Rapeseed Honey Research Articles

The Influence of Chemical Contaminants on the Physicochemical Properties of Unifloral and Multifloral Honey.

The aim of this study was to evaluate and compare the effect of antibiotic and pesticide residues on the physicochemical properties of unifloral and multifloral honey. The mineral elements content of honey was analyzed and correlated with antibiotic and pesticide residues, and a positive correlation was found between manganese and neonicotinoids. Potassium was found to be the most abundant mineral compound. Correlations were found between mineral content, color, and the content of antibiotic and pesticide residues of honey. In meadow honey, residues of antibiotics and pesticides were undetectable. In some of the other types of honey, the maximum residue limits regulated by European legislation were exceeded. Endosulfan residue was found in mint and rapeseed, honey with 0.42 and 5.14 ng/g, respectively. Neonicotinoids were found in 27% of the analyzed honey samples. Chloramphenicol was identified only in rapeseed honey, with concentrations ranging from 0.2 ng/g to 0.8 ng/g. Nitrofurans were found in 14%, and nitroimidazoles were found in 6% of the analyzed samples. According to EU legislation that is in force, the use of antibiotics in beekeeping is not allowed. The MRLs for neonicotinoids are 50 ng/g, and for coumaphos, the maximum limit is 100 ng/g. For the other pesticide residues, the maximum limit is 10 ng/g. The results of statistical analysis obtained using principal component analysis (PCA) showed a major difference in the levels of contamination of raspberry and meadow honey and the other types of honey.

Evaluation of consumer safety of Polish honey-the content of Cd and Pb in multifloral, monofloral and honeydew honeys.

The paper aimed to evaluate the degree of contamination of honey available on the Polish market with cadmium (Cd) and lead (Pb). The analyses involved 49 samples of honey: monofloral (n = 24): linden, raspberry, goldenrod, bean, dandelion, buckwheat and rapeseed honey, multifloral honey (n = 17) and coniferous honeydew honey (n = 8). The content of Cd and Pb was determined using Inductively Coupled Plasma-Optical Emission Spectrometers (ICP-OES). The content of Cd and Pb was confirmed in all the analysed honeys, but in 18% of samples the level of Cd was < LOQ. The analysed honeys contained from < LOQ to ca. 0.09 mg Cd per 1 kg, on average 0.025 mg kg-1. On average, they contained 0.193 mg Pb (range 0.014-1.007) per 1 kg of the raw product. The content of Cd and Pb can be presented as: honeydew honey > multifloral honey > monofloral honey. The content of Cd in monofloral honeys can be presented as follows: linden > other (raspberry, goldenrod, bean, linden + bean) > dandelion = buckwheat = rape, while the content of Pb as linden > other > rapeseed > buckwheat > dandelion honey. It should be emphasised that consuming 19 g of honey a week (mean honey consumption in Poland) is safe for human health, as it results in an intake of Cd at the level of 1.18E-04% PTWI and 0.553% PTWI for children and an intake of Pb at the level of 0.641% BMDL01 for adults and 5.916% BMDL for children. The obtained results lead to a conclusion that the risk of disorders related to chronic exposure to Cd and Pb ingested with honey is very low, which is demonstrated by the fact that both children and adults showed CDI, CR, THQ and HI that were lower than 1.

Physico-Chemical Profile of Four Types of Honey from the South of the Republic of Moldova

There are many studies that compare the quality and biological characteristics of honey with distinct geographical and botanical origins. However, the physico-chemical and biological properties of different types of honey in the same production regions are rarely mentioned. The honey used in this study: sunflower honey, rapeseed honey, manna honey and polyflora honey, came from GT “Malai C” in Taraclia village, Causeni district in the southern part of the Republic of Moldova and belonged to the flowering season of year 2020. Following the polynecological analysis, it was found that two types of honey are monofloral with a dominant pollen content of Helianthus spp. (49.15% - 93.12%) in sunflower honey and Brassica spp. (52.17% - 70.11%) in rapeseed honey. Mana honey and polyflora contain several types of pollen. Thus, four types were identified in manna honey, including: Acer platanoides (29.11% - 30.11%), Quercus robur (28.67% - 29.99%), Rubus idaeus (21.55% - 28.78%), Taraxacum officinale (22.21% - 28.76%). Polyflora honey contains: Helianthus annuus (24.91% - 31.11%), Brassica napus (23.45% - 29.18%), Tilia (28.95% - 31.92%). Based on a Pfund scale, it was found that the color of the honey varied from a lighter shade for rapeseed honey (water amber 7.66 ± 3.002 mm) to a darker color for sunflower honey and polyflora (extra light amber 34.366 ± 21.01 mm and 36.04 ± 1.115 mm respectively). Spectrophotometric determination of phenolic compounds in honey samples showed that their content ranged from 38.18 mg GAE/kg honey for rapeseed honey to 831.09 mg GAE/kg honey for manna honey. At the same time, the flavonoid content ranged from 28.41 mg QUE/kg honey for rapeseed honey to 151.72 mg QUE/kg honey for manna honey. Mana honey showed a better antioxidant activity than the other honey samples in the study (72.03%). The reported results suggest that manna honey has the best potential and its consumption in the human diet as food with valuable biological properties can be encouraged, despite the fact that in the Republic of Moldova it is in a small amount.

Quality Assessment of Honey Powders Obtained by High- and Low-Temperature Spray Drying

The paper aimed to compare the quality of rapeseed and honeydew honey powders, obtained by two methods of spray drying—traditional at a high temperature (inlet air 180 °C) and innovative low-temperature spray drying with the use of dehumidified air as a drying medium (inlet air 75 °C). Total polyphenol content, antioxidant activity, and the content and types of aromatic compounds were determined. In addition, Fourier-transform infrared spectroscopy (FTIR) coupled with chemometrics analyses was done. Powders obtained by the low-temperature spray drying method (with dehumidified air) were characterized by a higher content of polyphenols, antioxidant activity, and aromatic compounds, compared to powders obtained by the traditional method. Honeydew honey compared to rapeseed honey was characterized by a higher content of polyphenols, antioxidant activity, and composition of aromatic compounds. The results proved that the production method had a higher impact on the final properties of powders than the type of honey.

Fizykochemiczna analiza miodów z rejonu Podkarpacia

Introduction. Honey is a dietary component with exceptional taste and health benefits. It is one of the most frequently counterfeit food products. Aim. The aim of the study was to assess the quality of honey on the basis of selected parameters, their compliance with standards and to determine the antioxidant properties of honey. Material and methods. The experimental material consisted of 22 samples of four types of honey: rapeseed, acacia, honeydew and multiflorous honey. The tests included the determination of water and extract content, the amount of free acids (acidity). The electrical conductivity was measured and the content of: total phenolics (TP), carotenoids (TC), and sucrose was determined. The antioxidant activity was determined spectrophotometrically using the DPPH radical and the FRAP method. Results. The total polyphenols content ranges from 0.2 mg to about 1.2 mg in 1 g of honey, carotenoid content between 4.34 to 5.26 mg/kg, in two cases, the moisture content exceeded the required value, all honeys are appropriate conductivity (except for honeydew), acidity and sucrose content. Research on the antioxidant properties of various honey varieties (DPPH and FRAP) showed the advantage of honeydew honey over other varieties. Conclusions. Most of the tested honey met the requirements of the standards. Possible deviations were minor. It can be noticed that honeys of one variety of different origin have different parameters – which proves the influence of many factors on the honey production process.

Texture characteristics of raw rapeseed honey after storage at room temperature or freezing and heating up to 50°C

Texture characteristics of raw rapeseed honey after storage at room temperature or freezing and heating up to 50°C

Comparative study of the chemical composition and biological potential of honey from different regions of Serbia

A chemical characterization and biological activity of 7 honey types (multifloral, linden, rapeseed, sunflower, phacelia, acacia and honeydew honey) from different regions of Serbia were presented. The physicochemical characteristics, mineral content, antioxidant and antimicrobial activity were estimated and discussed. All honeys showed good nutritional characteristics, according to the adopted criteria of the standard codex for honey. The concentrations of 15 elements in honey samples were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Limits of quantification were in the range from 0.003 mg/kg (Cd, Cr, Cu, Mn, and Pb) to 1.50 mg/kg for sodium. Precision was expressed as relative standard deviation and its values were lower than 1.50%. Accuracy was evaluated with certified reference material (fish protein, DORM 4, NRC and cooking chocolate, SRM 2384, NIST) and obtained recovery percentages were 71-127%. The content of the most abundant elements (K, Mg, and Na) and microelements (Al, Cu, Fe, Mn, Ni, Se, Si, and Zn) showed a significant variability in accordance of their botanical and geographical origin, but also the influence of harvest conditions. The levels of toxic metals (As, Cd, Cr, and Pb) are much lower than the maximal allowed for these metals according to European Commission Regulation. The antioxidant activity was evaluated by DPPH (Diphenylpicrylhydrazyl) assay while antimicrobial activity against Gram positive and Gram negative bacteria (E. coli and S. aureus) and fungi Candidi albicans was estimated by microdilution assay. The free radical scavenging assay (%RSA) varies significantly among the honey samples. The highest antioxidant activity was observed with honeydew honeys (over 75% RSA) and the lowest was observed in the acacia, ranging from 22.96 to 24.57% RSA. All honeys tested in this study exhibited antibacterial activity, with inhibition of bacterial growth, generally the higher against E. coli (80% for linden honeys) than against S. aureus (mostly much lower than 50%). Activity against Candidi albicans was almost negligible. The dataset composed of all experimental results was subjected to a chemometric evaluation and cluster analysis as hierarchical nonsupervised method was applied. According to the obtained outcome of applied algorithms, both botanical and geographical origin have important role in the elemental composition, antioxidant and antimicrobial activities.

The role of hydrogen peroxide in the antibacterial activity of different floral honeys

Because of its powerful therapeutic potential in wound care, honey has been given much attention. One of the most relevant and researched characteristics of honey is its multifactorial antibacterial activity. Several antibacterial compounds have been identified including hydrogen peroxide (H2O2). The goal of the study was to characterize the antibacterial potential of honeys from various botanical origins (n = 233) against Staphylococcus aureus and Pseudomonas aeruginosa and establish the H2O2 content. Five types of honey were identified: acacia (n = 72), linden (n = 23), rapeseed (n = 9), sunflower (n = 8) and multi-floral (n = 121). The overall antibacterial activity of all the honey samples, expressed as a minimal inhibitory concentration of honey, strongly correlated with the level of H2O2. On the other hand, linden honey, which exhibited the strongest antibacterial effect, showed weak or no correlation between the antibacterial activity and the level of H2O2, depending on bacterial strain. The weakest antibacterial activity was documented in the rapeseed honey samples and it was associated with the low content of H2O2. These data suggest that antibacterial activity of honey is mainly H2O2-dependent; however, certain type of honey such as linden honey, showed a strong antibacterial effect which, may be, at least partially, attributed to non-peroxide factor(s).

Determination of the botanical origin of honeybee honeys based on the analysis of their selected physicochemical parameters coupled with chemometric assays

The aim of this paper was to study the select physicochemical parameters of 58 honey samples of 4 different botanical origins (buckwheat, linden, rape and acacia) using multivariate methods in order to classify honeys according to the botanical origin. Five standard physicochemical parameters were determined according to the international legislation: water content, electrical conductivity, total ash content, free acidity and pH. The results obtained were mostly in agreement with international regulations. Then, the results obtained were analysed by principal components analysis and cluster analysis. The chemometric analysis of results of determinations of the physicochemical parameters demonstrated such markers as electrical conductivity and ash content (i.e. parameters linked with minerals content) to be the most reliable markers in determining the botanical origin of linden and buckwheat honeys. Unfortunately, they appear insufficient for reliable identification of acacia and rapeseed honeys.

The Effect of Low-Temperature Spray Drying with Dehumidified Air on Phenolic Compounds, Antioxidant Activity, and Aroma Compounds of Rapeseed Honey Powders

The influence of low-temperature spray drying (inlet/outlet air, 75/50 °C) with the use of dehumidified air on rapeseed honey phenolics, antioxidant activity, and aroma compounds was investigated. Maltodextrin and NUTRIOSE® were used as carriers. Additionally, skimmed milk was tested as water substitute for feed solution preparation. Honey powders obtained by this method were characterized by high antioxidant activity and rich aroma. Changes in aroma profile during drying at low temperature were recognized as favorable and creating desirable fragrance of the product. In the case of 80% honey powders (20% of carrier), the investigated properties were not deteriorated comparing to pure honey before drying. Thus, this level of carrier addition can be treated as optimal from the point of view of bioactive properties retention during low-temperature spray drying. Such low carrier addition was not presented before in case of honey spray drying, and is favorable due to the perception of such product as natural. If used as food component, the dose of such honey-rich powder can be reduced comparing to traditional products containing higher amount of carrier (usually not lower than 50%).

The application of dehumidified air in rapeseed and honeydew honey spray drying - Process performance and powders properties considerations

Rapeseed and honeydew honey were spray dried by dehumidified air, with NUTRIOSE® as a drying carrier, to create a product with prebiotic properties, in line with current "clean label" trend. Because of the low inlet air humidity, drying temperature was decreased (inlet/outlet: 75/50 °C). Such an approach gave the possibility to reduce the amount of added carrier. Thus, honey powders containing 80% of honey solids were produced and characterized. Drying was performed with very high powder recovery (84.4–93.9%), especially in the variants containing 80% of honey solids. Although there were some differences in the physical properties between powders produced by the application of dehumidified air and by the traditional spray drying (but containing the same ratio of honey to carrier), the overall properties were comparable: low water content (below 2.5%) and low water activity (below 0.2), medium or high cohesiveness, high hygroscopicity (above 20%), bed porosity between 50 and 70%.

Pendant drops shed from a liquid lens formed by liquid draining down the inner wall of a wide vertical tube

When a viscous liquid empties from an initially full, wide vertical tube, the drainage behaviour changes from a filament to a regime in which individual drops are shed by a lens formed at the end of the tube: liquid drains down the wall and the lens grows until it becomes unstable. This drop shedding regime was investigated for four Newtonian liquids (rapeseed oil, glycerol, honey and golden syrup) in three tube sizes and two tube materials (Bond number based on tube i.d. >1 in all cases). The drop mass increased modestly with flow rate and the equivalent sphere diameter, d, was strongly related to the capillary length Lc ≡ (γ/ρg)1/2 rather than the tube diameter. The results were fitted to a correlation of the form d/Lc = f(Bond, Reynolds, Morton, sine of the contact angle) derived from dimensional analysis. The data were compared with existing models for drop formation from filled narrow capillaries and a new, simple model based on a quasi-static model of the lens. Agreement with these models was poor, particularly for larger tubes, indicating the need for more detailed analysis. Insights into the dynamics, generated by video analysis of the lens shape, are presented.

Study of the Anti-Staphylococcal Potential of Honeys Produced in Northern Poland.

The antimicrobial activity of 144 samples of honeys including 95 products from apiaries located in Northern Poland was evaluated. The antibacterial activity of those natural products, their thermal stability, and activity in the presence of catalase was investigated by microdilution assays in titration plates. The MTT assay was performed for the determination of anti-biofilm activity. Spectrophotometric assays were used for the determination of antioxidant potential, total phenolic content, and ability to generate hydrogen peroxide. Some of the investigated honeys exhibited surprisingly high antimicrobial, especially anti-staphylococcal, potential, with Minimal Inhibitory Concentration (MIC) values of only 1.56% (v/v). Much higher resistance was observed in the case of staphylococci growing as biofilms. Lower concentrations of the product, up to 12.5% (v/v) stimulated its growth and effective eradication of biofilm required concentration of at least 25% (v/v). Hydrogen peroxide has been identified as a crucial contributor to the antimicrobial activity of honeys supplied by Polish beekeepers. However, some of the results suggest that phytochemicals, especially polyphenols, play an important role depending on botanical source (both positive, e.g., in the case of buckwheat honeys as well as negative, e.g., in the case of some rapeseed honeys) in their antimicrobial potential.

Influence of Botanical Origin and Chemical Composition on the Protective Effect against Oxidative Damage and the Capacity to Reduce In Vitro Bacterial Biofilms of Monofloral Honeys from the Andean Region of Ecuador.

Three types of monofloral honey from the Andean regions of Ecuador (Avocado, Eucalyptus, and Rapeseed honey) were analyzed to determine their floral origin, physicochemical parameters, chemical composition, antioxidant capacity, and their capacity to reduce in vitro bacterial biofilms. The chemical composition varied considerably depending on floral origin. The highest values of bioactive compounds were found in Avocado honey, classified as dark amber in color, while the lowest values were found in Eucalyptus honey followed by Rapeseed honey, both classified as extra light amber. When compared to Eucalyptus and Rapeseed honey, Avocado honey showed a more effective superoxide scavenging activity, chelating metal ions capacity, and a higher ability to protect human erythrocyte membranes against lipid peroxidation. For antimicrobial activity, the hydrogen peroxide content and the capacity to inhibit the biofilm formation, and to remove preformed biofilm from Staphylococcus aureus and Klebsiella pneumoniae was determined. Avocado honey showed the highest values of hydrogen peroxide content, as well as the highest capacity to reduce in vitro bacterial biofilms. A correlation between color vs. phenolics content vs. superoxide scavenging activity vs. chelating metal ions capacity, and the capacity to protect human erythrocyte membranes against lipid peroxidation was found.

Comparative study of rapeseed, monofloral types and multifloral honey by some physicochemical parameters

Comparative study of rapeseed, monofloral types and multifloral honey by some physicochemical parameters

Microwave processing of honey negatively affects honey antibacterial activity by inactivation of bee-derived glucose oxidase and defensin-1

Microwave (MW) thermal heating has been proposed as an efficient method for honey liquefaction, while maintaining honey quality criteria. However, little is known about the effects of MW thermal heating on honey antibacterial activity. In this study, we aimed to determine the effects of MW heating on the antibacterial activity of raw rapeseed honeys against Pseudomonas aeruginosa and Staphylococcus aureus, with a particular focus on two major bee-derived antibacterial components, defensin-1 and hydrogen peroxide (H2O2).Our results demonstrated that MW thermal heating completely abolished honey antibacterial activity whereas conventional thermal treatment at 45 and 55°C did not affect the antibacterial activity of honey samples. A significant decrease in both glucose oxidase activity and H2O2 production as well as defensin-1 amount was observed in MW-treated samples.Given that defensin-1 and H2O2 are regular antibacterial components of all honeys, MW heating may have similar negative effects on every type of crystallized/liquid honey.

Characterization of Chinese Unifloral Honeys Based on Proline and Phenolic Content as Markers of Botanical Origin, Using Multivariate Analysis.

The phenolic and proline content were determined in honey samples of different floral origins (rapeseed, sunflower, buckwheat and Codonopsis) from five different regions of China. The phenolic and proline profile of these samples were used to construct a statistical model to distinguish honeys from different floral origins. Significant differences were identified among the studied honey samples from multivariate chemometric methods. The proline content varied among the four types of honeys, with the values decreasing in the order: buckwheat > Codonopsis > sunflower > rapeseed. Rapeseed honeys contained a high level of benzoic acid, while rutin, p-coumaric acid, p-hydroxybenzoic acid were present at relatively high levels in buckwheat honeys. Principal component analysis (PCA) revealed that rapeseed honey could be distinguished from the other three unifloral honeys, and benzoic acid, proline and kaempferol could serve as potential floral markers. Using 18 phenolic compounds and proline the honey samples were satisfactorily classified according to floral origin at 94% correct prediction by linear discriminant analysis (LDA). The results indicated that phenolic compounds and proline were useful for the identification of the floral origin of the four type honeys.

Effect of freezing and room temperatures storage for 18 months on quality of raw rapeseed honey (Brassica napus)

The physicochemical properties, colour characteristics and dynamic viscosity of fresh rapeseed honey (control, CON) and those stored for 18months at room temperature (RT) or in freezer (FRO) were compared. The significant decrease of pH after storage was found. Honey stored at RT showed an increase of 5-hydroxymethylfurfural (HMF) (+543.0%) and decrease of diastase activity (-24.4%), while in FRO samples the decreasing course (-50.5 and -7.3%, p>0.05) were found in comparison with CON samples (3.07 and 28.37mgkg-1). The negative correlation between HMF content and diastase activity was found. The temperature of storage significantly influenced colour parameters, however, RT differentiated colour of honey to a greater extent (ΔE=20.37) than FRO (ΔE=8.07). The lightness (L*), hue (h°), whiteness index (WI) and colour intensity (ABS450) of CON honey samples were similar to honey from FRO. The dynamic viscosity was significantly higher in honey stored in FRO in comparison to CON honey and honey stored at RT. However, in comparison with CON honey, higher (almost twice) viscosity for honey stored at RT was observed.

Content of metals and metabolites in honey originated from the vicinity of industrial town Košice (eastern Slovakia).

Composition of three types of honey (mixed forest honey and monofloral-black locust and rapeseed honeys) originated from the vicinity of an industrial town (Košice, Slovak Republic) was compared. Higher content of minerals including toxic metals in forest honey (1358.6 ng Ni/g, 85.6 ng Pb/g, and 52.4 ng Cd/g) than in rapeseed and black locust honeys confirmed that botanical origin rather than the distance for eventual source of pollution (steel factory) affects metal deposition. Benzoic acid derivatives were typically more accumulated in forest but cinnamic acid derivatives and some flavonoids in rapeseed honey (in free and/or glycoside-bound fraction). In terms of quantity, p-hydroxybenzoic and p-coumaric acids were mainly abundant. Total phenols, thiols, and proteins were abundant in forest honey. Some metals and phenols contributed to separation of honeys based on principal component analysis (PCA). Native amount of 5-(hydroxymethyl)furfural was not related to honey type (~11 μg/g) and was elevated after strong acid hydrolysis (200-350 μg/g) but it did not interfere with the assay of phenols by Folin-Ciocalteu reagent. This is the first report of metals and metabolites in the same study, and data are discussed with available literature. We conclude that black locust (acacia) honey is the most suitable for daily use and that central European monofloral honeys contain lower amounts of toxic metals in comparison with other geographical regions.

The determination of botanical origin of honeys based on enantiomer distribution of chiral volatile organic compounds

The enantiomer ratios of chiral volatile organic compounds in rapeseed, chestnut, orange, acacia, sunflower and linden honeys were determined by multi-dimensional gas chromatography using solid phase microextraction (SPME) as a sample pre-treatment procedure. Linalool oxides, linalool and hotrienol were present at the highest concentration levels, while significantly lower amounts of α-terpineol, 4-terpineol and all isomers of lilac aldehydes were found in all studied samples. On the other hand, enantiomer distribution of some chiral organic compounds in honey depends on their botanical origin. The significant differences in enantiomer ratio of linalool were observed for rapeseed honey that allows us to distinguish this type of honey from the other ones. The enantiomer ratios of lilac aldehydes were useful for distinguishing of orange and acacia honey from other studied monofloral honeys. Similarly, different enantiomer ratio of 4-terpineol was found for sunflower honeys.