Magdy Moheb El-Dein Saad - Academia.edu (original) (raw)

Papers by Magdy Moheb El-Dein Saad

Mycotoxin Research, 1993

Production of aflatoxins on both natural (rice and corn) and semisynthetic (YES) media was conduc... more Production of aflatoxins on both natural (rice and corn) and semisynthetic (YES) media was conducted using an identified toxin-producing strain ofAspergillus flavus. TheA flavus strain was able to produce 4 types of aflatoxins, namely B1, B2, G1, and G2 on rice, corn, and YES media. Quantitative data showed that the concentrations of aflatoxins B1 and G1 produced were 52, 40.3, and 39.6; and 64.7, 45.0, and 58.0jug for 50g of rice, corn, and YES media, respectively. In comparison, the yielded amounts of aflatoxins B2 and G2 were much lower: 11.5, 17.9, and 17.5; and 28.S, 40.3, and 39.5 μg for 50 g of rice, corn, and YES media, respectively.A bioassay was conducted using the following 5 standard bacterial strains:Bacillus megaterium. Bacillus subtilis, Streptococcus faecal is, Staphylococcus epidermidis, andParacoccus denitrificans as well as a field strain of Candida albicans. All strains exceptP denitrificans showed varied degrees of inhibition when applied with crude aflatoxins at 5 to 40μg/mL. The minimum concentration of crude aflatoxins needed to inhibitP denitrificans was 10μg/mL. Moreover,Candida albicans was not inhibited at any concentration of aflatoxins applied in this work.Both undiluted and diluted (1/10, 1/100, and 1/1000) bacterial broth cultures showed a direct relationship between the diameter of inhibition zones and the concentrations of crude aflatoxins. Mean diameters of (7.0-20.5), (5-14), (4.5-13.0), (3.0-12.0), and (1.5-11.0) mm were observed when various concentrations of aflatoxins were applied usingB megaterium, S epidermidis, S faecal is, B subtilis, andP denitrificans, respectively.Field trials were applied to testify the validity of our data. A 1/100 dilution was prepared from each strain of 4 different species to estimate aflatoxins in samples of contaminated corn. Both chemical and biological assays were carried out at the same time. Data revealed that the most sensitive organism inhibited by as low as 7.5μg aflatoxins/mL wasB megaterium giving an inhibition zone of 10.5 mm, followed byS epidermidis with an inhibition zone of 7.5mm. In relation, the other 2 organisms were less sensitive to crude aflatoxins. Similarly, the biological assay was applied to detect aflatoxins in some samples of wheat, corn, peanut, rice, and poultry rations. Of the 14 wheat and 10 corn samples, only 4 wheat and 2 corn samples were found to be positive. The same results were obtained using TLC analysis.

The present investigation was conducted to figure out the releasing pattern and rate of five phth... more The present investigation was conducted to figure out the releasing pattern and rate of five phthalates from the plastic bottles into the bottled beverages of fermented milk, fruit juice, and soft drink. The studied phthalates were di-methyl phthalate (DMP), di-ethyl phthalate (DEP), din -butyl phthalate (DBP), bis(2-ethyl hexyl) phthalate (DEHP), and din -octyl phthalate (DnOP). Phthalates were determined in fifty-four samples (eighteen samples from each beverage type) at the beginning, middle, and end of the shelf-life period in two different bottles sizes for from each beverage type. The resulted limits of detection and quantification for phthalates were in the range of 6.5±2.5 and 20±5 (ng), respectively. Recovery percentages ranged from 75.77±3.06 to 82.95±3.28 (%) in fermented milk, 77.68±4.54 to 80.51±3.06 (%) in fruit juice, and 80.09±5.57 to 88.70±6.72 (%) in soft drink. DnOP was the major detected compound in all the tested beverages, which had the highest concentrations (0.52 – 0.82 ppm) and releasing rates (85.5 – 2116.7 µg week-1) followed by DEHP in fermented milk, DMP in juice, and DBP in soft drink samples. The released phthalates in the big bottles were significantly higher than in the small bottles. The highest values of total phthalates for the three beverages were lower than the tolerable daily intake (TDI) for an adult person by 3-135 times, which means that the detected amounts of phthalates in the three beverages were within the safe limits.

This study aims to search for the organic lipophilic of phthalates in plastic packaged pasteurize... more This study aims to search for the organic lipophilic of phthalates in plastic packaged pasteurized milk and the dairy products of fermented milk "Rayeb" and Domuatti cheese, locally produced and marketed in Cairo of Egypt. A pre-validated method using GC-MS was applied to detect the residues of the 6 phthalate congeners commonly used as
plasticizers in bottles and food containers manufacturing. Such plasticizers are intentionally added to enhance the technical and industrial properties of the plastic containers used in food industry. Data of spiked samples obtained from the applied method showed average recovery percentages of 90.8 ± 5.3 and a percentage of coefficients of variation equivalent to 4.41 ± 0.6, depending upon both phthalate congener and the concentration of spiked samples. The corresponding percentages of recovery average of Rayeb and Domuatti cheese were 91.0 ± 2.1 and 88.3 ± 1.8, respectively, while the percentages of coefficient of variation were 3.31 ± 0.1 and 3.85 ± 0.9, respectively. However, data revealed that none of the 6 phthalates of DMP, DEP, DBP, BBP, DEHP and DOP were observed in any sample of milk, Rayeb and Domuatti cheese samples examined during the first month of production in both bottle and container sizes. As well, none of the 4 phthalates of DMP, DEP, DBP and/ or BBP were found in the 3 studied products up to the last month of expiry. Only 2 and 3, each out of 24 and 2 out of 18 samples of milk, Rayeb and Domuatti cheese, respectively showed low levels of contamination with DEHP or DOP. The determined residues of DEHP or DOP phthalates were ranged between 30-88 (ng/ml). Moreover, the effect of the variables of 6 phthalate congeners, different brands, different container sizes and the storage time were discussed in this work.

concern which is also extremely detrimental to economy. The aim of this study was to evaluate the... more concern which is also extremely detrimental to economy. The aim of this study was to evaluate the gender response and towards aflatoxin(s) contaminated diets in rats. Sixty albino rats weighting (60-80 g) were divided into six groups (10 rat each) Group 1: represent male rats control, Group 2; represent female rats control,Group 3 : male rats received low dose of aflatoxin B1(50 ppm) orally (4 doses /2 weeks). Group 4: female rats received low dose of Aflatoxin B1 (50 ppm) orally during treatment stage (4 doses /2 weeks).Group 5: male rats received high dose (150 ppm) of aflatoxin B1 (4 doses /2 weeks) Group 6: female albino rats received high dose (150 ppm) of Aflatoxin B1 (4 doses /2 weeks). Blood samples were collected at different time peroids (at the end of aflatoxin admistration and after 2 ,4 and 6 weeks to evaluate the healing effecincy). Results obtained showed that, sGOT was significantly increased in male,female of low dose and female of hight dose after 2weeks from admistration.After four weeks, ALP increased in male of hight dose and female of hight dose versus male while after six weeks, ALP was elevatated in both sex of low dose versus control.The activity of LDH was higher in female of low dose versus control group. After four weeks serum bilirubin was elevated in both sex administrated low or hight doses while in female high dose significantly higher than low dose.After six weeks, bilirubin was higher in female with low dose versus control. Serum cholesterol was elevated in both sex with low and female of hight dose after four weeks. While after six weeks cholesterol was elevated in both sex with low or hight doses. Serum glucose was elevated in male of low dose and female of hight dose versus control after two weeks. In conclusion no gender-specific responses to aflatoxin contaminated diet in rats were observed. These results support the view that aflatoxin induction of biochemical disturbances and healing efficiency after 8 weeks from administration

This study is an attempt to prevent or minimize the negative probabilities due to ingesting feed ... more This study is an attempt to prevent or minimize the negative probabilities due to ingesting feed contaminated with aflatoxins (AFs). A previous research studies for about 30 years leads to suggest this studied formula. An exposure study extended for 3 different stages was conducted using eighteen Egyptian male sheep at the growing ages. The 1 st stage (pre-treatment) was extended for 2 weeks and suggested to compare the performance of animal groupings under the normal conditions before receiving any treatment, either level of contamination(s) or dosage(s) of additive. The 2 nd stage (treatment) was extended for 4 weeks and the animals received different levels of aflatoxin(s) (10 mg/kilogram concentrated diet) and / or the studied formula at two levels (250 and 500 mg / head / day). The 3 rd stage (post-treatment) was extended for 4 weeks and suggested to transfer treated animal groupings to receive sound diets free from any level of contamination. Dry matter intake (DM), apparent nutrient digestibilities, nutritive values, serum chemistry profiles and AFs concentrations in feed intake, orts, feces and urine; were evaluated. Data revealed that aflatoxins contaminated rations induced significant decrease in daily feed intake and the averages of body weight, body weight gain and feed conversion rates were dramatically affected during the exposure stage to aflatoxins. Additionally, serum constituents and ruminal measurements indicated impaired liver function and digestive disturbances in sheep fed aflatoxin. An addition of studied formula at doses between 250 and 500 mg / head / day, for exactelly 28 days, were able to modify rumen fermentation by changing protozoal activity and motility and could approximately normalized the adverse effects of aflatoxin contamination.

Food safety is related to the presence of food borne hazards in food at the point of consumption ... more Food safety is related to the presence of food borne hazards in food at the point of consumption (intake by consumer). Hazards could occur at any stage of food chain, so adequate control throughout the food chain is essential. Undoubtedly, food safety is ensured through the combined efforts of all the parties interested and participating in the food chain from F (farm) to F (fork).Interested parties within the food chain include feed producers and primary producers through food manufacturers, transport, storage, operators and subcontractors to retail and food service outlets. At least, there are 8 main concepts controlling and limiting the issue of food safety which will be discussed in this current article. To establish food safety system 4 key elements were required to ensure food safety along the food chain up to the point of consumption. The International Standard (ISO 22000) offer the essential 4 requirements to any community and / or organization aiming to establish, manage, apply and implement food safety system. The 1 st element is "interactive communication" between customers and suppliers continuously about identified hazards and control measures. The 2 nd element "system management" refer to the mandatory team work responsibilities and authorities. The 3 rd element "prerequisite programmes PRP,s" refer to the preliminary steps to enable hazard analysis and to establish the operational prerequisite programmes (PRP's). Finally, the 4 th element "HACCP principles" is dealing with hazard identification, control and monitoring of the critical control point.

Mycotoxins are highly toxic secondary metabolites naturally produced when certain species of fung... more Mycotoxins are highly toxic secondary metabolites naturally produced when certain species of fungi infected agricultural commodities, foods and feedstuffs. Aflatoxins, in particular, had continuously received the attention of many research studies, because of their wide-spread occurrence and the wide range of affected foods beside their potency and toxicity to all mammals and humanbeing . Aflatoxins could be produced by certain species of Aspergillus flavus and/ or Aspergillus parasiticus when invade foods and feedstuffs. The most limiting environmental factors affecting and accelerating aflatoxins production were proved to be moisture content and relative humidity . So far, more than 20 derivative and metabolite of aflatoxins was identified and evaluated. There is evidence that only aflatoxin(s) B1, B2, G1 and G2 are the natural occurring aflatoxins on foods and feeds of plant origin, while aflatoxin(s) M1 and M2 were commonly found in milk and dairy products. Thus, aflatoxins M1 and M2 in milk of certain herbs of livestock is a proved indicator that such livestock was previously fed aflatoxins-contaminated ration . AFB1 was proved to be the parent compound and the most potent and toxic form of the naturally occurring aflatoxins, besides AFB1 is the most dominating form of contamination representing more than 60% of the aflatoxins contaminated foods and feeds (WHO, 1979). However, Ingestion of aflatoxins-contaminated diet leads to yield excessive free radicals as a result of the metabolic pathways and biotransformation processes of the contaminants. The highly oxygenated molecule of AFB1 goes through definite biotransformation processes of reduction, hydroxylation, hydrogenation, demethylation and epoxidation. All metabolic pathways, except epoxidation process, are the body immune response to detoxify and eliminate aflatoxin(s), but unfortunately the bio-processes are accompanied with excessive reactive oxygen species (ROS) free radicals. yielded more toxic and potent metabolite. The highly reactive metabolite of AFB1-2,3 epoxide might adduct proteins and nucleic acids through certain successive reactions . Such consequences of metabolic processes lead to liberate excessive reactive nitrogen species (RNS) free radicals. So, food of plant origin, in particular, fresh vegetables and fruits which are rich of antioxidants and constituents are recommended to get rid of, eliminate and/ or reduce the excessive released free radicals due to aflatoxin(s) and aflatoxicosis.

Antibiotic extraction from solid matrices is generally complicated unlike aqueous phases. Consequ... more Antibiotic extraction from solid matrices is generally complicated unlike aqueous phases. Consequently, increasing the extraction efficiency of antibiotics from solid matrices has received a great concern. Therefore, the main objective of this study was to determine three macrolide antibiotics; tylosin (TYL), spiramycin (SPIR), and erythromycin (ERY) in buffaloes’ meat using the recommended method of thin-layer chromatography-bioautography (TLC-B) after some modifications. Antibiotics were extracted by 0.2% metaphosphoric acid-methanol (6:4, 7p/7p), and then the extracts were cleaned up using an Oasis HLB cartridges (200 mg). The recovery ratios at 0.5, 1, and 2 maximum residue limits (MRLs) with high precision were 84.19–92.22%, 83.09–89.42%, and 84.89–90.28%, respectively. The detection limits were 12, 45, and 2 ng g−1 for TYL, SPIR, and ERY, respectively. Forty-five samples of Egyptian buffaloes’ meat were analyzed using the adapted method. Only 9 and 5 samples out of the 45 samples were positive for TYL and ERY, respectively, with mean concentrations of 42.59 and 31.21 (ng g−1) which were lower than the permitted MRLs recommended by the European community.

This work is an attempt to monitor the most recent hazards of phthalate(s) in bottled drinking wa... more This work is an attempt to monitor the most recent hazards of
phthalate(s) in bottled drinking water recently consumed in Egyptian markets. A simple and reliable method using GC-MS was validated and applied to detect the most common phthalate esters used in the manufacturing of different sizes of bottles of drinking water. Data of method validation showed that the linear range of the GC-MS calibration of the concentrations of 25, 50 & 100 ug/ ml, had a mean correlation coefficient of 0.991 ± 0.016. The detection limit was < 25
ng./ ul. and the recovery percentages were 90.6 6.9 depending upon the type of phthalate congener. An experimental nested classification design, include the variables of 3 different commercial brands of bottled water in 3 different bottle sizes (1, 3 & 5 liters) stored at 3 different time that, all the random collected samples of the 3 different brands were proved to be phthalate(s)-free at the intervals of 1 and 3 months of production date. By advancing storage time, traces of di-ethylhexyl phthalate (DEHP) and din-
octyl phthalate (DOP) were determined in small and medium bottled samples of 2 of the tested brands at the interval of 6 month storage. It's worthy to mention that the common used
plasticizers had only commercial names with no reference to the contents and/ or the percentages of its components of phthalate esters, which makes the process of inspection or
tracing the contaminants very difficult. Thus, further work is recommended to confirm the relation between storage period, temperature and the released phthalate congeners.

Books by Magdy Moheb El-Dein Saad

InTechOpen, 2018

Animals could become sick at any time of their lives, just like all people exposed. Many of the a... more Animals could become sick at any time of their lives, just like all people exposed. Many of the antibiotics administered to animals are identical to or closely drugs used in human. All animal species in general and food-producing animals, in particular, are commonly exposed to antibiotics to treat and prevent infectious diseases or to promote growth. Antibiotics would not be necessary if animals were raised differently under good veterinary and husbandry practices that were less crowded and more sanitary. The proper and responsible use of antibiotics in veterinary medicine mandate an active cooperation between all the interested parties involved in livestock production cycles. All parties are invited to act together to ensure the ultimate goals of maintaining the efficacy and safety of veterinary antibiotics and complying the established maximum residue limits (MRLs) of the products of animal origin intended for human consumption. Antibiotics as hazardous substances should be applied and directed during the different steps starting from prescription until ensuring the withdrawal period under the supervision of professionals and veterinarians. Practices indicated that there is a need to improve sensitivity testing services and facilities before prescribing the proper antibiotic.

Mycotoxin Research, 1993

InTechOpen, 2018