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1.
Foods ; 10(11)2021 Oct 28.
Article in English | MEDLINE | ID: mdl-34828889

ABSTRACT

Pozol is a Mexican beverage prepared from fermented nixtamalized maize dough. To contribute to understanding its complex microbial ecology, the effect of inoculating on MRS-starch pure and mixed cultures of amylolytic Sii-25124 and non-amylolytic W. confusa 17, isolated from pozol, were studied on their interactions and fermentation parameters. These were compared with L. plantarum A6, an amylolytic strain isolated from cassava. Microbial growth, kinetic parameters, amylolytic activity, lactic acid production, and hydrolysis products from starch fermentation were measured. The population dynamics were followed by qPCR. L. plantarum A6 showed higher enzymatic activity, lactic acid, biomass production, and kinetic parameters than pozol LAB in pure cultures. Mixed culture of each pozol LAB with L. plantarum A6 showed a significant decrease in amylolytic activity, lactic acid yield, specific growth rate, and specific rate of amylase production. The interaction between Sii-25124 and W. confusa 17 increased the global maximum specific growth rate (µ), the lactic acid yield from starch (Ylac/s), lactic acid yield from biomass (Ylac/x), and specific rate of lactic acid production (qlac) by 15, 30, 30, and 40%, respectively, compared with the pure culture of Sii-25124. Interactions between the two strains are essential for this fermentation.

2.
Crit Rev Food Sci Nutr ; 59(22): 3648-3666, 2019.
Article in English | MEDLINE | ID: mdl-30277794

ABSTRACT

Cell cultures are widely used in pharmaceutical, medical, food/nutrition and biological sciences. In food and nutrition science, intestinal cell culture models of human origin are attracting increasing interest but are still rarely used in investigations of the effects of bioactive food compounds on intestinal inflammation. However, such in vitro models would, among other benefits, limit the use of in vivo models and could provide new molecular data.This review is an overview of two-dimensional (2D) and three-dimensional (3D) intestinal cell culture models and their potential use in gut inflammation studies. After describing the features of healthy and inflamed intestinal barriers, we describe the main intestinal cell lines (Caco2, HT29, T84) and their use in investigations of the transport and antioxidant/anti-inflammatory potential of some bioactive food compounds. Finally, different co-culture models of gut inflammation, in association with immune cells (PBMC, THP1 and RAW 264.7 cell lines) in both 2D and 3D models are presented. 3D models called organs-on-chips or biochips are the most recent and very promising approach made possible by bioengineering and biotechnological improvements and more accurately mimic the gut microenvironment.


Subject(s)
Cell Culture Techniques , Food , Inflammation , Intestines , Leukocytes, Mononuclear , Caco-2 Cells , Food/adverse effects , Humans , Inflammation/etiology , Intestinal Mucosa/pathology , Intestines/cytology , Intestines/pathology
3.
Int J Food Microbiol ; 266: 79-86, 2018 Feb 02.
Article in English | MEDLINE | ID: mdl-29179099

ABSTRACT

Folate deficiency can cause a number of diseases including neural tube defects and megaloblastic anemia, and still occurs in both developed and developing countries. Cereal-based food products are staple foods in many countries, and may therefore be useful sources of folate. The production of folate by microorganisms has been demonstrated in some cereal-based fermented foods, but has never been studied in a traditional African cereal based food spontaneously fermented. The microbiota of ben-saalga, a pearl-millet based fermented porridge frequently consumed in Burkina Faso, has a good genetic potential for the synthesis of folate, but the folate content of ben-saalga is rather low, suggesting that folate is lost during the different processing steps. The aim of this study was therefore to monitor changes in folate content during the different steps of preparing ben-saalga, from pearl-millet grains to porridge. Traditional processing involves seven different steps: washing, soaking, grinding, kneading, sieving, (spontaneous) fermentation, and cooking. Two type of porridge were prepared, one using a process adapted from the traditional process, the other a modified process based on fermentation by backslopping. Dry matter and total folate contents were measured at each step, and a mass balance assessment was performed to follow folate losses and gains. Folate production was observed during the soaking of pearl-millet grains (+26% to +79%), but the folate content of sieved batters (2.5 to 3.4µg/100g fresh weight) was drastically lower than that of milled soaked grains (17.3 to 19.4µg/100g FW). The final folate content of the porridges was very low (1.5 to 2.4µg/100g FW). The fermentation had no significant impact on folate content, whatever the duration and the process used. This study led to a better understanding of the impact on folate of the different processing steps involved in the preparation of ben-saalga.


Subject(s)
Fermentation , Fermented Foods/analysis , Folic Acid/analysis , Food Microbiology , Pennisetum/metabolism , Pennisetum/microbiology , Burkina Faso , Cooking , Food Handling , Pennisetum/chemistry
4.
Int J Food Microbiol ; 266: 346-354, 2018 Feb 02.
Article in English | MEDLINE | ID: mdl-29037836

ABSTRACT

The objective of this work was to investigate the nutritional potential of Lactobacillus plantarum A6 in a food matrix using next generation sequencing. To this end, we characterized the genome of the A6 strain for a complete overview of its potential. We then compared its transcriptome when grown in a food matrix made from pearl millet to and its transcriptome when cultivated in a laboratory medium. Genomic comparison of the strain L. plantarum A6 with the strains WCFS1, ST-III, JDM1 and ATCC14917 led to the identification of five regions of genomic plasticity. More specifically, 362 coding sequences, mostly annotated as coding for proteins of unknown functions, were specific to L. plantarum A6. A total of 1201 genes were significantly differentially expressed in laboratory medium and food matrix. Among them, 821 genes were up-regulated in the food matrix compared to the laboratory medium, representing 23% of whole genomic objects. In the laboratory medium, the expression of 380 genes, representing 11% of the all genomic objects was at least double than in the food matrix. Genes encoding important functions for the nutritional quality of the food were identified. Considering its efficiency as an amylolytic strain, we investigated all genes involved in carbohydrate metabolism, paying particular attention to starch metabolism. An extracellular alpha amylase, a neopullulanase and maltodextrin transporters were identified, all of which were highly expressed in the food matrix. In addition, genes involved in alpha-galactoside metabolism were identified but only two of them were induced in food matrix than in laboratory medium. This may be because alpha galactosides were already eliminated during soaking. Different biosynthetic pathways involved in the synthesis of vitamin B (folate, riboflavin, and cobalamin) were identified. They allowed the identification of a potential of vitamin synthesis, which should be confirmed through biochemical analysis in further work. Surprisingly, some genes involved in metabolism and bioaccessibility of iron were identified. They were related directly to the use of transport of iron, or indirectly to metabolism of polyphenols, responsible of iron chelation in the food. The combination of genomics and transcriptomics not only revealed previously undocumented nutritional properties of L. plantarum A6, but also documented the behaviour of this bacterium in food.


Subject(s)
Edible Grain/metabolism , Fermented Foods/microbiology , Food Microbiology , Genome, Bacterial/genetics , Lactobacillus plantarum/genetics , Nutritive Value , Transcriptome , Carbohydrate Metabolism/genetics , Genomics , High-Throughput Nucleotide Sequencing , Lactobacillus plantarum/metabolism , Pennisetum/microbiology
5.
Microorganisms ; 5(3)2017 Jul 25.
Article in English | MEDLINE | ID: mdl-28757585

ABSTRACT

Cereal foods fermented by lactic acid bacteria are staples in many countries around the world particularly in developing countries, but some aspects of the nutritional and health benefits of traditional fermented foods in developing countries have not been sufficiently investigated compared to fermented foods in high-income countries. Today, malnutrition worldwide is characterized by a double burden, excess leading to non-communicable diseases like obesity or diabetes alongside micronutrient deficiencies. In addition, populations in developing countries suffer from infectious and parasitic diseases that can jeopardize the health benefits provided by their traditional fermented foods. Using examples, we argue that research on traditional fermented cereals in developing countries should focus more on their effect on inflammation and oxidative stress under conditions including infectious or non-infectious gut inflammation.

6.
Int J Food Microbiol ; 244: 103-110, 2017 Mar 06.
Article in English | MEDLINE | ID: mdl-28092820

ABSTRACT

Cereals are staple foods in most African countries, and many African cereal-based foods are spontaneously fermented. The nutritional quality of cereal products can be enhanced through fermentation, and traditional cereal-based fermented foods (CBFFs) are possible sources of lactic acid bacteria (LAB) with useful nutritional properties. The nutritional properties of LAB vary depending on the species and even on the strain, and the microbial composition of traditional CBFFs varies from one traditional production unit (TPU) to another. The nutritional quality of traditional CBFFs may thus vary depending on their microbial composition. As the isolation of potentially useful LAB from traditional CBFFs can be very time consuming, the aim of this study was to use PCR to assess the nutritional potential of LAB directly on the metagenomes of pearl-millet based fermented porridges (ben-saalga) from Burkina Faso. Genes encoding enzymes involved in different nutritional activities were screened in 50 metagenomes extracted from samples collected in 10 TPUs in Ouagadougou. The variability of the genetic potential was recorded. Certain genes were never detected in the metagenomes (genes involved in carotenoid synthesis) while others were frequently detected (genes involved in folate and riboflavin production, starch hydrolysis, polyphenol degradation). Highly variable microbial composition - assessed by real-time PCR - was observed among samples collected in different TPUs, but also among samples from the same TPU. The high frequency of the presence of genes did not necessarily correlate with in situ measurements of the expected products. Indeed, no significant correlation was found between the microbial variability and the variability of the genetic potential. In spite of the high rate of detection (80%) of both genes folP and folK, encoding enzymes involved in folate synthesis, the folate content in ben-saalga was rather low (median: 0.5µg/100g fresh weight basis). This work highlighted the limit of evaluating the nutritional potential of the microbiota of traditional fermented foods by the only screening of genes in metagenomes, and suggests that such a screening should be completed by a functional analysis.


Subject(s)
Edible Grain/microbiology , Limosilactobacillus fermentum/genetics , Metagenome/genetics , Microbiota/genetics , Pennisetum/microbiology , Yeasts/genetics , Bioreactors , Burkina Faso , Carotenoids/biosynthesis , Fermentation , Folic Acid/biosynthesis , Food Microbiology , Hydrolysis , Limosilactobacillus fermentum/metabolism , Nutritive Value , Polyphenols/metabolism , Real-Time Polymerase Chain Reaction , Riboflavin/biosynthesis , Starch/metabolism , Yeasts/metabolism
7.
Crit Rev Food Sci Nutr ; 57(5): 949-957, 2017 Mar 24.
Article in English | MEDLINE | ID: mdl-25976096

ABSTRACT

Dietary fiber is a complex nutritional concept whose definition and method of analysis has evolved over time. However, literature on the role of dietary fiber on mineral bioavailability has not followed pace. Although in vitro studies revealed mineral binding properties, both animal and human studies failed to show negative effects on mineral absorption, and even in some cases reported absorption enhancing properties. The existing literature suggests that dietary fibers have negative effects on mineral absorption in the gastrointestinal tract largely due to mineral binding or physical entrapment. However, colonic fermentation of dietary fibers may offset this negative effect by liberating bound minerals and promoting colonic absorption. However, existing studies are limited since they did not control for more potent mineral absorption inhibitors such as phytates and polyphenols. Animal studies have mostly been on rats and hence difficult to extrapolate to humans. Human studies have been mostly on healthy young men, who likely to have an adequate store of iron. The use of different types and amounts of fibers (isolated/added) with varying physiological and physicochemical properties makes it difficult to compare results. Future studies can make use of the opportunities offered by enzyme technologies to decipher the role of dietary fibers in mineral bioavailability.


Subject(s)
Dietary Fiber , Intestinal Absorption , Trace Elements/pharmacokinetics , Animals , Biological Availability , Humans , Iron, Dietary/pharmacokinetics , Models, Animal , Phytic Acid/pharmacokinetics , Polyphenols/pharmacokinetics
8.
Crit Rev Food Sci Nutr ; 57(18): 3894-3910, 2017 Dec 12.
Article in English | MEDLINE | ID: mdl-27351520

ABSTRACT

Folate is an essential micronutrient involved in numerous vital biological reactions. The dietary consumption of naturally occurring vitamin B9 is often inadequate in many countries, and supplementation or fortification programs (using synthetic folic acid) are implemented to alleviate folate deficiency. Other food-based alternatives are possible, such as the use of lactic acid bacteria (LAB) to synthesize folate during fermentation. Many studies have been conducted on this topic, and promising results were reported for some fermented dairy products. However, in other studies, folate consumption by LAB or rather low folate production were observed, resulting in fermented foods that may not significantly contribute to the recommended B9 intake. In addition, the optimum conditions for folate biosynthesis by LAB are still not clear. The aim of this review was thus to (i) clarify the ability of LAB to produce folate in food products, (ii) check if the production of folate by LAB in various fermented foods is sufficient to meet human vitamin B9 requirements and (iii) suggest ways to optimize folate production by LAB in fermented food products.


Subject(s)
Fermentation , Folic Acid Deficiency/prevention & control , Folic Acid/biosynthesis , Lactic Acid/metabolism , Lactobacillus/metabolism , Cultured Milk Products/microbiology , Dietary Supplements , Folic Acid/administration & dosage , Food Microbiology , Functional Food , Humans
9.
Food Microbiol ; 62: 169-177, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27889145

ABSTRACT

With the aim of selecting starter cultures with interesting probiotic potential and with the ability to produce folate in a food matrix, yeast strains isolated from fermented cereal-based African foods were investigated. A total of 93 yeast strains were screened for their tolerance to pH 2 and 0.3% of bile salts. Pichia kudriavzevii isolates gave the best results. Selected P. kudriavzevii strains were tested for survival to the simulated human digestion and for adhesion to Caco-2 cells. Moreover, presence of folate biosynthesis genes was verified and production of extra and intra-cellular folate determined during growth in culture medium. 31% of yeast strains could tolerate pH 2, while 99% bile salts. Survival rate after simulated digestion ranged between 11 and 45%, while adhesion rate between 12 and 40%. Folate production was mainly intracellular, maximum after 24 h of growth. To be closer to traditional cereal-based fermentations, a P. kudriavzevii strain with good probiotic potential was co-inoculated with Lactobacillus fermentum strains in a pearl millet gruel. This resulted in in situ folate production that peaked after 4 h. The use of strains with both probiotic and nutritional enrichment properties may have a greater impact for the consumers.


Subject(s)
Edible Grain/chemistry , Folic Acid/analysis , Pichia/physiology , Probiotics , Africa , Bile Acids and Salts , Caco-2 Cells , Fermentation , Folic Acid/biosynthesis , Food Microbiology , Food, Fortified/analysis , Food, Fortified/microbiology , Humans , Limosilactobacillus fermentum/metabolism , Microbial Viability , Nutritive Value , Pichia/isolation & purification , Probiotics/metabolism
10.
Syst Appl Microbiol ; 39(2): 115-21, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26776108

ABSTRACT

Lactic acid bacteria (LAB) synthesize a wide variety of biochemical compounds during food fermentation. Carotenoids provide important biological functions for bacteria, and their consumption by humans has many beneficial effects. In this study, the presence of several genes involved in the production of carotenoids was determined by BLAST analysis and PCR in a collection of 156 LAB isolated from traditional amylaceous African fermented foods. Only the crtE gene and the crtNM operon were present and detected in Lactobacillaceae. Most of the strains with positive PCR detection of the operon crtNM produced carotenoid-like compounds when grown in MRS broth. The carotenoids produced differed from compounds previously identified in other LAB except for one peak, which was closely related to 4,4'-diaponeurosporene already reported in the literature in Lactobacillus plantarum species. Most producing strains belonged to Lactobacillus fermentum and L. plantarum species but a few Pediococcus acidilactici were also producers. Furthermore, the most efficient L. plantarum was able to synthesize carotenoids in a cereal fermented food. Genetic screening was shown to be efficient since, in all cases, it eliminated the need for biochemical analysis of strains in which no amplicons of the operon crtNM were obtained.


Subject(s)
Carotenoids/biosynthesis , Genes, Bacterial , Lactobacillales/genetics , Lactobacillales/metabolism , Chromatography, High Pressure Liquid , Fermentation , Food Microbiology , Lactobacillales/classification , Operon , Polymerase Chain Reaction
11.
Food Chem ; 174: 60-7, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25529652

ABSTRACT

The effect of removing phytate (IP6), iron-binding polyphenols, and dietary fibers on iron bioaccessibility in wheat-red sorghum (WrS) and teff-white sorghum (TwS) flour blends used in Ethiopia to make injera, a fermented pancake, was evaluated through the application of exogenous enzymes. Phytase treatment led to >90% reduction in IP6 and to an IP6:Fe molar ratio <1, but iron bioaccessibility was not improved (P > 0.05). Phytase + xylanase + cellulase (P + X + C) treatment increased iron bioaccessibility in TwS (non-detectableto1.6%) and WrS (1.9-3.2%), whereas phytase + polyphenol oxidase (P + PPO) treatment only showed improvement in the TwS blend. P + X + C + PPO treatment of the WrS blend increased the soluble non-dialysable iron fraction (6.7%) more than P + PPO treatment (3.9%). Although responses to enzyme treatments and iron bioaccessibility were matrix dependent, a positive effect of dietary fiber hydrolysis with X + C was obtained, irrespective of the blend. Dietary fibers had a negative effect on iron bioaccessibility independent of phytates.


Subject(s)
Dietary Fiber/analysis , Flour/analysis , Iron/metabolism , Phytic Acid/chemistry , Polyphenols/chemistry , Sorghum/chemistry , 6-Phytase/chemistry , Biocatalysis , Cellulase/chemistry , Dietary Fiber/metabolism , Endo-1,4-beta Xylanases/chemistry , Ethiopia , Fermentation , Humans , Iron/analysis , Models, Biological , Phytic Acid/metabolism , Polyphenols/metabolism , Sorghum/metabolism
12.
Int J Food Microbiol ; 185: 103-11, 2014 Aug 18.
Article in English | MEDLINE | ID: mdl-24950021

ABSTRACT

Traditional fermented gruels prepared from cereals are widely used for complementary feeding of young children in Africa and usually have a low energy density. The amylase activity of some lactic acid bacteria (LAB) helps increase the energy content of gruels through partial hydrolysis of starch, thus enabling the incorporation of more starchy material while conserving the desired semi-liquid consistency for young children. Even if this ability is mainly related to the production of alpha-amylase (E.C. 3.2.1.1), in a recent molecular screening, genes coding for enzymes involved in starch metabolism were detected in the efficient amylolytic LAB Lactobacillus plantarum A6: alpha-glucosidase (E.C. 3.2.1.20), neopullulanase (E.C. 3.2.1.135), amylopectin phosphorylase (E.C. 2.4.1.1) and maltose phosphorylase (E.C. 2.4.1.8). The objective of this study was to investigate the expression of these genes in a model of starchy fermented food made from pearl millet (Pennisetum glaucum). Transcriptional and enzymatic analyses were performed during the 18-h fermentation period. Liquefaction was mainly caused by an extracellular alpha amylase encoded by the amyA gene specific to the A6 strain among L. plantarum species and found in both Lactobacillus amylovorus and Lactobacillus manihotivorans. The second most active enzyme was neopullulanase. Other starch metabolizing enzymes were less often detected. The dynamic detection of transcripts of gene during starch fermentation in pearl millet porridge suggests that the set of genes we investigated was not expressed continuously but transiently.


Subject(s)
Fermentation , Lactobacillus plantarum/genetics , Lactobacillus plantarum/metabolism , Pennisetum/microbiology , Starch/metabolism , Enzymes/genetics , Food Analysis , Food Microbiology , Gene Expression Regulation, Bacterial , Hydrolysis , Lactic Acid/metabolism , Lactobacillus plantarum/enzymology
13.
J Agric Food Chem ; 61(43): 10377-83, 2013 Oct 30.
Article in English | MEDLINE | ID: mdl-24083539

ABSTRACT

Nutritionally, contaminant iron in foods may lead to overestimation of the satisfaction of iron requirement while iron deficiencies remain a widespread health problem. Iron contamination was measured in millet and sorghum grains after decortication and in-field milling using different equipments in Burkina Faso. Total iron content did not change significantly after decortication, probably due to a balance between losses resulting from the removal of iron-rich peripheral parts and contamination. Total iron contents increased significantly after mechanical milling irrespective of whether iron or corundum grindstones were used. Contamination was highly variable, ranging from 3 to 6 mg iron/100 g DM, and was mainly due to wear of the milling equipment. After in vitro digestion of traditional cereal dishes prepared with iron-contaminated or uncontaminated flours, the contaminant iron was found mainly in the insoluble fraction. Only in sorghum was a small proportion (4%) bioaccessible, showing that contaminant iron has poor nutritional interest.


Subject(s)
Food Contamination/analysis , Food Handling , Iron/analysis , Panicum/chemistry , Sorghum/chemistry , Flour/analysis
14.
PLoS One ; 8(4): e57711, 2013.
Article in English | MEDLINE | ID: mdl-23577056

ABSTRACT

Most bacterial strains, which have been studied so far for their probiotic functions, are extensively used by manufacturers in developed countries. In our work, we sought to study a mix (called BSL) comprising three strains belonging to Lactobacillus fermentum, L. paraplantarum and L. salivarius, that were isolated from a traditional African pearl millet based fermented slurry. Our objective was to study this BSL cocktail in gnotobiotic rats, to evaluate their survival and their behavior in the digestive tract conditions. After a single oral inoculation of germfree rats with BSL, the species established stably in the digestive tract with the following hierarchy of abundance: L. salivarius> L. plantarum> L. fermentum. BSL cocktail was metabolically active since it produced 50 mM lactate and it expressed genes involved in binding mechanism in the caecum. Furthermore, the global morphology of the colon epithelium was not disturbed by the BSL cocktail. BSL cocktail did not modify mucus content and host mucus-related genes (MUC1, MUC2, MUC3 or resistin-like molecule ß). The cocktail of lactobacilli enhanced the proliferating cell nuclear antigen (PCNA) at a level comparable to what was observed in conventional rats. PCNA was involved in proliferation and DNA repair, but the presence of the cocktail did not provoke proliferative events (with Ki67 as indicator), so we suppose BSL may help gut preservation. This work is the first step towards the selection of strains that are derived from traditional fermented food to formulate new probiotic mixture.


Subject(s)
Fermentation , Food Handling , Germ-Free Life , Lactobacillus/isolation & purification , Lactobacillus/physiology , Pennisetum/metabolism , Animals , Cell Cycle , Cell Proliferation , Colon/cytology , Colon/microbiology , Gene Expression Regulation, Bacterial , Intestinal Mucosa/cytology , Intestinal Mucosa/microbiology , Lactic Acid/biosynthesis , Lactobacillus/genetics , Lactobacillus/metabolism , Male , Microbial Viability , Mucins/metabolism , Rats
15.
J Agric Food Chem ; 61(8): 1935-42, 2013 Feb 27.
Article in English | MEDLINE | ID: mdl-23373471

ABSTRACT

The aim of the present study was to assess the effects of sorghum bioprocessing into Gowé on iron bioavailability and antioxidant properties of the final products. Gowé is an African sour beverage, whose process combines malting and fermenting of sorghum grains. The effects of the durations of germination and fermentation on the phytochemicals were evaluated using a central composite design. The antioxidant capacity and iron bioavailability of the derived flour were also evaluated. During the germination process, the tannin content of the grain decreased from 429.5 to 174.1 mg/100 g DM, while the total phenolic content increased from 300.3 to 371.5 mg GAE/100 g DM. The phenolic acid contents of the flour were significantly modified as a result of the durations of germination and fermentation. Both germination and fermentation enhanced the antioxidant capacity of sorghum flour, and antioxidant characteristics were significantly correlated with the levels of total phenolics, tannins, and phenolic acids. Phytate content of sorghum grain decreased drastically from 1003 to 369.1 mg/100 g DM when the duration of germination or fermentation increased. This was associated with an increase in the bioavailability of iron.


Subject(s)
Alcoholic Beverages/analysis , Sorghum/chemistry , Tannins/analysis , Alcoholic Beverages/microbiology , Antioxidants/analysis , Antioxidants/metabolism , Bacteria/metabolism , Fermentation , Flour/analysis , Food Handling , Germination , Iron/analysis , Phenols/analysis , Phenols/metabolism , Phytic Acid/analysis , Phytic Acid/metabolism , Seeds/chemistry , Seeds/growth & development , Seeds/microbiology , Sorghum/growth & development , Sorghum/microbiology , Tannins/metabolism
16.
Food Chem ; 138(1): 430-6, 2013 May 01.
Article in English | MEDLINE | ID: mdl-23265508

ABSTRACT

The influence of cereal blends, teff-white sorghum (TwS), barley-wheat (BW) and wheat-red sorghum (WrS), on fermentation kinetics during traditional fermentation of dough to prepare injera, an Ethiopian traditional fermented pancake, was investigated in samples collected in households. Barley malt was used with BW and WrS flours. WrS- and BW-injera sourdough fermentations were characterised by a transient accumulation of glucose and maltose and a two-step fermentation process: lactic acid fermentation and alcoholic fermentation with ethanol as the main end product. Only transient accumulation of glucose was observed in TwS-injera, and equimolar concentrations of lactic acid and ethanol were produced simultaneously. Final α-galactoside concentrations were low in all sourdoughs. Phytic acid (IP6) was completely hydrolyzed in WrS and BW-injeras probably due to the combined action of endogenous malt and microbial phytases. Only 28% IP6 hydrolysis was observed in TwS injera. Ways to improve IP6 hydrolysis in TwS-injera need to be investigated.


Subject(s)
Bread/analysis , Flour/analysis , Hordeum/chemistry , Lactobacillus/metabolism , Phytic Acid/chemistry , Sorghum/chemistry , Triticum/chemistry , Bread/microbiology , Fermentation , Flour/microbiology , Food Handling , Hordeum/metabolism , Hordeum/microbiology , Hydrolysis , Kinetics , Sorghum/metabolism , Sorghum/microbiology , Triticum/metabolism , Triticum/microbiology
17.
Public Health Nutr ; 16(10): 1741-50, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23234764

ABSTRACT

OBJECTIVE: To characterize current feeding practices and to evaluate the adequacy of energy and nutrient intakes of young children in subsistence farming rural households in North Wollo, Ethiopia. DESIGN: A cross-sectional study examining sociodemographic status, anthropometry, breast-feeding and complementary feeding practices using two in-home non-consecutive 24 h recalls. SETTINGS: Two rural villages in the highlands and lowlands of Gobalafto district, North Wollo. SUBJECTS: Seventy-six young children aged 12-23 months, thirty-nine from the lowlands and thirty-seven from the highlands. RESULTS: About 33% of the children, ~46% in the highlands and 24% in the lowlands (P=0.05), were stunted. Complementary diets were low in animal products, fruits and vegetables. Cereals and legumes were the major sources of energy, protein, Ca, Fe, Zn and vitamin A. Legumes with potentially toxic components (grass pea, broad beans) and low nutrient-dense beverages such as tea were frequently consumed. Intakes of energy, Ca, Zn, vitamin A and vitamin C from complementary foods were below WHO recommendations assuming average breast-milk intakes. In contrast, Fe and protein intakes and densities met WHO recommendations. Although vitamin C intakes and densities were higher (P<0.05) for the lowlands, they remained far below WHO recommendations. CONCLUSIONS: Interventions promoting the WHO guiding principles for complementary feeding practices and behaviours that take the agro-ecological contexts into account are needed here. Furthermore, specific recommendations should be formulated to discourage the consumption of grass pea, broad beans and low nutrient-dense beverages such as tea.


Subject(s)
Beverages/analysis , Breast Feeding , Diet , Energy Intake , Infant Nutritional Physiological Phenomena , Anthropometry , Ascorbic Acid/administration & dosage , Calcium, Dietary/administration & dosage , Child, Preschool , Cross-Sectional Studies , Diet Surveys , Edible Grain , Ethiopia , Fabaceae , Female , Fruit , Humans , Infant , Iron, Dietary/administration & dosage , Male , Nutrition Assessment , Nutritive Value , Rural Population , Socioeconomic Factors , Vegetables , Vitamin A/administration & dosage , World Health Organization , Zinc/administration & dosage
18.
J Food Prot ; 75(9): 1642-5, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22947472

ABSTRACT

The objective of the present work was to estimate the prevalence of Bacillus cereus group species in traditional cereal-based lactic acid-fermented slurries and nonfermented flours used to prepare infant foods in an African context. High counts on mannitol-egg yolk-polymixin agar medium were determined for the fermented slurries (median, 4.5 × 10(4) CFU/ml of slurry) compared with the nonfermented flours, most of whose counts were lower than 10(-1) CFU/g. Virulence genes were characterized in 60 isolates from 26 traditional cereal-based foods in Ouagadougou (Burkina Faso). Seventy-two and 38 % of isolates were positive for the complete set of genes coding for hemolysin BL and nonhemolytic enterotoxin, respectively, suggesting a high enterotoxigenic potential for these foodborne isolates. No potentially emetic toxin-producing strains were detected. Because of the high counts found for fermented slurries, survival tests with vegetative cells inoculated in fermented slurries were performed, which showed that growth of B. cereus was inhibited. This result suggests that fermentation in traditional production units is presumably not adequately controlled, enabling growth during any unit operations before fermentation, or even during the fermentation step, when the process was poorly controlled. However, adding nisin (0.1 mg/ml) enabled a 5-log reduction in the B. cereus population in 5 h, suggesting that the use of nisin could be a way to upgrade the hygienic quality of this type of food.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacillus cereus/isolation & purification , Edible Grain/microbiology , Food Contamination/analysis , Infant Food/microbiology , Nisin/pharmacology , Bacillus cereus/drug effects , Colony Count, Microbial , Consumer Product Safety , Fermentation , Food Microbiology , Humans , Infant , Prevalence
19.
J Food Sci ; 77(8): M466-72, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22860595

ABSTRACT

UNLABELLED: The potential of tropical starchy plants such as plantain (Musa paradisiaca), breadfruit (Artocarpus communis), and sweet potato (Ipomoea batatas) for the development of new fermented foods was investigated by exploiting the capacity of some lactic acid bacteria to hydrolyze starch. The amylolytic lactic acid bacteria (ALAB) Lactobacillus plantarum A6 and Lactobacillus fermentum Ogi E1 were able to change the consistency of thick sticky gelatinized slurries of these starchy fruits and tubers into semiliquid to liquid products. Consequently, a decrease in apparent viscosity and an increase in Bostwick flow were observed. These changes and the production of maltooligosaccharides confirmed starch hydrolysis. Sucrose in sweet potato was not fermented by strain A6 and poorly fermented by strain Ogi E1, suggesting possible inhibition of sucrose fermentation. In all 3 starchy plants, rapidly digestible starch (RDS) was higher than slowly digestible starch (SDS) and resistant starch (RS) represented between 17% and 30% dry matter (DM). The digestibility of plantain was not affected by fermentation, whereas the RDS content of breadfruit and sweet potato decreased and the RS content increased after fermentation. PRACTICAL APPLICATION: The characteristics resulting from different combinations of gluten free starchy plants (plantain, breadfruit, sweet potato) and amylolytic lactic acid bacteria (ALAB) offer opportunities to develop new functional fermented beverages, mainly for breadfruit and sweet potato, after further investigation of their formulation, sensory attributes, nutritional, and prebiotic characteristics.


Subject(s)
Fermentation , Food Handling/methods , Food Microbiology , Lactobacillus plantarum/growth & development , Limosilactobacillus fermentum/growth & development , Starch/metabolism , Amylose/metabolism , Artocarpus/microbiology , Disaccharides/metabolism , Fruit/microbiology , Ipomoea batatas/microbiology , Monosaccharides/metabolism , Plantago/microbiology , Polysaccharides/metabolism , Vegetables/microbiology , Viscosity
20.
PLoS One ; 7(5): e38034, 2012.
Article in English | MEDLINE | ID: mdl-22675431

ABSTRACT

The analysis of collections of lactic acid bacteria (LAB) from traditional fermented plant foods in tropical countries may enable the detection of LAB with interesting properties. Binding capacity is often the main criterion used to investigate the probiotic characteristics of bacteria. In this study, we focused on a collection of 163 Lactobacillaceace comprising 156 bacteria isolated from traditional amylaceous fermented foods and seven strains taken from a collection and used as controls. The collection had a series of analyses to assess binding potential for the selection of new probiotic candidates. The presence/absence of 14 genes involved in binding to the gastrointestinal tract was assessed. This enabled the detection of all the housekeeping genes (ef-Tu, eno, gap, groEl and srtA) in the entire collection, of some of the other genes (apf, cnb, fpbA, mapA, mub) in 86% to 100% of LAB, and of the other genes (cbsA, gtf, msa, slpA) in 0% to 8% of LAB. Most of the bacteria isolated from traditional fermented foods exhibited a genetic profile favorable for their binding to the gastrointestinal tract. We selected 30 strains with different genetic profiles to test their binding ability to non-mucus (HT29) and mucus secreting (HT29-MTX) cell lines as well as their ability to degrade mucus. Assays on both lines revealed high variability in binding properties among the LAB, depending on the cell model used. Finally, we investigated if their binding ability was linked to tighter cross-talk between bacteria and eukaryotic cells by measuring the expression of bacterial genes and of the eukaryotic MUC2 gene. Results showed that wild LAB from tropical amylaceous fermented food had a much higher binding capacity than the two LAB currently known to be probiotics. However their adhesion was not linked to any particular genetic equipment.


Subject(s)
Bacterial Adhesion/genetics , Lactobacillaceae/genetics , Lactobacillaceae/metabolism , Gene Expression Regulation, Bacterial , Genome, Bacterial , HT29 Cells , Humans , Intestinal Mucosa/microbiology , Mucin-2/genetics , Mucin-2/metabolism , Mucins/genetics , Mucins/metabolism
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