No abstract

The aim of this work is to investigate the structural features, physicochemical, rheological, and emulsifying properties of pectin extracted from pumpkin “Cucurbita maxima” pulp and peel. After the peel and pulp of fresh pumpkin were solubilized in water at high temperature (80°C) and clarification, the obtained filtrate was treated with aluminum sulphate, which precipitates a fibrous coagulum. The results found that the major functional groups of pectin isolates identified by Fourier transform infrared are: –OH, CH2, C═C, –C–O–C–, and CH3. The results obtained using nuclear magnetic resonance methods suggest that these polysaccharides consist of two domains: the first one is homogalacturonan and the second is formed by rhamnogalacturonan. Mineral and metal ions on pectin surface detected using scanning electron microscopy coupled to energy dispersive X-ray analysis were different pulp and peel pectin. Rheological behavior of these biopolymers is suitably represented by the Herschel–Bulkley and power law models. The extracted pectin has a viscosity spectrum expressed by the following properties: G′, G′′, G*, and ∣ η ̇ ∣ ( ω ) | \dot{\eta }| (\omega ) which, respectively, have the following values: 0.28–57.63, 0.15–34.38, 0.39–67.12, and 1.82–831.08 Pa s. These macromolecules have a negative charge on their surface. Rheological properties and emulsifying activity are significantly influenced by the structural composition and physicochemical properties.

Pepper is an inevitable constituent in the diets of Algerian population. Unfortunately, the local landraces are endangered by both genetic erosion and pollution. This study aimed to perform agro-morphological characterization of hot peppers (Capsicum annuum L.) accessions. Twenty one accessions collected from the east and south of Algeria were evaluated for 24 quantitative and 38 qualitative morphological characters under green-house conditions. The trial was conducted in a Randomized Complete Block Design (RCBD), with four replicates at the experimental station of the Department of agronomical sciences of Biskra University in Southeast Algeria. Significant variations in most of the traits were strikingly demonstrated using variance analysis and coefficients of variation and the number of modalities, frequencies and Shannon–Weaver diversity index (H′) values for the quantitative and qualitative characters respectively indicating the heterogeneity of the studied accessions. The correlations between the studied quantitative variables showed that the yield parameters were correlated with the variables related to the vegetative part of the plant. The first five PCs explained 76.877 % of the total variation and identified the most discriminant variables related particularly to yield and fruit characteristics contributing to PC1: fruit width; fruit index; fruit weight, number of locules; placenta length, pedicel length, anther length, leaf width and plant height /stem length ratio. For several qualitative traits, an important degree of variability was observed. The first factorial dimension explained 42.5% of the variance and was mostly associated with: plant height; growth habit; flower position; corolla shape; number of flower per axil and fruit shape at pedicel attachment and at blossom end; calyx margin. Cluster analysis of the combined data grouped the pepper landraces into four clusters regardless of the localities and the closest accessions belonged to different localities and/or provinces. This study notably confirms the presence of considerable genetic diversity within and between accessions of hot pepper in Algeria and provides a basis for its active conservation and future selection to develop improved local pepper populations

No abstract

No abstract