Browsing by Author "Hamidechi Mohamed Abdelhafid"

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    COMPARATIVE STUDY OF THE PHYSICOCHEMICAL CHARACTERISTICS OF MILK COLLECTED FROM CAMELS (CAMELUS DROMEDARIUS) CONDUCTED IN TWO BREEDING SYSTEMS (EXTENSIVE AND SEMI-INTENSIVE)
    (researchgate, 2023-11) Hamidechi Mohamed Abdelhafid
    Abstract The camel milk sector is still little explored and especially the effect of the camel breeding system on certain properties and chemical compositions of camel milk. This study aims to assess the potential impact of the transition in the camel breeding system on milk productivity and the physicochemical composition of camel milk. To achieve this objective, a preliminary survey was conducted involving several breeders actively practicing the two targeted breeding systems (extensive and semi-intensive) in Algeria. This survey revealed milk production levels of 2 L/d and 3.5 L/d for the extensive and semi-intensive systems, respectively. Physicochemical analyses of these two types of camel milk (from extensive and semi-intensive breeding) were carried out. Various parameters were measured, including pH, acidity, density, total solids, solids-not-fat, ash levels, lactose, calcium, vitamin C, total proteins, whey proteins, and caseins. The results of these analyses indicate that the transition from extensive breeding system to the semi-intensive system significantly impacts the physicochemical quality of camel milk. Specifically, camel milk from the semi-intensive breeding system becomes less dense, more acidic and less rich in total dry matter particularly in solids-not-fat, which includes lactose, vitamin C, and minerals and notably calcium. Furthermore, this milk has become richer in proteins both total proteins and whey proteins, and more notably in caseins
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    In vivo evaluation of Aggressiveness, pathogenicity and patulin accumu-lation by three Penicillium expansum strains isolated from Algerian apples
    (South Asian J Exp Biol, 2020-10-21) Hamidechi Mohamed Abdelhafid
    Among the postharvest pathogens of apple fruit, Penicillium expansum (P.expansum) is considered to be one of the most common fungal pathogens worldwide. It is the causal agent of blue mold decay; the main serious eco-nomically disease of apple fruits, and the main producer of patulin (PAT). The principal objective of this work was to evaluate the aggressiveness and the PAT production of three isolated strains from apples produced in the East of Algeria. These strains were isolated then screened for their inhibitory activity against Escherichia coli and Bacillus subtilis (18 mm and 18 mm for S7; 10 mm and 11mm for S3), as well as their ability to cause blue rot (S4). The three strains S7, S3, and S4 (MN904448, MT023795 and MN904449, respectively) were identified as P. expansum by ITS1, ITS4, and β-tubulin gene sequences analysis. The in vitro ability to produce PAT was confirmed by Gas chromatography-mass spectrometry of strains’ crude extracts cul-tured on YES (Yeast-Extract-Sucrose) medium. Indeed, these strains exhibit-ed a great capacity to cause blue mold decay for all tested apples (26 to 52 mm lesion diameter), after nine days of incubation at 25°C. Apples rotten area analysis that was performed by UPLC analysis revealed that these three strains were able to produce PAT at different concentrations ranging from 0.57 to 469 μg/mL. Thus, these strains constitute a risk to consumer health because these amounts exceed the permissive level of PAT.