Mervat Foda - Academia.edu (original) (raw)

Papers by Mervat Foda

Food Chemistry, 1998

Two-level fractional factorial experiments were designed to study effects of enzyme (0.05 and 0.1... more Two-level fractional factorial experiments were designed to study effects of enzyme (0.05 and 0.1%) and initial lactose concentrations (L,: 14 and 23%), pH (5.0 and 7.0) and temperature (35 and 45°C) on enzymatic formation of oligosaccharides (OS) from whey UF-permeate in a batch reactor. B-D-galactosidase from A,ypergillus oryzae (A), Kluyveromyces lactis (B) and K. fragilis (C) were compared. Hydrolysis with B and C gave comparable yields which were higher than that from A at identical conditions. L, did not influence reaction time, but concentration of OS significantly increased by increasing L, for all enzymes. Increasing L, reduced the yield after hydrolysis with A and B, but improved the yield for C. L, had negligible effect on degree of hydrolysis (DH) for A and C. However, increasing L, significantly lowered DH for B. Increasing enzyme concentration significantly reduced reaction time for A, but it had no effect on that for B and C. DH significantly decreased after increasing concentration of A. Consequently, OS and yield were reduced. Applying B and C at higher concentration improved DH, OS and yield. Increasing temperature or pH reduced DH, OS and yield for A, but increased the responses for B and C. 0 1998 Elsevier Science Ltd. All rights reserved

International Journal of Dairy Science, 2008

Flaxseed contains high level of a-linolenic acid (omega- 3 fatty acid) which essential for humans... more Flaxseed contains high level of a-linolenic acid (omega- 3 fatty acid) which essential for humans and necessary to add to milk products to increase their health effects. To evaluate the acceptability of supplementing flaxseed to dairy products,fourteen lactating buffaloes were divided into two experimental groups. The first group used as control animals was fed ration without flaxseed (C) and the treated animals was fed rations supplemented with 433 g flaxseed/head/day (T1). Flaxseed directly added to part of the control milk to design the third milk sample (T2). All samples were used for stirred yoghurt production and their chemical composition, fatty acid profile, sensory evaluation and microbiological contents were evaluated. Flaxseed supplementation to ration increased fat content of donated milk. The results showed that supplementing control milk (T2) with ground flaxseed significantly increased the total concentrations of CLA and omega-3 fatty acids.

International Journal of Dairy Science, 2008

Process Biochemistry, 2000

Whey permeate (containing 14, 20 or 23% lactose) was used in the continuous production of oligosa... more Whey permeate (containing 14, 20 or 23% lactose) was used in the continuous production of oligosaccharides (OS) by hydrolysis from Maxilact 2000 L (Kluy6eromyces lactis b-D-galacosidase). Two types of membrane reactors were used: a laboratory scale, Amicon stirred cell, using a flat membrane (41.8 cm 2 ) and a pilot plant-scale membrane reactor using a Romicon hollow fiber cartridge (0.5 m 2 ). Batch experiments were run to determine the optimal reaction time (when the largest amount of OS are produced). This optimal reaction time was then used in the experiments in continuous mode as the mean residence time of the whey permeate in the reactor, which could be controlled by adjusting the rate of permeate and or the volume of the substrate in the system.

Background: Goat milk shows therapeutic virtues for individuals with certain dietetic problems, t... more Background: Goat milk shows therapeutic virtues for individuals with certain dietetic problems, thus physicians have traditionally recommended goats milk for infants, elders and other allergic. Also, galactooligosaccharides are readily fermented in the infant's colon where they selectively stimulate the growth of bifidobacteria and suppress the growth of pathogenic bacteria. Objective: Evaluation of supplementing goat's rations with different forms of Amino Acids on the milk production and its contents, then evaluate the consumer's acceptability. Materials and Methods: To maximize goat milk benefits different concentration of β-D-galactosidase were used to form galactooligosaccharides after supplementing the ration with lysine and methionine in protected and unprotected forms. Milk acceptability and its chemical composition were evaluated compared to control sample. Results and Discussion: Milk production, milk fat, lactose, total protein and milk yield were increased by adding the amino acids in different forms. Organoleptic evaluation indicated significant increase in taste and overall acceptability of goat milk containing higher concentration of galactooligosaccharides.

Journal of Pediatric Gastroenterology and Nutrition, 2004

The Oketani method is a program of breast massage and clinical counseling developed by the midwif... more The Oketani method is a program of breast massage and clinical counseling developed by the midwife Satomi Oketani. The purpose of this study is to examine the effects of the method on the quality of breast milk by determining the chemical composition of the milk before and after massage. Methods: Milk samples were obtained immediately before and after massage from healthy, exclusively breast-feeding Japanese mothers at two different periods of lactation one <3 months the other >3 months after parturition. Lipids, whey protein, casein, lactose, ash, and total solids in milk were measured in milk samples.The gross energy content of milk was estimated. Results: Breast massage significantly increased lipids in the late lactating period but not in the early lactating period. In the early lactating period casein was increased by breast massage but was not significantly affected in the late lactating period. Breast massage caused a significant increase in total solids from the first day to 11 months post partum. The gross energy in the late lactating period was significantly increased by breast massage but not in the early lactating period. Lactose was not significantly changed by breast massage. Conclusions: Breast massage improves the quality of human milk by significantly increasing total solids, lipids, and casein concentration and gross energy. The milk of mothers treated by Oketani breast massage may improve the growth and development of infants. JPGN 38: [484][485][486][487] 2004. Key Words: Breast massage-Chemical composition-Human milk-Oketani method.

International Journal of Food Microbiology, 1996

The effect of pH value, methanol, and salt concentration on the production of citric acid from ch... more The effect of pH value, methanol, and salt concentration on the production of citric acid from cheese whey by two strains of Aspergillus niger, i.e. CAIM Ill and CAIM 167, was investigated. Lactose concentration, utilized lactose, citric acid concentration, conversion coefficient of lactose to citric acid, and mycelial dry weight were measured during the fermentation process. The maximum citric acid concentration (1.06 and 0.82 g/l), and conversion coefficient (5.58 and 7.45%) were obtained at pH 3.5 after 9 days of fermentation for A. niger CAIM 111 and A. niger CAIM 167, respectively.

Food Chemistry, 2002

Alkaline-substituted (Na + , K + ) sepiolites were used as catalysts for the formation of lactulo... more Alkaline-substituted (Na + , K + ) sepiolites were used as catalysts for the formation of lactulose in milk permeate. Besides lactose and lactulose, other carbohydrates, such as galactose and epilactose, produced in side reactions, were determined. The effect of different washing cycles of sepiolite on the isomerisation of lactose and the exchange of cations with the permeate were also investigated. In general, the activity of the sodium sepiolite was higher than that of potassium form. Twenty per cent of lactulose formation (%1000 mg/100 ml), with respect to the initial lactose, was obtained after 150 min of reaction, using sodium sepiolite washed during 10 cycles. Under these conditions, 25% of lactose degradation was detected, whereas small amounts of epilactose and galactose were formed. The exchange of Na + between sepiolite and permeate decreased considerably with the number of washing cycles. The present work shows an appropriate method for obtaining lactulose in milk permeate with acceptable yields and without complicated purification steps. #

International Journal of Dairy Science, 2009

Food Chemistry, 1998

Two-level fractional factorial experiments were designed to study effects of enzyme (0.05 and 0.1... more Two-level fractional factorial experiments were designed to study effects of enzyme (0.05 and 0.1%) and initial lactose concentrations (L,: 14 and 23%), pH (5.0 and 7.0) and temperature (35 and 45°C) on enzymatic formation of oligosaccharides (OS) from whey UF-permeate in a batch reactor. B-D-galactosidase from A,ypergillus oryzae (A), Kluyveromyces lactis (B) and K. fragilis (C) were compared. Hydrolysis with B and C gave comparable yields which were higher than that from A at identical conditions. L, did not influence reaction time, but concentration of OS significantly increased by increasing L, for all enzymes. Increasing L, reduced the yield after hydrolysis with A and B, but improved the yield for C. L, had negligible effect on degree of hydrolysis (DH) for A and C. However, increasing L, significantly lowered DH for B. Increasing enzyme concentration significantly reduced reaction time for A, but it had no effect on that for B and C. DH significantly decreased after increasing concentration of A. Consequently, OS and yield were reduced. Applying B and C at higher concentration improved DH, OS and yield. Increasing temperature or pH reduced DH, OS and yield for A, but increased the responses for B and C. 0 1998 Elsevier Science Ltd. All rights reserved

International Journal of Dairy Science, 2008

Flaxseed contains high level of a-linolenic acid (omega- 3 fatty acid) which essential for humans... more Flaxseed contains high level of a-linolenic acid (omega- 3 fatty acid) which essential for humans and necessary to add to milk products to increase their health effects. To evaluate the acceptability of supplementing flaxseed to dairy products,fourteen lactating buffaloes were divided into two experimental groups. The first group used as control animals was fed ration without flaxseed (C) and the treated animals was fed rations supplemented with 433 g flaxseed/head/day (T1). Flaxseed directly added to part of the control milk to design the third milk sample (T2). All samples were used for stirred yoghurt production and their chemical composition, fatty acid profile, sensory evaluation and microbiological contents were evaluated. Flaxseed supplementation to ration increased fat content of donated milk. The results showed that supplementing control milk (T2) with ground flaxseed significantly increased the total concentrations of CLA and omega-3 fatty acids.

International Journal of Dairy Science, 2008

Process Biochemistry, 2000

Whey permeate (containing 14, 20 or 23% lactose) was used in the continuous production of oligosa... more Whey permeate (containing 14, 20 or 23% lactose) was used in the continuous production of oligosaccharides (OS) by hydrolysis from Maxilact 2000 L (Kluy6eromyces lactis b-D-galacosidase). Two types of membrane reactors were used: a laboratory scale, Amicon stirred cell, using a flat membrane (41.8 cm 2 ) and a pilot plant-scale membrane reactor using a Romicon hollow fiber cartridge (0.5 m 2 ). Batch experiments were run to determine the optimal reaction time (when the largest amount of OS are produced). This optimal reaction time was then used in the experiments in continuous mode as the mean residence time of the whey permeate in the reactor, which could be controlled by adjusting the rate of permeate and or the volume of the substrate in the system.

Background: Goat milk shows therapeutic virtues for individuals with certain dietetic problems, t... more Background: Goat milk shows therapeutic virtues for individuals with certain dietetic problems, thus physicians have traditionally recommended goats milk for infants, elders and other allergic. Also, galactooligosaccharides are readily fermented in the infant's colon where they selectively stimulate the growth of bifidobacteria and suppress the growth of pathogenic bacteria. Objective: Evaluation of supplementing goat's rations with different forms of Amino Acids on the milk production and its contents, then evaluate the consumer's acceptability. Materials and Methods: To maximize goat milk benefits different concentration of β-D-galactosidase were used to form galactooligosaccharides after supplementing the ration with lysine and methionine in protected and unprotected forms. Milk acceptability and its chemical composition were evaluated compared to control sample. Results and Discussion: Milk production, milk fat, lactose, total protein and milk yield were increased by adding the amino acids in different forms. Organoleptic evaluation indicated significant increase in taste and overall acceptability of goat milk containing higher concentration of galactooligosaccharides.

Journal of Pediatric Gastroenterology and Nutrition, 2004

The Oketani method is a program of breast massage and clinical counseling developed by the midwif... more The Oketani method is a program of breast massage and clinical counseling developed by the midwife Satomi Oketani. The purpose of this study is to examine the effects of the method on the quality of breast milk by determining the chemical composition of the milk before and after massage. Methods: Milk samples were obtained immediately before and after massage from healthy, exclusively breast-feeding Japanese mothers at two different periods of lactation one <3 months the other >3 months after parturition. Lipids, whey protein, casein, lactose, ash, and total solids in milk were measured in milk samples.The gross energy content of milk was estimated. Results: Breast massage significantly increased lipids in the late lactating period but not in the early lactating period. In the early lactating period casein was increased by breast massage but was not significantly affected in the late lactating period. Breast massage caused a significant increase in total solids from the first day to 11 months post partum. The gross energy in the late lactating period was significantly increased by breast massage but not in the early lactating period. Lactose was not significantly changed by breast massage. Conclusions: Breast massage improves the quality of human milk by significantly increasing total solids, lipids, and casein concentration and gross energy. The milk of mothers treated by Oketani breast massage may improve the growth and development of infants. JPGN 38: [484][485][486][487] 2004. Key Words: Breast massage-Chemical composition-Human milk-Oketani method.

International Journal of Food Microbiology, 1996

The effect of pH value, methanol, and salt concentration on the production of citric acid from ch... more The effect of pH value, methanol, and salt concentration on the production of citric acid from cheese whey by two strains of Aspergillus niger, i.e. CAIM Ill and CAIM 167, was investigated. Lactose concentration, utilized lactose, citric acid concentration, conversion coefficient of lactose to citric acid, and mycelial dry weight were measured during the fermentation process. The maximum citric acid concentration (1.06 and 0.82 g/l), and conversion coefficient (5.58 and 7.45%) were obtained at pH 3.5 after 9 days of fermentation for A. niger CAIM 111 and A. niger CAIM 167, respectively.

Food Chemistry, 2002

Alkaline-substituted (Na + , K + ) sepiolites were used as catalysts for the formation of lactulo... more Alkaline-substituted (Na + , K + ) sepiolites were used as catalysts for the formation of lactulose in milk permeate. Besides lactose and lactulose, other carbohydrates, such as galactose and epilactose, produced in side reactions, were determined. The effect of different washing cycles of sepiolite on the isomerisation of lactose and the exchange of cations with the permeate were also investigated. In general, the activity of the sodium sepiolite was higher than that of potassium form. Twenty per cent of lactulose formation (%1000 mg/100 ml), with respect to the initial lactose, was obtained after 150 min of reaction, using sodium sepiolite washed during 10 cycles. Under these conditions, 25% of lactose degradation was detected, whereas small amounts of epilactose and galactose were formed. The exchange of Na + between sepiolite and permeate decreased considerably with the number of washing cycles. The present work shows an appropriate method for obtaining lactulose in milk permeate with acceptable yields and without complicated purification steps. #

International Journal of Dairy Science, 2009