The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (E... more The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (EVOO) was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene (HDPE)-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate (PET)-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic.
American Journal of Food Science and Technology, 2014
The quality of extra virgin olive oil (EVOO) is intimately affected by packaging material and sto... more The quality of extra virgin olive oil (EVOO) is intimately affected by packaging material and storage temperature. In this study, the influence of packaging materials and elevated temperature on EVOO quality was investigated during six months. At ambient temperatures, oil maintained EVOO when stored in glass, polyethylene terephthalate (PET), high density polyethylene (HDPE), cans and Pottery in terms of chemical tests (acidity, peroxide value, K 232 , and K 270). Loss of phenols was the highest in pottery-stored oil and the lowest was found in glass-stored oil. Only PET-stored oil maintained the EVOO grade in terms of sensory evaluation when stored at room temperature. At elevated temperature, oil stored in all packaging materials lost extra virgin quality in terms of chemical tests. The loss of phenols was the largest in HDPE and smallest in cans-stored oil. Sensory evaluation, maintained glass-stored oil and PET-stored oil as EVOO. This study has reaffirmed that at both storage temperatures, the best container in maintaining the EVOO quality was glass and the worst was pottery. Grading of stored olive oil under investigation using sensory evaluation solely was not sufficient. Also it was clear that the absorption coefficient K 270 was the most sensitive determinant chemical test that determines the quality of stored olive oil and could be used as a rapid indicator test.
Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to ... more Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet [1]. Metabolites found in the extra virgin olive oils can be tracers for some enzymatic activity. The presence and activity of enzymes is strictly related to genetic factors (as olive cultivar) and environmental conditions. The characterization of minor components of extra virgin olive oil, in particular volatile compounds and phenolic molecules, may contribute to the identification of the cultivar– environment interaction. Many of these compounds can be considered to be direct metabolites produced by intracellular biogenic pathways.In this work different analytical approaches were applied for the characterization of extra virgin olive oils produced from autochthon varieties of olives from Brisighella area which has been sampled specifically to carry on a study of zoning, by sampling oils obtained in the same product geograph...
A Al lm ma a M Ma at te er r S St tu ud di io or ru um m-U Un ni iv ve er rs si it tà à d di i B ... more A Al lm ma a M Ma at te er r S St tu ud di io or ru um m-U Un ni iv ve er rs si it tà à d di i B Bo ol lo og gn na a DOTTORATO DI RICERCA IN Scienze e Tecnologie Agrarie, Ambientali e Alimentari Ciclo XXVII Settore Concorsuale di afferenza: 07/F1 Settore Scientifico disciplinare: AGR/15 TITOLO TESI Quality control of virgin olive oils with regard to different storage and shipment conditions Presentata da: Ziad Ayyad Coordinatore Dottorato Relatore
The authors wish to express their gratitude to the staff in the Palestinian Standard Institution ... more The authors wish to express their gratitude to the staff in the Palestinian Standard Institution (PSI) for their help in running the sensorial analysis for the samples namely Miss Tagreed Shhadeh.
The authors would like to thank Enhancement of the Palestinian University System (E- PLUS) for Ph... more The authors would like to thank Enhancement of the Palestinian University System (E- PLUS) for PhD scholarship grants financed by the Italian Ministry of Foreign Affairs-Directorate General for Cooperation and Development (coordinated by the University of Pavia).
Filtration of extra virgin olive oil is a process that may improve preservation of the quality du... more Filtration of extra virgin olive oil is a process that may improve preservation of the quality during storage. In the current study, different aliquots of extra virgin olive oils were subjected to filtration with a traditional filter press or an innovative patented alternative process of clarification by insufflating inert gas such as nitrogen and argon; all treated samples and, as control unfiltered ones, were stored for one year to evaluate the effects of these technologies on the quality of oil during shelf-life. Basic quality indexes, diglycerides, phenolics and volatiles, as well as the sensory characteristics of samples, were determined at 4 month intervals during storage. According to the volatile compounds, phenolics and sensory analysis, the novel technique had a beneficial effect on the storage of extra virgin olive oils; accordingly, this process could be exploited by the olive oil industry.
The authors wish to express their gratitude to the staff in Al-Jebrini Company for food Industrie... more The authors wish to express their gratitude to the staff in Al-Jebrini Company for food Industries for their help in running storage simulation and samples analysis namely Mr. Romel Qudemat.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
Virgin olive oil(VOO) is a product characterized by high economic and nutritional values, because... more Virgin olive oil(VOO) is a product characterized by high economic and nutritional values, because of its superior sensory characteristics and minor compounds (phenols and tocopherols) contents. Since the original quality of VOO may change during its storage, this study aimed to investigate the influence of different storage and shipment conditions on the quality of VOO, by studying different solutions such as filtration, dark storage and shipment inside insulated containers to protect it. Different analytical techniques were used to follow-up the quality changes during virgin olive oil storage and simulated shipments, in terms of basic quality parameters, sensory analysis and evaluation of minor components (phenolic compounds, diglycerides, volatile compounds). Four main research streams were presented in this PhD thesis: The results obtained from the first experimental section revealed that the application of filtration and/or clarification can decrease the unavoidable quality loss...
Purpose – Modern supply chains collect and deliver products worldwide and link vendors and consum... more Purpose – Modern supply chains collect and deliver products worldwide and link vendors and consumers over thousands of miles. In the food industry, the quality of products is affected by manufacturing/processing and logistics activities, such as transportation and packaging. Specifically, transportation is likely the most critical step throughout the “food journey” from farm to fork because of the potential stresses that affect the products during shipment and storage activities. The purpose of this paper is to present and apply an original assessment of quality, safety and environmental effects due to the international distribution of food products via different container solutions. A case study that examines the shipment of edible oils from Italy to Canada demonstrates that the quality of a product at the place of consumption can be significantly affected by the use of different containers. Design/methodology/approach – A simulation-based quality assessment, combined with a life c...
The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (E... more The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (EVOO) was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene (HDPE)-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate (PET)-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic.
American Journal of Food Science and Technology, 2014
The quality of extra virgin olive oil (EVOO) is intimately affected by packaging material and sto... more The quality of extra virgin olive oil (EVOO) is intimately affected by packaging material and storage temperature. In this study, the influence of packaging materials and elevated temperature on EVOO quality was investigated during six months. At ambient temperatures, oil maintained EVOO when stored in glass, polyethylene terephthalate (PET), high density polyethylene (HDPE), cans and Pottery in terms of chemical tests (acidity, peroxide value, K 232 , and K 270). Loss of phenols was the highest in pottery-stored oil and the lowest was found in glass-stored oil. Only PET-stored oil maintained the EVOO grade in terms of sensory evaluation when stored at room temperature. At elevated temperature, oil stored in all packaging materials lost extra virgin quality in terms of chemical tests. The loss of phenols was the largest in HDPE and smallest in cans-stored oil. Sensory evaluation, maintained glass-stored oil and PET-stored oil as EVOO. This study has reaffirmed that at both storage temperatures, the best container in maintaining the EVOO quality was glass and the worst was pottery. Grading of stored olive oil under investigation using sensory evaluation solely was not sufficient. Also it was clear that the absorption coefficient K 270 was the most sensitive determinant chemical test that determines the quality of stored olive oil and could be used as a rapid indicator test.
Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to ... more Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet [1]. Metabolites found in the extra virgin olive oils can be tracers for some enzymatic activity. The presence and activity of enzymes is strictly related to genetic factors (as olive cultivar) and environmental conditions. The characterization of minor components of extra virgin olive oil, in particular volatile compounds and phenolic molecules, may contribute to the identification of the cultivar– environment interaction. Many of these compounds can be considered to be direct metabolites produced by intracellular biogenic pathways.In this work different analytical approaches were applied for the characterization of extra virgin olive oils produced from autochthon varieties of olives from Brisighella area which has been sampled specifically to carry on a study of zoning, by sampling oils obtained in the same product geograph...
A Al lm ma a M Ma at te er r S St tu ud di io or ru um m-U Un ni iv ve er rs si it tà à d di i B ... more A Al lm ma a M Ma at te er r S St tu ud di io or ru um m-U Un ni iv ve er rs si it tà à d di i B Bo ol lo og gn na a DOTTORATO DI RICERCA IN Scienze e Tecnologie Agrarie, Ambientali e Alimentari Ciclo XXVII Settore Concorsuale di afferenza: 07/F1 Settore Scientifico disciplinare: AGR/15 TITOLO TESI Quality control of virgin olive oils with regard to different storage and shipment conditions Presentata da: Ziad Ayyad Coordinatore Dottorato Relatore
The authors wish to express their gratitude to the staff in the Palestinian Standard Institution ... more The authors wish to express their gratitude to the staff in the Palestinian Standard Institution (PSI) for their help in running the sensorial analysis for the samples namely Miss Tagreed Shhadeh.
The authors would like to thank Enhancement of the Palestinian University System (E- PLUS) for Ph... more The authors would like to thank Enhancement of the Palestinian University System (E- PLUS) for PhD scholarship grants financed by the Italian Ministry of Foreign Affairs-Directorate General for Cooperation and Development (coordinated by the University of Pavia).
Filtration of extra virgin olive oil is a process that may improve preservation of the quality du... more Filtration of extra virgin olive oil is a process that may improve preservation of the quality during storage. In the current study, different aliquots of extra virgin olive oils were subjected to filtration with a traditional filter press or an innovative patented alternative process of clarification by insufflating inert gas such as nitrogen and argon; all treated samples and, as control unfiltered ones, were stored for one year to evaluate the effects of these technologies on the quality of oil during shelf-life. Basic quality indexes, diglycerides, phenolics and volatiles, as well as the sensory characteristics of samples, were determined at 4 month intervals during storage. According to the volatile compounds, phenolics and sensory analysis, the novel technique had a beneficial effect on the storage of extra virgin olive oils; accordingly, this process could be exploited by the olive oil industry.
The authors wish to express their gratitude to the staff in Al-Jebrini Company for food Industrie... more The authors wish to express their gratitude to the staff in Al-Jebrini Company for food Industries for their help in running storage simulation and samples analysis namely Mr. Romel Qudemat.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglyc... more The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.
Virgin olive oil(VOO) is a product characterized by high economic and nutritional values, because... more Virgin olive oil(VOO) is a product characterized by high economic and nutritional values, because of its superior sensory characteristics and minor compounds (phenols and tocopherols) contents. Since the original quality of VOO may change during its storage, this study aimed to investigate the influence of different storage and shipment conditions on the quality of VOO, by studying different solutions such as filtration, dark storage and shipment inside insulated containers to protect it. Different analytical techniques were used to follow-up the quality changes during virgin olive oil storage and simulated shipments, in terms of basic quality parameters, sensory analysis and evaluation of minor components (phenolic compounds, diglycerides, volatile compounds). Four main research streams were presented in this PhD thesis: The results obtained from the first experimental section revealed that the application of filtration and/or clarification can decrease the unavoidable quality loss...
Purpose – Modern supply chains collect and deliver products worldwide and link vendors and consum... more Purpose – Modern supply chains collect and deliver products worldwide and link vendors and consumers over thousands of miles. In the food industry, the quality of products is affected by manufacturing/processing and logistics activities, such as transportation and packaging. Specifically, transportation is likely the most critical step throughout the “food journey” from farm to fork because of the potential stresses that affect the products during shipment and storage activities. The purpose of this paper is to present and apply an original assessment of quality, safety and environmental effects due to the international distribution of food products via different container solutions. A case study that examines the shipment of edible oils from Italy to Canada demonstrates that the quality of a product at the place of consumption can be significantly affected by the use of different containers. Design/methodology/approach – A simulation-based quality assessment, combined with a life c...
Uploads
Papers by Ziad Ayyad