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The effect of some plant extracts on polyphenol oxidase activity and enzymatic browning
Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576
S297
The need for specific and reliable analytical methods for its assay in complex matrices can be fulfilled by the new method based on the application of electro-spray ionization tandem mass spectrometry and on the use of trans--farnesene, a terpenoid analogue, as internal standard. Squalene is the more abundant microelement present in olive oil, a typical foodstuff of Mediterranean diet, the new method was, therefore, tested with Calabrian extra virgin olive oils produced from different genotype of olive cultivars. Squalene and analogues have been determined in different oils, generally by means of chromatographic procedures, i.e. gas chromatography and liquid chromatography. We now wish to introduce high pressure liquid chromatography coupled to electro-spray tandem mass spectrometry as a rapid and selective potential alternative.
Under experimental conditions, the fresh pineapple extract caused a stronger inhibitory effect on apple and banana polyphenol oxidase than did the garlic and olive leaf fresh extract, while polyphenol oxidase activity of potato was partially inhibited by both fresh and heat-treated olive leaf extract. When the olive leaf and garlic extract that had been treated at a high temperature was added, the polyphenol oxidase activity was strongly inhibited. While the addition of the fresh pineapple extract exhibited a higher inhibitory effect on polyphenol oxidase activity than that of the heated pineapple extract. Moreover, the results demonstrated that browning of banana, apple and potato for 30 min caused significant decrease in total phenolic content.
doi:10.1016/j.jbiotec.2010.09.249
[P-F.9]
[P-F.7]
Composition of plant virgin oils obtained from Oleaceae fruits
Determination of Polyphenol Oxidase Activity Using the Oxidoreduction Potential Method Rana
Mustafa ∗ ,
Duried Alwazeera
Department of Food Engineering, Faculty of Chemical and Petroleum Engineering, University of Al Baath, BO Box 77 Homs, Syrian Arab Republic Keywords: Myceliophthora thermophila laccase; Polyphenol oxidase; Enzyme kinetic; Oxido-reduction potential; Phenolic compound Polyphenol oxidases (PPOs) oxidize the phenolic compounds forming quinones, which exhibited non enzymatic reactions to develop color end compounds. The methods actually used to determine the activity of PPOs cannot permit to separate and distinguish between enzymatic and non enzymatic steps of phenolic compounds oxidation. This research aims to found a novel method to measure the activity of PPOs monitoring the measurement of oxidoreduction potential (ORP) of reaction. The results of this study showed that the monitoring of ORP of reaction medium permitted to determine the beginning and the end of enzymatic oxidation step of phenolic compound. It also allowed researchers to distinguish enzymatic step from non enzymatic one, which was not possible when using absorbance measurement method. No significant differences were observed between the kinetic parameters of enzymatic reaction (Km , Vmax ) determined by both absorbance and ORP methods. doi:10.1016/j.jbiotec.2010.09.250 [P-F.8] The effect of some plant extracts on polyphenol oxidase activity and enzymatic browning Rana Mustafa ∗ , Duried Alwazeer Department of Food Engineering, Faculty of Chemical and Petroleum Engineering, University of Al Baath, BO Box 77 Homs, Syrian Arab Republic Keywords: Polyphenol oxidase; inhibitory effect; enzymatic browning; Phenolic compound The aim of this study was to investigate the inhibitory effect of garlic, pineapple and olive leaf aqueous extract on banana, apple and potato polyphenol oxidase enzymatic browning.
doi:10.1016/j.jbiotec.2010.09.251
I. Muzzalupo 1,2,∗ , A. Russo 1 , A. Chippetta 3 , E. Romano 1 , E. Perri 1 1
CRA-Centro di Ricerca per l’olivicoltura e l’industria olearia (CRAOLI), Italy 2 CRA-Centro di Ricerca per le produzioni foraggere e lattiero-casearie (CRA-FLC), Italy 3 Università degli Studi della Calabria, Dip. di Ecologia, Italy Keywords: Food quality; Minor polar compounds; Fatty acid; Antioxidants
Virgin oils are primary metabolites of many higher plants that are economically important as sources of food and industrial oils. Chemically, plant oils are rich of triglycerides, made of different fatty acids. The virgin olive oil contain about 96-98% of the saponificable fraction. Oleic acid is the principal component (70-80%) of this matrix, succeeding linoleic (12%) and palmitic (6.5%) acids. Unsaponificable fraction contains: terpenes, chlorophylls tocopherols, sterols and phenolic compounds. Secoiridoids, like aglycone derivatives of oleuropein, demethyloleuropein and ligstroside, are present in olive fruit as most abundant virgin olive oil phenolic antioxidants. Several important biological activities (antioxidant, anti-inflammatory, chemopreventive and anti-cancer) and the characteristic pungent and bitter tasty properties have been attributed to virgin olive oil phenols. The olive tree is a member of the Oleaceae family, which contains the genera Fraxinus, Forsythia, Forestiera, Ligustrum and Syringa, as well as the genus Olea. Commercial olives are products of the Olea europaea L. species. Olive (Olea europaea L.) is a perennial evergreen tree that has grown naturally and been cultivated widely in the Mediterranean for centuries. The aim of this study was to compare the phenolics and fatty acids composition in two different olive oils. Particularly, one sample is obtained from ‘Coratina’ cultivar and the other is obtained from virgin Oleaceae oil (‘Coratina’ + other Oleaceae fruit). The procedure applied for the last sample preparation and analytical investigation is patent pending. Quali-quantitative analysis (performed by HPLC-MS/MS and GC-MS/MS) could be a useful tool to better correlate the typicity of the virgin Oleaceae oil with its phenolic compounds and fatty acids profile. Further studies are in progress to isolate unknown compounds and to further investigate the quality index of this food product. doi:10.1016/j.jbiotec.2010.09.252
S297
The need for specific and reliable analytical methods for its assay in complex matrices can be fulfilled by the new method based on the application of electro-spray ionization tandem mass spectrometry and on the use of trans--farnesene, a terpenoid analogue, as internal standard. Squalene is the more abundant microelement present in olive oil, a typical foodstuff of Mediterranean diet, the new method was, therefore, tested with Calabrian extra virgin olive oils produced from different genotype of olive cultivars. Squalene and analogues have been determined in different oils, generally by means of chromatographic procedures, i.e. gas chromatography and liquid chromatography. We now wish to introduce high pressure liquid chromatography coupled to electro-spray tandem mass spectrometry as a rapid and selective potential alternative.
Under experimental conditions, the fresh pineapple extract caused a stronger inhibitory effect on apple and banana polyphenol oxidase than did the garlic and olive leaf fresh extract, while polyphenol oxidase activity of potato was partially inhibited by both fresh and heat-treated olive leaf extract. When the olive leaf and garlic extract that had been treated at a high temperature was added, the polyphenol oxidase activity was strongly inhibited. While the addition of the fresh pineapple extract exhibited a higher inhibitory effect on polyphenol oxidase activity than that of the heated pineapple extract. Moreover, the results demonstrated that browning of banana, apple and potato for 30 min caused significant decrease in total phenolic content.
doi:10.1016/j.jbiotec.2010.09.249
[P-F.9]
[P-F.7]
Composition of plant virgin oils obtained from Oleaceae fruits
Determination of Polyphenol Oxidase Activity Using the Oxidoreduction Potential Method Rana
Mustafa ∗ ,
Duried Alwazeera
Department of Food Engineering, Faculty of Chemical and Petroleum Engineering, University of Al Baath, BO Box 77 Homs, Syrian Arab Republic Keywords: Myceliophthora thermophila laccase; Polyphenol oxidase; Enzyme kinetic; Oxido-reduction potential; Phenolic compound Polyphenol oxidases (PPOs) oxidize the phenolic compounds forming quinones, which exhibited non enzymatic reactions to develop color end compounds. The methods actually used to determine the activity of PPOs cannot permit to separate and distinguish between enzymatic and non enzymatic steps of phenolic compounds oxidation. This research aims to found a novel method to measure the activity of PPOs monitoring the measurement of oxidoreduction potential (ORP) of reaction. The results of this study showed that the monitoring of ORP of reaction medium permitted to determine the beginning and the end of enzymatic oxidation step of phenolic compound. It also allowed researchers to distinguish enzymatic step from non enzymatic one, which was not possible when using absorbance measurement method. No significant differences were observed between the kinetic parameters of enzymatic reaction (Km , Vmax ) determined by both absorbance and ORP methods. doi:10.1016/j.jbiotec.2010.09.250 [P-F.8] The effect of some plant extracts on polyphenol oxidase activity and enzymatic browning Rana Mustafa ∗ , Duried Alwazeer Department of Food Engineering, Faculty of Chemical and Petroleum Engineering, University of Al Baath, BO Box 77 Homs, Syrian Arab Republic Keywords: Polyphenol oxidase; inhibitory effect; enzymatic browning; Phenolic compound The aim of this study was to investigate the inhibitory effect of garlic, pineapple and olive leaf aqueous extract on banana, apple and potato polyphenol oxidase enzymatic browning.
doi:10.1016/j.jbiotec.2010.09.251
I. Muzzalupo 1,2,∗ , A. Russo 1 , A. Chippetta 3 , E. Romano 1 , E. Perri 1 1
CRA-Centro di Ricerca per l’olivicoltura e l’industria olearia (CRAOLI), Italy 2 CRA-Centro di Ricerca per le produzioni foraggere e lattiero-casearie (CRA-FLC), Italy 3 Università degli Studi della Calabria, Dip. di Ecologia, Italy Keywords: Food quality; Minor polar compounds; Fatty acid; Antioxidants
Virgin oils are primary metabolites of many higher plants that are economically important as sources of food and industrial oils. Chemically, plant oils are rich of triglycerides, made of different fatty acids. The virgin olive oil contain about 96-98% of the saponificable fraction. Oleic acid is the principal component (70-80%) of this matrix, succeeding linoleic (12%) and palmitic (6.5%) acids. Unsaponificable fraction contains: terpenes, chlorophylls tocopherols, sterols and phenolic compounds. Secoiridoids, like aglycone derivatives of oleuropein, demethyloleuropein and ligstroside, are present in olive fruit as most abundant virgin olive oil phenolic antioxidants. Several important biological activities (antioxidant, anti-inflammatory, chemopreventive and anti-cancer) and the characteristic pungent and bitter tasty properties have been attributed to virgin olive oil phenols. The olive tree is a member of the Oleaceae family, which contains the genera Fraxinus, Forsythia, Forestiera, Ligustrum and Syringa, as well as the genus Olea. Commercial olives are products of the Olea europaea L. species. Olive (Olea europaea L.) is a perennial evergreen tree that has grown naturally and been cultivated widely in the Mediterranean for centuries. The aim of this study was to compare the phenolics and fatty acids composition in two different olive oils. Particularly, one sample is obtained from ‘Coratina’ cultivar and the other is obtained from virgin Oleaceae oil (‘Coratina’ + other Oleaceae fruit). The procedure applied for the last sample preparation and analytical investigation is patent pending. Quali-quantitative analysis (performed by HPLC-MS/MS and GC-MS/MS) could be a useful tool to better correlate the typicity of the virgin Oleaceae oil with its phenolic compounds and fatty acids profile. Further studies are in progress to isolate unknown compounds and to further investigate the quality index of this food product. doi:10.1016/j.jbiotec.2010.09.252