Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above...Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.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Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.
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.
