Portuguese Honeys from Different Geographical and Botanical Origins: A 4-Year Stability Study Regarding Quality Parameters and Antioxidant Activity

Abstract

Portuguese honeys (n = 15) from different botanical and geographical origins were analysed regarding their quality parameters (diastase activity, hydroxymethylfurfural content, moisture and pH), colour (L*, a*, b*) and antioxidant profile (total phenolics content, total flavonoids content, DPPH• scavenging activity, and ferric reducing power). The samples were analysed fresh and after 4-years of storage (at 25 °C and protected from light). The hydroxymethylfurfural content and diastase activity of the fresh samples were in accordance with the recommended values described in the legislation. In general, the antioxidant activity of the samples correlated more with the bioactive compounds content than with colour. The storage affected differently each individual sample, especially regarding the antioxidant profile. Nevertheless, although in general the lightness of the samples decreased (and the redness increased), after 4 years, 11 samples still presented acceptable diastase activity and hydroxymethylfurfural values.

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

“…In relation to the dark colour of heather honey, this is probably due to the contribution of chestnut in its pollen spectrum. Even though one heather honey sample was used in the study, this preliminary finding in nature agrees with the results of Soares et al [21], involving heather honey produced in North and Centre Portugal (Vila Real, Bragança, Chaves, Boticas, Lousã, Penamacor, Vila Nova de Foz Côa and Viseu). In addition, greenish (negative a * values) and yellow components (positive b * values) (pigments) were present in all honey samples analysed in conformity with the aforementioned work [21].…”

“…The CIELAB system uses three parameters to evaluate colour in foodstuffs: (i) colour parameter L* corresponds to the degree of brightness; (ii) colour parameter a* (positive values) corresponds to the degree of redness and when a * shows negative values to the degree of greenness; and (iii) parameter b * corresponds to yellowness of colour (when positive) and to blueness of colour (when negative). What is remarkable is that the units within the L* , a* , b* system may provide equal perception of the colour difference to a human observer [21].…”

“…Even though there are previously published studies in the literature that highlight physicochemical composition and bio-functional properties, including that is, antioxidant and antimicrobial activity of Portuguese honeys [14,15,16,17,18,19,20,21], there is no study that combines palynological, physicochemical, volatile compounds and bio-activity parameter analysis data, to characterize Portuguese eucalyptus, chestnut and heather honeys, this contributing some new amendments to the state of the art.…”

The Antibacterial Activity of Libyan Honey against Gram Negative Bacilli: Potential Treatment Agent for Infectious Diseases?

“…However, in accord to the difference between the honey concentrations, undiluted (100% concentrations) were the most effective. Several authors have reported that different honey types vary substantially in the potency of their antibacterial activities, probably attributed to the natural variations in floral sources of nectar and geographical origins or chemical composition [27][28][29]. Likewise, the results generated from this study may be due to the collection of the representative samples of honey from different geographical locations in Libya.…”

Honey and Its Role in Relieving Multiple Facets of Atherosclerosis

“…It is known that diastase activity is low and HMF value is high in heated honey [60,61]. Even though the enzyme activity is much more variable than the HFM value of a honey, they are both used for the selection of appropriate processing and packaging techniques among technological applications of natural honey [62].…”