http://depot.umc.edu.dz/handle/123456789/9985 2026-10-21T17:09:39Z http://depot.umc.edu.dz/handle/123456789/14863 Petit déjeuner et obésité chez l’adulte Nebti, Oudjdane; Oulamara, Hayet Introduction. In recent years, many studies have demonstrated an association between skipping breakfast and weight status, but the results of different studies are inconsistent. Therefore, the main objective of the present study was to examine the relationship between breakfast and weight status in adults. Method. A cross-sectional survey was conducted on a sample of 1000 adults (60.2% female) with an average age of 33.9 ± 10.1 years. Data were collected using a questionnaire focusing on health status, breakfast related eating habits (consumption, frequency, conviviality and environment), and physical activity. Daily food intake was assessed using a 24-hour recall repeated three times. Anthropometric measurements included weight and height. Breakfast intake was evaluated using two methods: one based on frequency (more than three times per week) and the other on the energy intake of breakfast (15% of daily energy intake). Results and discussion. Our population comprises 55% overweight, including obese subjects, 21.7% of whom are obese. Nearly three-quarters of the subjects regularly have breakfast, with 83.8% having it more than three times per week, and over half (51.6%) have an energy intake at breakfast exceeding 300 kcal (15% of the total energy intake). Normalweight consumers have a longer sleep duration. Breakfast is a meal consumed at home by the majority of the population in less than 10 minutes on average. More than half of the individuals have it alone, without any activity. It usually consists of dairy products, mainly pasteurized semi-skimmed milk and coffee, accompanied by a cereal product (bread or cake), cakes or pastries. Over three-quarters of the subjects add sugar to coffee and milk consumed. Over three-quarters of the subjects add sugar to coffee and milk consumed. Breakfast constitutes a significant source of carbohydrates, lipids (especially cholesterol, saturated fatty acids, and monounsaturated fatty acids), and calcium. No significant difference was found in the prevalence of overweight and obesity between breakfast consumers and skippers. Although no correlation was found between the energy intake at breakfast and BMI, normal-weight consumers consume more calories at breakfast. Our study shows that regular breakfast consumption is not associated with body weight. 2024-12-11T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14855 Couscous sans gluten Boudouira, Nassira; Zidoune, Mohammed Nasreddine; Benatallah Benchikh El Feggoun, Leila The implementation of a gluten-free diet involves a variety of gluten-free foods, Thus, the aim of this work is to study the technological feasibility of rolled and extruded gluten-free couscous based on the supplementation of rice with legumes ( faba bean, chickpea and lentil) (90/10 and 70/30) g/g. The various couscous produced were characterised by determining yield, technological qualities, icrostructure, textural profile and sensory acceptability. The lightness of rolled couscous (between 59,93 et 69,19) decreased with increasing levels of supplementation (p<0,05). Rolled gluten-free couscous yields ranged from 79,46% to 85,53%. The majority of gluten-free rolled couscous were characterised by the dominance of small agglomerates (<530 µm) and their low bulk density (0,65g/cm3). Couscous enriched with chickpea (10% et 30%) or faba bean (30%) have the best water absorption capacities and swelling indices. The disintegration degrees of rolled gluten-free couscous varied between 8,89% and 10,94% and the hardness values between 151,88 N and 194,16 N. The cohesion ranges from 0,26 to 0,33. The rolled couscous enriched with faba bean (6,77 and 6,31) are ranked after the control couscous (7,54), followed by those enriched with chickpea (5,62 and 6,23) and lentil (5,62 and 4,85) respectively. Yields of extruded gluten-free couscous vary between 89,98% and 92,01%. The lightness of extruded gluten-free couscous (between 49,22 et 63,70) decreased as a function of faba bean or lentil content (p<0,05), the yellowness index (between 64,81 and 71,06) increased and the expansion ratio (between 0,90 and 0,94) decreased as a function of legumes content (p<0,05). Extruded couscous enriched with lentil has the lowest water absorption capacities (291,21% and 276,86%) and swelling indices. The disintegration degrees of extruded gluten-free couscous (between 10,15 and 16,40%) increased with the rate of legumes addition (p<0,05). The general acceptability ranking remained the same as for the rolled couscous. The final objective focused on the impact of manufacture process type (rolling or extrusion) on the properties of the couscous to be offered to the consumer. The extrusion yields (89,98 to 92,01%) are higher than those of manual rolling (79,46 to 88,91%) (p<0,05). In addition, the yellowness indexes of the extruded gluten-free couscous (64,81 to 71,06) are higher than those rolled (between 56,78 and 67,52). The highest bulk density values (0,65 and 0,67g/cm3) are attributed to rolled couscous, while the best water absorption capacities to extruded couscous (276,86 to 341,01%). Rolled couscous enriched with chickpea (10% and 30%) and those enriched with faba bean or lentil at 30% disintegrated less than extruded couscous of the same formula (p<0,05). The jury members gave a score above 5 and below 7 for all gluten-free couscous except for those enriched with 30% lentil, which obtained a score lower than 5. 2025-11-27T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14829 Formulation, fabrication et caractérisation de fromages frais aux laits de dromadaire et de chèvre. Bouras, Biya; Aissaoui Zitoun ép Hamama, Ouarda This study aims to improve the coagulation of camel milk for the production of fresh cheese by using goat's milk and various rennet substitutes. First, we studied the raw materials used, including the raw composition of camel and goat milk and the characteristics of camel rennet, goat rennet and chicken pepsin. Then, we studied the optimization of flocculation and coagulation parameters mainly pH and temperature with milk alone and camelgoat milk mixed with different formulations using response surface methodology (RSM). The optimum points obtained will be used for the manufacture of fresh cheese with enzymatic coagulation and with mixed coagulation by adding mesophilic lactic bacteria. The chemical and mineral analysis of camel milk and goat milk showed the specificity of the composition of camel milk in comparison with cow milk mainly in terms of protein, fat and total solids, lactose and even in chloride, sodium and copper. On the other hand, the characterization of the enzymatic extracts of camel rennet, goat rennet and chicken pepsin revealed variable protein contents and coagulant activities and good coagulant strength, respectively 1/4166.67, 1/2531.64, 1/6153.85. The optimization of the flocculation and coagulation time made it possible to highlight the specific optimum points according to the enzymatic extract used, the type of milk and the formulation tested. It appears that each enzyme acts differently on the coagulation of milk depending on the pH and the temperature, and even when we are under the same conditions, each enzyme gives a specific coagulum. Overall, the pH ranges from 5 to 6.7 and the temperature from 30°C to 42°C. At the level of the manufacture of fresh cheese, twelve formulations were produced and characterized, according to the proportions of camel and goat milk (75/25, 50/50, 25/75) and the type of enzyme. The best cheese yields of enzymatically coagulated fresh cheeses are those of camel rennet cheese with 19.3±0.9% of the FD25, goat rennet cheese with 13.45±0.5% of the FC25, chicken pepsin cheese with 16.65± 1.0% of FP25 and microbial coagulating agent cheese with 18.3±0.4% of FM50. Most of the cheeses obtained can be classified according to the food codex as soft and semi-fat. In rheological terms, the cheeses produced are quite firm. Cheese gel with camel rennet behaves like a dilating coagulum while those produced with chicken pepsin behave like a pseudoplastic coagulum. Whereas, cheeses produced with goat rennet and microbial coagulant behave as a dilating and pseudoplastic coagulum. This clearly shows the effect of the type of enzyme on the coagulation of the camel-goat milk mixture. In addition, electron microscope observations showed the specificity of each coagulum according to the enzymatic extract tested and according to the proportion of goat milk added to camel milk. The difference is noted in the number and diameter of the pores and the appearance of their compactness. Moreover, the statistical analysis of the amino acid concentration results revealed a significant difference (P<0.05) between most of the different formulations with the dominance in the cheeses of histidine. Finally, the best enzymatically coagulated cheeses according to sensory tests are the FD50, FC75, FP50 and FM25 formulations with an overall acceptability score on a score of 15 from 7.85±2.34 (FM25) to 10.05±3.81 (FC75). Finally, the physico-chemical characterization of the best four mixed coagulation formulations (FD50B, FC75B, FP50B and FM25B) gave cheeses with a total solids content of 25.66±0.5% to 43.55±1.2% and Fat/TS of 30.47±2.7 to 49.85±0.16 with a significant difference (P <0.05) for all parameters analyzed. From a sensory point of view, it should be noted that the addition of ferment has clearly resulted in more characteristic and more appreciated cheeses. The results obtained tend and converge towards the possibility of using camel rennet, goat rennet and chicken pepsin in cheese processing based on camel milk mixed with goat milk, taking into account the specific optimum points for each enzyme and each formulation. 2023-06-18T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14801 Analyse de la composition chimique et évaluation des propriétés biologiques des huiles essentielles de trois plantes aromatiques et médicinales (Thymus willdenowii, Aloysia citriodora et Cymbopogon citratus) et impact de leur incorporation dans le yaourt étuvé. Benguedouar, Karima; Barkat, Malika; Bencharif-Betina, Soumeya The characterization of three essential oils (EOs) of aromatic and medicinal plants : thyme (T. willdenowii), verbena (A. citriodora) and lemongrass (C. citratus) and their incorporation into yogurt were the subject of this study. A survey of Internet users via Google Forms revealed that a high percentage did not use EOs in cooking or drinking. Analysis of the chemical composition by GC/MS revealed citral with its two isomers E-citral (38.6%) and Z-citral (29.89%) for citronella, and E-citral (34.43 %) and Z-citral (27.85%) for verbena and linalool (89.55%) for thyme. The essential oil extraction yields are 1.23±0.23%, 0.83±0.35% and 0.83±0.27% respectively for lemongrass, thyme and verbena. Thyme has a higher antiradical activity than verbena and lemongrass as well as the highest content of phenolic compounds (405.67±13.08 µg GAE/mL of yogurt). A strong inhibition of pathogenic bacteria such as B. cereus, S. enteritidis, P. aeruginosa and E. coli is obtained with thyme EO. Lemongrass EO has proven to be the most inhibitory of lactic acid bacteria in yoghurt: L. bulgaricus and S. thermophilus. The antioxidant and antibacterial activities of verbena EO were weak. However, it showed an interesting inhibitory activity of the butyrylcholinesterase enzyme, just after lemongrass EO.The inhibitory activity of the α-amylase, urease and tyrosinase enzymes was weak for the EOs studied. The evaluation of the cytotoxic effect of EOs on Artemia salina larvae did not show any cytotoxicity. The incorporation of essential oils into yogurt at a dose of 25 µL/L maintained satisfactory microbiological quality of the products. The physico-chemical analysis of the different yogurts revealed a decrease in pH throughout the cold storage period. However, the pH values, significantly are elevated in yogurts incorporated essential oils of lemongrass and verbena. The incorporation of essential oils of lemongrass and thyme significantly increased the antioxidant potential of these yogurts on the seventh day of storage evaluated by the CUPRAC test, as well as on the 21st day of storage for the yogurt incorporating the essential oils of thyme evaluated by the test ORAC. The antioxidant potential of lactic acid bacteria increased after their fermentation with the different EOs studied. HPLC analysis of the organic acids and aromas produced revealed an increase in the production of lactic and citric acid at the end of cold storage for yogurts containing verbena and lemongrass essential oils. The three HEs also stimulated the production of the acetaldehyde aroma from the first day of storage. The evaluation of the phenolic compounds content of the formulated yogurts revealed an increase of these compounds in the lemongrass EO yogurt on the first day and in the thyme yogurt on the seventh day of storage. The yogurt incorporated with verbena EO was the most appreciated by the panel of tasters, followed by the yogurt incorporating lemongrass and thyme EO. 2023-07-11T00:00:00Z