Prospects for Food Fermentation in South-East Asia, Topics From the Tropical Fermentation and Biotechnology Network at the End of the AsiFood Erasmus+Project

Fermentation has been used for centuries to produce food in South-East Asia and some foods of this region are famous in the whole world. However, in the twenty first century, issues like food safety and quality must be addressed in a world changing from local business to globalization. In Western countries, the answer to these questions has been made through hygienisation, generalization of the use of starters, specialization of agriculture and use of long-distance transportation. This may have resulted in a loss in the taste and typicity of the products, in an extensive use of antibiotics and other chemicals and eventually, in a loss in the confidence of consumers to the products. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products and valorising by-products. At the end of the “AsiFood Erasmus+ project” (www.asifood.org), the goal of this paper is to present and discuss these challenges as addressed by the Tropical Fermentation Network, a group of researchers from universities, research centers and companies in Asia and Europe. This paper presents current actions and prospects on hygienic, environmental, sensorial and nutritional qualities of traditional fermented food including screening of functional bacteria and starters, food safety strategies, research for new antimicrobial compounds, development of more sustainable fermentations and valorisation of by-products. A specificity of this network is also the multidisciplinary approach dealing with microbiology, food, chemical, sensorial, and genetic analyses, biotechnology, food supply chain, consumers and ethnology

Revelation of aroma potential of grape pomace and spent coffee ground by the use of microbial glycosidases.

L’industrie agroalimentaire évolue et tend à réduire son impact environnemental, à maîtriser ses déchets et à valoriser la totalité de sa production. Le raisin et le café comptent parmi les principaux produits agricoles mondiaux et la totalité des coproduits issus de leurs transformations n’est toujours pas valorisée aujourd’hui. De nouvelles voies de valorisation sont recherchées afin de limiter les pertes de production. Pourtant, ces coproduits sont riches en glycosides dont la quantité peut être de deux à cinq fois supérieure à celle des composés volatils libres. Les marcs de raisin et de café pourraient être utilisés pour produire naturellement des composés volatils à partir de leurs glycosides. Ces composés volatils pourraient être utiles dans le cadre de la production de produits cosmétiques, par exemple. Les glycosides du café et ceux de ses coproduits ont été peu étudiés. Les glycosides du marc de raisin ont, quant à eux, déjà été caractérisés et des préparations d’enzymes commerciales ont été développées pour libérer les composés volatils des glycosides. Néanmoins, ces préparations contiennent de nombreuses activités enzymatiques secondaires qui peuvent produire des arômes phénoliques non désirés et leur utilisation peut s’avérer onéreuse à l’échelle industrielle. Au cours de cette thèse, nous avons d’abord étudié l’évolution des glycosides du café durant certaines étapes de la transformation des grains de café. Puis nous nous sommes intéressés au développement d’un criblage de bactéries productrices de glycosidases spécifiques de certains glycosides du marc de raisin. Ces travaux de thèse ont permis d’envisager une nouvelle voie de valorisation du marc de café via sa fraction glycosidique et ont pu démontrer l’intérêt de l’utilisation de certaines souches bactériennes dans la production de composés volatils variétaux à partir de glycosides du marc de raisin.The food industry is evolving and tends to reduce its environmental impact, to control its waste and to valorise all of its production. Grapes and coffee are among the main agricultural products in the world and not all of the byproducts resulting from their processing are still valued today. New ways of valorisation are seeked in order to limit production losses. Yet, these byproducts are rich in glycosides, the amount of which may be from two to five times greater than that of the free volatile compounds. Grape pomace and spent coffee ground could be used to naturally produce volatile compounds from their glycosides. These volatile compounds could be useful in the production of cosmetics, for example. The glycosides of coffee and those of its co-products have been little studied. Glycosides of grape pomace have already been characterized and commercial enzyme preparations have been developed to release volatile compounds from glycosides. However, these preparations contain side enzymatic activities that can produce phenolic off-flavours and their use can be expensive at industrial scale. During this PhD preparation, we first studied the evolution of coffee glycosides during certain stages of the processing of coffee beans. Then we were interested in the development of a screening for bacteria producing specific glycosidases of some glycosides in grape pomace. This study could envisage a new way of spent coffee ground valorisation via its glycosidic fraction and could demonstrate the interest of the use of certain bacterial strains in the production of varietal volatile compounds from grape pomace glycoside

Révélation du potentiel aromatique des marcs de raisin et de café par l’utilisation de glycosidases microbiennes

The food industry is evolving and tends to reduce its environmental impact, to control its waste and to valorise all of its production. Grapes and coffee are among the main agricultural products in the world and not all of the byproducts resulting from their processing are still valued today. New ways of valorisation are seeked in order to limit production losses. Yet, these byproducts are rich in glycosides, the amount of which may be from two to five times greater than that of the free volatile compounds. Grape pomace and spent coffee ground could be used to naturally produce volatile compounds from their glycosides. These volatile compounds could be useful in the production of cosmetics, for example. The glycosides of coffee and those of its co-products have been little studied. Glycosides of grape pomace have already been characterized and commercial enzyme preparations have been developed to release volatile compounds from glycosides. However, these preparations contain side enzymatic activities that can produce phenolic off-flavours and their use can be expensive at industrial scale. During this PhD preparation, we first studied the evolution of coffee glycosides during certain stages of the processing of coffee beans. Then we were interested in the development of a screening for bacteria producing specific glycosidases of some glycosides in grape pomace. This study could envisage a new way of spent coffee ground valorisation via its glycosidic fraction and could demonstrate the interest of the use of certain bacterial strains in the production of varietal volatile compounds from grape pomace glycosidesL’industrie agroalimentaire évolue et tend à réduire son impact environnemental, à maîtriser ses déchets et à valoriser la totalité de sa production. Le raisin et le café comptent parmi les principaux produits agricoles mondiaux et la totalité des coproduits issus de leurs transformations n’est toujours pas valorisée aujourd’hui. De nouvelles voies de valorisation sont recherchées afin de limiter les pertes de production. Pourtant, ces coproduits sont riches en glycosides dont la quantité peut être de deux à cinq fois supérieure à celle des composés volatils libres. Les marcs de raisin et de café pourraient être utilisés pour produire naturellement des composés volatils à partir de leurs glycosides. Ces composés volatils pourraient être utiles dans le cadre de la production de produits cosmétiques, par exemple. Les glycosides du café et ceux de ses coproduits ont été peu étudiés. Les glycosides du marc de raisin ont, quant à eux, déjà été caractérisés et des préparations d’enzymes commerciales ont été développées pour libérer les composés volatils des glycosides. Néanmoins, ces préparations contiennent de nombreuses activités enzymatiques secondaires qui peuvent produire des arômes phénoliques non désirés et leur utilisation peut s’avérer onéreuse à l’échelle industrielle. Au cours de cette thèse, nous avons d’abord étudié l’évolution des glycosides du café durant certaines étapes de la transformation des grains de café. Puis nous nous sommes intéressés au développement d’un criblage de bactéries productrices de glycosidases spécifiques de certains glycosides du marc de raisin. Ces travaux de thèse ont permis d’envisager une nouvelle voie de valorisation du marc de café via sa fraction glycosidique et ont pu démontrer l’intérêt de l’utilisation de certaines souches bactériennes dans la production de composés volatils variétaux à partir de glycosides du marc de raisin

Glycosidically bound volatile profiles of green and roasted coffee beans and aromatic potential of the spent coffee ground

International audienceCoffee volatile compounds formation has been studied for years and the main flavour precursors have been identified. Coffee glycosidically bound volatiles (GBVs) are still underexplored and, yet, can act as aroma precursors during the post-harvesting processing and roasting. Free volatile compounds and GBVs of green coffee beans (CB), roasted CB and spent coffee ground (SCG) were analysed. Roasting led to the formation of a new GBVs pool from green to roasted CB and SCG. Most of the GBVs of green CB were hydrolysed during roasting. On the other hand, pyrroles, cycloketones, pyridines and pyrans were identified for the first time as bound volatiles and occurred only after the roasting process. This study supports the importance of GBVs on coffee aroma formation during the post-harvest processing. The release of the GBVs of roasted CB during brewing could enhance the varietal aromas of industrial ready-to-drink coffees. Furthermore, the SCG GBVs could be used as a new source of natural flavours for perfume industries

Identification of Bacillus strains producing glycosidases active on rutin and grape glycosidic aroma precursors

International audienceMost of the glycosidic aroma precursors in grape consist of diglycosides such as rutinoside. Yeast glycosidases have been extensively studied but their activity is limited to monoglucosidic precursors. Yet, there is no study about application of glycosidases active on rutinoside in grape. In this study, we screened Bacillus isolates for their glycosidase activities on rutin and grape aroma precursors. One Bacillus amyloliquefaciens and one Bacillus licheniformis strains produced extracellular glycosidases, active on both rutin and para-nitrophenol-α-l-rhamnoside. The specific rutinosidic activities were 14 and 9.0 μkat/mg respectively, and supernatants were active on Muscat grape glycosidic aroma precursors. Both strains were able to release monoterpenoids and benzenoids. The most released monoterpenoid in grape pomace was neric acid, with 378 μg/kg and the most released benzenoid was 2-phenylethanol, with 189 μg/kg for B. licheniformis. These glycosidases are interesting tools to target rutinosidic glycosides in grape and can be applied as a new way of valorising grape pomace

Native bacterial communities and Listeria monocytogenes survival in soils collected from the Lower Mainland of British Columbia, Canada

Soil is an important reservoir for Listeria monocytogenes, a foodborne pathogen implicated in numerous produce-related outbreaks. Our objective was to (i) compare the survival of L. monocytogenes between three soils, (ii) compare the native bacterial communities across these soils, and (iii) investigate relationships between L. monocytogenes survival, native bacterial communities, and soil properties. Listeria spp. populations were monitored on PALCAM agar in three soils inoculated with L. monocytogenes (~5 x 106 CFU/g): conventionally farmed (CS), grassland transitioning to conventionally farmed (TS), and uncultivated grassland (GS). Bacterial diversity of the soils was analyzed using 16s rRNA targeted amplicon sequencing. A two-log reduction of Listeria spp. was observed in all soils within 10 days, but at a significantly lower rate in GS (Fisherâ s LSD; pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Microorganisms, the Ultimate Tool for Clean Label Foods?

Clean label is an important trend in the food industry. It aims at washing foods of chemicals perceived as unhealthy by consumers. Microorganisms are present in many foods (usually fermented), they exhibit a diversity of metabolism and some can bring probiotic properties. They are usually well considered by consumers and, with progresses in the knowledge of their physiology and behavior, they can become very precise tools to produce or degrade specific compounds. They are thus an interesting means to obtain clean label foods. In this review, we propose to discuss some current research to use microorganisms to produce clean label foods with examples improving sensorial, textural, health and nutritional properties

Prospects for food fermentation in South-East Asia, topics from the tropical fermentation and biotechnology network at the end o the AsiFood Erasmus plus project

Fermentation has been used for centuries to produce food in South-East Asia and some foods of this region are famous in the whole world. However, in the twenty first century, issues like food safety and quality must be addressed in a world changing from local business to globalization. In Western countries, the answer to these questions has been made through hygienisation, generalization of the use of starters, specialization of agriculture and use of long-distance transportation. This may have resulted in a loss in the taste and typicity of the products, in an extensive use of antibiotics and other chemicals and eventually, in a loss in the confidence of consumers to the products. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products and valorising by-products. At the end of the "AsiFood Erasmus+ project" (www.asifood.org ), the goal of this paper is to present and discuss these challenges as addressed by the Tropical Fermentation Network, a group of researchers from universities, research centers and companies in Asia and Europe. This paper presents current actions and prospects on hygienic, environmental, sensorial and nutritional qualities of traditional fermented food including screening of functional bacteria and starters, food safety strategies, research for new antimicrobial compounds, development of more sustainable fermentations and valorisation of by-products. A specificity of this network is also the multidisciplinary approach dealing with microbiology, food, chemical, sensorial, and genetic analyses, biotechnology, food supply chain, consumers and ethnology

Prospects for Food Fermentation in South-East Asia, Topics From the Tropical Fermentation and Biotechnology Network at the End of the AsiFood Erasmus+Project

Fermentation has been used for centuries to produce food in South-East Asia and some foods of this region are famous in the whole world. However, in the twenty first century, issues like food safety and quality must be addressed in a world changing from local business to globalization. In Western countries, the answer to these questions has been made through hygienisation, generalization of the use of starters, specialization of agriculture and use of long-distance transportation. This may have resulted in a loss in the taste and typicity of the products, in an extensive use of antibiotics and other chemicals and eventually, in a loss in the confidence of consumers to the products. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products and valorising by-products. At the end of the “AsiFood Erasmus+ project” (www.asifood.org), the goal of this paper is to present and discuss these challenges as addressed by the Tropical Fermentation Network, a group of researchers from universities, research centers and companies in Asia and Europe. This paper presents current actions and prospects on hygienic, environmental, sensorial and nutritional qualities of traditional fermented food including screening of functional bacteria and starters, food safety strategies, research for new antimicrobial compounds, development of more sustainable fermentations and valorisation of by-products. A specificity of this network is also the multidisciplinary approach dealing with microbiology, food, chemical, sensorial, and genetic analyses, biotechnology, food supply chain, consumers and ethnology