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

Criblage des bactéries lactiques pour leur utilisation comme ferments aromatiques lors de la fermentation des légumes

Lactic acid bacteria (LAB) have good growth capacities on various food matrices and produce very diverse enzymatic activities which are notably capable of positively modifying the organoleptic properties of fermented foods. Therefore, the selection of the LAB starters possessing good metabolic abilities and interesting enzymatic activities towards the plant matrix could improve the aroma profiles of fermented foods. The main objective of this study was to enhance the aroma profiles of fermented tomatoes by using the biotechnological pathway. To achieve this, firstly, 200 LAB isolated from Cambodian and Vietnamese fermented foods were screened for their β-glucosidase activity and duplicate isolates identified through RAPD-PCR analysis were discarded. Thereby, 40 strains were found positive for β-glucosidase using p-nitrophenyl-β-D-glucopyranoside as substrate. Among them, 14 displayed an activity greater than 10 nmol/min/mg dry cell. Thirteen were identified as Lactobacillus (Lactiplantibacillus) plantarum and one as Lactobacillus (Lactiplantibacillus) pentosus. Four strains of different phenotypes for β-glucosidase activity were tested for ADH activity. The highest reduction ability for hexanal and (E)-2-hexenal was obtained for Lactobacillus (Limosilactobacillus) fermentum V013-1A for which no β-glucosidase activity was detectable. The three other strains (L. plantarum C022-2B, C022-3B and V0023-4B2) exhibited a lower reduction ability and only for hexanal. Secondly, mashed tomatoes were fermented with these four strains individually to evaluate their ability to release volatile compounds from the tomato aroma precursors. Fifty-eight volatile compounds were identified and quantified by HS-SPME/GC-MS. Untreated tomatoes were rich in aldehydes. The tomatoes fermented with L. plantarum strains were rich in ketones whereas those with L. fermentum were rich in alcohols. However, for the generation of terpenoids that provide fruity and floral notes, our screening of β-glucosidase activity was not able to explain the differences among the strains. For ADH activity, L. fermentum exhibited high activity in fermentation as most of the target aldehydes and ketones disappeared and were replaced by their corresponding alcohols. The L. plantarum strains exhibited a lower activity, but with an important substrate-selectivity diversity. A better knowledge of the functionality of each LAB strain in the food matrix will permit to predict and shape the aroma profiles of fermented food.Les bactéries lactiques (LAB) ont de bonnes capacités de croissance sur différentes matrices alimentaires et produisent des activités enzymatiques très diverses qui sont notamment capables de modifier positivement les propriétés organoleptiques des aliments fermentés. Par conséquent, la sélection des ferments (starters) LAB possédant de bonnes capacités métaboliques et des activités enzymatiques intéressantes envers la matrice végétale pourrait améliorer les profils aromatiques des aliments fermentés. Le principal objectif de cette étude était d'améliorer les profils aromatiques des tomates fermentées en utilisant la voie biotechnologique. Pour y parvenir, premièrement, 200 LAB isolés à partir d'aliments fermentés cambodgiens et vietnamiens ont été criblées pour leur activité β-glucosidase et les isolats en double identifiés par analyse RAPD-PCR ont été rejetés. Ainsi, 40 souches étaient positives pour la β-glucosidase en utilisant le p-nitrophényl-β-D-glucopyranoside comme substrat. Parmi eux, 14 présentaient une activité supérieure à 10 nmol/min/mg de poids sec. Treize ont été identifiés comme Lactobacillus (Lactiplantibacillus) plantarum et un comme Lactobacillus (Lactiplantibacillus) pentosus. Quatre souches de phénotypes différents pour l'activité β-glucosidase ont été testées pour l'activité ADH. La capacité de réduction la plus élevée pour l'hexanal et le (E)-2-hexénal a été obtenue pour Lactobacillus (Limosilactobacillus) fermentum V013-1A pour laquelle aucune activité β-glucosidase n'était détectable. Les trois autres souches (L. plantarum C022-2B, C022-3B et V0023-4B2) présentaient une capacité de réduction plus faible et uniquement pour l'hexanal. Deuxièmement, les purées de tomates ont été fermentées avec ces quatre souches individuellement pour évaluer leur capacité à libérer des composés volatils à partir des précurseurs d’arômes de tomate. Cinquante-huit composés volatils ont été identifiés et quantifiés par HS-SPME/GC-MS. Les tomates non traitées étaient riches en aldéhydes. Les tomates fermentées avec les souches de L. plantarum étaient riches en cétones tandis que celles avec L. fermentum étaient riches en alcools. Cependant, pour la génération de terpénoïdes apportant des notes fruitées et florales, notre criblage de l'activité β-glucosidase n'a pas pu expliquer les différences entre les souches. Pour l'activité ADH, L. fermentum a montré une activité élevée dans la fermentation car la plupart des aldéhydes et cétones cibles ont disparu et ont été remplacés par leurs alcools correspondants. Les souches de L. plantarum ont montré une activité plus faible mais avec une importante diversité de sélectivité du substrat. Une meilleure connaissance de la fonctionnalité de chaque souche LAB dans la matrice alimentaire permettra de prédire et de façonner les profils aromatiques des aliments fermentés

Screening of lactic acid bacteria for their potential use as aromatic starters in fermented vegetables

International audienceLactic acid fermentation is a traditional process to preserve foods and to modify their organoleptic properties. This process is generally conducted in a spontaneous way, allowing indigenous lactic acid bacteria (LAB) of the matrix and of the environment to compete and grow. The aim of this study was to better characterise LAB strains ability to modify aroma profiles in fruit and vegetable matrices, by focusing on two key enzymatic activities: β-glucosidase and alcohol dehydrogenase (ADH). Firstly, 200 LAB isolated from Cambodian and Vietnamese fermented foods were screened for their β-glucosidase activity and duplicate isolates identified through RAPD-PCR analysis were discarded. Thereby, 40 strains were found positive for β-glucosidase using p-nitrophenyl-β-D-glucopyranoside as substrate. Among them, 14 displayed an activity greater than 10 nmol/min/mg dry cell. Thirteen were identified as Lactiplantibacillus (L.) plantarum and one as L. pentosus. Secondly, four strains of different phenotypes for β-glucosidase activity were tested for ADH activity. The highest reduction ability for hexanal and (E)-2-hexenal was obtained for Limosilactobacillus (L.) fermentum V013-1A for which no β-glucosidase activity was detectable. The three other strains (L. plantarum C022-2B, C022-3B, and V0023-4B2) exhibited a lower reduction ability and only for hexanal. Thirdly, mashed tomatoes were fermented with these four strains individually to evaluate their ability to release volatile compounds from the tomato precursors. Fifty-eight volatile compounds were identified and quantified by HS-SPME/GC-MS. Untreated tomatoes were rich in aldehydes. The tomatoes fermented with L. plantarum strains were rich in ketones whereas those with L. fermentum were rich in alcohols. However, for the generation of terpenoids that provide flower and fruit flavours, our screening of β-glucosidase activity was not able to explain the differences among the strains. For ADH activity, L. fermentum exhibited a high activity in fermentation as most of the target aldehydes and ketones disappeared and were replaced by their corresponding alcohols. The L. plantarum strains exhibited a lower activity but with an important substrate-selectivity diversity. A better knowledge of the functionality of each LAB strain in the food matrix will permit to predict and shape the aroma profiles of fermented food

How fermentation by lactic acid bacteria can address safety issues in legumes food products?

International audienceFermented Asian foods have recently gained popularity, crossing from Asian communities to mainstream markets, in many western countries. However, less attention has been paid to the safety of these foods. In South-East Asia, fermented products are still produced following traditional methods. Therefore, consumers are not confident in their microbial safety. 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. A possible solution could be the use of starter cultures able to increase the safety of food stuffs. Starters could also help to standardize the production process and reduce ripening times. The current review addresses the role of lactic acid bacteria on the microbiological and chemical safety of Asian legume based fermented products. In particular, their role in the reduction of anti nutritional compounds (e.g. phytates) and protein allergenicity is discussed. Moreover, starters can inihibit the development of amino acid-decarboxylating microbes preventing the accumulation of biogenic amines, they can also be useful to reduce the accumulation of mycotoxins and inhibit pathogens’ development. Finally, their role in the degradation of pesticides is analyzed

Explorer la biodiversité pour trouver de nouvelles souches microbiennes pour les innovations de produits alimentaires

Référence : 201511122729Entre les innovations alimentaires renforçant les propriétés sensorielles ou de santé ou améliorant le procédé, la demande de souches microbiennes nouvelles est forte. Toutefois, trouver de nouvelles souches libres de droits et efficaces n’est pas une tâche facile. Dans cet article, seront présentées des voies d’innovations pour augmenter le bénéfice sensoriel de fermentations et les activités du laboratoire international «Tropical Bioresources & Biotechnology» pour découvrir de nouvelles souches et de nouveaux procédés basés sur les fermentations traditionnelles de produits tropicaux

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