Skip to main content

John Tsaknis

Followers

10

Following

16

Co-authors

2

Public Views

Dr. John Tsaknis is Food Scientist, with two years postgraduate studies (M.phil) and Ph.D. in Food Technology (UK 1990-1996). From 1988 he is a Member of the Royal Society of Chemistry, UK having a Certificate of ‘Chartered Chemist’ and is also a member of the New York Academy of Sciences. He has a Certificate in “HACCP Principles and Their Application in Food Safety”, from Royal Institute of Public Health

less

Noor Hidayu Othman

Vassilis Dourtoglou

University of West Attica / Πανεπιστήμιο Δυτικής Αττικής

Dr. Suman Barua

University of Chittagong

UET, Lahore

parvin sharayei

Agricultural Research, Eduacation and Extension Organization (AREEO)

Alberto Schiraldi

Dimitar Dimitrov, PhD

Interests

Uploads

Papers by John Tsaknis

Quality changes of <i>Moringa oleífera</i>, variety Mbololo of Kenya, seed oil during frying

DOAJ (DOAJ: Directory of Open Access Journals), Jan 31, 1999

Cambios en la calidad de aceite de semilla Moringa oleífera variedad Mbololo de Kenya, durante la... more Cambios en la calidad de aceite de semilla Moringa oleífera variedad Mbololo de Kenya, durante la fritura. Se ha estudiado el comportamiento frente a la fritura, especialmente en el caso de frituras repetidas de aceite de semilla Moringa oleífera variedad Mbololo de Kenya (producido por presión en frío, extracción con n-hexano y una mezcla de cloroformo-metanol). Los aceites se usaron para la fritura intermitente de rodajas de patatas y filetes de bacalao a temperatura de 175 ± 5°C durante 5 días consecutivos. Bajo estas condiciones tuvo lugar la descomposición térmica y oxidativa de los aceites. Se evaluaron los cambios químicos ocurridos en los aceites. El contenido en ácidos grasos libres, índice de peróxido, extinción específica a 232 nm, compuestos polares, color y viscosidad de los aceites aumentaron, en tanto que el índice de iodo, punto de humo, contenido en ácidos grasos poliinsaturados, período de inducción y concentración en tocoferol disminuyeron. También se determinó el efecto de los aceites sobre la calidad organoléptica de estos alimentos fritos. Los datos analíticos y sensoriales mostraron que la deterioración más baja ocurrió en el aceite producido por presión en frío y la mayor en el aceite extraído con n-hexano.

A rapid HPLC method for the determination of lactoferrin in milk of various species

Journal of Dairy Research, Apr 30, 2019

This Technical Research Communication describes the adjusting and testing of a RP-HPLC method, pr... more This Technical Research Communication describes the adjusting and testing of a RP-HPLC method, previously tested for the determination of Lactoferrin in whey, for its applicability in milk samples of various species, namely, ovine, caprine, bovine, donkey and human milk. The advantage of this RP-HPLC method includes speed and convenience, as it does not include extensive pretreatment and separation steps. A simple pre-treatment step was added in order to remove fat and proteins of the casein family and the samples were tested.

A Preliminary Study on the Development of Donkey Milk Based Fermented Product

Donkey milk has been acknowledged for its unit properties since the ancient times. Hippocrates as... more Donkey milk has been acknowledged for its unit properties since the ancient times. Hippocrates as well as Pliny the Elder believed that donkey milk can act therapeutically in numerous cases, such as for liver problems, infections, fever and asthma [1]. It has nutritional properties that make it similar to human milk more than any other mammal milk [2], it is rich in natural antimicrobials [3] and it has been classified as hypoallergenic [4]. In addition, positive effects of the nano-galactose are recorded in the osteogenesis process, in the treatment of arteriosclerosis as a vasodilator, in the rehabilitation of patients with coronary artery disease or premature aging and in low cholesterol diets [5]. Finally, many studies have suggested that the addition of linolenic acid to diet can contribute to the treatment of atopic dermatitis [6], and that name can also be used as a food source of linolenic acid for children suffering from this condition [7].

Development of fermented products from donkey milk

Journal of experimental food chemistry, Aug 26, 2016

$Research paper thumbnail of Physicochemical characterization of liposomes encapsulating total fraction of Chios mastic gum$

Physicochemical characterization of liposomes encapsulating total fraction of Chios mastic gum

Journal of Food Processing and Technology, Aug 29, 2014

$Research paper thumbnail of Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes$

Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes

DIGITAL.CSIC (Spanish National Research Council (CSIC)), Aug 24, 2015

Composition and Antimicrobial Activity of the Essential Oil of<i>Cistus creticus</i>subsp.<i>eriocephalus</i>

Planta Medica, Oct 1, 1997

ABSTRACT The chemical composition of the essential oil of the leaves of Cistus creticus subsp. er... more ABSTRACT The chemical composition of the essential oil of the leaves of Cistus creticus subsp. eriocephalus (Viv.) Greuter &amp; Burdet, (Cistaceae), was investigated by GC/MS. Thirty-nine components were identified, representing 73.9% (based on % total peak area by GC) of the oil composition. The main components of the oil were alpha-cadinene (6.5%), delta-cadinene (5.6%), viridiflorol (5.4%), bulnesol (6.3%), ledol (3.8%), alpha-copaene (3.8%), beta-selinene (3.4%), cubenene (3.3%), manoyl oxide (9.9%) and 13-epi-manoyl oxide (3.4%). Antibacterial studies were carried out in vitro against Gram-positive and Gram-negative organisms.

Detection of Peanut Allergen Traces with a Real Time PCR Assay - The Challenge to Protect Food-Allergic Consumers

Journal of food research, Dec 6, 2017

The aim of the present study was the implementation of molecular techniques in the detection and ... more The aim of the present study was the implementation of molecular techniques in the detection and quantification of allergic substances of peanut in various kinds of food products, e.g., breakfast cereals, chocolates and biscuits that are frequently related to allergies. In some cases, the presence of peanuts can be due to contamination during production and are not declared on the label. A total of 152 samples were collected from supermarkets and were analysed by a Real Time PCR method. The results indicated that 125 samples (83,3%) were found positive in peanut traces but the most important finding is that from the 84 samples that had no allergen declaration for peanuts, 48 (57,1%) of them were found positive. In conclusion, Real Time PCR can be a very important tool for the rapid detection and quantification of food allergens.

Effectual Gold Nanoprobe Sensor for Screening Horse Adulteration in Meat Products

Journal of food research, Jun 3, 2017

A gold nanoparticle (AuNP) probe strategy for testing meat authenticity was developed, which reli... more A gold nanoparticle (AuNP) probe strategy for testing meat authenticity was developed, which relies on the colorimetric differentiation of a particular DNA sequence, due to the differential aggregation profiles exhibited by the AuNPs in the presence or absence of specific target hybridization. Gold nanoparticles were conjugated with thiolated oligonucleotides for specifically identifying a 69 bp fragment of the horse cytochrome b gene. In the presence of a complementary target preventing aggregation of the AuNPs when acid was added, the reaction mixtures retained the original pink colouration of the colloidal particles, whereas they turned purple in the opposite event. Fresh meatballs, prepared using pure bovine meat, were used as blanks, producing a purplish coloured solution with a peak at ≥570nm. Horse meat was used as positive control and the pink colour obtained after hybridization exhibited maximum absorption at 524 nm. Both the specificity and sensitivity of the tests performed were 100%. Visual observations and spectroscopic data indicated that the coloration produced by the AuNPs (positive-pink, negative-purple) was very stable, showing no change under normal laboratory conditions. The use of AuNPs for the colorimetric detection of DNA targets from undeclared species in meat products provides an inexpensive and easy-to-perform alternative to common molecular assays. The technology described here can be further developed to accommodate detection of many cases of adulteration and fraudulent practices.

Composition and antimicrobial activity of the essential oil of Salvia ringens

Planta Medica, 2001

Characterization of Moringa oleifera Seed Oil Variety ''Periyakulam 1

The oil from Moringa oleifera seeds variety Periyakulam 1 (PKM 1) from India was extracted using ... more The oil from Moringa oleifera seeds variety Periyakulam 1 (PKM 1) from India was extracted using three different procedures including cold press (CP), extraction with nhexane (H) and extraction with a mixture of chloroform:methanol (1:1) (CM). The oils were compared with those of a commercial virgin olive oil and Moringa oleifera var. Mbololo seed oil. The oil concentration ranged from 25.1% (CP) to 41.4% (CM). The density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, sterols, tocopherols (by HPLC), peroxide value, E 1% 1cm at 232 nm and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially oleic (up to 71.60%). The dominant saturated acids were palmitic and behenic (both up to 6.4%). The oil was also found to contain high levels of b-sitosterol (up to 45.58%), stigmasterol (up to 23.10%) and campesterol (up to 15.81%). a-, gand d-tocopherols were detected up to levels of 15.38, 25.40 and 15.51 mg/kg of oil, respectively. Moringa oleifera seed oil showed a long induction period (at 1201C), which however was reduced from 42.56 to 72.56% after degumming. The Moringa oleifera seed oil showed high stability to oxidative rancidity. Among the methods used for extraction, the mixture of chloroform:methanol (1:1) (CM) showed the higher resistance to oxidation.

Authentication of olive oil based on DNA analysis

Grasas y Aceites, 2020

Olive oil, which has been produced mainly in the Mediterranean area since the ancient times, has ... more Olive oil, which has been produced mainly in the Mediterranean area since the ancient times, has a high nutritional value linked to many health benefits. Extra virgin, which is the purest form of olive oil, has excellent quality and premium prices. Many cases of adulteration and fraud necessitate the development of reliable and accurate methods for olive oil authentication. DNA-based methods analyze the residual DNA extracted from olive oil and use molecular markers for genetic identification of different species, subspecies or cultivars because these markers act as signs which reflect distinct genetic profiles. This study reviews the process by which DNA from olive oil is extracted and analyzed by the most recently used markers in the authentication of olive oil, such as Simple Sequence Repeats (SSR) or microsatellites and the single nucleotide polymorphisms (SNPs). Methods of analysis such as qPCR and digital PCR are also discussed with a special emphasis placed on the method of H...

$Research paper thumbnail of Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes$

Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes

Journal of Food Processing and Technology, 2015

Healthy Nutritional Tips

A total characterisation of Moringa oleifera Malawi seed oil

Rivista Italiana delle Sostanze …, 1998

A total characterisation of Moringa oleifera Malawi seed oil J. TSAKNIS, S. LALAS V. GERGIS, V. S... more

Ciiaracteristics and composition of tomato seed oil

Características y composición del aceite de semilla de tomate Se separaron semillas de tomate de ... more Características y composición del aceite de semilla de tomate Se separaron semillas de tomate de la pulpa seca y posteriormente se trituraron y extrajeron con éter de petróleo en caliente. El aceite extraído se desgomó, neutralizó y decoloró, y luego se determinaron las características físicas y químicas de los aceites crudos y purificados. La purificación produjo una disminución en la acidez, color, insapon'rficables, E Í5n 232 y estabilidad oxidativa y un aumento en el punto de humo y EÍcm 270. Las propiedades físico-químicas no se afectaron por la purificación. Se encontró que el aceite de semilla de tomate contenía altos niveles de linoleico (54%), seguido por oleico (22%), mientras que los ácidos grasos saturados mayoritarios fueron el palmítico (14%) y el esteárico (6%). La purificación produjo también un aumento en el C 18:2 trans, mientras que el perfil de ácidos grasos del aceite permaneció inalterado. Se detectaron a-y Ô-tocoferóles a niveles de 202 y 1059 mg/kg; la purificación redujo el contenido en tocoferol a 161 y 898 mg/kg, respectivamente. El p-sitosterol fue el componente predominante de la fracción esterólica del aceite de semilla de tomate. Se detectó un alto porcentaje de colesterol (16%). Otros esteróles encontrados en porcentajes más elevados del 1.5% fueron el campesterol, estigmasterol y A^-avenasterol. Además, se encontraron como componentes minoritarios 24-metilenecolesterol, brasicasterol, A''-campesterol, clerosterol, ùJ^^estigmastadienol, A'^-estigmastanol, A^-avenasterol y eritrodiol. El perfil de esteróles no se afectó por la purificación.

Quality changes of Moringa oleifera variety of Blantyre, seed oil during frying

The frying performance of Moringa oleifera, local variety of Blantyre, area of Malawi, seed oil (... more The frying performance of Moringa oleifera, local variety of Blantyre, area of Malawi, seed oil (produced by cold pressure, extraction with n-hexane and a mixture of chloroform-methanol) was studied especially as regards repeated frying operations. The oils were used for intermittent frying of potato slices and cod filets at a temperature of 175±5°C for 5 consecutive days. Under such conditions thermal and oxidative decomposition of the oils take place. The chemical changes occurring in the oils were evaluated. Free fatty acid content, peroxide value, specific extinction at 232 nm, polar compounds colour and viscosity of the oils all increased, whereas the iodine values, smoke points, polyunsaturated fatty acid content, induction period and tocopherol concentration decreased. The effect of the oils on the organoleptic quality of these fried foods was also determined. The analytical and sensory data showed that the lowest deterioration occurred in the oil produced by cold pressure an...

Rapid high-performance liquid chromatographic method of determining malondialdehyde for evaluation of rancidity in edible oils

Analyst, 1998

A rapid HPLC method for the determination of lactoferrin in milk of various species

Journal of Dairy Research, 2019

This Research Communication describes the adaptation and testing of an RP-HPLC method, previously... more This Research Communication describes the adaptation and testing of an RP-HPLC method, previously tested for the determination of lactoferrin (LF) in whey, for its applicability to determine milk lactoferrin content. Milk samples of various species, namely, ovine, caprine, bovine, donkey and human milk, were tested. The advantage of this RP-HPLC method includes speed and convenience, as it does not include extensive pretreatment or separation steps. A simple pre-treatment step was added in order to remove fat and proteins of the casein family and the samples were tested. The results varied in terms of elution of the LF peak both between the milk of the different species as well as from the initial application on whey. The peak resolution was satisfactory in the cases of ovine, bovine and donkey milk samples while for caprine and human milk an interference with other peaks was observed. Nevertheless, quantification of LF was found possible for all samples. This new application of the...

Evaluation of a Real Time PCR Assay and a ELISA Method for the Detection of Walnuts and Almonds Allergen Traces in Food Products

Journal of Food Research, 2019

Food allergens are a well acknowledged issue in food industry and are regulated by legislation. T... more Food allergens are a well acknowledged issue in food industry and are regulated by legislation. The presence of allergens can either origin from the raw material or due to contamination during production. Allergen information on packaging is mandatory although it cannot be accurate in the case of contamination therefore warnings are used. The purpose of the study is the development and validation of a SYBR Green Real Time Polymerase Chain Reaction method using specific primer pairs based on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences to improve the sensitivity of Real Time Polymerase Chain Reaction techniques for detection of walnut and almond traces in commercial food products and its comparison with ELISA methodology in terms of detection ability. A total of 100 samples were collected from local markets and were analyzed by Real Time Polymerase Chain Reaction (RT-PCR) and ELISA methods. The results indicated that 16 samples (16%) were found positive in walnut traces an...

Quality changes of <i>Moringa oleífera</i>, variety Mbololo of Kenya, seed oil during frying

DOAJ (DOAJ: Directory of Open Access Journals), Jan 31, 1999

Cambios en la calidad de aceite de semilla Moringa oleífera variedad Mbololo de Kenya, durante la... more Cambios en la calidad de aceite de semilla Moringa oleífera variedad Mbololo de Kenya, durante la fritura. Se ha estudiado el comportamiento frente a la fritura, especialmente en el caso de frituras repetidas de aceite de semilla Moringa oleífera variedad Mbololo de Kenya (producido por presión en frío, extracción con n-hexano y una mezcla de cloroformo-metanol). Los aceites se usaron para la fritura intermitente de rodajas de patatas y filetes de bacalao a temperatura de 175 ± 5°C durante 5 días consecutivos. Bajo estas condiciones tuvo lugar la descomposición térmica y oxidativa de los aceites. Se evaluaron los cambios químicos ocurridos en los aceites. El contenido en ácidos grasos libres, índice de peróxido, extinción específica a 232 nm, compuestos polares, color y viscosidad de los aceites aumentaron, en tanto que el índice de iodo, punto de humo, contenido en ácidos grasos poliinsaturados, período de inducción y concentración en tocoferol disminuyeron. También se determinó el efecto de los aceites sobre la calidad organoléptica de estos alimentos fritos. Los datos analíticos y sensoriales mostraron que la deterioración más baja ocurrió en el aceite producido por presión en frío y la mayor en el aceite extraído con n-hexano.

A rapid HPLC method for the determination of lactoferrin in milk of various species

Journal of Dairy Research, Apr 30, 2019

This Technical Research Communication describes the adjusting and testing of a RP-HPLC method, pr... more This Technical Research Communication describes the adjusting and testing of a RP-HPLC method, previously tested for the determination of Lactoferrin in whey, for its applicability in milk samples of various species, namely, ovine, caprine, bovine, donkey and human milk. The advantage of this RP-HPLC method includes speed and convenience, as it does not include extensive pretreatment and separation steps. A simple pre-treatment step was added in order to remove fat and proteins of the casein family and the samples were tested.

A Preliminary Study on the Development of Donkey Milk Based Fermented Product

Donkey milk has been acknowledged for its unit properties since the ancient times. Hippocrates as... more Donkey milk has been acknowledged for its unit properties since the ancient times. Hippocrates as well as Pliny the Elder believed that donkey milk can act therapeutically in numerous cases, such as for liver problems, infections, fever and asthma [1]. It has nutritional properties that make it similar to human milk more than any other mammal milk [2], it is rich in natural antimicrobials [3] and it has been classified as hypoallergenic [4]. In addition, positive effects of the nano-galactose are recorded in the osteogenesis process, in the treatment of arteriosclerosis as a vasodilator, in the rehabilitation of patients with coronary artery disease or premature aging and in low cholesterol diets [5]. Finally, many studies have suggested that the addition of linolenic acid to diet can contribute to the treatment of atopic dermatitis [6], and that name can also be used as a food source of linolenic acid for children suffering from this condition [7].

Development of fermented products from donkey milk

Journal of experimental food chemistry, Aug 26, 2016

$Research paper thumbnail of Physicochemical characterization of liposomes encapsulating total fraction of Chios mastic gum$

Physicochemical characterization of liposomes encapsulating total fraction of Chios mastic gum

Journal of Food Processing and Technology, Aug 29, 2014

$Research paper thumbnail of Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes$

Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes

DIGITAL.CSIC (Spanish National Research Council (CSIC)), Aug 24, 2015

Composition and Antimicrobial Activity of the Essential Oil of<i>Cistus creticus</i>subsp.<i>eriocephalus</i>

Planta Medica, Oct 1, 1997

ABSTRACT The chemical composition of the essential oil of the leaves of Cistus creticus subsp. er... more ABSTRACT The chemical composition of the essential oil of the leaves of Cistus creticus subsp. eriocephalus (Viv.) Greuter &amp; Burdet, (Cistaceae), was investigated by GC/MS. Thirty-nine components were identified, representing 73.9% (based on % total peak area by GC) of the oil composition. The main components of the oil were alpha-cadinene (6.5%), delta-cadinene (5.6%), viridiflorol (5.4%), bulnesol (6.3%), ledol (3.8%), alpha-copaene (3.8%), beta-selinene (3.4%), cubenene (3.3%), manoyl oxide (9.9%) and 13-epi-manoyl oxide (3.4%). Antibacterial studies were carried out in vitro against Gram-positive and Gram-negative organisms.

Detection of Peanut Allergen Traces with a Real Time PCR Assay - The Challenge to Protect Food-Allergic Consumers

Journal of food research, Dec 6, 2017

The aim of the present study was the implementation of molecular techniques in the detection and ... more The aim of the present study was the implementation of molecular techniques in the detection and quantification of allergic substances of peanut in various kinds of food products, e.g., breakfast cereals, chocolates and biscuits that are frequently related to allergies. In some cases, the presence of peanuts can be due to contamination during production and are not declared on the label. A total of 152 samples were collected from supermarkets and were analysed by a Real Time PCR method. The results indicated that 125 samples (83,3%) were found positive in peanut traces but the most important finding is that from the 84 samples that had no allergen declaration for peanuts, 48 (57,1%) of them were found positive. In conclusion, Real Time PCR can be a very important tool for the rapid detection and quantification of food allergens.

Effectual Gold Nanoprobe Sensor for Screening Horse Adulteration in Meat Products

Journal of food research, Jun 3, 2017

A gold nanoparticle (AuNP) probe strategy for testing meat authenticity was developed, which reli... more A gold nanoparticle (AuNP) probe strategy for testing meat authenticity was developed, which relies on the colorimetric differentiation of a particular DNA sequence, due to the differential aggregation profiles exhibited by the AuNPs in the presence or absence of specific target hybridization. Gold nanoparticles were conjugated with thiolated oligonucleotides for specifically identifying a 69 bp fragment of the horse cytochrome b gene. In the presence of a complementary target preventing aggregation of the AuNPs when acid was added, the reaction mixtures retained the original pink colouration of the colloidal particles, whereas they turned purple in the opposite event. Fresh meatballs, prepared using pure bovine meat, were used as blanks, producing a purplish coloured solution with a peak at ≥570nm. Horse meat was used as positive control and the pink colour obtained after hybridization exhibited maximum absorption at 524 nm. Both the specificity and sensitivity of the tests performed were 100%. Visual observations and spectroscopic data indicated that the coloration produced by the AuNPs (positive-pink, negative-purple) was very stable, showing no change under normal laboratory conditions. The use of AuNPs for the colorimetric detection of DNA targets from undeclared species in meat products provides an inexpensive and easy-to-perform alternative to common molecular assays. The technology described here can be further developed to accommodate detection of many cases of adulteration and fraudulent practices.

Composition and antimicrobial activity of the essential oil of Salvia ringens

Planta Medica, 2001

Characterization of Moringa oleifera Seed Oil Variety ''Periyakulam 1

The oil from Moringa oleifera seeds variety Periyakulam 1 (PKM 1) from India was extracted using ... more The oil from Moringa oleifera seeds variety Periyakulam 1 (PKM 1) from India was extracted using three different procedures including cold press (CP), extraction with nhexane (H) and extraction with a mixture of chloroform:methanol (1:1) (CM). The oils were compared with those of a commercial virgin olive oil and Moringa oleifera var. Mbololo seed oil. The oil concentration ranged from 25.1% (CP) to 41.4% (CM). The density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, sterols, tocopherols (by HPLC), peroxide value, E 1% 1cm at 232 nm and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially oleic (up to 71.60%). The dominant saturated acids were palmitic and behenic (both up to 6.4%). The oil was also found to contain high levels of b-sitosterol (up to 45.58%), stigmasterol (up to 23.10%) and campesterol (up to 15.81%). a-, gand d-tocopherols were detected up to levels of 15.38, 25.40 and 15.51 mg/kg of oil, respectively. Moringa oleifera seed oil showed a long induction period (at 1201C), which however was reduced from 42.56 to 72.56% after degumming. The Moringa oleifera seed oil showed high stability to oxidative rancidity. Among the methods used for extraction, the mixture of chloroform:methanol (1:1) (CM) showed the higher resistance to oxidation.

Authentication of olive oil based on DNA analysis

Grasas y Aceites, 2020

Olive oil, which has been produced mainly in the Mediterranean area since the ancient times, has ... more Olive oil, which has been produced mainly in the Mediterranean area since the ancient times, has a high nutritional value linked to many health benefits. Extra virgin, which is the purest form of olive oil, has excellent quality and premium prices. Many cases of adulteration and fraud necessitate the development of reliable and accurate methods for olive oil authentication. DNA-based methods analyze the residual DNA extracted from olive oil and use molecular markers for genetic identification of different species, subspecies or cultivars because these markers act as signs which reflect distinct genetic profiles. This study reviews the process by which DNA from olive oil is extracted and analyzed by the most recently used markers in the authentication of olive oil, such as Simple Sequence Repeats (SSR) or microsatellites and the single nucleotide polymorphisms (SNPs). Methods of analysis such as qPCR and digital PCR are also discussed with a special emphasis placed on the method of H...

$Research paper thumbnail of Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes$

Assessment of biological activity of Chios mastic gum (acid, neutral and total fraction) extracts before and after encapsulation in liposomes

Journal of Food Processing and Technology, 2015

Healthy Nutritional Tips

A total characterisation of Moringa oleifera Malawi seed oil

Rivista Italiana delle Sostanze …, 1998

A total characterisation of Moringa oleifera Malawi seed oil J. TSAKNIS, S. LALAS V. GERGIS, V. S... more

Ciiaracteristics and composition of tomato seed oil

Características y composición del aceite de semilla de tomate Se separaron semillas de tomate de ... more Características y composición del aceite de semilla de tomate Se separaron semillas de tomate de la pulpa seca y posteriormente se trituraron y extrajeron con éter de petróleo en caliente. El aceite extraído se desgomó, neutralizó y decoloró, y luego se determinaron las características físicas y químicas de los aceites crudos y purificados. La purificación produjo una disminución en la acidez, color, insapon'rficables, E Í5n 232 y estabilidad oxidativa y un aumento en el punto de humo y EÍcm 270. Las propiedades físico-químicas no se afectaron por la purificación. Se encontró que el aceite de semilla de tomate contenía altos niveles de linoleico (54%), seguido por oleico (22%), mientras que los ácidos grasos saturados mayoritarios fueron el palmítico (14%) y el esteárico (6%). La purificación produjo también un aumento en el C 18:2 trans, mientras que el perfil de ácidos grasos del aceite permaneció inalterado. Se detectaron a-y Ô-tocoferóles a niveles de 202 y 1059 mg/kg; la purificación redujo el contenido en tocoferol a 161 y 898 mg/kg, respectivamente. El p-sitosterol fue el componente predominante de la fracción esterólica del aceite de semilla de tomate. Se detectó un alto porcentaje de colesterol (16%). Otros esteróles encontrados en porcentajes más elevados del 1.5% fueron el campesterol, estigmasterol y A^-avenasterol. Además, se encontraron como componentes minoritarios 24-metilenecolesterol, brasicasterol, A''-campesterol, clerosterol, ùJ^^estigmastadienol, A'^-estigmastanol, A^-avenasterol y eritrodiol. El perfil de esteróles no se afectó por la purificación.

Quality changes of Moringa oleifera variety of Blantyre, seed oil during frying

The frying performance of Moringa oleifera, local variety of Blantyre, area of Malawi, seed oil (... more The frying performance of Moringa oleifera, local variety of Blantyre, area of Malawi, seed oil (produced by cold pressure, extraction with n-hexane and a mixture of chloroform-methanol) was studied especially as regards repeated frying operations. The oils were used for intermittent frying of potato slices and cod filets at a temperature of 175±5°C for 5 consecutive days. Under such conditions thermal and oxidative decomposition of the oils take place. The chemical changes occurring in the oils were evaluated. Free fatty acid content, peroxide value, specific extinction at 232 nm, polar compounds colour and viscosity of the oils all increased, whereas the iodine values, smoke points, polyunsaturated fatty acid content, induction period and tocopherol concentration decreased. The effect of the oils on the organoleptic quality of these fried foods was also determined. The analytical and sensory data showed that the lowest deterioration occurred in the oil produced by cold pressure an...

Rapid high-performance liquid chromatographic method of determining malondialdehyde for evaluation of rancidity in edible oils

Analyst, 1998

A rapid HPLC method for the determination of lactoferrin in milk of various species

Journal of Dairy Research, 2019

This Research Communication describes the adaptation and testing of an RP-HPLC method, previously... more This Research Communication describes the adaptation and testing of an RP-HPLC method, previously tested for the determination of lactoferrin (LF) in whey, for its applicability to determine milk lactoferrin content. Milk samples of various species, namely, ovine, caprine, bovine, donkey and human milk, were tested. The advantage of this RP-HPLC method includes speed and convenience, as it does not include extensive pretreatment or separation steps. A simple pre-treatment step was added in order to remove fat and proteins of the casein family and the samples were tested. The results varied in terms of elution of the LF peak both between the milk of the different species as well as from the initial application on whey. The peak resolution was satisfactory in the cases of ovine, bovine and donkey milk samples while for caprine and human milk an interference with other peaks was observed. Nevertheless, quantification of LF was found possible for all samples. This new application of the...

Evaluation of a Real Time PCR Assay and a ELISA Method for the Detection of Walnuts and Almonds Allergen Traces in Food Products

Journal of Food Research, 2019

Food allergens are a well acknowledged issue in food industry and are regulated by legislation. T... more Food allergens are a well acknowledged issue in food industry and are regulated by legislation. The presence of allergens can either origin from the raw material or due to contamination during production. Allergen information on packaging is mandatory although it cannot be accurate in the case of contamination therefore warnings are used. The purpose of the study is the development and validation of a SYBR Green Real Time Polymerase Chain Reaction method using specific primer pairs based on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences to improve the sensitivity of Real Time Polymerase Chain Reaction techniques for detection of walnut and almond traces in commercial food products and its comparison with ELISA methodology in terms of detection ability. A total of 100 samples were collected from local markets and were analyzed by Real Time Polymerase Chain Reaction (RT-PCR) and ELISA methods. The results indicated that 16 samples (16%) were found positive in walnut traces an...