Characterization of lactic acid bacteria isolated from the one humped camel milk produced in Morocco.

One hundred and twenty (120) strains of lactic acid bacteria (LAB) were enumerated and isolated from raw dromedary milk in Morocco using various cultured media. Strains isolated were characterized by phenotypic, physiological and biochemical properties. Results showed that high counts of LAB were found. Presumptive lactobacilli counts ranged from 2.5x10(2) to 6x10(7)cfu/ml, presumptive lactococci levels varied from 5x10(2) to 6x10(7)cfu/ml, presumptive streptococci counts varied from 4.2x10(2) to 8x10(7)cfu/ml, presumptive leuconostoc levels ranged from 5.4x10(2) to 5.4x10(7)cfu/ml. Results showed also that Lactobacillus and Lactococcus were the predominant genera with 37.5% and 25.8%, respectively. The dominated species found were Lactococcus lactis subsp. lactis (17.5%), Lactobacillus helveticus (10%), Streptococcus salivarius subsp. thermophilus (9.20%), Lactobacillus casei subsp. casei (5.80%) and Lactobacillus plantarum (5%). This is the first report on the characterization of LAB strains isolated from the one humped camel milk produced in Morocco.

Effect of controlled lactic acid bacterial fermentation on the microbiological and chemical qualities of Moroccan sardines (Sardina pilchardus).

Lactic acid bacteria (LAB) strains were assayed for the conservation of fresh sardine "Sardina pilchardus". Lactobacillus delbrueckii subsp. delbrueckii was used for inoculation of sardine fillets in a solution of NaCl (5%, w/w) and glucose (4%, w/w) concentration in water. Microbial counts including Standard Plate Count (SPC), LAB, yeasts, coliforms, Salmonella, staphylococci and Clostridium were followed during two weeks of storage at 30 degrees C. Determinations of chemical parameters including pH, dry matter, fat, ash, total nitrogen (NT), total volatile basic nitrogen (TVBN) and trimethylamine (TMA) were carried out under the same conditions. Chemical determinations showed a net pH decrease from an initial value of 6.05 in raw sardine fillets to 4.3 after 16 days of fermentation. Increases in TMA content and TBVN were observed. Microbiological control showed that LAB counts reached a level up to 3.10(9) cfu/g after 4 days of fermentation. After two weeks, fermented fish was free of coliforms and Salmonella. The inhibition of pathogenic microflora including staphylococci and Clostridium was also observed. The results indicated that controlled LAB fermentation could be used as a successful process for biopreservation of sardines produced in huge quantities in Morocco.

Effect of natural starters used for sourdough bread in Morocco on phytate biodegradation.

Phytase activity was studied in natural sourdough bread starters to determine physicochemical characteristics (phytic acid hydrolysis, dough rising capacity and pH) in the flour and during sourdough fermentation. Fermentation microorganisms (yeasts and lactic acid bacteria) were also characterized. Results showed a decrease of phytic acid in sourdoughs started with traditional starters, and wide variation in phytase activity. Microorganism counts were high at the end of fermentation, indicating higher fermenting activity of the starters. Yeast populations showed wide variation and lactic acid bacteria had high counts in the fermentation. Phytase activity was demonstrated in starter cultures made of lactic acid bacteria and yeast isolates, the most interesting of which were Saccharomyces cerevisiae combined with Lactobacillus plantarum and Leuconostoc mesenteroides.

Effect of natural starters used for sourdough bread in Morocco on phytate biodegradation

Phytase activity was studied in natural sourdough bread starters to determine physicochemical characteristics [phytic acid hydrolysis, dough rising capacity and pH] in the flour and during sourdough fermentation. Fermentation microorganisms [yeasts and lactic acid bacteria] were also characterized. Results showed a decrease of phytic acid in sourdoughs started with traditional starters, and wide variation in phytase activity. Microorganism counts were high at the end of fermentation, indicating higher fermenting activity of the starters. Yeast populations showed wide variation and lactic acid bacteria had high counts in the fermentation. Phytase activity was demonstrated in starter cultures made of lactic acid bacteria and yeast isolates, the most interesting of which were Saccharomyces cerevisiae combined with Lactobacillus plantarum and Leuconostoc mesenteroides

Antibacterial and antifungal activity of essential oils of Mentha suaveolens.

The essential oils (EO) of Mentha suaveolens, a wild Labiatae, which grows in several regions in Morocco, were characterized and their antimicrobial activity assessed. The main aromatic constituents of this plant, as characterized by IR, NMR and MS studies, were pulegone, piperitenone oxide (PEO) and piperitone oxide (PO) occurring in different amounts depending on the subspecies. These constituents as well as a series of other aromatic products such as carvone, limonene and menthone, were tested for their antimicrobial activity against 19 bacteria including Gram-positive and Gram-negative and against three fungi, using solid phase and microtitration assays. Pulegone-rich essential oil inhibited efficiently all the micro-organisms tested with MICs ranging between 0.69 and 2.77 ppm. Among the components from Mentha suaveolens EO, pulegone was the most effective against the tested microorganisms, followed by PEO and PO. The structure-activity relationship is discussed on the basis of the activity of the other aromatic derivatives tested such as carvone, limonene, menthone and the profile of the essential oils of Mentha suaveolens was compared with other Mentha species.

Physico-chemical and microbiological characteristics of a dried salted meat product (Kaddid) in Morocco.

Samples of traditional Kaddid (a salted dried meat) were analysed for their microbiological and physico-chemical characteristics. Microbiological determinations included the Standard Plate Count (SPC), total and faecal coliforms, enterococci, staphylococci, Salmonella, Clostridium, and Pseudomonas, whereas physico-chemical properties were characterized by pH, aw, chlorides, total nitrogen (TN), non-protein nitrogen (NPN), total volatile nitrogen (TVN), fat content and the acid degree value (ADV). Results showed that the microbial profiles were high for all the micro-organisms studied. Staphylococci were the most abundant micro-organisms in the product, whereas Salmonella was not detected in any sample. Proteolytics and lipolytics were also present in high numbers. The physico-chemical characteristics showed high levels of the ADV, chlorides, NPN and the TVN, and low levels of the aw and humidity. The conditions established in Kaddid indicate that there is effective preservation against micro-organisms causing spoilage and/or which are hazardous. The physico-chemical characteristics may indicate a high level of lipolysis and a low level of proteolysis.