A survey of the in vitro antifungal activity of heather (Erica sp.) organic honey

Monofloral heather (Erica sp.) honey samples (n = 89), harvested in Portugal according to European organic beekeeping rules, were analyzed to test their antifungal effect against Candida albicans, Candida krusei, and Cryptococcus neoformans. A synthetic honey solution was also tested to determine antifungal activity attributable to sugars. The specific growth rate (l) values showed that growth of all the yeasts was reduced in the presence of honey. The honey concentration (% wt/vol) that inhibited 10% of the yeast growth (Xmin) was 13.5% for C. albicans, 20.5% for C. krusei, and 17.1% for C. neoformans. The respective concentrations of heather honey and synthetic honey in the C. krusei culture medium above 60% (wt/vol) that inhibited 90% of the yeast growth (Xmax) and Xmin, respectively, were established, whereas C. albicans and C. neoformans were more resistant because Xmax values were not reached over the range tested (10–60%, wt/vol). Heather honey might be tapped as a natural resource to look for new medicines for the treatment of mycotic infections. Further studies are now required to demonstrate if this antifungal activity has any clinical application

Study of organic honey from the Northeast of Portugal

Concerns about traces of numerous toxic substances and authenticity have prompted consumer demand for honey that is certified as organic, based on strict ecological, natural principles and traceability. The present study aims to characterize organic honey samples (n = 73) from Northeast Portugal, with respect to floral nectar origin, physicochemical parameters and microbial safety. The phenols and flavonoids contents, often referred to as responsible for honey’s bioactive properties, were also assessed. All organic honey samples were classified as monofloral lavender (Lavandula sp.), exceeded in quality the international physicochemical standards and showed low microbiological counts (yeast, moulds and aerobic mesophiles), with negative results in respect to fecal coliforms, Salmonella and sulphite-reducing Clostridium spp. Correlation of the palynological, physicochemical and microbiological results is necessary to check the authenticity, quality and sanitation of honey. Although not required by international legislation, results of those assessments provide a complete outlook and elucidation of the organic honey’s properties, which could promote its valorisation

Antifungal effect of lavender honey against Candida albicans, Candida krusei and Cryptococcus neoformans

Monofloral lavender honey samples (n=30), were analyzed to test antifungal effect against Candida albicans, Candida krusei, and Cryptococcus neoformans. The specific growth rates (μ) showed that all the yeast growths were reduced in the presence of honey. The honey concentration (% w/v) that inhibited 10% of the yeasts growth (Xmin) ranged from 31.0% (C. albicans), 16.8% (C. krusei) and 23.0% (C. neoformans). A synthetic honey solution was also tested to determine antifungal activity attributable to sugars. The presence of synthetic honey in the C. krusei culture medium at concentrations above 58.0% (w/v) was established as Xmin, while C. albicans and C. neoformans were more resistant, since Xmin values were not reached over the ranged tested (10–60%, w/v). What the data suggests is that the component in the lavender honey responsible for the observed antifungal in vitro properties is not sugar based. Honey might be tapped as a natural resource to look for new medicines for the treatment of mycotic infections. This could be very useful, onsidering the increasing resistance of antifungals. It should be noticed that this is the first study concerning the effect of lavender honey on the growth of pathogenic yeasts

Antimicrobial activity, phenolic profile and role in the inflammation of propolis

Nowadays a great amount of information regarding chemical and biological aspects of bee products is available in the literature, but few data on its therapeutic uses are found. The aim of this study was to evaluate the phenolic profile, the in vitro antimicrobial activity and effect in the hyaluronidase enzyme (widely related with the inflammation process) of propolis harvested in Portugal. The efficacy of three extracts (hydro-alcoholic, methanolic and aqueous) was also compared. It was chosen the hydroalcoholic extract, because this was the most effective for extracting phenolic compounds. The antimicrobial activity was accessed in Gram-positive and Gram-negative bacteria and yeasts, isolated from different biological fluids and the results were then compared with the obtained for reference microorganisms. The propolis from Bragança was the one that possessed the highest polyphenols’ content. The sample from Beja showed the less significant inhibition of the hyaluronidase enzyme. Concerning the antimicrobial activity, Candida albicans was the most resistant and Staphylococcus aureus the most sensitive. The reference microorganisms were more sensitive than the ones isolated from biological fluids

Characterization of artisanal honey produced on the Northwest of Portugal by melissopalynological and physico-chemical data

Honey has always been regarded as a food which is advantageous for one’s health and as a product which has healing qualities. For this reason, is necessary to protect consumers from the fraudulent mislabeling of inferior honeys. The purpose of this study was to investigate some properties of artisanal honey samples (n = 45) collected from the Northwest of Portugal by using different honey analysis tests such as moisture, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural (HMF), apparent sucrose, reducing sugars and diastase activity. 77.8% of the total exceeded the quality parameters and should be labeled as ‘‘virgin” (humidity 618% and HMF 6 25 mg/kg). The present study found a linear correlation (y = 0.551x 0.089; R = 0.995) between the electrical conductivity of honeys and their ash content. All of the samples showed an Erica sp. pollen percentageP15%, and 42% of the total were monofloral Erica sp. In respect to coliforms and Salmonella’s presence, all the honey’s samples shown to be negative. The existence of sulphite-reducing Clostridia was low, and well below the established limit by MERCOSUR. Yeasts, moulds and aerobic mesophiles were detected in low amounts

Palynological, physicochemical, and microbiological attributes of organic lavender (Lava ndula stoechas) honey from Portugal

At the present time, the quality, integrity, sanitation, and nutritional value of honeys receive attention on an international level due to the increasing content of chemicals in the aforementioned matrix. The present study aims to characterize organic honey (n=73) from Northeast Portugal, with respect to floral nectar origin, physicochemical parameters, microbial safety, and commercial quality. All organic honey samples can be classified as monofloral lavender (Lavandula stoechas L.), exceed in quality the international physicochemical standards, and show low microbiological counts (yeast, moulds, and aerobic mesophiles), with negative results in respect to faecal coliforms, Salmonella, and sulphite-reducing clostridia. Correlating the palynological, physicochemical, and microbiological results is necessary in order to check the authenticity, quality, and sanitation of honey

Organic honey from Trás-os-Montes region (Portugal): chemical, palynological, microbiological and bioactive compounds characterization

At the present time, the quality, integrity, sanitation and nutritional value of honeys receive attention on an international level due to the increasing content of chemicals in the aforementioned matrix. This work was conducted to evaluate the quality of 75 organic honey samples from the Trás-Os-Montes region (Portugal). Mean values obtained for physico-chemical parameters were: pH 3.7; 15.6% moisture; 0.26 mS/cm electrical conductivity; 0.25% ash; 1.1 mg/kg HMF; 15.3 Gothe diastase activity; 40.3 meq/kg free acidity; 67.8% invert sugars and 2.7% apparent sucrose. All honey samples can be classified as monofloral Erica sp., as showed by pollen features. The amounts of phenols and flavonoids in the samples were also determined. In respect to sanitary quality (fecal coliforms) and safety (sulfite-reducing clostridia and Salmonella), all organic honey samples were negative. Furthermore, yeast and molds were detected in low counts, with mean values obtained of 5.5 cfu/g and the value of total aerobic mesophiles obtained from honeys was established in 1.3 102 cfu/g ± 7.5 101 cfu/g. The levels of flavonoids had a stronger impact on both mesophiles (p = 0.0004) and molds (p = 0.0138) than the sucrose concentration (p = 0.001 and 0.0278; respectively). The results reported in this study should be introduced in the organic honey label, and may help beekeepers, the industry, researchers and consumers better understand honey properties

Physicochemical and pollen analysis of Local honeys from the Lima Valley (Portugal)

An evaluation was done on the physicochemical quality of nineteen (n=19) Apis mellifera honeys produced in the Lima Valley, Portugal. The rural landscape of the Lima Valley is valuable in social, environmental and economic terms and its conservation and preservation are essential. The evaluated physicochemical characteristics were: moisture, ash, electrical conductivity, pH, hydroxymethylfurfural (HMF), free acidity, apparent sucrose, reducing sugars and diastase activity. All honey samples met the International physicochemical quality standards. A short study of pollen source was done by acetolisis method. The families Fabaceae and Rosaceae were found with 6 and 2 pollen types each respectively. The most important pollen source is Erica, moreover two samples are listed as Erica monofloral honey

Study of organic honey from the northeast of Portugal

Concerns about traces of numerous toxic substances and authenticity have prompted consumer demand for honey that is certified as organic, based on strict ecological, natural principles and traceability. The present study aims to characterize organic honey samples (n = 73) from Northeast Portugal, with respect to floral nectar origin, physicochemical parameters and microbial safety. The phenols and flavonoids contents, often referred to as responsible for honey’s bioactive properties, were also assessed. All organic honey samples were classified as monofloral lavender (Lavandula sp.), exceeded in quality the international physicochemical standards and showed low microbiological counts (yeast, moulds and aerobic mesophiles), with negative results in respect to fecal coliforms, Salmonella and sulphite-reducing Clostridium spp. Correlation of the palynological, physicochemical and microbiological results is necessary to check the authenticity, quality and sanitation of honey. Although not required by international legislation, results of those assessments provide a complete outlook and elucidation of the organic honey’s properties, which could promote its valorisationS

Use of propolis in the sanitization of lettuce

The present study aimed to determine the effectiveness of propolis in reducing the microbial load in ready-to-eat (RTE) and fresh whole head (FWH) lettuces (Lactuca sativa L.) type Batavia. Two sanitizing solutions were employed: sodium hypochlorite (SH) and propolis (PS), during 15 and 30 min. Tap water (TW) was used as a control. Regarding the mean reduction on aerobic mesophiles, psychrotrophic and fecal coliforms, the SH and PS treatments showed the same pattern of variation. In all cases, PS was slightly more effective in the microbiological reduction in comparison with commercial SH. Reductions between two and three log cycles were obtained with PS on aerobic mesophiles and psychrotrophic counts. The information obtained in the present study can be used to evaluate the potential use of propolis as product for sanitizing other vegetables and for developing other food preservation technologies, with impact on human healthXesús Feás would like to thank Xunta de Galicia (Isidro Parga Pondal Program for young researchers, Grant No. IPP-020)S