PHENOLIC COMPOUNDS PROFILE OF A MIXED BEVERAGE ADDED WITH DIFFERENT VARIETIES OF FLORAL HONEY

Introduction
A balanced diet, including the consumption of fruits and vegetables and their derived products, contributes to the health maintenance. These protective effects are partly due to the high contents of bioactive compounds present in these foods, specially the phenolic compounds class. The association of different food sources that containing nutrients and bioactive compounds is interesting and the development of a mixed beverage of apple and passion fruit serves this purpose. The addition of honey in mixed beverages is interesting as it gives to this beverage a sweet taste and adds nutritional value by the increment of other phenolic compounds.
Objective
To evaluate the phenolic compounds profile of a mixed beverage made with apple and passion fruits and with different varieties of floral honey.
Methods
Control mixed beverage (CMB) was obtained by mixing water, passion fruit and apple with a blander without any. For mixed beverage with honey, four types of honey (orange blossom, eucalyptus, multifloral and “assa-peixe”) were added. Beverages were centrifuged and filtered through a 0.45 µm PTFE filter prior to analysis by HPLC-DAD-MS. A C-18 reverse phase column was used for chromatographic separation. The mobile phase consisted of a gradient of 1% aqueous formic acid (eluent A) and acetonitrile (eluent B) at a flow rate of 1.0 mL/min. Phenolic compounds were monitored by DAD from 190 to 370 nm. The ESI interface was operated in SCAN negative mode for phenolic compounds ionization. Identification of phenolics was performed by comparison with retention time, absorption spectrum and pseudomolecular ions of the respective standard. Quantification was performed by external calibration. ANOVA (p≤0.05) followed by Tukey's multiple comparison post-test was performed using GraphPad Prism and these experiments were made in triplicate.
Results and discussion
Total phenolic contents in CMB (20.24±0.23 mg/100 mL) was similar to that observed for beverage added with eucalyptus honey (19.20±0.10 mg/100 mL). These contents were higher than that observed for beverages added with orange blossom (18.58±0.06 mg/100 mL), “assa-peixe” (17.26±0.01 mg/100 mL) and multifloral (17.94±0.34 mg/100 mL) honeys.
Seven phenolic compounds (5-caffeoylquinic acid, 4-caffeoylquinic acid, catechin, quercetin-3-O-glucoside, kaempferol-3-O-hexoside and two isomers of p-coumaroylquinic acid) were identified in CMB, being 5-caffeoylquinic acid the most abundant phenolic (9.54±0.09 mg/100 mL; 47% of total phenolic contents). Beverages added with honey presented the same seven phenolics in addition to quercetin. In these honey mixed beverages 5-CQA was also the major phenolic (7.06±0.41 mg/100 mL, on average; representing 39% of total phenolics).
Catechin contents were higher in beverages added with honeys (4.11±0.38 mg/100 mL, on average) when compared to CMB (1.53±0.16 mg/100 mL). Quercetin contents were higher in beverage added with eucalyptus honey (1.40±0.04 mg/100 mL) when compared to beverages added with multifloral, orange blossom and “assa-peixe” honeys (1.14±0.03 mg/100 mL, on average).

Conclusions
The addition of eucalyptus honey in the mixed beverage showed to be interesting due to the higher contents and variety of phenolic compounds.

Financial support
CAPES, CNPq, FAPERJ, UFRJ