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First study on the interest of the determination of the total volatile basic nitrogen in the blue crab (Portunus segnis) in Tunisia

Première étude portant sur l’intérêt du dosage de l’azote basique volatil total chez le crabe bleu (Portunus segnisen Tunisie




1Laboratory of Food Microbiology, National School of Veterinary Medicine of Sidi Thabet, University Manouba, Tunisia.

2General Directorate of Veterinary Services. AgricultureMinistry, Tunisia.

Abstract - Our study aims to determine the Total Volatile Nitrogen Level (TVNL) in 60 samples of blue crab (30 fresh and 30 frozen) intended for human consumption and to compare them with the regulatory threshold value specific to crustaceans usually harvested in Tunisia especially shrimp or lobster. This comparison aims to verify the highly altered character of the blue crab meat and to specify the most appropriate marketing method for this specie (fresh or frozen). The method used in our study is the micro-diffusion described by CONWAY. Our results show that the difference between the two groups is significant (p <0.05). Indeed, the average of TVNL in fresh crabs is 46.10 mg of nitrogen /100g of soft tissue whereas in frozen crabs it is 28.18 mg of nitrogen /100g of soft tissue. With revere to our results, we can confirm the highly altered character of the crab meat. Although the Total Volatile Nitrogen Level does not provide information on the safety of the product, he remains a good indicator of freshness. To this end, it would be advisable to recommend the destination of blue crabs mainly to the industrial trail to proceed with either freezing or immediate thermal treatment of the products before their marketing.

Keywords: Total Volatile Nitrogen Level - blue crab - freezing.

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Trans fatty acids content of selected popular Tunisian fast food


1National Institute of Nutrition and Food Technology. 11, rue jebel lakhdar, Bab Sâadoun, 1007 Tunis, Tunisia. Departments: Food Technology; Study and Planning, SURVEN Laboratory.

Abstract – There are strict regulations regarding trans fatty acid TFA limitation from food supply across the world. However in Tunisia, there is scarcity of data on TFA content in fat, fast food products and their consumption levels. In order to assess fast food’s lipid, we measured total fat, fatty acid composition, and trans fatty acid s in the most commercialised fast food. Samples were categorized as six sandwich’s menus (chicken breast, chicken fingers, chawerma, tuna, kaftaji and salami/ham) and pie. Frying fats (oil and margarine) were also studied. Total fat ranged from 7.38 to 50.28 g/100g of fresh product and the maximum was found in pie. About 85% of the tested fast food (sandwich) contained between 0.5 and 2 % TFA and 10% more than 10% TFA. Trans 18:3 isomers were the major group of TFA present in chicken breast sandwich, tuna sandwich, kaftaji sandwich and chawerma sandwich, representing 42.15 to 52.11% of total trans isomers. Trans 18:1 isomers content were also the major fatty acid in chicken fingers sandwich and pie representing 63.95% and 97.31% respectively of total trans isomers. The moderate content of TFA in the studied samples showed similarities to those reported in similar product categories in developing countries. This study is the first one to report data on the TFA content in fast food and margarines products in Tunisia and the importance of introduce effective policies for reducing the intake of fat and TFA.

Key words: Tunisian fast food, Frying oil, Margarine, Trans fatty acids.

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Computed Tomography And Magnetic Resonance Imaging of The Brain And Associated Structures Of The One Humped Camel (Camelusdromedarius): a comparative study


1Department of Anatomy and Embryology, National School of Veterinary Medicine, SidiThabet Tunisia

2 School of Veterinary Medicine, University of California, USA

3District of Animal Production Of Medenine Tunisia

Abstract – We aimed to compare two medical imaging techniques; computed tomographyand magnetic resonance imaging in the exploration of various anatomical components of the brain and its associated structures in the dromedary. A total of four healthy dromedary heads were used; two heads underwent anatomical sections; two other heads were imaged respectively by computed tomography and by magnetic resonance imaging. We selected eight snapshots of each of the techniques that gave excellent correspondence with the anatomical sections. Magnetic resonance images were characterized by their excellent contrast between gray and white matter and ventricles. They allowed us to identify the majority of the brain’s structures. Computed tomography images provide good differentiation between bones and soft tissues of the head. This comparative analysis demonstrates that magnetic resonance imaging is clearly superior to computed tomography in identifying key brain elements. These computed tomography and magnetic resonance images are intended to be a useful anatomical tool in the interpretation of clinical imaging studies of the encephalon and associated structures in camels.

Key words: anatomy; cross sections; dromedary; encephalon;imaging techniques 

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Long storage and breeder age influences on egg and morphological chick quality



1Laboratory LMMA and UCAR, Department of Animal Sciences, National Agronomic Institute of Tunisia, 43 Avenue Charles Nicolle, Tunis 1082; University of Carthage-Tunisia

2National School of Veterinary Medicine, Ariana, SidiThabet 2020; University of Manouba-Tunisia

Abstract – A good quality of one-day-old chicks is a crucial hinge between the hatchery and the broiler farm. Storage duration and breeder age are factors that can affect the chick quality. To evaluate this impact, we studied the effect of three storage durations (5, 9 and 23 days) and two breeder ages (31 and 60 weeks) on egg and chickquality. Long storage (23 days) decreased the egg and the albumen weight and increased the yolk weight, the yolk to albumen ratio (∆= +4.54%), the yolk diameter (∆= +2.78 mm) and the albumen pH (∆= +0.39, all<0.05). Long storage (23 days) decreased also, the chick length, the chick weight, the chick length corrected to egg weight (∆23-9 days = -5.49 mm/g), the yolk free body mass (∆23-5 days = -2.15 g) and the Pasgar score (∆5-9 days = -0.27 point; all, p<0.05). The increase of breeder age increased the egg, the yolk, the albumen and the shell weights as well the yolk to albumen ratio (∆= +9.62%) and the yolk diameter (∆= +5.24 mm) and decreased the shell to egg ratio (∆= -0.99%) and the shell thickness (∆ = -0.04 mm; all, p<0.05). The chick length and weight, the yolk free body mass (∆= +6.09 g), the residual yolk weight and the residual yolk percentage (∆= +2.26%) increased also when the breeder age increases. However, the chick length corrected to egg weight (∆= -6.03 mm/g) and the Pasgar score decreased (∆= -0.2; all, p<0.05).

Key words: Egg storage, breeder age, egg quality, chick quality.

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Use of Olive Leaf Aqueous Extract (Olea europaea) In Growing Rabbits’Diets


1RL « Management of the health and quality of animal productions »

University of Manouba, National School of Veterinary Medecine – Sidi Thabet, 2020, TUNISIA

Abstract – This study aimed to investigate the effects of olive leaves aqueous extract (OLAE) on zootechnical performances and cæcal content of growing rabbits. The study was performed during 5 weeks with 24 New Zealand rabbits. Rabbits were distributed into 2 groups of 12 animals distributed on 6 pens (2 animals per pen). Experimental group (G20) received 20 ml OLAE / 1000 ml drinking water. Control group (G0) received water without OLAE addition. The OLAE addition increased (p-value=0.007) the average daily gain throughout the study period and decreased (p-value=0.01) the feed conversion ratio essentially in the third experimental week. The water consumption increased (p-value<0.0001) by the OLAE addition during the whole experimental period. The bacteriological examination revealed no effect on the caecal microflora.

Key words: Olive Leaf, rabbit, phenol, growth, microflora.

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This article is published under license to Journal of New Sciences. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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