Antioxidant Activity of Ethanolic Extracts from Several Asparagus Cultivars

Abstract

Three different methods (antiradical activity, inhibition of primary oxidation, and ferric reducing power) have been used to evaluate the antioxidant activity of eight different asparagus cultivars and byproducts: white and green asparagus from Alcalá del Río (Guadalquivir Valley, Seville) and American hybrids, native spears, and their byproducts from Huétor-Tájar (Vega de Granada). The correlation between antioxidant activity and total phenol content was studied. Six standards were also tested to validate the modified methods for antioxidant activity determination. Results obtained for antiradical capacity and reducing power were very similar, and a high correlation with phenols was found (R > or = 0.9 for both tests). Sample origin was an important factor, spears from Huétor-Tájar having higher values (ARC between 7 and 10 and P(R) of 0.25-0.33) than those from Alcalá del Río (ARC 0.6-2 and P(R) of 0.05-0.07). Significant differences were found between spears with the same origin, suggesting that genetics are another factor to take into account. Asparagus inhibits lipid primary oxidation, but no correlation between the inhibition percentage and phenols was observed. Asparagus origin was the only factor that led to significant differences: samples from Huétor-Tájar had higher values (POIC between 18 and 32) than those from Alcalá del Río (POIC of 5-9). Byproducts from the canning industry at Huétor-Tájar were also assayed for antioxidant activity; the results obtained suggested that byproducts could be considered as an excellent source of natural antioxidants.

Heinz body anaemia in two dogs after Catalan spring onion ("calcot") ingestion: a case report

“…It has been shown that, compared to other onions, it reduces their content in flavonoids, a group of polyphenolic compounds with antioxidant activity (Santas et al, 2008), probably in a similar way to what occurs to white asparagus (Rodriguez et al, 2005). According to their differential flavour, pungency and odour -characteristics known to be associated with organosulphur compounds (Jones et al, 2004;Lanzotti, 2006) -"calcots" also probably contain lower, but still significant, levels of these toxins.…”

“…It is planted, replanted and successively covered in soil in order to prevent photosynthesis, so that the edible part remains white. The process is similar to the production of white asparagus (Asparagus officinalis), another liliaceae, a fact that explains the differences between the organoleptic and chemical composition of the white and green types of this vegetable (Rodriguez et al, 2005). The "calcot" is collected young, before the plant fully develops, and is 15-25 cm long and 1.7-2.5 cm diameter in the edible stem (onion bulb not yet present), which makes its shape similar to a green onion, but with a distinctive colour and flavour.…”

Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under diff erent sunlight conditions

“…The effi ciency of the extraction processes is dependent on the properties of the compounds extracted, or their solubility in the solvent used (Rodríguez et al, 2005;Suhaj, 2006). According to the general principle .…”

In Vitro Antioxidant Activity of Aqueous Ethanol Extract of Flacourtia Indica Merr.

“…As the odd electron of the radical becomes paired off in the presence of a hydrogen donor that is a free radical scavenging antioxidant the absorption strength decreases and the resulting decolorization is stiochiometric with respect to the number of electrons captured 26 . This reaction has been widely used to test the ability of compounds to act as free radical scavengers or hydrogen donors and to evaluate the anti-oxidative activity of foods and plant extracts [27][28][29][30] . The extract showed to possess DPPH radical scavenging ability as compared to the standard.…”