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Papers by Claudia Veneziani Passos

ABSTRACT Procyanidins are polyphenolic compounds containing flavan-3-ol units linked by C4- C8 or... more ABSTRACT Procyanidins are polyphenolic compounds containing flavan-3-ol units linked by C4- C8 or C4-C6 bonds (type-B structures) or doubly linked by an additional C2-C7 acetal bond (type-A structures). Gallic acid can occur as an ester at C3 position. In grape seed tissues, procyanidins represent more than 70% of the total flavan-3-ol composition. Procyanidins have been described to possess a wide spectrum of pharmacological and therapeutic effects such as antioxidant, anti-inflammatory, and antimicrobial abilities, as well as significant cardioprotective properties and potential high blood pressure lowering benefit. The degree of polymerisation of procyanidins may influence their action intensity, which suggests previous fractionation of crude extracts in order to inspect such relation. These issues are addressed in this chapter for the specific cases of the antioxidant activity and the inhibitory action upon Angiotensin I-converting enzyme (ACE). ACE catalyses the production of Angiotensin II (powerful vasoconstrictor) and inhibits bradykinin (powerful vasodilator). Hence, procyanidins may have potential action in lowering both systolic and diastolic blood pressure values.

Chlorogenic acids are the main phenolic compounds present in coffee grounds, reaching about 7% of... more Chlorogenic acids are the main phenolic compounds present in coffee grounds, reaching about 7% of its constitution [1]. These acids are a family of esters formed by quinic acid and trans-cinnamic acids, mainly caffeic, ferulic, and p-coumaric. Several chlorogenic acids have already been identified in coffee grounds, being 5-O-caffeoylquinic acid the most abundant [2]. Many beneficial effects have been attributed to these compounds due to their antioxidant activity, such as protective activity against chronic degenerative diseases and carcinogenesis, among others [3]. Several studies had demonstrated that these phenolic compounds still remain in the spent coffee after the beverage preparation. Therefore, the coffee residue can be considered a good raw material with low costs associated, and with great potential to be used for the attainment of bioactive compounds and for their use as food additives [4]. Microwave assisted extraction (MAE) has recently gained much interest on investig...

Food Chemistry, 2014

Instant coffee was prepared and fractionated into higher (&am... more Instant coffee was prepared and fractionated into higher (>100kDa), medium (5-10, 10-30, 30-100kDa) and lower (1-5, <1kDa) molecular weight fractions. Sugars and linkage composition characteristics of arabinogalactans and galactomannans were recovered in all fractions. Also, amino acid analysis performed after hydrolysis showed similar compositions in all fractions. On the contrary, free chlorogenic acids and caffeine were only detected in the lowest molecular weight fraction (<1kDa). A direct relationship between the melanoidins browning index and the molecular weight was observed. The fractions obtained were incubated in vitro with murine spleen lymphocytes in order to evaluate their possible immunostimulatory abilities. The surface expression of CD69 (early activation marker) on different lymphocyte sub-populations showed that the fraction with 1-5kDa was able to induce activation of B-lymphocytes. This was the only fraction to induce B-lymphocyte activation, since all the other fractions failed, even when higher concentrations were used.

Carbohydrate Polymers, 2013

The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source o... more The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source of polysaccharides. In the present work, the feasibility of microwave superheated water extraction of polysaccharides from SCG was studied. Different ratios of mass of SCG to water, from 1:30 to 1:5 (g:mL) were used for a total volume of 80 mL. Although the amount of material extracted/batch (MAE1) increased with the increase of the concentration of the sample, the amount of polysaccharides achieved a maximum of 0.57 g/batch for 1:10. Glycosidic-linkage composition showed that all extraction conditions allowed to obtain mainly arabinogalactans. When the unextracted insoluble material was re-extracted under the same conditions (MAE2), a further extraction of polysaccharides was observed (0.34 g/batch for 1:10), mainly galactomannans. Also, a high amount of oligosaccharides, mainly derived from galactomannans, can be obtained in MAE2 (0.96 g/batch for 1:10). This technology allows to obtain galactomannans and arabinogalactans in proportions that are dependent on the operating conditions.

Food Chemistry, 2009

ABSTRACT The application of an enzymatic pre-treatment to increase the yield of grape seed oil ex... more ABSTRACT The application of an enzymatic pre-treatment to increase the yield of grape seed oil extraction was studied. Experiments were carried out to measure the effects that reaction time, temperature, pH, particle size and enzyme concentration have upon the enzymatic activity.The following set of parameters was optimised: time = 24 h, pH 4, temperature 30–40 °C, particle diameters 1.0–1.4 mm, and cocktail concentration of: cellulase = 29, protease = 1191, xylanase = 21, and pectinase = 569 U/g of seed sample. The extraction yield was 13.7%, which represents an increment of 106% over non-treated samples. For 120 h the yield achieved was 17.5%, and the increment reached 163%. Such results indicate that a prolonged enzymatic treatment may certainly be used to enhance oil extraction.

ABSTRACT Procyanidins are polyphenolic compounds containing flavan-3-ol units linked by C4- C8 or... more ABSTRACT Procyanidins are polyphenolic compounds containing flavan-3-ol units linked by C4- C8 or C4-C6 bonds (type-B structures) or doubly linked by an additional C2-C7 acetal bond (type-A structures). Gallic acid can occur as an ester at C3 position. In grape seed tissues, procyanidins represent more than 70% of the total flavan-3-ol composition. Procyanidins have been described to possess a wide spectrum of pharmacological and therapeutic effects such as antioxidant, anti-inflammatory, and antimicrobial abilities, as well as significant cardioprotective properties and potential high blood pressure lowering benefit. The degree of polymerisation of procyanidins may influence their action intensity, which suggests previous fractionation of crude extracts in order to inspect such relation. These issues are addressed in this chapter for the specific cases of the antioxidant activity and the inhibitory action upon Angiotensin I-converting enzyme (ACE). ACE catalyses the production of Angiotensin II (powerful vasoconstrictor) and inhibits bradykinin (powerful vasodilator). Hence, procyanidins may have potential action in lowering both systolic and diastolic blood pressure values.

Chlorogenic acids are the main phenolic compounds present in coffee grounds, reaching about 7% of... more Chlorogenic acids are the main phenolic compounds present in coffee grounds, reaching about 7% of its constitution [1]. These acids are a family of esters formed by quinic acid and trans-cinnamic acids, mainly caffeic, ferulic, and p-coumaric. Several chlorogenic acids have already been identified in coffee grounds, being 5-O-caffeoylquinic acid the most abundant [2]. Many beneficial effects have been attributed to these compounds due to their antioxidant activity, such as protective activity against chronic degenerative diseases and carcinogenesis, among others [3]. Several studies had demonstrated that these phenolic compounds still remain in the spent coffee after the beverage preparation. Therefore, the coffee residue can be considered a good raw material with low costs associated, and with great potential to be used for the attainment of bioactive compounds and for their use as food additives [4]. Microwave assisted extraction (MAE) has recently gained much interest on investig...

Food Chemistry, 2014

Instant coffee was prepared and fractionated into higher (&am... more Instant coffee was prepared and fractionated into higher (>100kDa), medium (5-10, 10-30, 30-100kDa) and lower (1-5, <1kDa) molecular weight fractions. Sugars and linkage composition characteristics of arabinogalactans and galactomannans were recovered in all fractions. Also, amino acid analysis performed after hydrolysis showed similar compositions in all fractions. On the contrary, free chlorogenic acids and caffeine were only detected in the lowest molecular weight fraction (<1kDa). A direct relationship between the melanoidins browning index and the molecular weight was observed. The fractions obtained were incubated in vitro with murine spleen lymphocytes in order to evaluate their possible immunostimulatory abilities. The surface expression of CD69 (early activation marker) on different lymphocyte sub-populations showed that the fraction with 1-5kDa was able to induce activation of B-lymphocytes. This was the only fraction to induce B-lymphocyte activation, since all the other fractions failed, even when higher concentrations were used.

Carbohydrate Polymers, 2013

The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source o... more The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source of polysaccharides. In the present work, the feasibility of microwave superheated water extraction of polysaccharides from SCG was studied. Different ratios of mass of SCG to water, from 1:30 to 1:5 (g:mL) were used for a total volume of 80 mL. Although the amount of material extracted/batch (MAE1) increased with the increase of the concentration of the sample, the amount of polysaccharides achieved a maximum of 0.57 g/batch for 1:10. Glycosidic-linkage composition showed that all extraction conditions allowed to obtain mainly arabinogalactans. When the unextracted insoluble material was re-extracted under the same conditions (MAE2), a further extraction of polysaccharides was observed (0.34 g/batch for 1:10), mainly galactomannans. Also, a high amount of oligosaccharides, mainly derived from galactomannans, can be obtained in MAE2 (0.96 g/batch for 1:10). This technology allows to obtain galactomannans and arabinogalactans in proportions that are dependent on the operating conditions.

Food Chemistry, 2009

ABSTRACT The application of an enzymatic pre-treatment to increase the yield of grape seed oil ex... more ABSTRACT The application of an enzymatic pre-treatment to increase the yield of grape seed oil extraction was studied. Experiments were carried out to measure the effects that reaction time, temperature, pH, particle size and enzyme concentration have upon the enzymatic activity.The following set of parameters was optimised: time = 24 h, pH 4, temperature 30–40 °C, particle diameters 1.0–1.4 mm, and cocktail concentration of: cellulase = 29, protease = 1191, xylanase = 21, and pectinase = 569 U/g of seed sample. The extraction yield was 13.7%, which represents an increment of 106% over non-treated samples. For 120 h the yield achieved was 17.5%, and the increment reached 163%. Such results indicate that a prolonged enzymatic treatment may certainly be used to enhance oil extraction.