Characterization of Eucalyptus, Chestnut and Heather Honeys from Portugal Using Multi-Parameter Analysis and Chemo-Calculus

Abstract

The present study was conducted to evaluate the quality and bio-functional properties of Portuguese honeys of different botanical and geographical origins. Quality parameter analyses included the determination of palynological (predominant, secondary, minor and isolated pollen percentage), physicochemical (°Brix, moisture content, pH, electrical conductivity, free acidity, total dissolved solids, salinity, vitamin C content and specific weight) including colour-metrics (CIELAB, Pfund and colour intensity determinations), along with volatile compounds identification using solid phase micro-extraction coupled to gas chromatography mass spectrometry. Bio-activity parameter analysis included the determination of in vitro antioxidant activity and total phenolic content using the 2,2-diphenyl-1-picryl-hydrazyl and Folin-Ciocalteu assays, respectively. Melissopalynological analysis showed that Portuguese honeys were classified as eucalyptus, chestnut and heather, recording significant variations (p < 0.05) among physicochemical, volatile and bio-activity parameter analyses according to both: botanical and geographical origin. Based on the multi-parameter analysis data Portuguese honeys could be characterized by a distinctive colour, a characteristic aroma, whereas conform to the European legislation relating to honey identity and quality. Specific attention should be given in the case of heather honey which showed the highest in vitro antioxidant activity and total phenolic content. Parameters that were also highly correlated using bivariate statistics.

Authentication of honeys from Caramulo region (Portugal): Pollen spectrum, physicochemical characteristics, mineral content, and phenolic profile

“…In the present study, all samples had a percentage of moisture content below the imposed limit of ≤20%, the maximum acceptable moisture content of honey by the European Community Directive (Ministry of Agriculture, Rural Development and Fisheries, ; Codex Alimentarius, ). The results presented herein are in accordance with those of other works (Can et al., ; Estevinho et al., ; Karabagias et al., ; Silva et al., , ; Zhou et al., ).…”

“…All samples are below the maximum limit allowed (800 µs/cm) by Portuguese and European legislation (Ministry of Agriculture, Rural Development and Fisheries, ; Codex Alimentarius, ). These values are similar to those found in other studies (Belay et al., ; Karabagias et al., ; Louppis, Karabagias, Kontakos, Kontominas, & Papastephanou, ; Mondragón‐Cortez et al., ; Silva et al., ; Zhou et al., ). Several works reported that a linear relationship exists between the ash content and the electrical conductivity (Buba et al., ; Mondragón‐Cortez et al., ; Silva et al., , ).…”

“…Additionally, the total acidity varied between 20.1 ± 0.55 (CM16) and 54.3 ± 2.1 (CM1) meq/kg, with an average of 35.1 ± 11.28 meq/kg (Table ). These results are similar to those reported earlier for Portuguese honeys (mean values of 14.3 and 40.3 meq/kg for free acidity, 5.7 and 9.6 meq/kg for lactonic acidity, and 31.2 and 39.3 meq/kg for total acidity) (Estevinho et al., ; Karabagias et al., ; Silva et al., , ), and for samples collected from other sites (10.31 to 39.8 meq/kg for free acidity, 2.8 to 21.4 meq/kg for lactone acidity, and between 6.22 and 36.6 meq/kg for total acidity) (Louppis et al., ; Mondragón‐Cortez et al., ; Terrab et al., ).…”

“…The total soluble solids were measured as °Brix, and anomalous values are an indicator of adulteration (Andrade et al., ). The analyzed honey samples presented values of Brix degree that varied between 79.5 ± 0.50 (CM8) and 82.3 ± 0.29 (CM7) °Brix, with an average of 81.4 °Brix (Table ), being within the proposed limits (Codex Alimentarius, ), and in accordance with other Portuguese honeys (Andrade et al., ; Karabagias et al., ; Silva et al., , ), and from Brazil (72.5 to 80.0 °Brix) (Silva et al., ), Mexico (79.1 to 81.6 °Brix) (Mondragón‐Cortez et al., ), and Spain (78.8 to 84.0 °Brix) (Terrab et al., ).…”

“…The obtained results are in accordance with the Portuguese legislation (Ministry of Agriculture, Rural Development and Fisheriesugal, 2003) and are within the standard limit that ensures the freshness of honey samples (pH 3.40 ± 0.002 to 6.10 ± 0.003) (Bogdanov et al, 1999). Furthermore, the results of this study are consistent with other from previous studies, namely, in Portuguese honeys from Castelo Branco (3.34 to 5.33) , Luso (3.45 to 4.70) (Silva et al, 2009), Trás-Os-Montes (3.50 to 4.00) (Estevinho et al, 2012), and Braga (3.62 to 4.42) (Karabagias et al, 2018), and also similar to Italian (3.89 to 5.42) (Truzzi et al, 2014), Spanish (3.56 to 4.79) (Terrab et al, 2004), and Brazilian (2.96 to 4.95) honeys .…”