Riadh Ben Salah

Purification of Turkey Pancreatic Phospholipase A2

Turkey pancreatic phospholipase (TPP) has been purified from delipidated pancreases. The purification included ammonium sulfate fractionation, acidic (pH 5) treatment, followed by sequencial column chromatographies on DEAE-cellulose, Sephadex G-75, and reverse phase high pressure liquid chromatography. The purified enzyme was found to be a monomeric protein with molecular mass of 14 kDa. The optimal activity was measured at pH 8 and 37°C using egg yolk emulsion as substrate. Our results show that the enzyme (TPP) was not stable for 1 h at 60°C, and that bile salt and Ca2+ were required for the expression of the purified enzyme. The sequence of the N-terminal amino acids of the purified enzyme shows a very close similarity between TPP and all other known pancreatic phospholipases.

Using Barley Beta Glucan, Citrus, and Carrot Fibers as a Meat Substitute in Turkey Meat Sausages and Their Effects on Sensory Characteristics and Properties

This study was aimed to evaluate the effect of addition of two levels (1% and 2%) of Barley Beta Glucan (BBG), citrus (Ceamfibre 7000), and carrot (ID809) fibers on chemical, sensorial properties, oxidation and microbial quality of turkey meat sausage, during 21 days of storage at 4°C. The findings indicated that the addition of the three fibers decreased fat and protein contents but increased moisture content. Color parameters were significantly (p<0.05) affected by the fiber type and content. The meat substitution resulted in a tendency toward lighter coloration. A significant progression in the textural hardness, elasticity and chewiness of fiber-added sausages, was observed. The addition of the three fibers, at 1% and 2% level, induced a decrease in hardness when compared to control. Furthermore, color, taste, flavor and overall acceptability attributes were similar to the control when the fibers were incorporated. According to sensorial evaluations, the three polysaccharides remained at 1% to the consumer acceptability of sausage. Besides, the addition of the three polysaccharides had a significant effect on sausage safety because of its reduction of the lipid oxidation degree monitored by TBARS and it had no effect on microbial proliferation. Overall, the results of this study indicate that the three polysaccharides can be applied at 1% in turkey meat sausage to increase their nutritional status whilst maintaining the quality and safety attributes of the product.

Effects of Cooking Methods on Physicochemical and MicrobiologicalCharacteristics of Zebra Blenny (Salaria basilisca) Fillets

This study was undertaken to determine the effects of two appropriate household cooking methods, steam and microwave-cooking, on proximate chemical composition, energetic values, fatty acids profiles, texture profile analysis and bacteriological characteristics of zebra blenny (Salaria basilisca) fillets from Tunisian coasts. The nutritional values of the fish fillets were improved after the two cooking methods. Fatty acid profiles of zebra blenny fillets showed that Polyunsaturated Fatty Acids (PUFA) contents are higher than those of Saturated Fatty Acids (SFA). They showed also differences between cooking methods. All textural attributes of zebra blenny fillets were influenced by cooking process. Microbiological changes [Total viable counts (TVC), Lactic Acid Bacteria (LAB), Enterobacteriaceae, Listeria monocytogenes as well as fungi] were monitored as a function of treatment and storage time. On day 5 of storage under refrigeration the number of micro-organisms is always minimal for samples heat treated comparing with those raw.