Unifloral clover honeys of Argentina. characterization of antioxidant potential, flavonoid content and colour.

MIRIAM OFELIA IURLINA; AMELIA IVONE SAIZ; MARIA FLORENCIA FANGIO; ROSALÍA FRITZ

Ciudad Autónoma de Buenos Aires

Congreso; Congreso Internacional Apimondia; 2011

SADA y APIMONDIA

There is an special interest in dietary antioxidants due to their protective effect against to oxidative damage. Honey contains different compounds with antioxidant capacity such as phenolic acids and flavonoids. Honeys came from diffrent botanical and geographical sources show differences in composition and antioxidant capacity. The aim of this study was to determine in vitro the antioxidant potential, flavonoid content and colour of honeys with a predominance of clover pollen. In addition, data were statistically tested using principal component analysis (PCA) with the aim of classifying honeys and identifying the most significant parameters. Honeys came from different regions of Argentina were analyzed, being the botanical source confirmed by pollen analysis. The phenolic compound content was determined according to the Folin?Ciocalteu method. The antioxidant capacity was determined by scavenging of the radical 2,2 diphenyl- 1- pycrilhydrazyl (DPPH). The total flavonoid content and colour were measured using a spectrophotometric method. Honeys were clustered as: 1) unifloral honeys were from Trifolium sp., Melilotus sp., Medicago sativa, Lotus sp., 2) clover honeys had a prevalence for the pollen above mentioned higher than 45%, when these types are considered all together, 3) mixed honeys when the  dominance of these pollen was between 16-45%. Samples were identified as light honeys, varying from extra white to light amber. Medicago sativa honeys showed the lowest phenolic compound content, expressed as gallic equivalent, being in average value 19 mg/100g of honey. The radical scavenging activity, expressed as inhibition perentage of DPPH, showed that this activity varied among the different honeys. The highest content of total flavonoid expressed as mg of quercetin corresponded to Lotus sp. being in average value 5,05 mg/100g of honey. The PCA analysis showed that the studied parameters allowed to discriminate to Lotus sp. honeys, being flavonoid content the variable with the greatest discriminatory power.