Search results for "Maximum level"
showing 6 items of 6 documents
Presence of aflatoxin M1 in pasteurized milk from Morocco
2007
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 …
Comparing conventional and organic citrus grower efficiency in Spain
2014
This paper compares the organic and conventional citriculture systems in Spain from the perspective of their technical efficiency. The primary objective of the research is to compare the relative efficiency of these two systems in relation to a metafrontier that envelops both technologies. In addition, the article analyses how efficient each growing system is at using its own technology, that is, when farms’ efficiency is benchmarked in relation to the best practices in their group. Contrary to conventional practice, farms’ performance is analyzed in terms of specific growing tasks: soil and plant cover management, pruning, fertilization and phytosanitary treatments. The results obtained hi…
Comparison of near and mid infrared spectroscopy as green analytical tools for the determination of total polar materials in fried oils
2017
Abstract Total polar materials (TPM) are used as an indicator of the quality in the frying oil because of high values may be harmful for human health. Spanish legislation establishes the maximum level of total polar materials for frying fats and oils for human consumption around 25% (w/w). Official methods to monitor oil quality are time consuming and use a lot of chemicals; therefore it is necessary a simple and quick analytical technique to evaluate fried oils. Transmittance near-infrared (NIR) and attenuated total reflection mid-infrared (ATR-MIR) spectroscopy measurements, combined with partial least squares (PLS) regression, offer alternatives to determine TPM in fried oils with relati…
Ochratoxin A in rice on the Moroccan retail market
2008
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…
Pressurized liquid extraction coupled to liquid chromatography for the analysis of ochratoxin A in breakfast and infants cereals from Morocco
2010
Abstract A sensitive and reliable method using pressurized liquid extraction (PLE) and liquid chromatography (LC) has been developed for the analysis of ochratoxin A (OTA) in breakfast and infants cereals. Influence of several extraction solvents that affect PLE efficiency was studied. The selected PLE operating method was: 10 g of sample was packed into 22 ml stainless-steel cell and OTA was extracted with acetonitrile/water (80:20) at 40 °C, 34 atm in one cycle of 5 min at 60% flush. The mean recovery of OTA was 82 ± 4 at fortification level of 3 ng/g OTA. The limit of quantification (LOQ) of OTA was 0.25 ng/g. The proposed method was successfully applied to the analysis of 68 samples of …
Occurrence of ochratoxin A in bread consumed in Morocco
2007
Abstract One hundred samples of commercial bread purchased from January to October (2006) from retail bakeshops in five different cities (Rabat, Temara, Sale, Casablanca and Meknes) in Morocco were surveyed for the presence of ochratoxin A (OTA) using liquid chromatography coupled to fluorescence detection. The identification of OTA in positive bread samples was confirmed by methyl ester derivatization. Analytical results showed that forty eight (48%) samples were positive with OTA greater than the limit of quantification (LOQ = 0.051 ng/g). Levels of OTA in positive samples ranged between 0.14 and 149 ng/g. The average contamination of bread samples with OTA was 13 ± 1.5 ng/g. The highest …