Ivone Almeida - Academia.edu (original) (raw)

Papers by Ivone Almeida

Research paper thumbnail of Isoflavones in Coffee: Influence of Species, Roast Degree, and Brewing Method

Journal of Agricultural and Food Chemistry, 2010

This paper reports the isoflavone contents of roasted coffee beans and brews, as influenced by co... more This paper reports the isoflavone contents of roasted coffee beans and brews, as influenced by coffee species, roast degree, and brewing procedure. Total isoflavone level is 6-fold higher in robusta coffees than in arabica ones, mainly due to formononetin. During roasting, the content of isoflavones decreases, whereas their extractability increases (especially for formononetin). Total isoflavones in espresso coffee (30 mL) varied from approximately 40 microg (100% arabica) to approximately 285 microg (100% robusta), with long espressos (70 mL) attaining more than double isoflavones of short ones (20 mL). Espressos (30 mL) prepared from commercial blends contained average amounts of 6, 17, and 78 microg of genistein, daidzein, and formononetin, respectively. Comparison of different brewing methods revealed that espresso contained more isoflavones ( approximately 170 microg/30 mL) than a cup of press-pot coffee ( approximately 130 microg/60 mL), less than a mocha coffee ( approximately 360 microg/60 mL), and amounts similar to those of a filtered coffee cup ( approximately 180 microg/120 mL).

Research paper thumbnail of Dietary antioxidant supplements: Benefits of their combined use

Food and Chemical Toxicology, 2011

Several dietary supplements claim medicinal benefits due to their composition in hydrophilic and ... more Several dietary supplements claim medicinal benefits due to their composition in hydrophilic and lipophilic molecules, natural extracts or synthetic compounds with antioxidant properties. In the present work, the antioxidant activity of selected supplements taken in pills, capsules or infusions were studied either individually or combined. Linear discriminant analysis (LDA) was used to categorize the condensed formulations (pills and capsules), infusion bags and combined samples according with their antioxidant activity measured by radical scavenging activity, reducing power and lipid peroxidation inhibition using brain homogenates as models. AAF proved to have the highest antioxidant activity in all the assayed methods, either singly taken or included in mixtures. Furthermore, the mixtures containing this supplement revealed synergistic effects in 92% of the cases. The intake of antioxidant mixtures might provide some additional benefits.

Research paper thumbnail of Method development and validation for isoflavones quantification in coffee

Food Chemistry, 2010

... Isoflavones are mainly characterised as weak estrogens (Franke, Custer, Cerna, & Narala, ... more ... Isoflavones are mainly characterised as weak estrogens (Franke, Custer, Cerna, & Narala, 1994), and their role in modulating hormone-dependent processes is ... For that reason, a previous purification by solid-phase extraction is usually recommended (Grace & Teale, 2006). ...

Research paper thumbnail of Isoflavones in Coffee: Influence of Species, Roast Degree, and Brewing Method

Journal of Agricultural and Food Chemistry, 2010

This paper reports the isoflavone contents of roasted coffee beans and brews, as influenced by co... more This paper reports the isoflavone contents of roasted coffee beans and brews, as influenced by coffee species, roast degree, and brewing procedure. Total isoflavone level is 6-fold higher in robusta coffees than in arabica ones, mainly due to formononetin. During roasting, the content of isoflavones decreases, whereas their extractability increases (especially for formononetin). Total isoflavones in espresso coffee (30 mL) varied from approximately 40 microg (100% arabica) to approximately 285 microg (100% robusta), with long espressos (70 mL) attaining more than double isoflavones of short ones (20 mL). Espressos (30 mL) prepared from commercial blends contained average amounts of 6, 17, and 78 microg of genistein, daidzein, and formononetin, respectively. Comparison of different brewing methods revealed that espresso contained more isoflavones ( approximately 170 microg/30 mL) than a cup of press-pot coffee ( approximately 130 microg/60 mL), less than a mocha coffee ( approximately 360 microg/60 mL), and amounts similar to those of a filtered coffee cup ( approximately 180 microg/120 mL).

Research paper thumbnail of Dietary antioxidant supplements: Benefits of their combined use

Food and Chemical Toxicology, 2011

Several dietary supplements claim medicinal benefits due to their composition in hydrophilic and ... more Several dietary supplements claim medicinal benefits due to their composition in hydrophilic and lipophilic molecules, natural extracts or synthetic compounds with antioxidant properties. In the present work, the antioxidant activity of selected supplements taken in pills, capsules or infusions were studied either individually or combined. Linear discriminant analysis (LDA) was used to categorize the condensed formulations (pills and capsules), infusion bags and combined samples according with their antioxidant activity measured by radical scavenging activity, reducing power and lipid peroxidation inhibition using brain homogenates as models. AAF proved to have the highest antioxidant activity in all the assayed methods, either singly taken or included in mixtures. Furthermore, the mixtures containing this supplement revealed synergistic effects in 92% of the cases. The intake of antioxidant mixtures might provide some additional benefits.

Research paper thumbnail of Method development and validation for isoflavones quantification in coffee

Food Chemistry, 2010

... Isoflavones are mainly characterised as weak estrogens (Franke, Custer, Cerna, & Narala, ... more ... Isoflavones are mainly characterised as weak estrogens (Franke, Custer, Cerna, & Narala, 1994), and their role in modulating hormone-dependent processes is ... For that reason, a previous purification by solid-phase extraction is usually recommended (Grace & Teale, 2006). ...