Bio-mediated generation of food flavors – Towards sustainable flavor production inspired by nature

BackgroundThe consumers’ trend toward naturalness and “clean-label” products advocates the development of “bio-mediated” tools including new processes for the generation of flavors. Today, many fundamental studies demonstrate the feasibility of producing individual flavor compounds or more complex flavoring preparations by fermentation or by enzymatic reactions. However, to turn research into industrial applications, the processes have to be simplified and optimized by combining chemistry, biology and process engineering know-how.Scope and approachThis review summarises recent basic research and development on cell and enzyme based formation of volatile flavors with focus on smart combinations of biocatalytic and thermal steps to enrich the natural flavor profile of foods. Ideally, targeted bioconversion of specific raw materials and ingredients will release flavor precursors required to generate the desired flavor profile by appropriate thermal processing.Key findings and conclusionsThe combination of fermentation or enzymatic treatment of raw materials with heat-induced food processes (e.g. drying, extrusion, roasting) represent an elegant approach in industrial food processing to generate flavors under mild conditions. This requires a good control of fermentation or enzymatic reaction steps to produce suitable substrates at the optimal concentrations adapted to the thermal processes. Using traditional cooking and minimal processing conditions (nature-inspired strategies) has become an attractive approach to generate authentic flavor profiles resonating with consumers’ demand for more naturalness.     

芝麻香型白酒酿酒微生物研究进展

芝麻香型白酒是我国传统白酒的创新香型之一,因其所具有的独特风味越来越受到消费者的喜爱,近年来对于芝麻香型白酒酿造过程中微生物的探索也成为白酒研究中的热点领域之一。该文系统综述了芝麻香型白酒酿酒微生物的多样性分析、产香味成分分析、酶活性研究以及酿酒微生物在芝麻香型白酒生产中应用的最新研究进展,并对芝麻香型白酒酿酒微生物的未来的研究与利用提出了思考与展望,为后续芝麻香型白酒酿酒微生物的相关研究提供必要的信息参考。     

Enzymes and food flavor‐A review

The use of enzymes in flavor generation in food technology is reviewed. In the first part, important products derived from natural macromolecules present in foods such as fats, proteins, nucleic acids and flavor precursors are discussed in terms of the enzymes involved in the reactions and the relation of the products with flavor. Enzymes that are used to eliminate natural or process induced off‐flavors are also discussed. In the second part, the use of enzymes for the direct synthesis of flavoring compounds is presented.     

烟用增香物质的分析技术进展

卷烟中的增香物质是卷烟生产中不可或缺的原料,该物质既能减少焦油含量,同时也能影响卷烟口味。然而卷烟中的增香物质化学成分复杂,很多物质有不同程度的生理毒性,因此对烟草中增香成分的测定具有显著意义。目前烟用增香物质的的前处理和检测技术多种多样,本文对烟用增香物质的前处理和检测技术进行了综述和比较,对一些新的分析技术也作了简要介绍,拟为卷烟中增香物质的检测提供依据。     

The relationship between lipid oxidation and antioxidant content in postharvest vegetables

Abstract

Lipid oxidation is the quality limiting attribute in many vegetables that generates off‐flavors. Lipoxygenases, which catalyze the oxygenation of polyunsaturated fatty acids are key enzymes in this pathway and their presence is believed to be the chief reason for the need for blanching (i.e., inactivation of enzymes) enabling frozen storage. Off‐flavor production in legumes, such as garden peas, is a particular problem, due to high levels of this enzyme found in these seeds.

The lipid oxidation pathway is triggered in response to tissue wounding which occurs during mechanical harvesting of peas in the field. Bruised peas that are not blanched develop strong off‐flavors within a few hours.

A number of studies has shown that antioxidants are consumed during lipid oxidation. Vitamin C (ascorbate) is an antioxidant and also an important micronutrient in peas. It is possible that the level of vitamin C is affected by the progress of lipid oxidation in postharvest peas.     

生物质原料的酶解及其在制浆造纸工业中的应用

纤维素、半纤维素和木素是主要的生物质原料,它们对自然界的碳循环是必不可少的.每种聚合物都可被能产生协同作用的酶系的多种微生物降解.不久的将来,基于微生物和酶的新工艺会引起新的环境友好技术.主要介绍了三大生物质原料的生物降解所需要的微生物和酶,对主要酶的作用机制和分子生物学进展也进行了阐述,另外概述了基于木质纤维原料酶水解的生物制浆和生物漂白的研究进展.     

果酒中香气化合物的生物转化与调控机制研究进展

果酒发酵过程中微生物及其代谢酶引发的一系列生化反应对其风味形成具有重要作用,但目前仍存在生物调控手段不完善,香气形成机理不清晰等问题,制约着我国果酒产品的开发和品质提升。本文对不同果酒中香气化合物种类及其生成途径进行阐述,分析香气前体物质代谢和微生物发酵对果酒香气的贡献;从生物调控角度重点论述不同果酒发酵过程香气成分的变化规律及微生物和酶对果酒香气化合物的影响机制,分析发酵菌种、发酵方式、微生物产酶能力及其酶活力大小等因素对果酒香气形成的作用,深入介绍微生物、酶同果酒香气的关系;最后,对未来果酒的研究热点进行展望,为建立以风味导向为基础的果酒定向调控手段提供理论依据和技术支持。     

Protein hydrolysis—the key to meat flavoring systems

Abstract

The flavors produced by stewing, broiling, or roasting make meat one of the most popular items in the human diet. No “key” compounds are responsible for meat flavors. However, protein degradation appears essential to the development of meat flavor precursors whose interactions are responsible for characteristic meat flavors. This review examines simulated meat flavor systems based on the protein degradation products produced by acid hydrolysis using strong mineral acids, yeast autolysis, and enzyme degradation of natural meat proteins by pure proteinases. In addition, the contributions to meat flavor made by heating protein hydrolysates in the presence of sugars and organic sulfur compounds are reviewed. This paper also describes the work in applied meat flavor research carried out in the former East Germany.     

发酵酸菜的研究及其进展

酸菜是我国蔬菜加工产品中产量较多的一种, 主要以各种蔬菜为主要原料, 通过微生物发酵作用制成的一种发酵食品。它不仅保留了蔬菜原有的营养成分如维生素C、氨基酸以及膳食纤维等营养物质, 而且还含有乳酸菌等功能性微生物。微生物发酵对酸菜的质量、风味等有着重要的影响。因此, 探讨酸菜发酵的机制及其发酵过程中微生物的多样性、营养成分、风味物质以及其他化学物质的变化具有重要的意义。根据近些年的研究结果, 本文对酸菜发酵机制、发酵过程中微生物多样性及营养成分研究等现状进行了综述, 并提出发酵酸菜微生物资源发掘及其规模化生产的发展方向。     

发酵类食品中微生物鉴定方法及功能研究进展

发酵类食品是主要通过直接接种微生物而产生特殊风味或者将食物浸入含有微生物的臭卤水中,从而获得特殊食品风味的中国传统食品。其中,采用含有微生物的卤水进行发酵是常见的发酵方式。因此,微生物在该类食品中一直扮演着一种非常重要的角色,具有较高的研究价值。本文阐述了发酵类型的食品所需要的卤水中微生物的鉴定常用方法,以及卤水微生物与风味成分的产生之间的关系,同时论述了卤水中微生物在各种发酵食品制作过程中所起到的功能特性,包括提高豆制品的营养价值、延长保质期、去除有害成分等问题,并提出了较为可行的新型发酵类食品卤水改进方向,为进一步开发理想的食品微生物发酵剂,控制有害物质的残留、拓展相关有益微生物资源的研究提供较为明确的指导方向。     

Product-oriented flavor research: learnings from the past, visions for the future

In the past flavor research and the development of new flavorings were constantly driven by the interaction of flavor analysis, structure elucidation, and chemical synthesis accompanied by sensory. Highly potent flavor compounds were identified in numerous food products and helped to establish a powerful toolbox for flavorists. Nowadays we experience the merging of various scientific disciplines, for example medicine, biology, chemistry, and various technologies in the field of flavor research, which shows direct impact on our understanding of flavors. At the same time modern life has profoundly changed our eating habits. This situation generates new challenges for product development teams, which represent all facets of technologies. This paper will illustrate different examples for the evolution of product-oriented flavor research and future trends.     

我们的使命:"创造完美口味"——访威尔德集团副总裁FranciscoCliment先生

<正>威尔德集团是全球领先的食品饮料天然配料制造商和世界最大的香精配料企业之一,并向食品饮料工业提供最现代化的生产加工技术设备。其中公司生产的纯天然儿童饮料佳必爽果汁饮料,     

Generation of Flavors and Fragrances Through Biotransformation and De Novo Synthesis

Flavors and fragrances are the result of the presence of volatile and non-volatile compounds, appreciated mostly by the sense of smell once they usually have pleasant odors. They are used in perfumes and perfumed products, as well as for the flavoring of foods and beverages. In fact the ability of the microorganisms to produce flavors and fragrances has been described for a long time, but the relationship between the flavor formation and the microbial growth was only recently established. After that, efforts have been put in the analysis and optimization of food fermentations that led to the investigation of microorganisms and their capacity to produce flavors and fragrances, either by de novo synthesis or biotransformation. In this review, we aim to resume the recent achievements in the production of the most relevant flavors by bioconversion/biotransformation or de novo synthesis, its market value, prominent strains used, and their production rates/maximum concentrations.     

Transforming the fermented fish landscape: Microbiota enable novel,safe, flavorful,and healthy products for modern consumers

Regular consumption of fish promotes sustainable health while reducing negative environmental impacts. Fermentation has long been used for preserving perishable foods, including fish. Fermented fish products are popular consumer foods of historical and cultural significance owing to their abundant essential nutrients and distinct flavor. This review discusses the recent scientific progress on fermented fish, especially the involved flavor formation processes, microbial metabolic activities, and interconnected biochemical pathways (e.g., enzymatic/non-enzymatic reactions associated with lipids, proteins, and their interactions). The multiple roles of fermentation in preservation of fish, development of desirable flavors, and production of health-promoting nutrients and bioactive substances are also discussed. Finally, prospects for further studies on fermented fish are proposed, including the need of monitoring microorganisms, along with the precise control of a fermentation process to transform the traditional fermented fish to novel, flavorful, healthy, and affordable products for modern consumers. Microbial-enabled innovative fermented fish products that consider both flavor and health benefits are expected to become a significant segment in global food markets. The integration of multi-omics technologies, biotechnology-based approaches (including synthetic biology and metabolic engineering) and sensory and consumer sciences, is crucial for technological innovations related to fermented fish. The findings of this review will provide guidance on future development of new or improved fermented fish products through regulating microbial metabolic processes and enzymatic activities.     

High‐pressure processing and preservation of food

Abstract

High pressure alone or in combination with other technologies offers great potential for producing foods with natural characteristics. Pressure works independent of size and geometry of food resulting in even preservation. The preservative effect itself is influenced by a number of factors with different foods requiring different levels of pressure. Various microorganisms also vary in their response to high pressure and the effect depends on the physical state of the microorganism and the composition of the medium. Because enzymes have a high resistance to pressure, enzymatic and oxidative spoilage are the major limiting factors in shelf‐life extension of pressure‐processed foods. This paper briefly reviews the effects of high pressure on various foods, enzymes, and microorganisms; and discusses some of the advantages and disadvantages associated with the use of this technology.     

新技术在调香过程中的应用

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Biotechnological production of zeaxanthin by microorganisms

BackgroundZeaxanthin is a natural xanthophyll carotenoid that is widely produced by plants, algae and microorganisms and plays a critical role in the prevention of age-related eye diseases, such as macular degeneration and cataracts. Zeaxanthin is also used in the food, pharmaceutical and nutraceutical industries because of its strong antioxidant and anti-cancer properties. To date, zeaxanthin has been primarily produced by extraction from natural resources, especially plants, which is costly and environmentally unfriendly. The biosynthesis of zeaxanthin by microorganisms has been reported in lots of works to provide another potential route for zeaxanthin production.Scope and approachIn this review, we discuss the zeaxanthin biosynthetic pathway, naturally occurring zeaxanthin-accumulating microorganisms containing bacteria and microalgae, the optimization of fermentation conditions using these microorganisms, and zeaxanthin production using microbial cells factory constructed by metabolic engineering. The different metabolic engineering strategies and the zeaxanthin-accumulating level of the reviewed wild and engineered microorganisms are also considered. Furthermore, this work presents perspectives concerning the microbial production of zeaxanthin, especially the trends to construct the metabolically engineered microorganisms for zeaxanthin production.Key findings and conclusionsTo date, all the reported wild zeaxanthin-accumulating microorganisms belong to either bacteria or microalgae, while most of the reported engineering microorganisms for zeaxanthin production are Escherichia coli or yeast. A feasible strategy for zeaxanthin production is the use of metabolic engineering to construct a zeaxanthin-accumulating microbial cells factories followed by the optimization of fermentation with the engineered strain. Besides the simple overexpression of the biosynthesizing genes, the dynamic regulation of the constructed pathway has also been used for zeaxanthin production by metabolic engineering. Construction of better microbial cells factories which produce more zeaxanthin will profit from the breakthrough of the following fields: Introduction of higher plant zeaxanthin biosynthesizing genes into microorganisms; Characterization of novel zeaxanthin pathway genes from the wild microorganisms producing high level of zeaxanthin; Deep investigation of the farnesyl diphosphate formation pathway; Construction of microbial host with weak antioxidative capacity.     

The biogenesis of food‐related Pyrazines

Abstract

Biogenetically formed pyrazines are important flavor compounds in view of the current industry trend toward all‐natural flavors in foods. Food‐related pyrazines are reviewed and summary data are used as a basis to discuss possible chemical and biochemical mechanisms for their formation.     

Enzyme-Assisted Process for Production of Superior Quality Vanilla Extracts from Green Vanilla Pods Using Tea Leaf Enzymes

Vanilla planifolia Andrews is a perennial tropical vine and is an orchid grown for its pleasant flavor. There is an increasing trend world over for using natural flavors. Vanilla being an important food flavoring ingredient, the demand for natural vanilla extract is increasing. Hence, the aim of the present study was to prepare vanilla extract from green beans without going through the elaborate and time-consuming conventional curing process. Vanilla beans after size reduction were mixed in a suitable proportion with tea leaf enzyme extract (TLEE) and incubated to facilitate action of enzymes on vanilla flavor precursors. The beans mix was squeezed, and the filtrate was treated with ethanol to extract the vanilla flavor. TLEE-treated extracts had higher vanillin content (4.2%) compared to Viscozyme extract (2.4%). Also, it had higher intensity of vanilla flavor, sweet, and floral notes. Further, electronic nose analysis confirmed the discrimination between extracts. It was concluded that the use of TLEE is very much useful to obtain higher yield of vanilla extract and superior quality vanilla flavor, which avoids the traditional laborious and time-consuming curing process.     

植物精油结合非热杀菌技术在肉品中应用的研究进展

植物精油是从植物中提取的天然成分,可以有效抑制微生物生长,但过高的用量会损害食品的感官质量。新兴非热杀菌技术的应用可以抑制微生物生长,但高强度的物理技术可能会影响产品品质。研究发现,将植物精油和非热技术结合,可以减少精油用量、降低非热技术加工功率、缩短处理时间。本文就植物精油与冷等离子体、高压和辐照3种非热技术相结合应用于肉制品中的方法进行探讨,并对其细菌生长的抑制效果和机制进行阐述,为进一步研究植物精油与非热杀菌技术在肉类产品中的协同作用及推广提供一定的理论依据。