Natural remedies have proven to be very effective and have fewer side effects than commercial antibiotics.The objectives of this work were to determine the chemical compounds and biological (antibacterial and antioxidant) activities of Allium sativum L. essential oil against three multi-drug strains of bacteria isolated from buccal cavity affected by caries namely Aerococcus viridans, Staphylococcus epidermidis, and S. xylosus.The essential oil was extracted by hydrodistillation, chemical compounds were quantified by gas chromatography-mass spectrometry and gas chromatography with flame ionization detection.2,2-diphenyl-1picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing power were used to study antioxidant activity.Antibacterial activity was carried out by the disk diffusion method.The average yield of the essential oil was 0.173±0.009%(w/w).All tested strains were resistant to three different classes of antibiotics.Diallyl disulfide (39.22%) and diallyl trisulfide (34.85%) were the main components of Allium sativum L. essential oils.DPPH radical scavenging assay showed the median inhibitory concentration (IC50) value of 51.12±11.77mg/ml, while the ferric reducing power assay recorded the median effective concentration (EC50) value of 6.54 ± 0.63 mg/ml.The results showed that all multidrug-resistant bacteria strains tested are sensitive to essential oils.The results indicate that Allium sativum L. essential oil exercises good in-vitro antibacterial and weak to moderate in-vitro antioxidant activities.

Wheat bread is a widely consumed commodity around the world. It is poor and imbalanced in some essential amino acids. The aim of this study is to fortify wheat bread with whey proteins (WP), in order to inhence its nutri-tional value and to improve the balance of its essential amino acids. The composition of the different flours and breads enriched with WP was deter-mined by standard methods. The alveograph’s results show that the tenacity increases and the deformation energy decreases with increasing incorpora-tion of WP. The addition of WP leads to a dough that is resistant to defor-mation, extensible for incorporation rates of 2.5% and 3% and less extensible for 10% and 20%. The results on the composition of the different breads show that the addition of WP contributes to the improvement of the amino acid profiles of the breads, especially for P10 and P20. It corrects, especially, the deficit and imbalance of the bread in essential amino acids. The assess-ments of the organoleptic characteristics show that the majority of the tast-ers find the P2.5 and P3 breads are very close to the commercial breads and sometimes better. These loaves have a nice external appearance, regular shape, crispy golden crust, light texture, good taste and smell. The develop-ment of the breads during vacuum storage is very satisfactory. They keep their crispness and a good crumbliness after 7 days.

Objectives : The technological characteristics and flavour formation capacities of cheeses depend on the starter strains and the ripening conditions. The present study aimed at using autochthonous lactic acid bacteria strains with interesting technological and enzymatic properties, suitable as starter cultures to produce semi-hard cheese, such as Gouda, based on pasteurized cow’s milk. Methods: This study allowed the formulation of local lactic ferments, with autochthonous strains; thanks to which we have made a semi-hard cheese, Gouda type, made from pasteurized cow’s milk. Physicochemical (dry matter, fat, protein, chloride, and ash) and organoleptic (texture, color, taste, odor, aroma) analysis were carried out. Findings: The protein composition is very important (average value of 24.18 0.46g / 100g). The results of the sensory analysis did not show any defects in the cheese studied. The taste is sweet, characteristic; the aroma is pure, pleasant, well developed. The color is uniform yellowish, the rind is dry. Novelty: The use of pasteurized milk and autochthonous lactic ferments have helped maintain the typical characteristics of the cheeses. Keywords: Cheese; Gouda; Lactic ferment; physicochemical analysis; Semihard paste; Sensory analysis

In addition to the nutritional value of green oak acorns they have also differ-ent biological properties. The object of this research is to examine the anti-oxidant and antibacterial activities of almond, tegument and pericarp of green oak acorn (Quercus ilex) from Algeria. Four methods were used to evaluate the antioxidant activity, with analysis of Phenolic compound, as well as the study of antibacterial activity. The analysis of acorn shows different levels of total polyphenols, flavonoids, and condensed tannins in its three compounds where the pericarp and tegument have high levels compared to the almond. The extract of pericarp showed the highest antioxidant activity to trap the DPPH radical (IC50: 86.37 μg/ ml), inhibit β-carotene bleaching (RAA = 90.19 %) and reduce molybdenum (TAA: 467.57 AAE/100g of extract), whereas the tegument has a strong ability to give hydrogen to reduce iron. In addition, the pericarp of acorn was efficient to inhibit growth of pathogenic bacteria, mostly against Bacillus cereus and Staphylococcus aureus, with the lowest Minimum Inhibitory and Bactericidal Concentrations. These results confirm the importance of consumption of green oak acorns (Quercus ilex) and signify that they are an excellent source of natural antioxidants and antibacterial compounds, which could be exploited in pharmaceutic, cosmetic and agri-food sectors.

The toxic effects of ACR monomer include carcinogenesis, cellular genotoxic, and neurotoxicity. In this study, we examined the effect of acrylamide on biochemical and hematologic parameters in Wistar rats and explored the renal and hepatic function of these animals through a complementary anatomopathologic study. For it, thirty female Wistar rats aged 4 weeks and weighing 100 +/- 10 g were housed six animals per cage and divided as follows: two groups were exposed for 2 months to drinking water containing 5 mg (Group 2) or 10 mg acrylamide (Group 3); one group of 12 rats received the median lethal dose of acrylamide by gavage (Group 4); and the control group (Group 1) received pure water. The results clearly showed that acrylamide affects various biochemical parameters, such as creatinine, urea, and serum globulin levels and the lipid balance, which are directly related to renal and hepatic dysfunction and disruption of the hematologic system. In addition, the data revealed changes in the complete blood count (CBC); significant increases in the number of leukocytes (9.95 +/- 1.44 and 10.44 +/- 1.21) and lymphocytes (6.11 +/- 0.48 and 6.33 +/- 0.76) in Groups 3 and 4, respectively; and decreases in total protein (88.95 +/- 6.36), albumin (37.65 +/- 1.65) and alpha-1 globulin levels (24.84 +/- 2.10) in Group 3. The anatomopathologic study confirmed liver damage in the animals administered an acrylamide containing diet compared with those in the control group. The present study confirmed the effects of acrylamide on different hematologic, biochemical and immunologic parameters, with a specific focus on the liver and kidney, and on the induction of neurotoxic disorders. The results showed that oral exposure to acrylamide via drinking water or gavage induces kidney damage, hepatocellular insufficiency and chronic liver disease, resulting in primary immunodeficiency and activation of the immune system following the possible expression of certain immunoreaction genes.

The objective of this work is to investigate how exposed is the Algerian population to ACR. It is a toxic chemical that forms during the cooking of certain foods. Acrylamide content was analyzed in food typically found in the Algerian diet. The food was acquired randomly and classified into five groups: i) potatoes and derivatives; ii) cereals and cereal products; iii) stimulants; iv) protein-rich foods such as meat, fish and milk; v) non-carbonated beverages, and vi) others. ACR content was analyzed according to the ISO-EN-16618:2015 using liquid chromatography coupled with tandem mass spectrometry. Potato-based foods contained the highest level of ACR. ACR consumption levels were studied to estimate both, the frequency of consumption and the level of exposure to ACR. A questionnaire assessing the amount and the type of food consumed was used in 788 households families. The survey results were combined with the acrylamide content analysis. The study showed that Algerians were exposed to an average ACR concentration of 0.2 to 0.4 mu g per kg of body weight per day. The major contributors to this exposure were potato fries and biscuits. Each person in the population studied appeared to have been exposed to ACR through diet. Mitigation strategies must be introduced to reduce ACR exposure among the Algerian population.

Algeria imports more than half of her needs for milk and cereals. Faced with this situation, she must now think of finding a way to reduce this dependence by replacing cow's milk, in part, with another commodity abundant in the world and cheaper. In this work we used whey powder in bread making. The results showed that 71.5% of tasters found that PA bread (100% whey) was extremely pleasant and gave it a score of 9/9. The breads obtained have optimal characteristics with a beautiful appearance including a good appearance, regular shape and a smooth crust. The interior is also pleasant, with a very supple crease, little elastic, non-sticky and easy tearing. These good rheological characteristics are the result of a good balance between elasticity and extensibility. The whey breads have kept a good quality (organoleptic and microbiological) after 7 days of storage at 6ºC in plastic packaging.

Algeria imports more than half of her milk requirements. The annual bill exceeds $ 1 billion. Faced with this situation, she must now think about finding a way to reduce this dependence by replacing cow's milk, in part, with another commodity abundant in the world and cheaper. In this work we used whey powder in the preparation of pastry creams. The results showed that 80% of tasters find the CA cream (100% whey) is extremely pleasant and gave it a 9/9 rating. The comparison between different pastry creams revealed that the cream prepared with 100% whey (CA) presents the best appreciations. Similarly, it presents texture improvements, smooth and homogeneous with a clear appearance and a very pleasant smell. Among the positive points we noted that the addition of whey improves water retention and reduces syneresis. Whey creams have kept a good quality after 7 days of storage at 6ºC.

A Staphylococcus aureus strain, isolated from an Algerian biotope, secretes a non-induced lipase in the culture medium. The S. aureus lipase (SAL) was purified to homogeneity. Pure SAL is a monomeric protein (43kDa). The 20 N-terminal amino acid residues showed a high degree of homology with other staphylococcal lipase sequences. SAL presents specific activities of about 1600 and 555 U mg(-1) using tributyrin and olive oil emulsion as substrates, respectively. In contrast to other staphylococcal lipases previously characterized, SAL was stable at a pH range from 6 to 9 after 1h incubation, and retained 50% of its activity after 10min incubation at 50 degrees C. The purified enzyme was also characterized using monolayer technique. Lipase activity can be measured only when the surface pressure exceeds 15mNm(-1). The critical surface pressure (pi(c)) measured with egg-PC films was estimated at 33 mNm(-1). SAL showed a preference for the distal ester groups of the diglyceride isomers at low surface pressure, for the adjacent ester groups at high surface pressure and a preference for the sn-3 position of the 2,3-sn-enantiomer of dicaprin. Cloned and sequenced gene part, encoding the mature lipase shows, in comparison with S. aureus lipase 3 (SAL3), a deletion of three residues (LKA) at the N-terminal extremity and a substitution of glycine 208 and isoleucine 226 with an arginine and leucine, respectively.

The ingestion of low or high lipid diets enriched with fructo-oligosaccharide (FOS) affects energy homeostasis. Ingesting protein diets also induces a depression of energy intake and decreases body weight. The goal of this study was to investigate the ability of FOS, combined or not with a high level of protein (P), to affect energy intake and body composition when included in diets containing different levels of lipids (L). We performed two studies of similar design over a period of 5 weeks. During the first experiment (exp1), after a 3-week period of adaptation to a normal protein-low fat diet, the rats received one of the following four diets for 5 weeks (6 rats per group): (i) normal protein (14% P/E (Energy) low fat (10% L/E) diet, (ii) normal protein, low fat diet supplemented with 10% FOS, (iii) high protein (55%P/E) low fat diet, and (iv) high protein, low fat diet supplemented with 10% FOS. In a second experiment (exp2) after the 3-week period of adaptation to a normal protein-high fat diet, the rats received one of the following 4 diets for 5 weeks (6 rats per group): (i) normal protein, high fat diet (35% of fat), (ii) normal protein, high fat diet supplemented with 10% FOS, (iii) high protein high fat diet and (iv) high protein high fat diet supplemented with 10% FOS. In low-fat fed rats, FOS did not affect lean body mass (LBM) and fat mass but the protein level reduced fat mass and tended to reduce adiposity. In high-fat fed rats, FOS did not affect LBM but reduced fat mass and adiposity. No additive or antagonistic effects between FOS and the protein level were observed. FOS reduced energy intake in low-fat fed rats, did not affect energy intake in normal-protein high-fat fed rats but surprisingly, and significantly, increased energy intake in high-protein high-fat fed rats. The results thus showed that FOS added to a high-fat diet reduced body fat and body adiposity.

This study aimed to evaluate the antioxidant activity of five Algerian olive oil samples from Chlef, Jijel, Tissemsilt, Bejaia and Tizi Ouzou regions. Thus the following results were found physicochemical caracterisation revealed that the samples are conform to standards prescribed by IOC (2013) as they are type-oleic and linoleic varies between virgin and extra virgin Chlef, Djijel and Bejaia oils are richer in carotenoids than those of Tizi Ouzou and Tissemsilt. Chlef and Tissemsilt oils are richer in phenolic compounds than other oils and have revealed very important antioxidant activity and the largest inhibitory power of peroxidation.

An extracellular serine metalloprotease produced by Lactococcus lactis subsp lactis BR16 isolated from Algerian traditional fermented food was used for hydrolyzing bovine casein in order to identify antibacterial peptide. Antibacterial peptide was separated from peptic hydrolysates by adsorption/desorption then analyzed using reverse phase high performance liquid chromatography (RP-HPLC) and active fraction was analyzed by MALDI-TOF mass spectrometry. A new antibacterial peptide was identified as SSSEESII from the subunit αs2 of casein corresponding of the fragment (24–31). This peptide demonstrated antibacterial activity against two Gram-positive bacteria: Listeria innocua ATCC 33090 and Micrococcus luteus ATCC 4698, and two Gram-negative bacteria: Escherichia coli ATCC 25922 and Salmonella enteritidis ATCC13076. Prediction of peptide secondary structure indicated that this peptide is anionic and must have random coil structure with a small region of hydrophobicity, which confers to the peptide unusual behavior compared to conventional antimicrobial peptides.

The raw milk is an important reservoir of microbial diversity can have important biotechnological applications, in particular to improve the unique characteristics of dairy products. For this effect, eight strains of autochthonus Lactobacilli have been isolated from goat and cow raw milk of the local Algerian populations (Setifian and Kabyle). The strains were then identified by phenotypic and molecular approaches by amplification and sequencing of 16S rDNA as Lb.casei (C4, C5, V2 and V5), Lb. paracasei (C6) and Lb.plantarum (C7, C8, C10). Virtually all the strains studied, from a technological point of view, produced lactic acid concentrations at or above 0.89g.100 mL-1. Most strains exhibit a high capacity and are actively producing proteolytic proteases in the stationary phase between 24 and 30 hours. The strains studied can be used in the starter cultures or co-cultures for making cheese. Keywords: Lactobacillus , identification, acidification, proteolysis.

Wheat bread constitutes the most regularly consumed food in the World, the international market for wheat undergoes strong pressure and prices are unceasingly increasing. The aim of this study is to substitute wheat flour by potato starch in bread preparation. Mixtures flours were characterized for composition, damaged starch, and Alveograph properties. According to the results of alveograph parameters, they decrease with the rate of incorporation of potato starch. This decrease can be corrected by adding vital gluten. The results of physicochemical analysis showed a decrease in protein levels, an increase in moisture content (about 2%) and carbohydrates levels due to the composition of potato starch. However, sensory analysis (p ≤ 0.05) showed that the addition 80% of potato starch leads to bread with better characteristics: taste, colour and odour, based on that, it is highly advisable as an ingredient in the standard preparation of wheat bread.

The milk remains a major food supply to the Man and his demand is ever growing. This important application involves high price of a liter of milk and thus an inability of certain non- producer to meet the needs of their peoples countries. Faced with this situation some countries including Algeria must think of now is to find a way to reduce this dependence by substituting cow's milk, in part, by another abundant commodity in the world and cheaper. In this work we extracted milk by grinding soybeans mixed with water and then brought to boiling and filtered. Similarly, we used the soy flour. Soymilk, we extract and then improved by 20 % of cow milk, is a healthy drink liquid, and organoleptic (flavor, color, appearance, odor) and satisfactory nutritional. Similarly, the yogurt obtained by this mixture has a smooth, creamy texture, smooth and with a significant characteristic white color in mammalian milk. Similarly, the nutritional value is very close to that of cow milk yogurt. This milk is as a very interesting alternative.

Fermentable dietary fibre such as fructo-oligosaccharide and viscous dietary fibers such as guar gum and alginate affect energy homeostasis. The goal of this study was to compare the impact of long term intake of these three dietary fibers on food intake, meal pattern, body weight and fat accumulation in mice. Over a period of 3weeks, the mice were fed daily with a preload containing 32mg of fructo-oligosaccharide or alginate or 13mg of guar gum. Food intake and body weight were monitored weekly, while meal patterns, adiposity and the expression of hypothalamic neuropeptide genes were evaluated at the end of the study period. The 3 dietary fibers produced a similar decrease in total daily food intake (14 to 22%) at the end of the first week, and this effect disappeared over time. The 3 dietary fibers induced a slight variation in satiation parameters. Body weight and expression of hypothalamic neuropeptide genes were not affected by any of the treatment. Preload of fructo-oligosaccharide and guar gum induced a similar and substantial decrease in the development of adiposity (17% and 14%, respectively), while alginate had no effect. Our results demonstrate mainly that the inhibitory effect of dietary fiber on food intake is lost over time, and that guar gum limits fat storage.

Staphylococcus aureus is a pathogenic bacterium that infects the milk and dairy products including cheese, causing food borne infections in humans. The objective is to scrutinize the growth and evolution of S. Aureus in cheese made with lactic acid bacteria isolated from local plants that are Lactococcus lactis subsp. cremoris and Lactococcus lactis subsp.lactis biovar diacetylactis. In the first part, the milk that was used in the manufacture of cheese was contaminated with Staphylococcus aureus , the antimicrobial activity was studied vis-a-vis S. aureus and the antagonistic effect of the latter against the lactic strains. In the second part, we performed counts of lactococci and S. aureus as the contaminated cheese in various stages of cheese production. From contaminated milk before manufacture of cheese, we have noticed a steady decline of lactic ferments after curdling and in parallel we have seen a decrease in the number of S. aureus during the early stages of production to increase again in the salting. The results of contaminated cheeses after their manufacture revealed a significant decrease in lactic strains and the pathogenic strain in both types of cheese after 24 and 72 h of their contamination. Lactococci don't have inhibitory activity vis-a-vis S. aureus , and S. aureus did not inhibit lactic strains used in the manufacture of cheese. Thus, it preserves its contamination and poses a risk to human health.

Several lactic acid bacteria strains were screened for the production of antibacterial substances active against some pathogenic bacteria. The inhibitory mechanism was investigated and was shown to be dependant of bacteriocin production. The objective was to isolate LAB with antibacterial activity from raib and to select strains that could be used for the determination of probiotic properties. Results showed that 6 LAB cultures retained activity in the supernatants after neutralization and catalase treatment. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacteriocin production profiles showed that the maximal bacteriocin production by S. thermophilus T2 cells was measured by the end of the late-log phase (90 AU ml −1 ) with a bacteriocin production rate of 9.3 (AU ml -1 h -1 ). In addition, our findings showed that the bacteriocin, produced by S. thermophilus T2, was stable over a wide pH range (4 - 8), indicating that such bacteriocin may be useful in acidic as well as non acidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food. Around 40% of these strains, mainly isolated from Algerian fermented milks in MRS agar, were pre-selected for testing as potential probiotics by their ability to grow adequately at low pH values. In vivo study indicates that number of Sc T2 and Lb . B2 remains important as long as rabbits consume some fermented products. Antibacterial activity of Lactobacillus and Streptococcus against indicator bacteria is a good probiotic property. Transfer of these antimicrobial activities to in vivo conditions is beneficial for the maintenance of the intestinal microflora. Keywords : Bacteriocin, lactic acid bacteria, Streptococcus thermophilus. Lactobacillus bulgaricu, probiotic African Journal of Biotechnology Vol. 12(20), pp. 2949-2956

Natural, solid and porous support named pouzzolane was used for two Lactococcus lactis subsp. lactis immobilization and lactic acid and hydrogen peroxide (H2O2) production by stains immobilization in batch fermentation process was investigated using a bioreactor with recycling. Lactic acid fermentation using syrup of molasses treated and diluted at 50% (MSTD 50%) was not supplemented by ingredients concentrations. Cells immobilization showed higher sugar utilization, higher H2O2 accumulation and higher lactic acid production than did free cells. Improvement in compounds production was noticed with immobilization of Lactococcus lactis isolated from the molasses (Lc.l(ML)) compared with strains isolated from the cow's milk (Lc.l(CM)). In pure culture, the kinetic of the production of lactic acid and H2O2 by the two strains in MSTD 50% was compared with than did in Elliker broth.

This study is related to the isolation and identification of strains of local thermophilic lactic acid bacteria belonging to the species, Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria can exist under extreme conditions of the digestive tract (acidity and high concentration of bile salts) and have a high capacity to degrade lactose. The aim is to produce yoguort with the bacteria that remain viable and active in the digestive tract, so as to enhance lactase activity at the intolerant lactose. The results also show considerable variations between genera, species and strains of the same species in the decomposition of lactose in pure and mixed cultures (Sc.t(5) and Sc.t(3), respectively, with 48 and 42%) (YSLB2, YSLB4 and YSLB1, respectively, with 90.44, 87.22 and 84.28%) of initial lactose after 6 h of incubation at 37 degrees C while keeping a level of viability higher than 107 cells/ml. In the presence of pH (2.5, 4.5 and 6.5), put with or without 0.3% of bile salts, the results are also unmatched. The best cultures will be used to manufacture fermented milks (yoghurts) in order to correct intolerance with lactose in man after having to test them, in a second part, in vivo.