DEVELOPMENT OF FROZEN-FRIED YAM SLICES: OPTIMIZATION OF THE PROCESSING CONDITIONS

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was to optimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by pre-frying temperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yam slices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yam tuber

Starch-based edible films of improved cassava varieties Yavo and TMS reinforced with microcrystalline cellulose

The results of a recent study on starch-based films of improved cassava varieties show that these films have poor barrier properties and lower mechanical strength. Thus, for some applications, improving their resistance to breaking forces is a key factor in making their use possible and sustainable. In this study, to the starch of two improved varieties of cassava (Yavo and TMS), combined with peanut oil, soybean lecithin, glycerol was added microcrystalline cellulose (MCC) at 0, 7, 15 and 30 %. The addition of microcrystalline cellulose has resulted in an increase in the opacity (223.91 nm.UA to 425.33 nm.UA for Yavo and 251.42 nm.UA to 434.51 nm.UA for TMS), tensile strength (7.15 MPa–10.99 MPa for Yavo and 7.77 MPa–13.18 MPa for TMS), and Young's modulus (331.29 MPa–1351.08 for Yavo and 343.79 MPa–1476.08 MPa for TMS) of films. However, MCC induced a decrease in moisture content (15.99 %–11.43 % for Yavo and 14.24 %–10.66 % for TMS), water solubility (24.84 %–20.61 % for Yavo and 24.15 %–19.36 % for TMS), elongation at break (22.75 %–1.31 % for Yavo and 21.25 %–1.19 % for TMS) and water vapour permeability (WVP) (1.98 * 10-11 to 1.39 * 10-11 g Pa-1. s-1.m1 for Yavo and 1.93 * 10-11 to 1.29 * 10-11 g Pa-1. s-1.m1). The MCC has also produced yellowish-coloured films. MCC has been shown to be effective in improving starch-based films of improved cassava varieties Yavo and TMS. These two varieties can be used in combination with MCC to produce food packaging

Effect of glycerol, peanut oil and soybean lecithin contents on the properties of biodegradable film of improved cassava starches from Côte d’Ivoire

— Edible films have been successfully used in the food packaging industry for several decades. Today natural polysaccharides, including cassava starch,are increasingly being used in the production of such biodegradable edible films and food packaging. In Côte d'Ivoire, there are improved cassava varieties whose starches have not yet been tested in the production of biodegradable films. In thisstudy, the optical and mechanical properties and the water solubility of starch-based composite films of four improved cassava varieties withadded glycerol, peanut oil and soy lecithin were determined. Starchwas obtained by cold water extraction from native cassava from the varieties Bocou 1, Bocou 2, Yavo and TMS. Films preparation was made bycasting methodwithcassava, glycerol (25-30 %), peanutoil (5-10 %) and soybean lecithin (0-5 %). Increasing the glycerol content, increased L*color valueand elongationat break and decreased a*, b*, colourdifference (ΔE*ab) and tensilestrength of the composite films. Also, increasing the oil content from 5 to 10%, increased the opacity, b*, ΔE*ab, water solubility, elongationat break but decreased L*, a* and tensilestrength. Similarly, increasing the soy lecithin content from 0 to 5%, increased the opacity, L*, b* and ΔE*ab, but decreased a*, of the starch-based composite films. The results suggest an ideal formulation of 4% starch/25% glycerol/5% oil/5% soy lecithinfor a film with optimum mechanical properties with low solubility

Effect of glycerol, peanut oil and soybean lecithin contents on the properties of biodegradable film of improved cassava starches from Côte d’Ivoire

peer reviewedEdible films have been successfully used in the food packaging industry for several decades. Today natural polysaccharides, including cassava starch, are increasingly being used in the production of such biodegradable edible films and food packaging. In Côte d'Ivoire, there are improved cassava varieties whose starches have not yet been tested in the production of biodegradable films. In this study, the optical and mechanical properties and the water solubility of starchbased composite films of four improved cassava varieties with added glycerol, peanut oil and soy lecithin were determined. Starch was obtained by cold water extraction from native cassava from the varieties Bocou 1, Bocou 2, Yavo and TMS. Films preparation was made bycasting method with cassava, glycerol (25-30 %), peanut oil (5-10%) and soybean lecithin (0-5 %). Increasing the glycerol content, increased L*color value and elongation at break and decreased a*, b*, colourdifference (ΔE* ab) and tensiles trength of the composite films. Also, increasing the oil content from 5 to 10%, increased the opacity, b*, ΔE*ab, water solubility, elongation at break but decreased L*, a* and tensiles trength. Similarly, increasing the soy lecithin content from 0 to 5%, increased the opacity, L*, b* and ΔE*ab, but decreased a*, of the starch-based composite films. The results suggest an ideal formulation of 4% starch/25% glycerol/5% oil/5% soy lecithin for a film with optimum mechanical properties with low solubility

The effects of iron fortification on the gut microbiota in African children: a randomized controlled trial in Cote d'Ivoire.

BACKGROUND: Iron is essential for the growth and virulence of many pathogenic enterobacteria, whereas beneficial barrier bacteria, such as lactobacilli, do not require iron. Thus, increasing colonic iron could select gut microbiota for humans that are unfavorable to the host. OBJECTIVE: The objective was to determine the effect of iron fortification on gut microbiota and gut inflammation in African children. DESIGN: In a 6-mo, randomized, double-blind, controlled trial, 6-14-y-old Ivorian children (n = 139) received iron-fortified biscuits, which contained 20 mg Fe/d, 4 times/wk as electrolytic iron or nonfortifoed biscuits. We measured changes in hemoglobin concentrations, inflammation, iron status, helminths, diarrhea, fecal calprotectin concentrations, and microbiota diversity and composition (n = 60) and the prevalence of selected enteropathogens. RESULTS: At baseline, there were greater numbers of fecal enterobacteria than of lactobacilli and bifidobacteria (P < 0.02). Iron fortification was ineffective; there were no differences in iron status, anemia, or hookworm prevalence at 6 mo. The fecal microbiota was modified by iron fortification as shown by a significant increase in profile dissimilarity (P < 0.0001) in the iron group as compared with the control group. There was a significant increase in the number of enterobacteria (P < 0.005) and a decrease in lactobacilli (P < 0.0001) in the iron group after 6 mo. In the iron group, there was an increase in the mean fecal calprotectin concentration (P < 0.01), which is a marker of gut inflammation, that correlated with the increase in fecal enterobacteria (P < 0.05). CONCLUSIONS: Anemic African children carry an unfavorable ratio of fecal enterobacteria to bifidobacteria and lactobacilli, which is increased by iron fortification. Thus, iron fortification in this population produces a potentially more pathogenic gut microbiota profile, and this profile is associated with increased gut inflammation. This trial was registered at controlled-trials.com as ISRCTN21782274

Les Indications Géographiques (IG) en Côte d'Ivoire : acquis et défis

Notre contribution évalue les acquis et les défis réalisés en matière d'IG en Côte d'Ivoire. Nous avons du l'inscrire dans la thématique 2.d. Vous pourriez nous orienter se le manuscrit conviendrait à une autre thématique. Merci!International audienceLes Indications Géographiques (IG) en Côte d'Ivoire : acquis et défi

Water Vapor Permeability of Edible Films Based on Improved Cassava (Manihot esculenta Crantz) Native Starches

peer reviewedStarch is used in the production of edible biodegradable packaging as an attractive alternative to synthetic polymers because it is a natural biopolymer of low cost and high availability. Many studies have been carried out on films based on cassava starch and the results show that these have good flexibility and low water vapor permeability. This present research was conducted to analyse the effect of glycerol, peanut oil and soybean lecithin on the water vapor permeability (WVP) of edible films based on improved cassava (Manihot esculenta Crantz) native starches from Côte d’Ivoire. The films were prepared using 4 g cassava starch, 25% and 30% glycerol (w/w), 5% and 10% peanut oil (w/w) and 0% to 5% soybean lecithin (w/w oil) in Petri dishes. The WVP of the films was determined at 25°C and 75% relative humidity. The moisture content of the films was determined in an oven at 105°C and the film thickness was determined manually using a micrometer. The resulting films were homogeneous, transparent and crack-free. WVP, moisture content and thickness of the films increased with increasing glycerol concentration. Increasing the concentrations of the peanut oil and soybean lecithin decreased the thickness and increased the moisture content of the films. The combination of glycerol and peanut oil increased the WVP of the films, whereas addition of soybean lecithin had no effect. The lowest WVP values were obtained using 25% glycerol, 5% peanut oil and 5% soybean lecithin. Starch obtained from improved cassava varieties cultivated in Côte d’Ivoire can be a potential ingredient in the production of food packaging

Effect of Edible Coating based on improved Cassava Starch on Post-Harvest quality of fresh Tomatoes (solanum lycopersicum l.)

peer reviewedComposite coatings based on improved cassava starch have the capacity to preserve the quality and extend the shelf life of fresh tomatoes. Two new edible composites coatings C1 (4% starch/25% glycerol/5% oil/5% soybean lecithin) and C2 (4% cassava starch/microcrystalline cellulose 30%/25% glycerol/5% oil/5% lecithin) were compared with the commercially available SemperfreshTM coating and no coating. Different coatings/no coating were applied to fresh tomatoes that were subsequently stored at 20 ± 2°C and 70 ± 2% relative humidity for 4 weeks. Tomatoes coated with the composite coatings C1 and C2 based on improved cassava starch showed a significant (P < 0.05) delay in changes of firmness, weight, titratable acidity, pH, total soluble solids, sugar/acidity ratio and colour development compared with both SemperfreshTM and uncoated control fruit. The results demonstrated that our assessed combination of improved cassava variety starch vegetable oil, glycerol, soy lecithin and cellulose and derivates can be used as edible coating to increase the shelf life of tomatoes stored at 20 ± 2°C up to four weeks

Water absorption as an evaluation method of cooking quality for yam (Dioscorea alata) and cassava (Manihot esculenta crantz)

AbstractWater absorption as a new method of cooking quality (hard cooking or mealy cooking) of yam and cassava cultivars determination was studied by cooking eight (08) cultivars. 30g of each were boiled in 500ml of water during 20minutes and dried at 70°C for 15hours and 103°C for 3hours in a vacuum oven. Results showed that cassava and yam have different cooking quality. Dry matter content does not influence the cooking quality of yam and cassava. Mealy cooking quality of yam absorbs less water (6.6%) during cooking but looses more soluble dry matter (9.5%) during the same process. Hard cooking quality of yam absorbs much water (23.5%), but looses less soluble dry matter (3.9%). The soluble dry matter is the main parameter to determine the quality of D. alata. It stands at 9.5% ± 2.9 for mealy cooking quality and 3.9 ± 0.73 for hard cooking quality cultivars of D. alata. Water absorbed by mealy cooking cassava (27.6%) is significantly (p < 0.05) higher compared to water absorbed of hard cooking cassava (12.4%). Water absorbed during cooking is the main parameter in determining the quality of cassava cultivars. Water absorbed stands at 27.6% ± 8.8 for mealy cooked quality and 12.4% ± 1.9, for hard cooked quality of cassava cultivars. A close relation between water absorption and cooking quality was revealed to contribute to a better selection procedure for cultivars in the frame of food security