Physicochemical properties and microbial qualities of honey produced by a stingless bee (Meliponula beccarii L.) in the Oromia region, Ethiopia

AbstractThis study is aimed at determining the physicochemical and microbiological quality of stingless bee honey (Meliponula beccarii) collected in potential areas in the Oromia region of Ethiopia. Thirty-nine honey samples from underground soils were collected. The findings of the investigation indicated that the mean values of physicochemical properties for stingless bee honey samples were: moisture content (30.69 ± 0.29%), pH value (3.30 ± 0.03), free acidity (92.39 ± 4.45 meq/kg), ash content (0.16 ± 0.01%), electrical conductivity (0.44 ± 0.2 mS/cm), HMF (6.58 ± 0.36 mg/kg), fructose (36.48 ± 0.54%), glucose (27.67 ± 0.43%), reducing sugar (64.15 ± 0.75%) sucrose (1.24 ± 0.18%) and maltose content (1.2 ± 0.18%). The honey sample studied from Meliponulla beccarii was mostly characterized as having a light amber color (50%). Honey produced by stingless bees is distinguished from Apis mellifera honey by having a lower level of sugar, a higher amount of moisture, and free acidity. There were 2.55 × 104 to 1.9 × 103 CFU/mL of Aerobic Mesophiles, 1.68 × 104 to 9 × 102 CFU/mL of yeast, and 1.8 × 103 to 2 × 102 CFU/mL of mold in the Meliponulla beccarii honey sample. Staphylococcus species could only be detected in a sample taken from the Guduru area; however, an aerobic spore-forming bacteria was undetectable in all stingless bee samples. This suggested that there may have been cross-contamination from primary and secondary sources during pre-harvesting and post-harvest handling. Specific quality specifications must be established to promote commercialization since the physicochemical and microbiological characteristics of stingless bee honey differ from those of A. mellifera

Phytochemical and antioxidant profile of citrus peel extracts in relation to different extraction parameters

ABSTRACTThe citrus processing industry generates around 50% fruit waste, encompassing peels, pulp, seeds, and other residues. Citrus peel, among these by-products, contains significant amounts of bioactive compounds, representing a sustainable and renewable source of phenolics. In this context, the present study was conducted to probe phytochemical profile and antioxidant potency of orange peel extracts. Moreover, the quantification of hesperidin and nobiletin was carried out using HPLC. The extracts were obtained using water and 50% aqueous-methanol and aqueous-ethanol, separately alongside varying time intervals, i.e. 30, 45 and 60 min. The obtained extracts were then investigated for their phytochemical and antioxidant profile. Afterwards, three best treatments, one from each extracts (aqueous-ethanol, methanol, and water), were chosen based on their phytochemical profiling. The phytochemical analyses and in vitro antioxidant assays showed the highest total phenolics (2010 mg GAE/100 g), flavonoids (90 mg/100 g), and flavonols (2.2 mg/100 g) in methanolic extracts obtained at 60 min. Likewise, the highest DPPH (60.55%), antioxidant activity (51.7 %), FRAP (13.6 mg TE/g), and ABTS (7.4 µmol TE/g) were also attributed to methanolic extract of orange peel obtained at 60 min except for antioxidant activity which was obtained at 30 min. Likewise, HPLC analysis depicted maximum content of hesperidin and nobiletin (133.70 and 8.50 mg/g) in methanol extract as compared to ethanol (98.80 and 5.50 mg/g) and water (61.90 and 1.25 mg/g), correspondingly. It was concluded that aqueous-methanol could be used as solvent of choice for isolation of orange peel flavonoids with extraction duration of 60 min. Flavonoid and antioxidant levels in orange peel extracts are significantly influenced by extraction time and solvent type

Chemical and functional characteristics to detect sugar syrup adulteration in honey from different botanical origins

ABSTRACTThe objective of this study was to detect the changes in physicochemical and functional properties of raw and processed divergent honey varieties after adulterating with different sugar syrups. Specifically, when 25% to 55% cane syrup was added to raw Acacia honey, the HMF content increased from 46.25 to 101.6 mg/kg. In processed honey that contained 55% cane syrup, HMF content was even higher, reaching up to 402.47 mg/kg. The reported values for HMF (>80 mg/kg) content and DN (>8 DN) were above the described quality evaluation standard of honey. The results indicated that adulterating Acacia honey with up to 55% corn and corn syrup caused a reduction in diastase content to below 3.5 DN, and an increase in HMF content above 93.28 mg/kg. Similarly, adding 10% corn syrup to raw Ziziphus honey resulted in a decrease in both DPPH and ABTS+ values from 83.16% and 88.58%, respectively, to 72.83% and 76.97%. The findings in this study demonstrated that the addition of malt syrup (55%) to raw Trifolium honey resulted in an increase in the phytochemical content, with the TPC value reaching 805.15 mg GAE/100 g. However, processing Trifolium honey caused a significant decrease in TPC content to 505.15 mg GAE/100 g. This work highlights the need for more research into unexplored honey varieties and adulteration methods to improve quality evaluation standards and mitigate authenticity issues