The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supp...The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supplementary amounts of α-tocopherol. Three oil samples, with initial peroxide values of 13.3, 19.5 (moderately oxidized oils), and 28.9 (oxidized oil), were supplemented with 100, 250 and 500 ppm of α-tocopherol and subjected to the oxidation at 50°C for 9 days. The level of oxidation was determined by measuring peroxide value (PV), conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS). Chemometric analysis indicated that, under the conditions of the present study, PV was the most suitable indicator of oil oxidation. The results have shown that the α-tocopherol could have an anti- oxidant or pro-oxidant effects, depending on its concentration and initial level of oil oxidation. Results also show that α-tocopherol addition at all the concentrations tested resulted in pro-oxidation of the moderately oxidized oils;hence additional supplementation with α-tocopherol could not be recommended to delay oxidation of unrefined almond oil.展开更多
Pomegranate fruit and its derived products are rich sources of bioactive compounds.They have many biological activities.Pomegranate molasses(PM)is a thick,traditional Middle Eastern syrup used in many recipes for Leba...Pomegranate fruit and its derived products are rich sources of bioactive compounds.They have many biological activities.Pomegranate molasses(PM)is a thick,traditional Middle Eastern syrup used in many recipes for Lebanese and international cuisines.It is a highly nutritious product which makes it of great interest.The purpose of this study was to assess the phytochemical composition,antioxidant and anti-diabetic properties of homemade and commercial PM consumed in Lebanon using samples collected from households in rural areas(n=4)and the market(n=28).The objectives of this study were to determine their total phenolic content using the Follin-Ciocalteu method,their total flavonoid content using aluminum chloride method,their antioxidant activity using DPPH radical scavenging as well as ferrous ion chelating assays and their anti-diabetic activity usingα-amylase andα-glucosidase inhibitory activities with acarbose,a known anti-diabetic drug,used as the standard reference.Homemade PM samples exhibited a higher antioxidant activity than commercial samples,with the most active homemade PM sample having IC_(50)values of 0.09 mg/mL(DPPH radical scavenging assay)and 46.78%ferrous ion chelating assay).Homemade PM samples also showed higher anti-diabetic activity than commercial samples,with the most active homemade PM sample having an IC_(50)values of 0.63 mg/mL(α-amylase inhibitory activity)and of 0.41 mg/mL(α-glucosidase inhibitory activity)and being almost as active as acarbose with both enzymes(1.5 times).Significant inverse strong/moderate correlations were observed between total phenolic content/total flavonoid content and the IC_(50)value of DPPH radical scavenging assay,indicating positive associations between total phenolic and flavonoid contents and antioxidant activity.In addition,significant negative moderate correlations were observed between total phenolic/flavonoid contents andα-amylase inhibitory activity,indicating positive associations between total phenolic and flavonoid contents and anti-diabetic activity.展开更多
文摘The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supplementary amounts of α-tocopherol. Three oil samples, with initial peroxide values of 13.3, 19.5 (moderately oxidized oils), and 28.9 (oxidized oil), were supplemented with 100, 250 and 500 ppm of α-tocopherol and subjected to the oxidation at 50°C for 9 days. The level of oxidation was determined by measuring peroxide value (PV), conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS). Chemometric analysis indicated that, under the conditions of the present study, PV was the most suitable indicator of oil oxidation. The results have shown that the α-tocopherol could have an anti- oxidant or pro-oxidant effects, depending on its concentration and initial level of oil oxidation. Results also show that α-tocopherol addition at all the concentrations tested resulted in pro-oxidation of the moderately oxidized oils;hence additional supplementation with α-tocopherol could not be recommended to delay oxidation of unrefined almond oil.
文摘Pomegranate fruit and its derived products are rich sources of bioactive compounds.They have many biological activities.Pomegranate molasses(PM)is a thick,traditional Middle Eastern syrup used in many recipes for Lebanese and international cuisines.It is a highly nutritious product which makes it of great interest.The purpose of this study was to assess the phytochemical composition,antioxidant and anti-diabetic properties of homemade and commercial PM consumed in Lebanon using samples collected from households in rural areas(n=4)and the market(n=28).The objectives of this study were to determine their total phenolic content using the Follin-Ciocalteu method,their total flavonoid content using aluminum chloride method,their antioxidant activity using DPPH radical scavenging as well as ferrous ion chelating assays and their anti-diabetic activity usingα-amylase andα-glucosidase inhibitory activities with acarbose,a known anti-diabetic drug,used as the standard reference.Homemade PM samples exhibited a higher antioxidant activity than commercial samples,with the most active homemade PM sample having IC_(50)values of 0.09 mg/mL(DPPH radical scavenging assay)and 46.78%ferrous ion chelating assay).Homemade PM samples also showed higher anti-diabetic activity than commercial samples,with the most active homemade PM sample having an IC_(50)values of 0.63 mg/mL(α-amylase inhibitory activity)and of 0.41 mg/mL(α-glucosidase inhibitory activity)and being almost as active as acarbose with both enzymes(1.5 times).Significant inverse strong/moderate correlations were observed between total phenolic content/total flavonoid content and the IC_(50)value of DPPH radical scavenging assay,indicating positive associations between total phenolic and flavonoid contents and antioxidant activity.In addition,significant negative moderate correlations were observed between total phenolic/flavonoid contents andα-amylase inhibitory activity,indicating positive associations between total phenolic and flavonoid contents and anti-diabetic activity.
