Characterization of the harmful effect of olive mill wastewater on spearmint.

In this study, changes in viability, biomass production, essential oil yield and essential oil composition of Mentha spicata L. (spearmint) exposed to olive mill wastewater (OMW) were investigated. Spearmint cuttings were sensitive to OMW and, after 6h of incubation in raw or diluted OMW, their viability was null. The short contact of raw OMW with mint cuttings caused an irreversible damage in rhizogenesis and shoots development. Roots were more sensitive to phytotoxicity than shoots. In a field essay, spearmint showed a good capability to recover when OMW was spread at 8 l m(-2) at the vegetative phase of growth (45 days after plantation). At this dose, a slight increase of mostly of the mint essential oil constituents was obtained. When the dose applied was 16 l m(-2), phytotoxicity was manifested by a high reduction of biomass and essential oil yield. The essential oil composition was also affected and a disappearance of many of mint essential oil constituents was observed with an increase of 59% for carvone, the major compound of spearmint essential oil. As far as we know, this is the first report on the effect of field application of OMW on an aromatic plant essential oil yield and composition.

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.

Ochratoxin A in rice on the Moroccan retail market.

One hundred (100) samples of rice purchased from retail markets in five different cities (Rabat, Témara, Salé, Casablanca and Méknès) in Morocco from January to October 2006 were surveyed for the presence of ochratoxin A (OTA) using Accelerated Solvent Extraction (ASE) coupled to liquid chromatography with fluorescence detection. The identification of OTA in positive rice samples was confirmed by methyl ester derivatization. Analytical results showed a frequency of contamination of 26% of total analyzed rice samples. The percentage of contamination of samples was 24, 26.6, 16.6, 27.7 and 30% in Rabat, Témara, Méknès, Salé and Casablanca respectively. Levels of OTA in positive samples ranged between 0.08 and 47 ng/g. The average contamination of all analyzed samples was 3.5 ng/g. The highest frequency of positive samples (30%) and the most contaminated sample (47 ng/g) was found in a sample from Casablanca city. 14 out of 100 total samples exceeded the maximum level of 5 ng/g set by European regulations for OTA in cereals. Based in the results presented in this study, the estimated daily intake of OTA in rice was 0.32 ng/kg bw/day for Moroccan consumers.

Incidence of ochratoxin A in rice and dried fruits from Rabat and Salé area, Morocco.

One hundred samples of dried fruits (20 dried raisins, 20 walnuts, 20 peanuts, 20 dried figs and 20 pistachios) and 20 samples of rice purchased from retail shops in the Rabat and Salé area in Morocco were analysed for ochratoxin A (OTA) by immunoaffinity clean-up (IAC) and liquid chromatography (LC) with fluorescence detection. The limit of quantification (LOQ) (S/N = 10:1) of OTA was 0.02 ng g(-1) in rice, 0.03 ng g(-1) in pistachio, peanut and walnut, and 0.03 ng g(-1) in dried raisins and dried figs. The incidences of occurrence of OTA in dried raisins, walnuts, peanuts, dried figs and rice were 30, 35, 25, 65 and 90%, respectively. Analytical results showed that pistachio samples contained no detectable OTA, but concentrations ranged from 0.02 +/- 0.01 to 32.4 +/- 2.10 ng g(-1) in rice, from 0.10 +/- 0.05 to 2.36 +/- 0.75 in peanut, from 0.03 +/- 0.01 to 1.42 +/- 0.45 in dried figs, from 0.05 +/- 0.02 to 4.95 +/- 0.02 in dried raisins, and from 0.04 +/- 0.01 to 0.23 +/- 0.05 in walnuts. The results also showed that 15% of the total number of rice samples analysed exceeded the 2002 regulatory limit set by European Union regulations for cereals. This is the first report on the occurrence of OTA in dried fruits and rice available in Morocco.

Limited survey for the occurrence of aflatoxins in cereals and poultry feeds from Rabat, Morocco.

Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n=21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column (IAC) clean-up and fluorimetric detection. The incidence of AF in corn, wheat flour and poultry feeds was about 80, 17.6 and 66.6% respectively. High contamination levels were found in corn and poultry feeds samples. Levels of contamination of analyzed samples with AFB1 ranged from 0.23 to 11.2, 0.03 to 0.15 and 0.05 to 5.38 ng/g for corn, wheat and poultry feeds respectively. Results showed also that the contamination of 10% of samples of corn was higher than the limit set by EU regulations for AFB1 and total AF. This is the first report on the determination of AF in corn, wheat and poultry feeds from Morocco by HPLC and IAC.

Presence of aflatoxin M1 in pasteurized milk from Morocco.

Fifty four samples of pasteurized milk produced by five different dairies from Morocco were surveyed for the presence of aflatoxin M1 (AFM1) using immunoaffinity columns and liquid chromatography coupled to fluorescence detection. Confirmation of AFM1 identity in positive samples was based on the formation of AFM1 hemi-acetal derivative (AFM2a) after derivatization with trifluoracetic acid. Analytical results showed that 88.8% of the samples were contaminated with AFM1; 7.4% being above the maximum level of 0.05 microg/L set by the Moroccan and European regulations for AFM1 in liquid milk. The incidence of AFM1 in milk from these dairies was 100, 92.3, 90, 83.3 and 77.7% respectively, with AFM1 levels ranging from 0.001 to 0.117 microg/L and a mean value of 0.0186 microg/L. Based on the results presented in this study, the estimated daily intake of AFM1 was 3.26 ng/person/day. In this work, data on the natural occurrence of AFM1 in pasteurized milk produced in Morocco is presented for the first time.