Safety methods for chlorpyrifos removal from date fruits and its relation with sugars, phenolics and antioxidant capacity of fruits.

The effectiveness of different postharvest wash treatments at two levels (10 and 20 g/l) for different dipping times was determined to remove chlorpyrifos from date fruits treated at concentration of 2 mg/l. The recovered amount of chlorpyrifos was extracted based on the solid phase extraction (SPE) method and then analyzed by gas chromatography with mass spectrometry (GC-MS). The results demonstrate that the removal of chlorpyrifos increased in the order of acetic acid (AA)> citric acid (CA)> hydrogen peroxide (H2O2)> potassium permanganate (KMnO4)> running water (H2O), and the percent of pesticide residue on date fruits depended on the concentration of tested washing treatments and dipping time without the formation of the toxic by-product, chlorpyrifos-oxon. Kinetic studies revealed that chlorpyrifos was found to be more easily removable from date fruits treated with the tested chemical solutions with t1/2 values of 12-29 min compared with roughly 53 min in case of running water. The impact of these washing treatments on quality of date fruits illustrated that all treatments exerted a little negative effect on total sugars content but H2O2 and KMnO4 at level of 2 % had more drastic effect. Whereas, running water, 10 and 20 g/l CA caused significant increases in total phenolic contents, during all the tested contact times compared with control. Except the insignificant effect of KMnO4 treatments, antioxidant capacity of date fruits tended to increase in all wash treatments, when the contact times were 5 or 15 min.

Monitoring of pesticide residues in vegetables marketed in Al-Qassim region, Saudi Arabia.

A total of 23 pesticides from different chemical groups in 160 different domestic vegetables collected from four major big supermarkets located in Al-Qassim region, Saudi Arabia, were identified by gas chromatography with mass spectrometry (GC-MS). Residues were found in 89 of the 160 samples and 53 samples were above the maximum residue levels (MRLs). The most frequently found pesticides were carbaryl followed by biphenyl and then carbofuran. Cabbage was the most positive and violated MLRs (16 and 11 samples), followed by carrot and green pepper (12 and 7 samples), cucumber (12 and 6 samples), egg-plant (12 and 5 samples), squash (11 and 7 samples), lettuce (11 and 6 samples) and tomato (11 and 4 samples). The highest concentrations were found in lettuce (ethiofencarb, 7.648), followed by tomato (tolclofos-methyl, 7.312 mg/kg), cabbage (chlropyrifos, 6.207 mg/kg), carrot (heptanophos, 3.267 mg/kg), green pepper (carbaryl, 2.228 mg/kg) and egg-plant (carbaryl, 1.917 mg/kg). These findings pointed to the following recommendation: the need for a monitoring program for pesticide residues in vegetables cultivated under greenhouse conditions at the national level to protect consumers' health.

Effect of feeding Acacia abyssinica and of its extracts given by different routes on rats.

The effect of a diet consisting of 2% and 10% of Acacia abyssinica bark on Wistar rats treated for 6 weeks was examined. A 2% A. abyssinica diet was not toxic to rats. Impairment of growth and hepatonephropathy were observed in rats on a 10% A. abyssinica diet. By whatever route it was administered, either intraperitoneally (i.p.) or orally (p.o.), the ethyl acetate extract in daily doses of 500 mg/kg body weight was the most toxic and lethal to rats and caused hepatonephropathy, widespread hemorrhage and congestion and fibrinous peritonitis following i.p. administration. The aqueous and ethanol extracts i n similar doses to ethyl acetate extract were only lethal to rats when given via the i.p. route. Lesions were accompanied by anemia, leukopenia and alterations in serum AST activity and concentrations of urea, total protein and albumin.

Toxicity of Chrozophora obliqua in rats.

The toxicity to Wistar rats of Saudi Chrozophora obliqua used in traditional medicine for the treatment of diverse ailments was investigated. C. obliqua leaves were fed to rats at 2% or 10% of the standard diet. When compared with controls, body weight gains and feed efficiency were adversely affected by both treatments. Although the rats fed 10% C. obliqua diet had the lowest growth rate, bouts of soft faeces and enterohepatonephropathy no death occurred among the rats. These changes were accompanied by increases in serum GGT and AST activities, in urea and cholesterol concentrations, decreases in total protein and albumin levels, macrocytic hypochromic anaemia and leucopenia.