ACRYLAMIDE IN FOOD : AN OVERVIEW
text
article
2004
eng
The risk of acrylamide has only come to the attention of scientists recently, as its discovery in foods was accidental.Acrylamide is formed in many types of food cooked at high temperatures, presence of acrylamide in manyfoods has been recently reported. Four main theories have been proposed to explain the mechanisms by whichacrylamide is formed in food: Theory 1 : Direct formation from amino acids; Theory 2 : Pathways based on acroleinintermediates; Theory 3 : Pathways based on an acrylic acid intermediate and Theory 4 : Pathways based on Maillardbrowning precursors .A hypothesis that acrylamide is formed by/upon cooking was confirmed in experimental animalsby verification of the identity of the acrylamide adduct in haemoglobin (Hb). This was comprehensively approvedby GC/MS analysis and the demonstration that the increased adduct levels were compatible with expectationfrom the contents of acrylamide determined in fried feeds. A significant dependence of acrylamide formation on temperaturewas demonstrated. Extensive efforts have been made to assess human exposure to acrylamide by monitoringseveral metabolites excreted in the urine as well as products resulting from biological alkylation by acrylamide. Resultsfrom in vivo studies conducted on rats explored that dermal absorption ranged from approximately 14 to 61% ofthe applied dose. Meanwhile, it was obvious that acrylamide is widely distributed in all tissues of the body. The majormetabolite formed from acrylamide via the cytochrome P450 pathway is glycidamide. Conjugation to reducedglutathione (GSH) catalyzed by glutathione S-transferase (GST) and excretion as mercapturic acid is a major pathwayfor the metabolism of acrylamide. Experiments revealed neuro and reproductive toxicity of acrylamide. Notwithstanding,the International Agency of Research on Cancer (IARC) has classified acrylamide as “probably carcinogenicto humans”. Acrylamide in foods can be determined by GC/MS, HPLC and liquid chromatography-mass spectrometry(LC-MS) using the MS/MS mode. For the GC/MS and HPLC methods, the achieved detection level ofacrylamide was 5 μg/kg while for LC-MS/MS method was 10 μg/kg. The latter method is simple and preferable forroutine analysis.
Alexandria Journal of Food Science and Technology
The Scientific Society of Food Industries, Alexandria, Egypt.
1687-3920
1
v.
1
no.
2004
1
22
https://ajfs.journals.ekb.eg/article_18933_f5086e67f6f2e551a9e2176b821d571b.pdf
dx.doi.org/10.21608/ajfs.2004.18933
VELOCITY OF SPECIFIC SELECTIVE ENZYMES IN MANGO (Mangifera indica L.) TREATED WITH γ- RAYS
text
article
2004
eng
The problem at hand is dealing with; to what extend velocities of polyphenol oxidase (PPO), peroxidase(POD) and pectinmethylesterase (PME) are affected by irradiation?. To reach such target, the investigated mangofruits were irradiated with different doses of γ- rays namely .500, 1000, 1500, 2500 and 5000 Gy produced from Co60.Velocity reaction of the aforementioned enzymes in relation to different substrate and enzyme concentrations werestudied. Kinetic properties in terms of affinity, maximum velocity, activity coefficient, and slope of reaction werecalculated through a specific computer program namely “Enzyme kinetics”. Changes in the velocity patterns of theinvestigated enzymes as affected by storage for three weeks at 20±2oC were also studied. On the basis of the obtainedresults, it was found that a dose of 2500 Gy could be recommended to reach higher inhibition level of the three testedenzymes, a pattern which improves the quality and extends shelf-life of mango fruit.
Alexandria Journal of Food Science and Technology
The Scientific Society of Food Industries, Alexandria, Egypt.
1687-3920
1
v.
1
no.
2004
23
41
https://ajfs.journals.ekb.eg/article_19589_8b3ec5c8e1c131546e006303bf1ace07.pdf
dx.doi.org/10.21608/ajfs.2004.19589
PEROXIDASE, PECTIN METHYLESTERASE AND SOME CONSTITUENTS OF PISTACHIO NUTS (Pistachia vera L.) TREATED WITH γ-RAYS
text
article
2004
eng
Pistachio nuts (Pistachia vera L.) variety Halapy, Family Anacardiaceae were obtained from “Aleppo City”, Arab Republic of Syria. The investigated pistachios were kept in perforated standard carton boxes of 45 × 30 × 12 cm dimensions, under a good ventilation conditions. They were irradiated at the National Centre for Radiation Re-search and Technology (NCRRT) at “Nasr City”, Cairo, Egypt. Irradiation treatments were applied using Cobalt – 60 facilities “Egypt Mega Gamma 1” model AECL 6500 and the dose levels were 250, 500, and 2000 Gy. The irradiated samples were stored at 20°C for 6 months through which the activities of peroxidase (POD/EC. 1.11.1.7) and pectin methylesterase (PME/EC 3.1.1.11) were followed. The kinetic parameters in terms of Km, Vmax., angle of activity, catalytic efficiency, slope of activity and inhibition levels were considered within a storage period of 6 months. Amino acids and fatty acids profiles of irradiated pistachio were also given. Experiments proved the preference of a dose 500 Gy for inhibiting both of the two tested enzymes in the investigated pistachios during the whole period of storage.
Alexandria Journal of Food Science and Technology
The Scientific Society of Food Industries, Alexandria, Egypt.
1687-3920
1
v.
1
no.
2004
42
58
https://ajfs.journals.ekb.eg/article_19590_d41d8cd98f00b204e9800998ecf8427e.pdf
dx.doi.org/10.21608/ajfs.2004.19590
CONTAMINANTS IN TERMS OF PESTICIDE RESIDUES IN SELECTED FISH SOURCES
text
article
2004
eng
The problem at hand is dealing with the assessment of selected fish species with respect to their content of pesticideresidues. The investigated fish include; Caranx, Red Mullet, Crabs, Clams, Sole of Qaroun, lake Sole of Bardawillagoon and Catfish.The results indicated the presence of 15 components of organochlorine pesticides, namely; α-benzene hexachloride(α-BHC), γ-benzene hexachloride + β-benzene hexachloride (γ-BHC + β-BHC), Heptachlor, Aldrin, Heptachorepoxide,γ-chlordane, α-chlordane, 1,1-dichloro-2,2-bis (P-chlorophenyl) ethylene (P,P-DDE), Dieldrine, Endrin,1,1-dichloro 2,2-bis (P-chlorophenyl) ethane (P,P-DDD), 1,1,1-trichloro-2,2-bis (P-chlorophenyl) ethane (P,P-DDT),Endosulfan sulfate, Methoxychlor and Endrin ketone.Concentrations of chlorinated hydrocarbons in tissues, serve as good indicators of environmental loads. The determinationof organochlorine residues became necessary since in high-polluted regions, the polychlorinated biphenyls(PCBs) are a point of discussion.With respect to fish samples (Sole) collected from Bardawil lagoon, the obtained results indicated that none ofthe identified pesticides were detected in it. Subsequently, it could be stated that Bardawil lagoon is the best source offish and is considered to be completely free from pollutants. On contrary Sole of Qaroun Lake contain six types ofpesticides and the lowest frequently detected one was 8.49 μg /Kg as Heptachlor while the highest concentration ofmethoxychlor was 1268.68 μg /Kg in the same sample.The residual concentration of the aforementioned pesticides varied within the tested fishes and Sole of Bardawillagoon proved to be completely free from any residual amounts of the investigated pesticides as indicated and provedby statistical analysis, through the principal component and factorial analysis.
Alexandria Journal of Food Science and Technology
The Scientific Society of Food Industries, Alexandria, Egypt.
1687-3920
1
v.
1
no.
2004
59
68
https://ajfs.journals.ekb.eg/article_19591_52f205732f0e52a98f04b7972d15c845.pdf
dx.doi.org/10.21608/ajfs.2004.19591
DEVELOPMENTS IN EGYPTIAN KASHKAVAL CHEESE: AN OVERVIEW ARTICLE
text
article
2004
eng
Egyptian Kashkaval cheese is produced in minor quantities in Egypt. It is rather similar to the typical Kashkavaltype cheese originated in Eastern Europe and Balkan Peninsula countries. This overview article deals with EgyptianKashkaval cheese manufacturing. The improvement of the manufacture process, chemical composition, microbiology,and ripening of Egyptian Kashkaval cheese are intensively reviewed.
Alexandria Journal of Food Science and Technology
The Scientific Society of Food Industries, Alexandria, Egypt.
1687-3920
1
v.
1
no.
2004
69
73
https://ajfs.journals.ekb.eg/article_19592_669bacc12ecd9ad3ee78b2faba3ddb4d.pdf
dx.doi.org/10.21608/ajfs.2004.19592