Fakhriya Taha - Academia.edu (original) (raw)

Papers by Fakhriya Taha

Dynamics of limnological features of two man-made lakes in relation to fish production

Production of functional protein hydrolysates from Egyptian breeds of soybean and lupin seeds

The goal of the present study was to improve the extraction yield of phenolic compounds from cott... more The goal of the present study was to improve the extraction yield of phenolic compounds from cottonseed meal. First the phenolic compounds (PC) were extracted with several solvents namely 80% acetone, ethanol, methanol and isopropanol from azeotropic extracted cottonseed meal (very low in gossypol). Acetone 80% extracted highest amount of phenolic compounds 2.19 mg /100g meal. This was followed by investigating the effect of different acetone concentrations on the yield of PC. 40% acetone proved to be our choice solvent extracting 3.51 mg /100g meal. An attempt was made to increase PC extractability by enzymatically hydrolyzing the meal prior to extraction with acetone. The enzymes used were Macerozyme (a mixture of cellulase, hemicellulase, and pectinase), Protease and a mixture of Macrozyme + Protease (1:1). The PC extracted with 40% acetone after treating meal with enzymes were 5.54, 5.28, 6.06 mg PC /100 g meal, respectively. The antioxidant activity (AOA) of all investigated ac...

2 Abstract: The goal of the present work was to prepare bioactive hydrolysates and peptides from ... more 2 Abstract: The goal of the present work was to prepare bioactive hydrolysates and peptides from sunflower protein isolate (free of chlorogenic acid). To reach this goal the protein isolate was hydrolysed using several enzymes and enzyme mixtures, including: pepsin, trypsin, chymotrypsin and a mixture of the three enzymes (mixture I); also alcalase, flavourzyme and a mixture of the two enzymes (mixture II). These enzymes were used at 2% concentration and at pH and temperature reported by the manufacturer. During hydrolysis, at certain time intervals, 30, 60 and 120 min. aliquots were withdrawn from the reaction mixture to give peptide fractions and at the end of 3h give hydrolysate. The peptic fractions exhibited prooxidant activities at 30, 60 and 120 min. Other hydrolysis products revealed moderate antioxidant activity (AOA). Tryptic peptide at 60 min. hydrolysis showed the highest AOA (94.32%), followed by 61.21% for the hydrolysate at 180 min. and very low AOA values were exhibi...

Peanut hull and skin are waste products of the food industry. Adding value to these products was ... more Peanut hull and skin are waste products of the food industry. Adding value to these products was the aim of this work. This goal was achieved by studying the phenolic content of the skin, hull and defatted flour of both roasted and unroasted peanuts. The antioxidant activity of the phenolic extracts was determined. The roasted peanut skin extract was then chosen and tested for its power of inhibition of flaxseed oil oxidation. The anticarcinogenic activity of the roasted peanut skin extract on different cell line carcinomas was examined. Both the extractable polyphenols (EPP) and the non extractable polyphenols (NEPP) were determined in the examined parts of the peanuts. Results revealed that NEPP was always higher than EPP and that highest phenolic content was found to be present in the skin. Roasted hull, unroasted hull, roasted skin, unroasted skin, roasted defatted flour, and unroasted defatted flour contained EPP 4.33, 3.38, 41.5, 56.2, 7.33 and 7.23 mg/g, respectively; and con...

Guava seeds waste not yet used for any beneficial purpose, while the proximate composition of def... more Guava seeds waste not yet used for any beneficial purpose, while the proximate composition of defatted guava seeds meal contain 11.52% protein, 0.54% oil and 79.62% crude fiber. Extraction of total phenolic compounds (TP) from guava seed meal was optimized using ethanol, methanol, acetone or iso-propanol, at different meal:solvent (M:S) ratios. Extraction TP from meal by using 80% acetone was higher than those extracted by other solvents, where TP reached to 91.05 mg TP/100g meal at 1:20 (M:S ratio). Two methods were carried out to determine antioxidant activity of guava seeds meal, the first was Free Radical Scavenging Activity (FRSA) using Diphenyl picrylhydrazyl (DPPH). All extracts at 1:15 and 1:20 M:S ratios exhibited greater scavenging activity than those extracted at 1:10 M:S ratio. The same trend was also observed by using the second method of β- carotene bleaching assay, where the ratios of 1:15 and 1:20 M:S gave extracts characterized with its higher antioxidant activity (...

World applied sciences journal, 2014

Proteins and phenolic compounds are essential for the maintenance of good health. Peanuts are ric... more Proteins and phenolic compounds are essential for the maintenance of good health. Peanuts are rich sources of both proteins and phenolic compounds. Unfortunately several factors cause the binding of phenolic compounds to proteins, thus forming complexes which affect the availability of proteins and the phenolic compounds rendering them unavailable for the human body. The aim of this work is to study the solubility of both the proteins and the phenolic compounds at a wide range of pH in order to determine the pH at which the binding takes place, also the optimum pH for phenolic extraction. In this study the focus will be on the effect of pH on the solubility of proteins, amino acids, soluble and insoluble phenolic compounds present in peanut meal (PM). The results revealed the least solubility of the PM protein is at its isoelectric point between pH 4-5 where only 6.3-5.43% of the protein is solubilized and highest amount of protein remains precipitated 50.7-51.57%, respectively. Goi...

To our Knowledge no work up to the present moment has been reported in the literature on the phen... more To our Knowledge no work up to the present moment has been reported in the literature on the phenolic extracts of jojoba hull. Thus the aim of the present work was to add value to this waste product by investigating the potentiality of different jojoba hull extracts as neutraceuticals. The efficiency of methanol, ethanol, acetone, isopropanol and ethyl acetate at concentrations of 100, 80, 70, 60, and 50% to extract phenolic compounds were investigated. Results revealed that 60% acetone extracted optimum phenolic compounds (13.9 mg/g hulls). Extraction at room temperature yielded more phenolic compounds than extraction at 45ᴼC. On the other hand, 70% methanol extract of jojoba hulls exhibited the highest AOA (95.33%). The 70% methanol extract was added to a butter cake at 100 and 200 ppm as well as 200 ppm BHT. The cake was stored at room temperature and the butter analyzed every week for acid, iodine and peroxide values. Results proved that the addition of methanol extract delayed ...

Asian Journal of Scientific Research

Journal of Agricultural Chemistry and Biotechnology

Asian Journal of Scientific Research, Feb 1, 2019

Bulletin of the National Research Centre

Bulletin of the National Research Centre

Background There is a worldwide demand for phenolic compounds (PC) because they exhibit several b... more Background There is a worldwide demand for phenolic compounds (PC) because they exhibit several biological activities. The present investigation deals with a comprehensive study on the biological activities of phenolic compounds extracted from flaxseed meal (FM) with the aid of ultrasonic waves. Results The antioxidant activity of the PC extract of FM is considerably high when measuring it by the three methods (the β-carotene coupled oxidation method, the DPPH free radical scavenging activity method, and measuring the reducing antioxidant power). The toxicity test revealed that the PC extract was nontoxic on normal retina cell line. Also, it has no anticoagulating activity. Evaluation of antimicrobial activity showed that it is effective towards four strains only from seven. FM phenolic extract has been evaluated as chemo-preventive agents by testing the product for any cytotoxic activity against human tumor cell lines. The highest inhibitory effect was achieved on cell lines of col...

American Journal of Food Technology, 2017

American Journal of Food Technology, 2017

American Journal of Food Technology, 2016

Egyptian Journal of Food Science, 2002

American Journal of Food Technology, 2016

Grasas y Aceites

Hydrolyzing soybean, sesame, and ricebran meals with papain and bromelain enzymes under previousl... more Hydrolyzing soybean, sesame, and ricebran meals with papain and bromelain enzymes under previously determined optimum conditions was accomplished. Aliquots were withdrawn from the bulk hydrolysates at different time intervals to determine the rate of enzymatic degradation, as well as the degree of hydrolysis of the hydrolysates at different time, intervals. Twelve hydrolysates were then chosen with low and high degree of hydrolysis. They also represented hydrolysates from the three substrates hydrolysed with the two enzymes used. Some functional properties of the twelve hydrolysates were examined and then an attempt to correlate the functional properties with the degree of hydrolysis was done. The investigated functional properties included: wettability, dispersibility, flowability, bulk density, nitrogen solubility index, water absorption capacity, oil holding capacity, gelation, thermostability, emulsifying capacity and foam stability. Results showed a direct relation between incr...

Dynamics of limnological features of two man-made lakes in relation to fish production

Production of functional protein hydrolysates from Egyptian breeds of soybean and lupin seeds

The goal of the present study was to improve the extraction yield of phenolic compounds from cott... more The goal of the present study was to improve the extraction yield of phenolic compounds from cottonseed meal. First the phenolic compounds (PC) were extracted with several solvents namely 80% acetone, ethanol, methanol and isopropanol from azeotropic extracted cottonseed meal (very low in gossypol). Acetone 80% extracted highest amount of phenolic compounds 2.19 mg /100g meal. This was followed by investigating the effect of different acetone concentrations on the yield of PC. 40% acetone proved to be our choice solvent extracting 3.51 mg /100g meal. An attempt was made to increase PC extractability by enzymatically hydrolyzing the meal prior to extraction with acetone. The enzymes used were Macerozyme (a mixture of cellulase, hemicellulase, and pectinase), Protease and a mixture of Macrozyme + Protease (1:1). The PC extracted with 40% acetone after treating meal with enzymes were 5.54, 5.28, 6.06 mg PC /100 g meal, respectively. The antioxidant activity (AOA) of all investigated ac...

2 Abstract: The goal of the present work was to prepare bioactive hydrolysates and peptides from ... more 2 Abstract: The goal of the present work was to prepare bioactive hydrolysates and peptides from sunflower protein isolate (free of chlorogenic acid). To reach this goal the protein isolate was hydrolysed using several enzymes and enzyme mixtures, including: pepsin, trypsin, chymotrypsin and a mixture of the three enzymes (mixture I); also alcalase, flavourzyme and a mixture of the two enzymes (mixture II). These enzymes were used at 2% concentration and at pH and temperature reported by the manufacturer. During hydrolysis, at certain time intervals, 30, 60 and 120 min. aliquots were withdrawn from the reaction mixture to give peptide fractions and at the end of 3h give hydrolysate. The peptic fractions exhibited prooxidant activities at 30, 60 and 120 min. Other hydrolysis products revealed moderate antioxidant activity (AOA). Tryptic peptide at 60 min. hydrolysis showed the highest AOA (94.32%), followed by 61.21% for the hydrolysate at 180 min. and very low AOA values were exhibi...

Peanut hull and skin are waste products of the food industry. Adding value to these products was ... more Peanut hull and skin are waste products of the food industry. Adding value to these products was the aim of this work. This goal was achieved by studying the phenolic content of the skin, hull and defatted flour of both roasted and unroasted peanuts. The antioxidant activity of the phenolic extracts was determined. The roasted peanut skin extract was then chosen and tested for its power of inhibition of flaxseed oil oxidation. The anticarcinogenic activity of the roasted peanut skin extract on different cell line carcinomas was examined. Both the extractable polyphenols (EPP) and the non extractable polyphenols (NEPP) were determined in the examined parts of the peanuts. Results revealed that NEPP was always higher than EPP and that highest phenolic content was found to be present in the skin. Roasted hull, unroasted hull, roasted skin, unroasted skin, roasted defatted flour, and unroasted defatted flour contained EPP 4.33, 3.38, 41.5, 56.2, 7.33 and 7.23 mg/g, respectively; and con...

Guava seeds waste not yet used for any beneficial purpose, while the proximate composition of def... more Guava seeds waste not yet used for any beneficial purpose, while the proximate composition of defatted guava seeds meal contain 11.52% protein, 0.54% oil and 79.62% crude fiber. Extraction of total phenolic compounds (TP) from guava seed meal was optimized using ethanol, methanol, acetone or iso-propanol, at different meal:solvent (M:S) ratios. Extraction TP from meal by using 80% acetone was higher than those extracted by other solvents, where TP reached to 91.05 mg TP/100g meal at 1:20 (M:S ratio). Two methods were carried out to determine antioxidant activity of guava seeds meal, the first was Free Radical Scavenging Activity (FRSA) using Diphenyl picrylhydrazyl (DPPH). All extracts at 1:15 and 1:20 M:S ratios exhibited greater scavenging activity than those extracted at 1:10 M:S ratio. The same trend was also observed by using the second method of β- carotene bleaching assay, where the ratios of 1:15 and 1:20 M:S gave extracts characterized with its higher antioxidant activity (...

World applied sciences journal, 2014

Proteins and phenolic compounds are essential for the maintenance of good health. Peanuts are ric... more Proteins and phenolic compounds are essential for the maintenance of good health. Peanuts are rich sources of both proteins and phenolic compounds. Unfortunately several factors cause the binding of phenolic compounds to proteins, thus forming complexes which affect the availability of proteins and the phenolic compounds rendering them unavailable for the human body. The aim of this work is to study the solubility of both the proteins and the phenolic compounds at a wide range of pH in order to determine the pH at which the binding takes place, also the optimum pH for phenolic extraction. In this study the focus will be on the effect of pH on the solubility of proteins, amino acids, soluble and insoluble phenolic compounds present in peanut meal (PM). The results revealed the least solubility of the PM protein is at its isoelectric point between pH 4-5 where only 6.3-5.43% of the protein is solubilized and highest amount of protein remains precipitated 50.7-51.57%, respectively. Goi...

To our Knowledge no work up to the present moment has been reported in the literature on the phen... more To our Knowledge no work up to the present moment has been reported in the literature on the phenolic extracts of jojoba hull. Thus the aim of the present work was to add value to this waste product by investigating the potentiality of different jojoba hull extracts as neutraceuticals. The efficiency of methanol, ethanol, acetone, isopropanol and ethyl acetate at concentrations of 100, 80, 70, 60, and 50% to extract phenolic compounds were investigated. Results revealed that 60% acetone extracted optimum phenolic compounds (13.9 mg/g hulls). Extraction at room temperature yielded more phenolic compounds than extraction at 45ᴼC. On the other hand, 70% methanol extract of jojoba hulls exhibited the highest AOA (95.33%). The 70% methanol extract was added to a butter cake at 100 and 200 ppm as well as 200 ppm BHT. The cake was stored at room temperature and the butter analyzed every week for acid, iodine and peroxide values. Results proved that the addition of methanol extract delayed ...

Asian Journal of Scientific Research

Journal of Agricultural Chemistry and Biotechnology

Asian Journal of Scientific Research, Feb 1, 2019

Bulletin of the National Research Centre

Bulletin of the National Research Centre

Background There is a worldwide demand for phenolic compounds (PC) because they exhibit several b... more Background There is a worldwide demand for phenolic compounds (PC) because they exhibit several biological activities. The present investigation deals with a comprehensive study on the biological activities of phenolic compounds extracted from flaxseed meal (FM) with the aid of ultrasonic waves. Results The antioxidant activity of the PC extract of FM is considerably high when measuring it by the three methods (the β-carotene coupled oxidation method, the DPPH free radical scavenging activity method, and measuring the reducing antioxidant power). The toxicity test revealed that the PC extract was nontoxic on normal retina cell line. Also, it has no anticoagulating activity. Evaluation of antimicrobial activity showed that it is effective towards four strains only from seven. FM phenolic extract has been evaluated as chemo-preventive agents by testing the product for any cytotoxic activity against human tumor cell lines. The highest inhibitory effect was achieved on cell lines of col...

American Journal of Food Technology, 2017

American Journal of Food Technology, 2017

American Journal of Food Technology, 2016

Egyptian Journal of Food Science, 2002

American Journal of Food Technology, 2016

Grasas y Aceites

Hydrolyzing soybean, sesame, and ricebran meals with papain and bromelain enzymes under previousl... more Hydrolyzing soybean, sesame, and ricebran meals with papain and bromelain enzymes under previously determined optimum conditions was accomplished. Aliquots were withdrawn from the bulk hydrolysates at different time intervals to determine the rate of enzymatic degradation, as well as the degree of hydrolysis of the hydrolysates at different time, intervals. Twelve hydrolysates were then chosen with low and high degree of hydrolysis. They also represented hydrolysates from the three substrates hydrolysed with the two enzymes used. Some functional properties of the twelve hydrolysates were examined and then an attempt to correlate the functional properties with the degree of hydrolysis was done. The investigated functional properties included: wettability, dispersibility, flowability, bulk density, nitrogen solubility index, water absorption capacity, oil holding capacity, gelation, thermostability, emulsifying capacity and foam stability. Results showed a direct relation between incr...