Polygalacturonases constitute the major part of pectinase preparations for many bioprocess purposes. Investigation on the digestive juice of snail Limicolaria flammea led to purification of two polygalacturonases named PG1 and PG2. Properties of these enzymes were examined to explore their potential in biotechnology applications. A three steps procedure including size exclusion, anion and cation exchange and hydrophobic interaction chromatography were used for purification. The enzymes PG1 and PG2 had native molecular weights of approximately 46 and 86 kDa, respectively and functioned both as monomeric structures. The purified polygalacturonases PG1 and PG2 showed optimum hydrolysis activities at 50°C in sodium acetate buffer pH 5.6. The common inhibitor of the two purified polygalacturonases activity were Mn2+, Ca2+, Zn2+, EDTA, SDS and L-cystein. NH3+  stimulate            the polygalacturonase PG1 while Ba2+ was an activator for polygalacturonase PG2. Substrate specificity indicated that these enzymes hydrolyse a broad range of pectin from different sources. The highest activity of PG1 was observed with apple pectin and lemon pectin while PG2 showed its highest activity with orange pectin. The catalytic efficiency of PG1 was highest for lemon pectin (0.125 µmol/min/mL) and orange pectin (0.124 µmol/min/mL). PG2 displayed highest catalytic efficiency (0.325 µmol/min/mL) towards orange pectin. These results suggest that orange and lemon pectin would be the potential physiological substrates of the two purified enzymes.

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In Côte d'Ivoire, malnutrition is still a public health problem. To remedy this, international institutions involved in this fight recommend the promotion of local resources rich in proteins such as insects and caterpillars. Thus, this study aims to enhance the enrichment of sorghum tôh with shea caterpillar flour (Cirina butyrospermie) in order to solve the problems of malnutrition. To do so, 25 young rats of Wistar strain, aged to 50±05 days with an average weight between 45 and 55±5 g were divided into 5 batches were fed respectively with tôh formulated with 5%, 10% and 15% of shea caterpillar flour during 15 days. At the end of this period, the nutritional parameters were calculated and biometric study was conducted to evaluate the impact of enriched food on well-being of young rats. The results obtained reveal interesting nutritional potentialities in most parameters. For example, the weight gains obtained varied from 4.86±0.45 g/d to 6.05±0.39 g/d in to rats fed with different formulations of tôh enriched with shea caterpillar flour and the diet STScF2 did not show any significant difference with control diet. In terms of biological value, values obtained vary from 84.12% to 90.64% while those of protein retention vary from 11.66±1.85 g to 12.99±0.89 g respectively for young rat fed with diets STScF3 and STScF1. Concerning biometric study, no abnormality was noted following the consumption of these foods. In view of the nutritional potential developed by young rats, the tôh enriched with 10% shea caterpillar four, could be retained to solve malnutrition problems.

Sweet peppers are consumed less in Korhogo, in the north of Côte d'Ivoire, than other hotter peppers. In addition, the sweet pepper is underexploited, it encounters problems of conservation, distribution. This study is a valorization of the sweet pepper. The physical properties are: 5.8-6.93 cm for length, 14.21-15.03 cm for circumference, 34.28-42.65 g for weight, 91.19-91.80 % for humidity, 0.49-0.61 % for ash content. The contents of biochemical elements are: 5.42-5.54 for the pH, 2.92 meq / 100 g on average for the titratable acidity, 177.45-254.57 mg / 100g for reducing sugars, 3,42-4.29 % for total sugars, 0.36 % on average for lipids, 0.73-1 % for proteins, 2.03-3 % for fibers, 6.62-6.93 % for total carbohydrates, 32.64-34.7 Kcal / 100 g for energy value. The amounts of vitamin C, polyphenols, flavonoids, tannins are respectively: 26.67-51.25 mg / 100 g; 116.16-131.28 mg / 100 g; 1.97-4.43 mg / 100 g; 14.74-19.12 mg / 100 g. The contents of anti-nutritional compounds are 363-388.67 mg / 100 g for oxalates, 20.08-22.20 mg / 100 g for phytates. Sweet pepper contains 0.14 % DM on average phosphorus, 0.33-0.37 % DM for potassium, 0.30-0.31 % DM for calcium, 0.167-0.174 % DM for magnesium, 2.76 -3.80 ppm copper, 7.5-7.92 ppm iron, 0.59-0.69 ppm manganese, 16.24-16.34 ppm zinc, 6.46-20.15 ppm sodium. Processed before consumption, Sweet pepper constitutes a significant source of food fibre, natural antioxidant, and mineral elements for local population.

Polygalacturonases are extensively used in food industries for pectic substances degradation. In this paper, we investigate on thermal stability parameters of two Polygalacturonases previously isolated from digestive juice of the snail Limicolaria flammea for several industrial applications such as fruit juice clarification. Thermal inactivation was carried out in the temperature range of 55°C to 80°C from 15 to 120 min. All results were statistically analysed. The results shown that thermal inactivation of studied acid phosphatases follows first order kinetics. At their optimum temperatures, these enzymes showed high half-lives ranging from 462.06 to 630.10 min and D values from 1535.00 to 2093.64 min suggesting that these two enzymes had a large thermal stability. The high values of ΔG# (93.96 to 94.97 kJ/mol) reveal a better resistance to denaturation. The relatively high activation energies (from 120.35 to 129.13 kJ/mol) and average enthalpy values (from 117.67 to 126.44 kJ.mol−1) could corroborate the good stability of these biocatalyst. All these results suggest that Polygalacturonases from digestive juice of the snail Limicolaria flammea may be profitably exploited in future food industrial applications.