REDUCTION OF ACRYLAMIDE FORMATION IN POTATO CHIPS BY AQUEOUS EXTRACT OF ROSELLE

Acrylamide (AA) is an industrial chemical formed in some foods; particularly starchy foods, during heating process such as frying, baking and roasting. AA is proven to be carcinogenic in animals and a probable human carcinogen formed in foods by the reaction of free amino acid with reducing sugars as part of the Maillard reaction during heating under high temperature and low moisture conditions. Therefore, the aim of this study was to use aqueous extract of roselle as a natural source of antioxidants to reduce AA formed in potato chips. The results showed that the percentages of reduction of AA were 10.1% and 12.92% in samples that were treated with 1% of aqueous extract of roselle and soaked at 10 and 20 mins respectively. There was observed increase in AA reduction by it was 75.41% and 82.46% after soaking  at 10 and 20 mins respectively with 5% extract. Conclusively, the aqueous extract of roselle is effective in reducing the AA formed in potato chips due as it contains of antioxidant compounds. Keywords: acrylamide (AA), potato, roselle, soaking and reduction Â

CLOVE (SYZYGIUM AROMATICUM L.) AND THEIR EFFECT ON THE FORMATION OF HETEROCYCLIC AMINES

Heterocyclic amines (HCAs) are a group of toxic chemicals, play an important role in the etiology of human cancer which formed at high temperature during cooking meat and fish. Antioxidants have proved to inhibit the formation of HCAs due to different mechanisms scavenging free radical, inhibits oxidative enzymes like cyochrome P450 and chelates metal ions like Fe+2 as well as protecting lipids against oxidation. Clove has potent antioxidants and antimicrobial activities standing out among the other species. Therefore current study done to show efficiency of 0.5% clove at preventing the formation of two most common HCAs: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through seasoning of beef steaks before grilling and estimate antioxidant status of animals fed on the experimental diets. HCAs levels in food and blood samples were analyzed by HPLC.  The results showed that content of MeIQx and PhIP in grilled beef meat steak were 23.0 ±2.87 and 15.0±2.14 ng/g, respectively. While the content of MeIQx and PhIP in seasoning grilled steak were degraded to 1.9 ± 0.31 and 1.6 ± 0.23 ng/g, respectively. On the other hand the results showed that the percentages of reduction of MeIQx and PhIP were 91.7 and 89.3% in seasoning grilled steak, respectively comparing with un- seasoning grilled steak. The levels of tested HCAs also showed significant differences among rat groups fed on the experimental diets. The highest MeIQx and PhIP concentrate in serum rats group fed on untreated grilled meat diet (positive control) were11.1±1.85  and 8.77±8.77 ng/ml, respectively, while seasoning with 0.5% clove before grilling led to decrease in MeIQx and PhIP concentrate to 0.82±0.16 and 0.51±0.09  ng/ml respectively with decreasing percent reached  92.6 % and   94.2%  respectively. In addition, the results revealed that fed rats on un-seasoning grilled steak (positive control) caused high significant increased in lipid peroxide (malonaldhyde, MDA) accompanied by significant decreased in the levels of reduced glutathione content (GSH)  and activities of antioxidant defense enzymes glutathione peroxidase (GHPx) and catalase (CAT),  compared with basal diet group (negative control). However, clove treatment group lowered the level of lipid peroxidation and enhanced the antioxidant status of animals. Seasoning beef meat steaks before grilling with potent antioxidant clove species inhibit HCAs formation and their potential hazards to human health. This might be due to the powerful antioxidant activity of clove as strong hydrogen donating, metal chelating and scavenging of free radicals, hydrogen peroxide and superoxide. Keywords: Heterocyclic amines (HCAs), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) , 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), clove, grilled beef meat, antioxidant plants, lipid peroxide, antioxidant defense enzymes

Amelioration of The Dielectric Properties of Ceramic Insulators Using Nano-alumina

Outdoor HV porcelain insulators face various environmental stresses that cause their degradation. Consequently, amelioration of their insulating properties becomes a target of recent researches to survive higher voltage levels. Investigating the impact of the addition of 0, 5, 10, and 15 wt. % nano- alumina (NA) on the dielectric and physical characteristics of porcelain materials at elevated sintering temperatures is the aim of this study. Porcelain specimens were synthesized from kaolin, feldspar, and quartz as available low-cost raw materials. The specimens were sintered at 1100, 1200, 1300, and 1400°C for 2 h. For some specimens, the microstructure and phases formed were identified using scanning electron microscopy and X-ray diffraction techniques. The changes that occur upon heating (include melting, phase transition, sublimation, and decomposition) were identified by Differential Thermogravimetric Analysis. The dielectric strength, relative permittivity, and loss tangent of different samples were measured at a large scale of frequencies. Breakdown strength values of different samples were verified by applying the Finite Element Method. The best electrical and physical properties were achieved at 1300ºC. At this temperature the porcelain sample containing 5 wt. % NA presented optimum physical characteristics as well as good insulating properties assent the feasibility of producing electro-technical porcelai

PROTECTIVE EFFECT OF AQUEOUS EXTRACT POMEGRANATE PEEL AGAINST STERIGMATOCYSTIN TOXICITY IN RAT

Introduction and Aim: Sterigmatocystin (Stg) a mycotoxin with mutagenic and carcinogenic properties is commonly found as the contaminant in grains and animal feeds. Pomegranate peel is a rich source of antioxidants, flavonoids and other phenolic compounds. So the aim of the current study was to evaluate the protective effects of aqueous extract of red Pomegranate peel against Stg toxicity in liver, kidney, intestine and lung as well as final body weight using male rats. Methods: Forty eight Sprague-Dawley male rats were divided into six groups (8rats/group) including the control group that fed on a standard diet and water without any treatment, group 2 fed on standard diet plus aqueous extract of RPP (250 mg/rat/day), group 3 fed on standard diet plus aqueous extract of RPP (500 mg/ rat/day), group 4 fed on a standard diet and orally Stg. dissolved at a dose (18µg/rat/day), group 5 fed on a standard diet and Stg  plus aqueous extract of RPP (250mg/day) and group 6 fed on a standard diet and Stg. plus aqueous extract of RPP (500mg/day). At the end of the experimental period, blood samples were collected for serum biochemical analyses. After collecting the blood samples all animals were scarified and dissected samples of liver, kidney, intestine and lung were collected for histological examination. Results: The total phenols and total flavonoids, compounds in aqueous extract of RPP were 1.38 mg/ml and 680.28 mg/ml, respectively. However, the antioxidant activity amounted to 68.0% in the determination of radical DPPH scavenging activity. On the other hand, results indicated that rat orally Stg plus aqueous extract of RPP with low dose and high doses showed a significant improvement in final body weight compared with group administrated of Stg alone. While, the effect of aqueous extract of RPP on kidney and liver function of rats, the results indicated that the rat orally Stg alone caused significant increased in urea, creatinine and uric acid compared with the control group. The aqueous extract of RPP alone at the two tested doses did not induce any significant changes in the biochemical parameters or the histological picture. The combined treatment showed significant improvements in all tested parameters and histological pictures in the liver tissues. Moreover, this improvement was more pronounced in the group received the high dose of aqueous extract of RPP. Conclusion: From results it can be concluded that u the aqueous extract of RPP has a potent antioxidant activity and a protective effect against Stg toxicity and this protection was dose dependent. Keywords: Sterigmatocystin, Red pomegranate peels (RPP), aqueous extract, liver and kidney

Genetic Engineering of Schizosaccharomyces pombe to Produce Bacterial Polyhydroxyalkanotes

A commercial use of microbial produced products, like polyhydroxyalkanotes (PHAs), in the sense of an environmental precaution appears meaningful and necessary. In order to more economically produce microbial products, this investigation was focused on suitable producers, like the yeast Schizosaccharomyces pombe. Since it is not capable of the PHA synthesis, easily cultured and they must be modified genetically. Therefore, the genes of the phb biosynthesis pathway of Ralstonia eutropha [beta-ketothiolase (phbARe); acetoacetyl-CoA reductase (phbBRe); as well as phb synthase (phbCRe), located onto the plasmid pBHR68 were cloned into the cohesive ended pYIplac128 integrated vector that transformed into the chromosome of the yeast Schizosaccharomyces pombe strain Q01. Under the optimized cultivation conditions, the transgenic yeast S. pombe strain Q01/phb was able to produce phb and accumulated up to 9.018 % phb. The presence of heterologous DNA in the transgenic yeast was examined by means of Western blot analysis. In addition, both PHA synthase activity and kinetics were determined. The UV/Vis, 1H and 13C NMR spectral analysis have confirmed that the polymer produced by the yeast S. pombe strain Q01/phb is a pure homopolymer of 3-hydroxybutyric acid

Efficiency of Selected Lactic Acid Bacteria Isolated from some Dairy Products on Aflatoxin B1 and Ochratoxin A

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are two of the most important of mycotoxins associated with tropical and subtropical climate as in Egypt. Therefore, this study aimed to isolated lactic acid bacteria (LAB) and Bifidobacteria from some local dairy products from Egypt and using some strains to reduce/or remove AFB1 and OTA toxins. Fifty samples, of milk and dairy products, including ten samples each, of Kareish, Damietta cheese (soft type), buffalo’s milk, yoghurt (zabady), and naturally acidified milk (Rayeb)were screened for their load of Lactobacilli, Lactococci and Bifidobacteria, using MRS agar, M17 agar and (MRS-Cys) agar, respectively. The obtained data indicated that 38, 31 and 22 isolates belonged to Lactobacillus, Lactococcus and genus Bifidobacterium, respectively. Fourteen strains isolated from LAB and Bifidobacterium were tested on AFB1 and OTA in PBs contaminated by10 ppb with three times incubation periods (6, 12 and 36 hours) at 37°C. The results indicated that all tested strains were able to reduce AFB1 at different rates ranging between 12.1 to 65.4% after incubation for 6 h. These rates increased to 78.8% and 89.9% after incubation at 37°C for 12 and 36h, respectively. The same results were with OTA, where percentages of reduction ranging from 81.4 to 80.4% were obtained when incubation with LAB cells was done at 37°C and prolonged to 36 h. According to the results, the percentage of reduction increased with the increasing time for each strain

Statistical Inference of Modified Frechet–Exponential Distribution with Applications to Real-Life Data

This paper introduces a new lifetime model, referred to as modified Frechet–Exponential distribution (MFED), is developed on the basis of the modified Frechet method. Numerous statistical properties of the suggested model are derived and discussed including ordinary and incomplete moments, quantile, mode, the moment generating functions, reliability and order statistics. The observed Fisher’s information matrix is provided, and the model parameters are estimated using the maximum likelihood technique. The suggested model is very adaptable and has the capacity to simulate datasets with monotonic and nonmonotonic failure rates. The proposed model is applied on three real datasets for checking its performance in comparison with available well-known models. The motivation of this work that the suggested model has shown good performance in comparison with the available versions of the Exponential distribution used in the literature

النواة اللامتغيرة بالإزاحة وا لمعممة ذو متغيرات لا نهائية البعد

In the theory of spectral analysis of positive-definite j<.ernels, there exist well-developed methods based on the ideas of Krein connected with the construction of a Hilbert space by means of a kernel [ 1, 11]. In the main, our formulation deals with translation-invariant positive-definite generalized kernels.وفي هذه الورقة تدرس نواة ذات متغيرات لا نهائية البعد في فراغات نووية وتحقق الخواص اللاتغير بالنسبة للازاحة وفي الوقت نفسه معممة وموجبة ويوجد الشرط الكافي للحصول على تمثيل تكاملي لها