Effect of the extraction method on phytochemical composition and antioxidant activity of high dietary fibre powders obtained from asparagus by-products

Abstract

a b s t r a c tAsparagus (Asparagus officinalis L.) spears are highly appreciated for their composition of bioactive compounds. The method by which their by-products are treated affects the phytochemical composition and antioxidant activity of the fibre-rich powders. Factors such as the treatment intensity, the solvent used, and the drying system were studied. Among the asparagus phytochemicals, hydroxycinnamic acids (HCA), saponins, flavonoids, sterols, and fructans were quantified. HCA varied from 2.31 and 4.91 mg/g of fibre, the content being affected by the drying system and, in some cases, the solvent. Fibres from intense treatments had significantly higher amounts of saponin than samples isolated by gentle treatments. Saponin content ranged from 2.14 to 3.64 mg/g of fibre. Flavonoids were the most affected by processing conditions, being present (0.6-1.8 mg/g of fibre) only in three of the samples analysed. Continuous stirring during processing could be the main reason for this result. Sterols and fructans were present in minor amounts, 0.63-1.03 mg/g of fibre and 0.2-1.4 mg/g of fibre, respectively. Soluble and total antioxidant activities were also measured. Fibres with the highest activities corresponded to those with the highest levels of flavonoids and HCA.

Valorization of Tunisian secondary date varieties (Phoenix dactylifera L.) by hydrothermal treatments: New fiber concentrates with antioxidant properties

“…Despite the decrease in WHC, the obtained values are in the range of other agricultural byproducts proposed as valuable dietary fiber sources, such as pear pomace, 5 mL water/g (Mckee & Latner, 2000) and grapefruit peel, 8.5 mL water/g (Larrauri, Rup erez, Borroto, & Saura-Calixto, 1997). Of great interest was the high value of OHC which was similar to the highest values found in the bibliography, 5e8 mL/g for asparagus byproduct (Fuentes-Alventosa et al, 2009). These results for WHC and OHC make date FC valuable as texture or viscosity modifier.…”

“…The antiradical activity of the insoluble residue after ethanol extraction was evaluated as described by Fuentes-Alventosa et al (2009). As for soluble antiradical activity, EC 50 was also calculated.…”

Development of a Rapid HPLC‐UV Method for Simultaneous Quantification of Protodioscin and Rutin in White and Green Asparagus Spears

“…Asparagus ( Asparagus officinalis L.) spears are highly valued for their abundance of bioactive compounds, such as saponins, flavonoids, hydroxycinnamic acids, sterols, fructan, carotenoids, and amino acids (Deli and others 2000; Fuentes‐Alventosa and others 2009a, 2009b). There is increasing interest in asparagus saponins, which have several health‐promoting properties.…”

“…Several methods are currently in use for the analysis of saponins or protodioscin in herbal medicinal plants, rat plasma membranes, and asparagus. The most commonly used protocols include a colorimetric method based on reactive anisaldehyde‐sulphuric acid‐acetic acid for thin‐layer chromatography (TLC) staining (Fuentes‐Alventosa and others 2009a), high‐performance TLC with postchromatographic derivatization using anisaldehyde‐reagent (Ganzera and others 2001; Schwarzbach and others 2006), high‐performance liquid chromatography (HPLC) (Shimoyamada and others 1996), and liquid chromatography (LC)‐mass spectrometry (MS) or MS/MS methods (Wang and others 2003; Wang and others 2007a, 2007b; Dinchev and others 2008). …”

Activity of water-soluble turmeric extract using hydrophilic excipients

“…The processing conditions used during extraction often degrade, alter, or lose some of the more unstable principle components, aromas, flavors, or pigments. Flavonoids, which are mainly responsible for antioxidant activity, get affected by oxidation and lost under most processing conditions, decreasing the overall antioxidant potential (Fuentes-Alventosa et al, 2009).…”