulating the heating/cooling processes in the food industry. The use of numerical methods such as finite difference, finite element and finite volume analysis to describe the heating/cooling processes in the food industry has produced a large number of models. However, the accuracy of numerical models can further be improved by more information about the surface heat and mass transfer coefficients, food properties, volume change during processes and sensitivity analysis for justifying the acceptability of assumptions in modelling. More research should also be stressed on incorporation of numerical heat and mass transfer models with other models for directly evaluating the safety and quality of a food product during heating/cooling processes. It is expected that more research will be carried out on the heat and mass transfer through porous foods, microwave heating and turbulence flow in heating/cooling processes.     

频率波动范围对家用微波炉加热模式的影响

从频率的波动范围入手,基于数值模拟的手段,研究在多模腔体设计下,实现食品热形可重复的方法。首先测量了某家用微波炉在空腔和负载加热时的频率变化,并根据其物理模型建立了数值模型,利用验证后的数值模型分析频率波动范围对受热食品温度分布的影响。结果表明:家用微波炉加热时,其加热频率随时间不断变化,当频率波动范围较大时,即使加热同一规格的食品,得到的温度分布也不相同;随着频率波动范围的缩小,食品的温度分布越来越稳定,当频率波动范围缩小为中心频率±2MHz时,受热食品的温度分布不再随频率的波动而变化。因此在多模设计的加热腔体内,可以通过控制家用微波炉的频率波动范围实现食品的稳定可重复加热。