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African locust bean (Parkia biglobosa) is a legume widely spread in west Africa. The major consumed part is the seeds after processing in the so-called Soumbala in Ivory Coast. It is rich in proteins and lipids and used as a condiment to enhance sauce flavour. The seeds processing can be generalized as a first cooking to allow the dehulling of the seeds, a second cooking of the almond, an alkaline spontaneous fermentation of 2 to 3 days before final sun-drying. During fermentation, microorganisms belonging to the genus Bacillus are responsible of an extensive proteolysis (Odunfa et Adewuyi, 1985) and lipolysis (Ouoba et al. 2003). This gives the specific flavour to the product but may lead to toxic compounds such as biogenic amines. Biogenic amines accumulate by microbial decarboxylation of free amino acids and are thus susceptible to be present in fermented protein rich foods. They were reported in wine, cheese and fermented fish while they have not been studied yet in processed African locust bean seeds. The objective is to evaluate amino acids decarboxylation activities of Bacillus spp. isolates from Soumbala and biogenic amines content. Soumbala samples were collected among 6 producers in 3 regions of Ivory Coast. 52 Bacillus spp. strains were isolated and identified using API 50 CHB kits. Histidine, lysine, arginine, phenylalanine and ornithine decarboxylation activities and arginine dehydrogenase activities were determined in order to study their ability to produce histamine, cadaverine, phenylethylamine and putrescine. Soumbala samples were analysed for histamine, cadaverine, phenylethylamine and putrescine content. Bacillus spp. strains were identified as followed: B. subtilis (16); B. lentus (3), B. pumilus (1), Geobacillus stearothermophillus (5), B. megaterium (9), B. firmus (2), B. circulans (2), Brevibacillus non reactive (5), B. licheniformis (4), Aneurinibacillus aneuriniliticus (4), B. cereus (1). 16 strains did not show arginine deshydrogenase activities and histidine, lysine, ornithine, or phenylalanine decarboxylation activities. Biogenic amines content of Soumbala was in average 82 mg.kg-1 for histamine, 36 mg.kg-1 for cadaverine, 45 mg.kg-1 for putrescine and 272 mg.kg-1 for phenylethylamine, some samples reaching high levels. Strategies for the control of biogenic amines production in African locust bean fermented seeds are discussed.

International audience; Kitoza is a traditional product from Madagascar manufactured either with strips of pork or beef meat. lt is an artisanal product manufactured in rural and urban regions. The first step of the process is salting with coarse salt mixed with spices and then either a drying or smoking step is carried out. Samples from pork and beef and both processes have been analysed. The microbiological analyses revealed the process allowed the selection of microorganisms with potential technological interest. Thus a high level of coagulase negative staphylococci (CNS) was noticed: between 5 to7 log CFU/g. These technological bacteria seemed well adapted to the two processes drying or smoking. 811 isolates of presumed CNS from Manitol Salt agar have been identified. Two approaches have been applied: a PCR multiplex as developed by Corbière Morot-Bizot et al. (2004. J. Appl. Microbial. 97, 1087-1094) or a staph array developed by Giammarinaro et al. (2005. J. Clin. Microbiol., 3673-3680) allowing the identification of 36 CNS species. A total of 9 species of CNS were identified in the Kitoza with 7 species for the beef and 8 for the pork meats. Staphylococcus saprophyticus was the dominant species in all the products and the major one in dried pork and beef smoked or dried. While in smoked pork, in addition of S. saprophyticus (50%), S. xy/osus (13%), S. equorum (15%), S. succinus (13%) and S. epidermidis (9%) were identified. This study highlighted that the process: salting and drying or smoking allowed the selection of coagulase negative staphylococci. These CNS are well described in the literature as contributing to the quality of meat products, with some species such as S. xylosus already used as starter cultures for the manufacture of meat products. This work was funded by EU, 7th Framework Programme, AFTER project (grant agreement 245025). (Résumé d'auteur)

International audience; Traditional meat preservation processes often combine unit operations such as salting, smoking, fermentation and drying. In tropical countries, elevated temperatures and high relative humidity, poor infrastructure and improper slaughterhouse practices explain the need for more drastic processes (more salt, more water loss) when it comes to meat preservation. The end goal of our research is to assemble a new process that enables the production, in tropical conditions of shelf-stable and ready-to-eat meat products by combining Dehydration- Impregnation by Soaking (DIS) as a rapid pre-treatment of meat, a controlled lactic fermentation, and a final drying step. We analyzed the feasibility of coupling DIS with a subsequent lactic fermentation in the treatment of meat. A series of beef fillets were subjected to three different DIS treatments. The resulting DIS-treated fillets had three different characteristics in terms of water activity, salt and fermentable sugars contents. Fillets issued from the DIS treatment with the shortest immersion time and the highest salt concentration in the DIS bath were inoculated with Lactobacillus sakei (a control group was left without inoculation). After 24 h incubation at 25°C, only inoculated fillets showed signs of lactic fermentation: presence of D-lactic acid and a high population of L. sakei. Thus, the original coupling of DIS with lactic fermentation by surface inoculation with L. sakei was validated. However, the heterogeneity of the meat and its endogenous flora as well as the complexity of the simultaneous mechanisms that take place during DIS and fermentation both justify the need for a more controlled experimental device. Model foods will be used in further research in order to better understand the simultaneous mechanisms that take place during the fermentation step of a DIS treated matrix. (Résumé d'auteur)

International audience; Reunion Island is a French department located in Indian Ocean and suffering from a great occurrence of metabolic disorders such as obesity and diabetes. Actually, chicken is the main meat consumed in Reunion Island (42 kg/year/inhabitant against 23 kg/year/inhabitant in metropolitan France), thus enriching it in poly-unsaturated omega-3 fatty acids (n3-PUFAs) should improve Reunionese's health. In the present trials, chickens (JA757 strain) were raised in an experimental poultry house for 56 days. The experimental diets were modified over 2 criteria: flax seed content (0, 3, 6 and 9%) and level of vitamin E supplementation (0 and 150 ppm). After slaughter, thigh meat was analyzed to determine fatty acids composition, vitamin E content and lipid oxidation susceptibility by measuring malondialdehyde (MDA) content. Results showed that meats were enriched in n3-PUFAs proportionally to the flax seed content of the diet which is directly linked with the n3-PUFAs content of the diet. The quantity of n3- PUFAs found in meat is positively correlated with the quantity of n3-PUFAs ingested by the chickens. The transfer efficiency can be calculated by dividing the n3-PUFAs content in meat by the quantity of n3-PUFAs ingested. This efficiency decreases when the amounts of n3- PUFAs consumed increase, leading to a negative correlation between the transfer efficiency and the consumed n3-PUFAs quantity. The vitamin E supplementation did not play a role in the n3-PUFAs enrichment but meats issued from animals fed with these supplemented diets have exhibited higher vitamin E contents. Oxidation was lower in meats enriched with omega 3 and vitamin E than in those just enriched in omega 3. This difference in oxidation level was maintained during the meat storage at 4 °C for several days and even after cooking. (Résumé d'auteur)

Enrichment of chicken meat with Omega-3 in tropical conditions. 2012 EFFoST Annual Meeting - A Lunch Box for Tomorrow : An interactive combination of integrated analysis and specialized knowledge of food

International audience; Lipid oxidation is a classic parameter of meat quality evaluation, mostly when the composition of the meat is modified, even by modifying the animal's diet or by adding food supplements during postslaughter meat processing. Malondialdehyde (MDA) is commonly accepted as the major lipid oxidation product in meat and considered as a terminal accumulating compound. It is generally measured together with the other coloured aldehydes resulting from lipid oxidation, with a global methodology called TBARS (thiobarbituric acid reactive substances) index. This index is expressed as equivalent MDA, considering MDA as the preponderant compound by way of a calibration using 1,1,3,3-tetramethoxypropane (TMP) or 1,1,3,3-tetraethoxypropane (TEP). For more precision, MDA is sometimes directly quantified by high performance liquid chromatography (HPLC). The TBARS index or MDA content are mostly measured on fresh meat, but several studies have focused on their changes during meat processing (storage, cooking or other processes). This study set out to characterize changes in MDA content during meat cooking. For this purpose, small samples (1.5 g) of ground chicken thighs were conditioned in plastic bags to form thin films of less than 0.5 mm. The plastic bags were then immersed in a water bath at different temperatures (50, 70 and 100°C) for different immersion times (from 0 to 30 min). Due to the very thin layer of meat, the temperature was considered as constant from the immersion time to the cooling time in an ice bath. MDA content was measured by HPLC. Different meat samples enriched with omega 3 poly-unsaturated fatty acids (transferred in the meat from a dietary flax seeds supplementation) were used to determine the differences in MDA content depending on the vitamin E and xanthophylls' contents in the diets administered to the chickens. The results showed that the appearance kinetics of MDA depended on the heating temperature. At 70°C, three phases were observed in MDA content change: first an increasing phase, then a plateau phase and finally a decreasing phase. At 100°C, the three phases also appeared but the results were more dispersed, probably because of contradictory MDA appearance and disappearance reactions at the same time. Finally, at 50°C, no modification on the MDA content was observed. So, the best temperature for studying MDA content changes during meat cooking was 70°C. It was selected to study differences between the meat sources. The diet composition had no effect on the kinetics of MDA content changes but it greatly affected the MDA contents. The highest MDA contents were determined in meats from chickens reared without a vitamin E dietary supplement. (Texte intégral)

International audience; Kitoza is a traditional product of Madagascar which was previously prepared for kings and nobles. It is made from beef or pork strips, 20 to 50 cm long and 2 to 4 cm wide, salted and then dried and/or smoked. Kitoza consumption has currently increased because of its ready availability on local market. Within the framework of AFTER (African Food Tradition Revisited by Research), a project which aims in improving the quality and safety of African traditional food, quality of kitoza made from beef and pork was analyzed. Kitoza samples were collected in Antananarivo.Physico chemical and microbiological quality was measured on 60 samples, including 15 salted/smoked kitoza and 15 salted/dried kitoza for each type of meat. Their moisture, lipid, protein and salt contents, water activity, pH and the phenol content for smoked products were measured. According to microbiological analyses, there was no Salmonella in all types of kitoza. However, pork kitoza and dried beef kitoza presented high total microbial counts. The level of Escherichia coli was high in pork kitoza while it was satisfactory in beef. A sensory profile study was undertaken on 8 beef and pork smoked kitoza. Sensory data were analyzed using Principal component analysis (PCA) and Cluster analysis. PCA representation showed that there was a clear difference between pork and beef samples. Pork samples were more associated to fatty and salty attributes. Four samples into 4 clusters were selected for a consumer study with about 200 Malagasy and European consumers. (Résumé d'auteur)

International audience; Enriching food with omega 3 is a largely explored way of improving nutritional quality of feedstuffs. Concerning fresh meat, supplementing the animal diet with natural omega 3 seems to be the best way. However, omega 3 are fragile compounds with a high susceptibility to lipid oxidation. In Reunion Island, a study called NUTRIVOL aimed to enrich poultry meat with omega 3 by providing the animals a diet enriched with flax seeds and vitamin E as antioxidant. For 3 different diets, 160 labelled yellow female chickens were raised. They were fed during 37 days with a classical diet and the last 18 days with the test diets (control without flax seeds or vitamin E enrichment, +9% flax seeds without vitamin E enrichment, and +9% fIax seeds with vitamin E enrichment). After slaughter, meat (thigh and breast) was analysed for lipid content and fatty acid composition. Lipid oxidation was evaluated by different methods after different refrigerated storage times (2 and 9 days for breast; 3 and 10 days for thigh) and after cooking under vacuum till 72°C (after 2 and 9 days of refrigerated storage for breast and after 13 days for thigh). (Résumé d'auteur)

International audience; Traditional processes of meat fermentation involve sequential operations of salting, fermentation and drying. An alternative process·for the fermentation of non-comminuted meat consists of two successive operations: a first osmotic treatment to partially dehydrate and to impregnate the meat with salt and sugars, followed by a fermentation with added starter culture. This innovative sequential operations combination is proposed in an attempt to shorten and simplify the process and to minimise sanitary risks associated with the fermentation step, especially under tropical conditions. In what extent meat can be subjected to a pre drying step before fermentation? To answer this question, we evaluated the effect of water loss during the osmotic treatment on the kinetics of fermentation. Beef meat fillets were immersed in solutions with concentrated solutions of salt and glucose syrup. Salt concentration of the soaking solution and immersion time were designed in order to obtain water loss from 20 to 30, salt and sugar gain of 2 g/100g initial mass (usual meat products salt and sugar contents). Then they were inoculated with Lactobacillus sake; and incubated at 25°C and 98% relative humidity. At known incubation time intervals, meat samples were assayed for their microbiological load, pH, glucose, lactic and acetic acid contents. Kinetics of fermentation showed that for both conditions, lactic acid bacteria growth was accompanied by a decrease of the pH, glucose and L-lactic acid contents, and an increase in acetic acid content within 72 hours of incubation. D-Iactic acid was produced within 24 hours after which this amount decreased. These results indicated that lactic acid fermentation occurred in both cases. There was a significant effect of the water loss on the D-Iactic acid content produced within 24 hours. D-Iactic acid content was 0.6% dry basis and 0.2% for an osmotic treatment allowing a water loss of 20% and 30% respectively. Moreover, glucose consumption was more rapid in the second case, suggesting that both sugar formulation and water loss must be studied in order to identify the best formulation by osmotic treatment that allow optimal fermentation. This innovative process could be an alternative to traditional preservation meat processes. (Texte intégral)