Impact of small scale fermentation technology on food safety in developing countries

Fermentation is one of the oldest technologies used for food preservation. Over the centuries, it has evolved and been refined and diversified. Today, a variety of food products is derived from this technology in households, small-scale food industries as well as in large enterprises. Furthermore, fermentation is an affordable food preservation technology and of economic importance to developing countries. In the report of an FAO/WHO Workshop (FAO/WHO, 1996), fermentation was reviewed and the nutritional and safety aspects of fermentation technologies and their products were assessed. Fermentation enhances the nutritional quality of foods and contributes to food safety particularly under conditions where refrigeration or other foods processing facilities are not available. Hazard Analysis and Critical Control Point (HACCP) studies of some fermented products have demonstrated that depending on the process and the hygienic conditions observed during preparation, some fermented foods, e.g. togwa prepared in Tanzania, may pose a safety risk. Fermented foods must therefore be studied following HACCP principles and small-scale food industries and households must be advised on the critical control points of fermentation processes and the control measures to be applied at these points. This paper reviews the risks and benefits of fermentation and demonstrates the application of the HACCP system to some fermented foods in developing countries.     

Diverse food-based applications of nuclear magnetic resonance (NMR) technology

Nuclear magnetic resonance (NMR) spectroscopy is one of the most common investigative techniques used by both chemists and biochemists to identify molecular structures as well as to study the progress of chemical reactions. Magnetic resonance imaging (MRI), another type of NMR technology, has extensively been used in medical radiology to obtain soft tissue images for diagnostic purposes in medicine. Food scientists have also explored the use of both NMR and MRI and continue to develop a wide range of applications for food analysis and food processing. This review begins with a brief introduction to NMR and then focuses on current diverse NMR applications in food research and manufacturing. Topics covered include chemical compositional analysis and structural identification of functional components in foods, determination of composition and formulation of packaging materials, detection of food authentication, optimization of food processing parameters, and inspection of microbiological, physical and chemical quality of foods. This review also emphasizes the pros and cons of specific NMR applications in the analysis of representative foods such as wine, cheese, fruits, vegetables, meat, fish, beverages (i.e. tomato juice and pulp, green tea, coffee) and edible oils, as well as discussing both the challenges and future opportunities in NMR applications in food science.     

New trends in food processing

In this work some of the newest trends in food processing are reviewed. This revision intends to provide an updated overview (including works published until February 2001) on the newest food processes, including food manufacturing, preservation, and control. Modern processes for food and food ingredients manufacturing based on membrane technology, super-critical fluid technology, and some applications of biotechnology are presented, mainly applied to obtain functional foods, "all-natural" enriched foods, probiotics and prebiotics. Also included is a critical assessment concerning non-thermal preservation techniques used for food preservation, such as high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, hurdle systems, etc. Finally, a group of new analytical techniques (i.e., molecular techniques such as Polymerase Chain Reaction (PCR), food image analysis, and biosensors) and their use for food and process control is reviewed.     

质子转移反应质谱在食品挥发性有机物检测分析中的应用

挥发性有机化合物(volatile organic compounds,VOCs)是食品风味的主要组成成分,同时也包含了食品特性的大量信息。直接检测食品释放的VOCs来进行食品科学和技术方面的研究具有便利的优点,已成为食品检测领域的重要研究方向。质子转移反应质谱(proton transfer reaction-mass spectrometry,PTR-MS)作为一种痕量VOCs检测技术,具有灵敏度高、响应时间短、操作简单且样品无需前处理等优点,可以在几秒钟内获得VOCs的绝对浓度,因此能够实时监测食品相关过程中VOCs的变化情况,对食品安全监督、质量控制以及新产品的研发等提供有力帮助。本文首先介绍了PTR-MS的工作原理、基本结构及发展现状,然后按照PTR-MS的全谱图扫描检测和VOCs实时监测两种检测方式详细总结了其在食品领域的应用和研究现状,并对其发展前景做出了展望。     

辐照技术对食品及包装材料迁移规律的影响

随着食品辐照技术的迅速发展,辐照食品的安全性也逐渐受到广大消费者的重视。辐照技术可以杀死食物中的致病微生物及部分的腐败细菌,抑制食物劣变的生理和生化过程,使食物不易腐败,起到保持食物新鲜的作用。辐照技术的优势很多,但是辐照技术对包装材料的物理化学变化也不容忽视,食品包装中大多数的食品是与包装材料直接接触,辐照对包装材料的影响也会直接影响到食品的安全。目前国内外对60Co-γ辐照技术和电子束辐照技术的应用最为广泛,文章将分别论述2种辐照技术的特点及研究、应用现状,旨在为今后辐照技术的安全发展提供参考。     

脂质组学技术及其在食品科学领域应用研究进展

脂质是食品中重要的营养物质之一,作为一类复杂的生物分子,在不同的生物分子加工过程中发挥着许多关键作用,脂质也影响着食品的品质、营养和安全,与许多慢性疾病的发生有直接的联系。脂质组学作为组学技术中的新兴学科,被广泛应用于食品科学等重要领域,随着检测技术手段的不断发展和完善,脂质组学技术也在不断地更新。本文主要介绍了脂质分类和功能与脂质组学技术及其在食品科学领域中的应用,以期为脂质组学技术在食品科学领域的应用提供参考。     

Food Technological Applications for Optimal Nutrition: An Overview of Opportunities for the Food Industry

Abstract: An increasingly important determinant in food choice is the growing consumer concern about nutrition and health. This focusing of consumer interest on the food supply, and also extensive research and technological developments in food science will provide further opportunities for new product development. The Food‐Based Dietary Guidelines of the World Health Organization (WHO) and European Union (EU) legislation on health claims play an important role in regulating information to the public about a wholesome diet and for improving the availability and affordability of nutritious food choices to consumers. More specifically, the food industry can contribute by reducing the number of energy‐dense products; by improving the nutrient profile of processed food through the reduction of salt, added sugar, trans‐fatty acid, and saturated fat content. As a result, food science and technology are prompted to create a new framework for these food‐based dietary guidelines, principally in the areas of food physics, methods of food storage and preservation, nutrient restoration and fortification of foods, and the development of health‐focused designer foods and functional foods. The aim of this review is to provide an overview of some further opportunities for new product development and nutrition research. Some topics related to the energy reduction of foods include: dilution and structure design, carbohydrate and/or fat substitutes, and inhibition of enzymes in carbohydrate and/or fat digestion; additionally, regulation of some metabolic functions with food‐derived bioactive peptides and probiotics, and enrichment of foods with bioactive compounds are reviewed in this overview as the most promising issues.     

未来食品的发展：植物蛋白肉与细胞培养肉

随着人们对健康、环保及美味食品追求,未来食品成为食品领域研究人员和民众广泛关注的话题。生物科学与食品技术的快速发展,越来越多的未来食品将走向人工合成制造的道路,成为今后很长一段时期内食品高技术发展的引导与驱动。合成生物学与食品科学技术在人造肉等未来食品定制化生产方面已经取得了一系列突破,并开始逐步实现商业化,成为现有传统农业与食品行业的有效补充和替代。作者以植物蛋白肉、细胞培养肉等典型的未来食品为例,通过分析其生物制造过程中的关键任务和主要挑战,综述合成生物学、组织工程、发酵工程等生物技术在未来食品中的应用,进一步展望了未来食品在生物制造中多学科交叉集成的前景。     

食品感官科学研究：挑战与可能

食品感官科学作为食品科学属下的一门独立学科,已有半个多世纪的发展历史,取得了许多标志性成果,形成了比较系统的理论体系。传统的食品感官科学研究主要以材料科学的方法为研究手段,关注食品的结构和组成成分,而忽视了消费者个体的生理学和心理学行为对食品感官的重要影响。本文从食品感官的基本概念切入,从不同视角剖析食品感官科学的一些本质性问题,进而讨论当代食品感官研究的挑战和可能突破的领域方向,以期引发我国食品感官科学工作者的更多思考和争论,共同推动食品感官科学事业的发展。     

Fermentation for tailoring the technological and health related functionality of food products

Abstract

Fermented foods are experiencing a resurgence due to the consumers’ growing interest in foods that are natural and health promoting. Microbial fermentation is a biotechnological process which transforms food raw materials into palatable, nutritious and healthy food products. Fermentation imparts unique aroma, flavor and texture to food, improves digestibility, degrades anti-nutritional factors, toxins and allergens, converts phytochemicals such as polyphenols into more bioactive and bioavailable forms, and enriches the nutritional quality of food. Fermentation also modifies the physical functional properties of food materials, rendering them differentiated ingredients for use in formulated foods. The science of fermentation and the technological and health functionality of fermented foods is reviewed considering the growing interest worldwide in fermented foods and beverages and the huge potential of the technology for reducing food loss and improving nutritional food security.     

Aspects of high hydrostatic pressure food processing: Perspectives on technology and food safety

The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical development and fundamental aspects of HHP, as well as on potential risks associated with HHP food applications based on available literature. Beside the combination of pressure and temperature, as major factors impacting inactivation of vegetative bacterial cells, bacterial endospores, viruses, and parasites, factors, such as food matrix, water content, presence of dissolved substances, and pH value, also have significant influence on their inactivation by pressure. As a result, pressure treatment of foods should be considered for specific food groups and in accordance with their specific chemical and physical properties. The pressure necessary for inactivation of viruses is in many instances slightly lower than that for vegetative bacterial cells; however, data for food relevant human virus types are missing due to the lack of methods for determining their infectivity. Parasites can be inactivated by comparatively lower pressure than vegetative bacterial cells. The degrees to which chemical reactions progress under pressure treatments are different to those of conventional thermal processes, for example, HHP leads to lower amounts of acrylamide and furan. Additionally, the formation of new unknown or unexpected substances has not yet been observed. To date, no safety-relevant chemical changes have been described for foods treated by HHP. Based on existing sensitization to non-HHP-treated food, the allergenic potential of HHP-treated food is more likely to be equivalent to untreated food. Initial findings on changes in packaging materials under HHP have not yet been adequately supported by scientific data.     

Beyond water activity: recent advances based on an alternative approach to the assessment of food quality and safety.

Water, the most abundant constituent of natural foods, is a ubiquitous plasticizer of most natural and fabricated food ingredients and products. Many of the new concepts and developments in modern food science and technology revolve around the role of water, and its manipulation, in food manufacturing, processing, and preservation. This article reviews the effects of water, as a near-universal solvent and plasticizer, on the behavior of polymeric (as well as oligomeric and monomeric) food materials and systems, with emphasis on the impact of water content (in terms of increasing system mobility and eventual water "availability") on food quality, safety, stability, and technological performance. This review describes a new perspective on moisture management, an old and established discipline now evolving to a theoretical basis of fundamental structure-property principles from the field of synthetic polymer science, including the innovative concepts of "water dynamics" and "glass dynamics". These integrated concepts focus on the non-equilibrium nature of all "real world" food products and processes, and stress the importance to successful moisture management of the maintenance of food systems in kinetically metastable, dynamically constrained glassy states rather than equilibrium thermodynamic phases. The understanding derived from this "food polymer science" approach to water relationships in foods has led to new insights and advances beyond the limited applicability of traditional concepts involving water activity. This article is neither a conventional nor comprehensive review of water activity, but rather a critical overview that presents and discusses current, usable information on moisture management theory, research, and practice applicable to food systems covering the broadest ranges of moisture content and processing/storage temperature conditions.     

The safety and social acceptance of novel foods.

The regulatory processes employed in the UK and the European Union to assess the safety of novel foods and novel food ingredients, including those resulting from the application of recombinant DNA technology (genetically modified foods), are described. Examples are given of yeasts that have been genetically modified and can be used in food and drink manufacture and food enzymes derived from genetically modified microorganisms that have been deemed safe for use by the UK regulatory system. Social acceptance of such novel foods or food ingredients is not uniform in countries of the developed world. Consumer concerns can be based on ethical considerations (scientists "playing God") or safety worries ("more testing needs to be done"). The general acceptance of such foods and food ingredients in Europe is still unclear.     

Three-dimensional MRI mapping of minimum temperatures achieved in microwave and conventional food processing

Microbiological assurance protocols for food preservation are based on the 'worst-case' slowest heating point within the food product. For conduction-limited processing, this leads to well-known overheating near surface regions of products, with resultant quality loss. For volumetric heating processes such as microwave heating, it is practically impossible to guarantee where the slowest heating point will be. Consequently, microwave heating regimes are generally excessive and product quality is often similar to conventional conduction-limited heating processes. It is well known that Magnetic Resonance Imaging (MRI) can provide three-dimensional (3D) images which quantify the spatial distribution of water in foods, and also that the MRI parameters of water are temperature dependent. The present study demonstrates that a combination of these two concepts has led to a new approach for the validation of thermal processing in food manufacture. The potential for on-line assurance of minimum and maximum temperatures for manufacture of microbiologically assured, minimally processed, high quality food is discussed.     

Food Process Engineering: The Last 25 Years and Challenges Ahead

In the first part of this contribution, an overview is given of some of the main developments in food process engineering in the last 25 years of the 20th century. This overview is, of course, colored by the personal experience of the authors, but a sincere effort was made to maintain a general perspective. Topics that will be briefly discussed are: progress in understanding how to control food microstructure formation during processing, separation processes, conversion processes and stabilization processes, progress in flavor technology and understanding of flavor retention during processing and release. In the 2nd part, in our view, the most exiting future developments are briefly discussed. The major items here are: processing requirements for functional foods, integrated process design approaches, application of novel‘fields’in food processes,‘precision’processing, supply chain approaches to food manufacturing, and more.     

Perspectives on the 21st century development of functional foods: bridging Chinese medicated diet and functional foods

Functional foods, also known as nutraceuticals, medical foods or nutritional foods, are driving food markets around the world and are expected to be one of the emerging trends for the food industry in the new millennium. The concept of functional foods is rooted in a tradition, particularly in Asia, where people have always believed that a balanced diet and some herbal foods are therapeutic. However, while extensive studies in biochemistry and immunology, as well as clinical trials, have been conducted on selected functional foods or ingredients, the scientific features of most traditional herbals remain almost unknown. However, the fastest growing food market in the United States is that of herbal-based nutraceuticals such as ginseng, garlic and medical mushrooms. This review describes different aspects of functional foods and the Chinese medicated diet on the basis of current knowledge, discusses the building blocks for the science of functional foods and proposes a possible way to fuse a Chinese medicated diet into functional foods.     

益生菌在我国保健食品中的应用进展

由于益生菌类原料在调节肠道菌群和增强免疫力保健功能的研究比较系统,健康功效明确,因此,其在保健食品中应用越来越广泛,而且部分菌株已被国家市场监督管理总局明文规定允许用于婴幼儿食品的开发.随着科学技术的快速发展以及相关研究的不断深入,益生菌类原料具有的其它保健功能不断被发掘,而且作用机理也不断明晰,这为其在保健食品行业的...