Innovative Flavoring of Rapeseed Honey with Selected Essential Oils—Chemical, Antioxidant and Organoleptic Evaluation

Abstract

Two essential oils: cinnamon and clove were used to aromatize rapeseed honey for the first time. For comparison self-distilled and commercially purchased essential oils were used. All essential oils and obtained flavored honeys were assessed for antioxidant activity, volatile fraction composition (GC-MS) and polyphenolic profiles (HPTLC). The results indicated that while in the case of clove oils the differences in the enrichment of the honey composition were not dependent on the origin of essential oil, the effect of the self-distilled cinnamon oil addition was completely different than for its market equivalent. The commercial cinnamon oil contained a larger amount (59.58%) of eugenol than the self-produced oil, probably as a result of the admixture of cinnamon leaf oil or different raw material used for commercial essential oil production. The described studies may constitute a basis for introducing to the market a new type of product based on honey and phytoadditives. The essential oil flavored honey is characterized not only by new desirable organoleptic features but also by highly enhanced antioxidant and probably antibacterial properties, which, however, requires further research.

1. Introduction

The number of consumers looking for natural products with a beneficial effect on health and well-being is constantly growing. Food products with a beneficial health effect, especially those based on natural ingredients, are becoming increasingly popular. Undoubtedly, honey, herbs, medicinal plant extracts as well as essential oils are among such products. New concepts are emerging, which aim to increase the benefits of honey by combining it with various additives: other bee products, fruits, herbs and spices [1,2,3,4,5]. Such combinations are attractive to consumers, expand the product range and allow for innovative introduction of bee products and medicinal plants into the diet. It has been proven that the addition of herbs and fruits in dried or freeze-dried form has a positive effect on the antioxidant, antimicrobial and antiviral potential of such products [2,3,4,5,6], making them an interesting category of functional foods. The latest trends in enriching honey with phytochemicals include the introduction of plant extracts, which can facilitate product standardization. Known and studied examples include the addition of extracts from Sophora flowers [7], pine buds [8], chokeberry fruit [9] and a mixture of multiple extracts and essential oils [10]. The migration of elements and polyphenolic compounds from herbs and spices into the matrix of infused honey was also studied, confirming the significant influence of additives on the nutritional potential of infused honeys [11].

Essential oils (EOs), which are mixtures of volatile substances obtained from plants, have numerous well-known biological properties. They have long been used in medicine, cosmetics and food industries. Their main components belong to the groups of terpenes and terpenoids, aromatic compounds, phenols, aliphatic alcohols and ketones, and esters [12]. They exhibit antibacterial, antiviral, antioxidant, anti-inflammatory, insecticidal, anthelminthic, antiparasitic and cytotoxic effects [12,13]. One of the particularly well-known and described properties of essential oils is their antimicrobial effect. The complex composition of each oil is reflected not only in its characteristic mode of action but above all in its fragrance properties, guarantying their use to impart fragrance to cosmetics or food products. The method of obtaining oils depends on the physicochemical properties of the plant from which they are obtained, the diversified quality of the raw material and the place and time of collection. The main methods of obtaining essential oils include hydrodistillation, steam distillation, solvent extraction, enfleurage, cold pressing and maceration; various modern methods are also being sought [12].

Mixing honey with essential oils is a completely new idea, which not only creates new specific sensory properties but can also shape the bioactivity of obtained enriched honeys. The term ‘flavored honey’ is sometimes used to describe honey with the addition of fruit, juices or plant extracts, which also change the sensory characteristics of the honey [14]. The only known report of infusing honey with essential oils is the study of Mateescu et al. [15], who mixed mint, sage, basil and fennel oils with honey, obtaining products of good quality and at the same time an enriched profile of volatile aroma compounds. In turn, Paduraru et al. [10] used essential oils from Matricaria chamomilla, Salvia sclarea and Salvia officinalis together with royal jelly and numerous plant additives to enrich honey. Attempts have already been made to assess bioactivity of honey combined with essential oils (from eucalyptus, oregano and lavender) in in vitro and in vivo studies, achieving synergistic antioxidant, antibacterial and anti-inflammatory effects [16,17,18]. This gives rise to the assumption that the novel product in the form of honey enriched with essential oils also has enhanced biological potential while achieving a convenient form to incorporate into the diet. The aim of this study was to prepare and evaluate the effect of the addition of various essential oils (cinnamon and clove) on the antioxidant properties and consumer acceptability of rapeseed honey. Additionally, for the first time the impact of the type of oil (commercially available and self-distilled) was compared.

2. Materials and Methods

2.1. Material and Chemicals

Rapeseed honey was obtained from a local apiary (Sieklówka, Poland). Essential oils (clove and cinnamon) were purchased from Etja (Elblag, Poland). Cloves and cinnamon bark (unspecified botanical origin) (Prymat, Jastrzębie-Zdrój, Poland) were purchased at a local grocery store. Analytical standards (eugenol, cinnamaldehyde and kaempferol) were obtained from Sigma Aldrich (St. Louis, MO, USA). All used chemicals were of at least analytical grade.

2.2. Essential Oils Distillation

The essential oils were obtained by hydrodistillation using a Deryng apparatus (Lab-Szkło, Kraków, Poland). In a round-bottomed flask, 50 g of crushed raw material was weighed and then 500 mL of distilled water was poured. The flask was connected to the Deryng apparatus, the receiver was filled with water, and the setting and tightness of the tap were checked. The cooling water flow was turned on and heated for 3 h counted from the moment the contents of the flask began to boil and the first drops of oil appeared. The process was repeated as needed to obtain the appropriate volume of oils; 2.5 mL of clove oil and 1.5 mL of cinnamon oil were obtained in total.

2.3. Preparation of Flavored Honeys

One hundred grams of previously liquefied rapeseed honey was weighed into glass jars. Each sample was then subjected to a creaming process, which consisted of mixing them with a hand mixer for 3 min. Appropriate volumes of tested EOs were added to the honey samples prepared in this way, obtaining samples flavored with 0.1 and 0.3% (v/w) of each EO. The honey samples combined with the oils were further creamed for 2 more days in the same manner as before. After the creaming process, the honey was placed in the refrigerator (5 °C) for 2 weeks stabilization and then stored in dark conditions at room temperature (20 ± 2 °C). Honey analyses were performed after 1 and 6 months of storage.

2.4. Total Phenolic Content

Total phenolic content was determined for EOs (diluted with methanol) and honeys (20% aqueous solutions, further diluted if necessary) using the method described by Miłek et al. [3]. Total phenolic content was expressed in gallic acid equivalents based on the standard curve y = 0.336x (r² = 0.9914).

2.5. Antioxidant Capacity

Antioxidant capacity was assessed by DPPH and FRAP (only for flavored honeys) methods, as described by Miłek et al. [3]. The same sample dilutions were used as in the case of the analysis of phenolic compounds. Results were expressed in Trolox equivalents based on standard curves (y = 15.553x; r² = 0.9975 for DPPH and y = 0.1523x; r² = 0.9995 for FRAP).

2.6. HPTLC Analysis

To prepare samples for HPTLC analysis, honeys were subjected to solid-phase extraction, removing sugars and concentrating polyphenols, according to a slightly modified method of Grabek-Lejko et al. [4], using Sep-Pak Plus Short C18 columns (Waters, Milford, MA, USA). The extraction procedure was carried out by passing through the columns sequentially: 10 mL of methanol, 10 mL of water acidified with HCl (pH 2), 100 mL of the sample (100 mL of 20% solution in acidified water), 100 mL of water at pH 2, and 5 mL of methanol. The purified fraction was subjected to chromatographic analyses. Chromatographic separation was performed using the HPTLC set (CAMAG, Muttenz, Switzerland), as in the work of Miłek et al. [3]. To determine polyphenolic compounds, HPTLC SilicaGel 60 F254 plates (Merck, Darmstadt, Germany) were used, on which 3 μL of appropriate extract or essential oil was applied as 8 mm wide bands from the lower edge of the plate. The standards used were kaempferol, eugenol and cinnamaldehyde (250 μg/mL). The separation was carried out in a chromatography chamber saturated with the mobile phase (chloroform, ethyl acetate and formic acid, 5:4:1). The obtained results were visualized using an HPTLC imager (TLC Visualizer, CAMAG, Muttenz, Switzerland) at wavelengths of 254 and 366 nm. Additionally, the plate was derivatized with p-anisaldehyde using an automatic TLC derivatizer (CAMAG, Derivatizer, Muttenz, Switzerland). The results were again documented in visible light and UV 366 nm.

2.7. GC-MS Analysis

Chromatographic analysis was performed to identify volatile organic compounds (VOCs) in essential oils (EOs) and selected honey samples spiked with EOs. The isolation of VOCs from a honey sample using headspace solid-phase microextraction (HS-SPME) and their chromatographic analysis (GC-MS) was carried out according to the method described by Matłok et al. [19]. Twenty grams of each honey sample were weighed into glass beakers and sealed with aluminum foil. A polydimethylsiloxane (PDMS) fiber (100 µm, Supelco, Bellefonte, PA, USA) was introduced into the control honey sample for 30 min and into the EO-enriched honey for 2 min. The fiber was then transferred to a Varian 450-GC gas chromatograph (Palo Alto, CA, USA) coupled with a Varian 250-MS mass spectrometer (Palo Alto, CA, USA) for analysis. A capillary column (30 m × 0.23 mm × 0.25 µm) with a moderately polar HP-5 stationary phase (Agilent Technologies, Santa Clara, CA, USA) and helium (purity >99.99%) as the mobile phase (flow rate: 1 mL/min) were used. During the analysis, the oven temperature was initially held at 50 °C for 5 min (isothermal) then increased at a rate of 10 °C/min to 300 °C and held at this final temperature for 5 min (isothermal). The essential oil was analyzed using the same chromatographic separation conditions as above, with the difference that 1 µL of essential oil was injected directly into the chromatograph dispenser (split 1:100). The total analysis time was 35 min. The identification of compounds was verified based on the comparison of their mass spectra with data available in the NIST 08 library, supported by Kovats retention indices. The Kovats retention indices were determined in accordance with the procedure described by Matłok et al. [19], by prior injection of a mixture of n-alkanes (C7–C30) into the gas chromatograph.

2.8. Organoleptic Evaluation

In order to analyze acceptance of the honey samples enriched with essential oils, the 10-point hedonic scale was used. The organoleptic evaluation included color, smell, consistency and taste as well as the overall note. Intensity of perception was evaluated from 1 (dislike extremely) to 10 (like extremely) by a 10-person sensory panel. Approximately 50 g of honey samples were given, with approximately 2 g taken for taste testing. Mineral water was used as a neutralizer between individual samples.

2.9. Statistical Analysis

The studies were performed in triplicate, and the obtained results were presented as the mean value with standard deviation (±SD). Statistical analysis of the significance of differences was performed using a t-test and Šidák’s multiple comparison test, preceded by a two-way ANOVA analysis, using GraphPad Prism 10.4.1 software (GraphPad Software Inc., San Diego, CA, USA).

3. Results and Discussion

3.1. Essential Oils Evaluation

In the first step, the essential oils used to enrich rapeseed honey were assessed for their composition and properties. For both types of oil, clove and cinnamon, two variants were compared: self-obtained by hydrodistillation and commercial equivalents purchased. In all four EO samples, the total content of phenolic compounds and antioxidant activity were assessed using the DPPH method (

Table 1. Total phenolic content and antiradical activity of used essential oils.

Essential Oil		Total Phenolic Content [mg GAE/mL]	DPPH [μmol TE/mL]
Cinnamon	commercial	409.03 ± 2.98	538.00 ± 4.03
	distilled	1.98 ± 0.26 ***	0.61 ± 0.22 ***
Clove	commercial	591.15 ± 4.09	1195.16 ± 43.51
	distilled	698.66 ± 1.49 ***	1350.42 ± 17.91 **

Significant differences between appropriate distilled and commercial EOs (t-test): ***—p < 0.001, **—p < 0.01).

).

The values of the antioxidant potential of essential oils given in the literature vary greatly and are presented in different ways, which makes it difficult for comparison. While both tested clove oils were approximately similar in terms of both analyzed parameters (TPC and DPPH), the commercial cinnamon oil contained about 200 times more compounds, reducing the Folin-Ciocalteu reagent, than the self-distilled one. Similarly, the antiradical activity was many times higher for this EO (p < 0.001). For clove oils, significant differences were also shown, but the values were comparable. The total phenol content was also similar to the data reported in the scientific literature. Sarrami et al. [20] found a phenol content of 345.95 mg GAE/g for clove EO, while Zengin and Baysal [21] found 635.32 mg GAE/g. The data in the literature are often converted to mass rather than volume of the oil, but considering its density, reported in the range of 1.019–1.070 g/cm³ [22,23], it can be assumed that our results are in line with the literature data. In turn, for cinnamon oil, the density is, according to various data, 1.053–1.104 g/cm³ [24,25]. However, the content of phenolic compounds is strongly depending on the type of cinnamon or the addition or contamination of the essential oil from the leaves of this plant. The content of polyphenols, especially flavonoids, is higher in the leaves than in the bark of cinnamon [26]. In the study by Dev et al. [27], TPC values obtained for EO from Indian cinnamon bark of unspecified species ranged from 0.17 to 1.39 mg GAE/mL, depending on the roasting conditions of the bark. These values are similar to ours obtained for the oil distilled under laboratory conditions (1.98 mg GAE/mL). Moreover, a higher result (5.7 mg/g of oil) was obtained by Kamaliroosta et al. [28] for the essential oil from C. zeylanicum bark. In turn, Aydin et al. [29] report a value of 268.2 mg/mL for commercially purchased C. zeylanicum oil, but it is not precisely specified whether this was pure oil from cinnamon bark. High phenolic contents may suggest the presence of cinnamon leaf essential oil. For clove oils, IC50 values for the DPPH method range from 15.8 to 108.85 μg/mL according to Alfikri et al. [23], depending on the degree of maturity of the clove buds. In turn, for the FRAP method, based on a different mechanism, the value of the reducing power was 4357.45 mmol TE/mL [21]. For cinnamon essential oils the data scatter is even greater: IC50 values range from 147 μg/L [30] to 0.41 mg/mL [31].

The profile of volatile compounds present in the analyzed essential oils was also determined using GC-MS (

Table 2. Volatile composition of essential oils tested.

R.T. [min]	Compound	CAS No	R.I. (Calc.)	R.I. (Ref.)	Essential Oil
					% of Total Peak Area
					Cinnamon C	Cinnamon D	Clove C	Clove D
6.564	styrene	100-42-5	890	890–891	tr	nd	nd	nd
7.697	3-carene	13466-78-9	938	1004–1011	tr	0.140	nd	nd
8.045	camphene	79-92-5	953	952–953	nd	0.083	nd	nd
8.288	4-benzoyl-3-phenyl-5-isoxazoline	41836-94-6	963	N/A	nd	0.235	nd	nd
8.704	pseudolimonene	499-97-8	980	996–1005	tr	tr	nd	nd
9.718	p-cymene	99-87-6	1028	1026–1033	tr	tr	nd	nd
9.811	D-limonene	138-86-3	1033	1031–1039	tr	0.107	nd	nd
9.861	eucalyptol	470-82-6	1035	1030–1039	nd	0.415	nd	nd
11.146	linalool	78-70-6	1102	1098–1112	1.872	tr	nd	nd
11.425	fenchol	1195-79-5	1119	1094	nd	tr	nd	nd
11.956	benzofuran, 2-methyl-	4265-25-2	1151	1109	nd	0.095	nd	nd
12.047	4-isopropyl-1-phenyl-hexa-1,5-dien-3-ol	N/A	1156	N/A	nd	tr	nd	nd
12.239	isobornyl methyl ether	5331-32-8	1168	N/A	nd	0.196	nd	nd
12.248	benzenepropanal	104-53-0	1169	N/A	nd	0.728	nd	nd
12.702	terpinen-4-ol	562-74-3	1178	1177–1179	nd	0.187	nd	nd
12.713	L-alpha-terpineol	98-55-5	1196	1185–1207	0.153	0.393	nd	nd
12.762	methyl salicylate	119-36-8	1199	1190–1206	nd	nd	0.064	0.147
13.152	(Z)-cinnamaldehyde	57194-69-1	1226	1214–1215	0.192	0.768	nd	nd
13.455	trans-verbenol	1820-09-3	1246	1144–1150	0.280	nd	nd	nd
13.606	phenol, 4-(2-propenyl)	501-92-8	1256	1253–1254	nd	nd	0.139	0.835
13.906	(E)-cinammaldehyde	14371-10-9	1277	1266–1287	34.615	89.615	nd	0.912
14.148	bornyl actetate	76-49-3	1293	1285–1302	nd	nd	0.132	nd
14.473	2-propen-1-ol, 3-phenyl	104-54-1	1316	1259–1312	nd	0.099	nd	nd
15.194	eugenol	97-53-0	1356	1351–1356	59.584	0.085	78.551	78.826
15.464	copaene	18252-44-3	1389	1416	tr	0.541	0.183	0.834
15.713	cinnamaldehyde dimethyl acetal	4364-06-1	1408	N/A	nd	0.362	nd	nd
16.074	caryophyllene	87-44-5	1437	1428–1467	0.709	0.102	7.125	8.965
16.254	cinnamyl acetate	21040-45-9	1451	1433	0.671	nd	nd	0.051
16.308	1,6-diphenyl-1,5-hexadiene	4439-45-6	1455	N/A	nd	4.446	nd	nd
16.504	alpha-humulene	6753-98-6	1471	1444–1454	tr	nd	0.759	1.244
16.717	isoledene	95910-36-4	1488	1373–1723	nd	nd	0.025	nd
16.760	alpha-muurolene	10208-80-7	1491	1480–1499	nd	0.356	nd	nd
16.838	germacrene d	23986-74-5	1497	N/A	nd	nd	nd	0.171
17.265	eugenol acetate	93-28-7	1533	1524	1.283	nd	12.186	6.345
17.315	cadina-1(6),4-diene	16729-00-3	1537	N/A	nd	0.557	nd	1.098
17.443	alpha-cubebene	17699-14-8	1548	1345–1351	nd	nd	nd	0.198
17.638	(Z)-2-methoxycinnamaldehyde	76760-43-5	1565	N/A	nd	0.490	nd	nd
17.725	1H-indene, 1-ethylideneoctahydro-7a-methyl-, cis-	56362-87-9	1572	N/A	nd	nd	0.121	nd
18.109	caryophyllene oxide	1139-30-6	1604	1573–1606	tr	nd	0.394	0.374
19.229	2′,3′,4′ trimethoxyacetophenone	13909-73-4	1702	N/A	nd	nd	0.321	nd
20.058	benzyl benzoate	120-51-4	1742	1762	0.641	nd	nd	nd

C—commercial EO, D—distilled EO, tr—trace: the signal for a given peak is lower than the signal-to-noise ratio threshold (S/N = 20). R.T.—retention time; R.I. (calc.)—Kováts retention index calculated. R.I. (ref.)—reference Kováts retention index from: https://www.pherobase.com/ (Accessed 4 October 2025); N/A—not available; nd—not detected.

).

Chromatographic analysis showed that the compound found in the largest amount in distilled cinnamon EO was cinnamaldehyde (89.62%), while in commercial oil it was eugenol (59.58%). Eugenol is known to be the main component of cinnamon leaf essential oil, ranging up to 75% [32]; therefore, its dominance in commercial oil suggests the admixture of leaf oil. Cinnamaldehyde was also found in a significant amount in commercial oil (34.62%); however, due to the dominance of eugenol in this case it constituted a smaller percentage of the total composition. Similarly, in the study by Gotmare and Tambe [33], the main component of cinnamon EO obtained by distillation was cinnamaldehyde in the amount of 91.5%. Moreover, gas chromatography (GC-MS) of the EO obtained from the bark of Cinnamomum zeylanicum identified 71.5% of cinnamaldehyde, which was the main component of this oil [34]. Compounds such as linalool or eugenol acetate, which also only occurred in commercial oil, accounted for more than 1%. However, less than 1% were observed for caryophyllene, cinnamyl acetate or benzyl benzoate content. Other compounds identified in commercial oil such as camphene, D-limonene, 3-carene or copaene and others presented in the table occurred in trace amounts. In turn, in the distilled oil, apart from cinnamaldehyde, 1,6-diphenyl-1,5-hexadiene was detected, constituting 4.45%. Less than 1% was copaene or (Z)-3-phenylacrylaldehyde, which also occur in the commercial oil. Others identified included benzopropanal (0.73%), cineole (0.42%) and (Z)-2-methoxycinnamaldehyde (0.49%). Trace amounts also included styrene and fenchol. A total of 20 compounds were identified in the commercial oil and 27 in the distilled oil. In the case of cinnamon EOs, the plant species is strongly important. Studies have shown that raw materials of unspecified geographical origin usually contain large amounts of coumarin, a compound with hepatotoxic properties, while in good quality Ceylon cinnamon (Cinamonum verum), the content of this compound was trace, whereas other bioactive components were dominated [35].

Also, GC-MS analysis of clove EOs, including both distilled and commercial variants, revealed significant differences in their chemical composition, which may affect their properties and potential applications. In both samples, eugenol was the dominant compound, accounting for 78.826% and 78.551% of the self-distilled and commercial EOs, respectively. Caryophyllene was the second most abundant compound, accounting for 8.965% of the distilled oil and 7.125% of the commercial oil. It is a sesquiterpene known for its anti-inflammatory properties. Humulene (1.244%) was also identified in the distilled oil, which was not present in the commercial oil. Eugenol acetate was present in both samples but at a higher level in the commercial oil (12.186%) than in the distilled oil (6.345%). This compound adds a sweet, balsamic note to the scent of clove oil.

Although the strong differences were found for commercial and self-distilled EOs, both were used to spike rapeseed honey.

3.2. Enriched Honeys Evaluation

The total content of phenolic compounds and antioxidant capacity (DPPH and FRAP methods) were checked in honeys enriched with essential oils in comparison to the control rapeseed honey (

Table 3. Total phenolic content and antioxidant capacity of flavored honeys.

	TPC [mg GAE/100 g]		FRAP [μmol TE/100 g]		DPPH [μmol TE/100 g]
	1 Month	6 Months	1 Month	6 Months	1 Month	6 Months
Control	19.44 ± 1.01 a	20.85 ± 2.25 a	29.65 ± 0.89 a	37.34 ± 6.81 a	18.29 ± 3.85 a	22.01 ± 2.34 a
Cinnamon C 0.1	112.35 ± 12.89 b	109.00 ± 7.43 b	453.13 ± 14.80 b*	431.74 ± 14.56 b*	245.63 ± 79.94 b*	189.55 ± 25.52 b*
Cinnamon C 0.3	261.53 ± 20.13 c*	239.58 ± 41.70 c*	1379.11 ± 51.62 c	1393.91 ± 79.28 c	564.24 ± 70.92 c*	428.03 ± 34.04 c*
Cinnamon D 0.1	20.80 ± 0.56 a	22.30 ± 0.36 a	31.62 ± 0.68 d	36.64 ± 6.19 a	19.80 ± 1.45 a	20.35 ± 1.38 a
Cinnamon D 0.3	19.74 ± 1.54 a	22.23 ± 1.64 a	29.81 ± 1.27 a,d	40.95 ± 10.05 a	21.09 ± 3.24 a	20.22 ± 1.25 a
Clove C 0.1	115.56 ± 2.88 b	125.65 ± 4.89 b	601.18 ± 27.21 b*	767.27 ± 7.26 b*	249.16 ± 29.06 b	265.39 ± 66.67 b
Clove C 0.3	235.40 ± 13.32 c	246.09 ± 6.18 c	1735.79 ± 14.30 c*	2082.85 ± 141.53 c*	683.88 ± 30.33 c*	539.21 ± 44.86 c*
Clove D 0.1	142.97 ± 30.63 b*	124,72 ± 4.92 b*	699.12 ± 136.70 b	764.80 ± 21.03 b	294.06 ± 25.44 d*	236.54 ± 8.85 b*
Clove D 0.3	243.67 ± 15.21 c	248.42 ± 10.11 c	1717.93 ± 80.73 c*	2190.17 ± 127.23 d*	650.96 ± 22.79 e*	513.69 ± 6.65 c*

^a,b,c,d,e—significant differences compared to the control sample within the same type of additive (cinnamon vs. clove) (p < 0.001); *—significant differences after storage (p < 0.05). C—commercial EO; D—distilled EO; 0.1, 0.3—percentage of EO added to honey.

).

In all cases, except for the addition of laboratory-distilled cinnamon oil, a multiple enhancement of the antioxidant activity of honey and the content of total phenolic compounds was noted. Moreover, the enrichment was dose dependent, the higher proportion of EO added to the honey, the higher enrichment was observed. The lack of significant enrichment with the addition of distilled cinnamon oil correlates with its weaker properties as such. The strongest effect of enhancing the properties of honey was achieved in the case of antioxidant potential measured by the FRAP method, which reached above 50 times the initial value for pure honey. A significant concentration of active compounds or synergistic action of the oil components affects its antioxidant activity. According to Nurzyńska-Wierdak [36], the presence of eugenol most likely influenced the strong antioxidant properties of basil or clove oil. Our own studies showed that eugenol was the compound found in the largest amount in commercial cinnamon EO, while in distilled EO a small amount was determined. In commercial oil, larger amounts of compounds with antioxidant activity were identified, while in distilled oil, the same compounds were found in trace amounts or not at all. Hence, enriching honey with commercial oil could have translated into strengthening its antioxidant activity compared to honey with the addition of distilled oil, which did not show this strengthening.

Rapeseed honey is known to be one of the weakest varieties of honey in terms of antioxidant potential, which is why it is justified to choose this variety for enrichment [5]. Similarly, the enhancement of its health-promoting properties has been observed many times before with the introduction of various plant additives [3,4,5,11]. This method of increasing the health-promoting potential of honey can be considered biofortification and can also be achieved by adding extracts isolated from plants [8]. Essential oils were previously occasionally used to flavor honey, but it has been shown that this does not deteriorate the quality parameters of honey [15]. The use of essential oils instead of powdered herbs or spices may have the advantage of reducing the risk of microbiological contamination of such a product. Introducing plant additives may carry such a risk [14]. From the point of view of the bioactivity of such a new product, the combination of honey with essential oils may promote better dissolution of the oils and their absorption in the intestines [17]. It is worth emphasizing that there were no changes in honey features such as color or consistency with the low amount of the additive introduced. Moreover, there was no separation observed during storage, which sometimes happens when herbs or fruits are added.

The prepared flavored honeys were also assessed for storage stability for a period of 6 months. In most cases, no significant changes nor significant increases in the tested properties were observed. A statistically significant reduction in the antiradical potential of DPPH was observed only in the case of honeys with a higher admixture of clove oil and commercial cinnamon oil. Previous studies indicate different behavior of honeys with additives during storage. Both significant decreases in antioxidant properties and increases, even up to 150% compared to the product before storage, were observed [5]. However, when the additive is introduced in the form of solid particles, there is variability caused by the degree of fragmentation of the additive and the ability to migrate bioactive substances into the honey matrix.

Honeys enriched with a higher content of each essential oil as well as the control rapeseed honey were also subjected to analysis of the volatile composition (

Table 4. Volatile composition of control honey and honeys enriched with EOs.

R.T. [min]	Compound	CAS No	R.I. (Calc.)	R.I. (Ref.)	Honey
					% of Total Peak Area
					Control	+Cinnamon C 0.3%	+Cinnamon D 0.3%	+Clove C 0.3%	+Clove D 0.3%
6.56	styrene	100-42-5	772	890–895	nd	nd	tr	nd	nd
7.701	3-carene	13466-78-9	938	1004–1011	nd	nd	0.162	nd	nd
8.055	camphene	79-92-5	953	952–953	nd	nd	tr	nd	nd
8.285	4-benzoyl-3-phenyl-5-isoxazoline	41836-94-6	963	N/A	nd	nd	tr	nd	nd
8.316	benzaldehyde	100-52-7	964	961–996	nd	0.212	1.311	nd	nd
8.754	pseudolimonene	499-97-8	982	996–1005	nd	nd	tr	nd	nd
9.012	tert-butylbenzene	98-06-6	993	991	nd	nd	tr	nd	nd
9.132	benzofuran	271-89-6	998	986	nd	nd	tr	nd	nd
9.813	D-limonene	138-86-3	1033	1031–1039	nd	nd	0.179	nd	nd
9.871	eucalyptol	470-82-6	1036	1030–1039	nd	nd	2.588	nd	nd
10.525	ethanone, 2-(formyloxy)-1-phenyl	55153-12-3	1070	N/A	nd	nd	tr	nd	nd
10.717	2,5-furandicarboxaldehyde	823-82-5	1080	1034	3.184	nd	nd	nd	nd
10.865	alpha-campholenal	4501-58-0	1087	1127–1130	nd	nd	tr	nd	nd
10.962	cyclohexene, 1-methyl-4-(1-methyletylidene)	586-62-9	1092	1084–1096	nd	nd	tr	nd	nd
11.392	2-phenylethanol	60-12-8	1117	1110–1122	6.149	nd	nd	0.021	0.022
11.405	linalool	78-70-6	1118	1098–1112	nd	1.868	0.167	nd	nd
11.952	benzofuran, 2-methyl-	4265-25-2	1151	1109	nd	nd	0.641	nd	nd
12.245	benzenepropanal	104-53-0	1168	1160–1178	nd	nd	1.042	nd	nd
12.272	benzoic acid	65-85-0	1170	1171–1310	9.857	nd	nd	0.034	nd
12.387	isobornyl methyl ether	5331-32-8	1177	N/A	nd	nd	0.207	nd	nd
12.623	3,7-octadiene-2,6-diol, 2,6-dimethyl	13741-21-4	1191	1189–1204	4.532	nd	nd	nd	nd
12.701	L-alpha-terpineol	98-55-5	1196	1185–1207	nd	0.153	1.089	nd	nd
12.765	methyl salicylate	119-36-8	1204	1190–1206	nd	nd	nd	0.046	0.129
13.156	(Z)-cinnamaldehyde	57194-69-1	1229	1214–1215	nd	0.193	0.661	nd	nd
13.449	trans-verbenol	1820-09-3	1248	1144–1150	nd	0.279	nd	nd	nd
13.600	phenol, 4-(2-propenyl)	501-92-8	1258	1253–1254	nd	nd	nd	0.308	0.572
13.910	(E)-cinnamaldehyde	14371-10-9	1278	1266–1287	nd	34.541	90.288	nd	0.896
14.150	bornyl acetate	76-49-3	1293	1285–1302	nd	nd	tr	0.042	nd
15.187	eugenol	97-53-0	1356	1351–1356	nd	59.457	0.87	96.447	94.379
15.478	copaene	18252-44-3	1390	1416	nd	nd	0.33	nd	nd
15.711	cinnamaldehyde dimethyl acetal	4364-06-1	1408	N/A	nd	nd	tr	nd	nd
16.072	caryophyllene	87-44-5	1436	1428–1467	nd	0.707	tr	0.246	1.901
16.180	3,5-dimethoxybenzaldehyde	7311-34-4	1445	N/A	2.935	nd	nd	nd	nd
16.250	cinnamyl acetate	21040-45-9	1451	1433	nd	0.67	nd	nd	0.026
16.264	methoxyacetic acid, 3-phenyl-2-propenyl ester	7492-65-1	1452	N/A	nd	nd	tr	nd	nd
16.300	1,6-diphenyl-1,5-hexadiene	4439-45-6	1455	N/A	nd	nd	tr	nd	nd
16.323	shyobunol	69350-61-4	1456	1505–1517	2.17	nd	nd	nd	nd
16.504	alpha-humulene	6753-98-6	1471	1444–1454	nd	nd	nd	0.028	0.28
16.588	2,5-di-tert-butyl-1,4-benzoquinone	2460-77-7	1477	N/A	6.609	nd	nd	nd	nd
16.830	germacrene D	23986-74-5	1497	N/A	nd	nd	nd	nd	0.089
17.048	alpha-muurolene	10208-80-7	1515	1480–1499	nd	nd	0.174	nd	nd
17.071	2,4-di-tert-butylphenol	96-76-4	1517	1502	31.366	nd	nd	0.033	0.063
17.133	butylated hydroxytoluene	128-37-0	1522	1504–1512	2.2	nd	nd	nd	nd
17.254	eugenol acetate	93-28-7	1532	1524	nd	1.281	nd	2.556	1.317
17.315	cadina-1(6),4-diene	16729-00-3	1537	N/A	nd	nd	0.291	nd	0.21
17.442	alpha-cubebene	17699-14-8	1548	1345–1351	nd	nd	nd	nd	0.051
17.521	2-hexadecanol	14852-31-4	1555	N/A	4.556	nd	nd	nd	nd
17.640	(Z)-2-methoxycinnamaldehyde	76760-43-5	1565	N/A	nd	nd	tr	nd	nd
18.115	caryophyllene oxide	1139-30-6	1605	1573–1606	nd	nd	tr	0.057	0.049
18.850	1,3,5,6,7-pentamethylbicyclo [3.2.0]hepta-2,6-diene	2422-86-8	1670	N/A	15.126	nd	nd	0.022	0.016
18.592	phenol, 2.6-bis(1,1-dimethylethyl)-4-(1-methylpropyl)-	34624-81-2	1647	N/A	nd	nd	tr	nd	nd
19.226	2′,3′,4′ trimethoxyacetophenone	13909-73-4	1702	N/A	nd	nd	nd	0.16	nd
19.505	benzoic acid, 3,4,5-trimethoxy-, methyl ester	1916-07-0	1715	N/A	3.309	nd	nd	nd	nd
20.092	benzyl benzoate	120-51-4	1744	1762	nd	0.639	tr	nd	nd
21.558	7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione	82304-66-3	1829	N/A	4.576	nd	nd	nd	nd
21.968	phthalic acid, butyl 2-pentyl ester	3461-29-8	1871	N/A	3.431	nd	nd	nd	nd

C—commercial EO, D—distilled EO, tr—trace: the signal for a given peak is lower than the signal-to-noise ratio threshold (S/N = 20). R.T.—retention time; R.I. (calc.)—Kováts retention index calculated. R.I. (ref.)—reference Kováts retention index from: https://www.pherobase.com/ (Accessed 4 October 2025); N/A—not available; nd—not detected.

).

Analysis of the volatile fraction of the control rapeseed honey confirms that its composition is not particularly rich. Its volatile fraction was dominated by two compounds: 2,4-di-tert-butylphenol (31.366%) and 1,3,5,6,7-pentamethylbicyclo [3.2.0] hepta-2,6-diene (15.126%). In addition, benzoic acid, common in Polish varietal honeys [37], and 2-phenylethanol, previously identified in rapeseed honeys [38], were also identified in smaller amounts.

Cinnamaldehyde, in the case of honey with distilled oil, constituted 90.29% and was the compound present in the largest amount by far. In honey with commercial oil, it constituted 34.54%. The main compound in honey with commercial oil was eugenol (59.46%). The compounds identified for it, which constituted more than 1%, linalool or 2-methoxy-4-(2-propenyl)phenol acetate, did not occur in honey with distilled oil. Less than 1%, in both the case of honey with distilled oil and commercial oil, was (Z)-3-phenylacrylaldehyde. In addition, in honey with commercial oil, one can also distinguish, among others, benzyl benzoate and caryophyllene, which constitute trace amounts in honey with distilled oil. Cineole was detected only for honey with distilled oil in an amount of more than 2%. Other compounds identified exclusively for this sample and constituting less than 1% or trace amounts included copaene, benzofuran, D-limonene, camphene, styrene, bornyl acetate and others. Eugenol appears in high concentrations in honey with the addition of clove oils, dominating the chemical composition (over 94% in both cases with additives). The presence of dominant volatile compounds originating from essential oils, mainly eugenol and cinnamaldehyde, covers the natural fragrance notes of rapeseed honey, which is analytical evidence of the effective flavoring of honey by introducing essential oils into it. The effective transfer of characteristic volatile compounds into honey has been observed previously when honey was enriched with rosemary, sage, oregano, mint, thyme, fennel oil and basil oil [15].

The extracts of honeys flavored with essential oils prepared by SPE as well as the oils themselves were subjected to additional qualitative composition analyses by HPTLC with p-anisaldehyde derivatization. The image of the plates in UV light 254 nm (before derivatization) and white light and UV 366 nm (after derivatization) is shown in Figure 1 and Figure 2 for honeys with cinnamon and clove oil, respectively.

In chromatographical images of all honey extracts tested, a similar arrangement of bands corresponding to compounds originating from the initial rapeseed honey was observed. The identified characteristic marker is kaempferol (Rf = 0.51), a flavonoid abundantly found in Polish honey of this variety [37], as well as another compound, not identified in detail, with a band at Rf = 0.12 with a characteristic navy blue color.

In the case of the admixture of cinnamon oils distilled in laboratory conditions, the revealed pattern of bands in the chromatograms is richer than for the commercial oil. However, there is no clear band originating from eugenol (Rf = 0.78). A very intense, overloaded eugenol band was also present in the commercial oil, which confirms the results from the GC-MS analysis. In a similar Rf range, cinnamaldehyde occurs (present in both oils and honeys with their addition), but the band differs in color from the eugenol band. In addition, in the visualization in UV light 254, an additional band for cinnamaldehyde is revealed, probably from the isomer, which is also visible in all samples. Eugenol was also the dominant band visible in both tested clove oils and honeys with their addition. In fact, next to it, only in honey samples with 0.3% addition of both oils, an additional red band is visible in visible light after derivatization above eugenol (Rf = 0.86). HPTLC analyses confirm that rapeseed honey was significantly enriched by the addition of essential oils, but only the dominant components of the oils were detectable. However, this method allows for quick and relatively easy comparison of individual samples.

The results of the organoleptic evaluation are presented in the form of radar charts (Figure 3).

In terms of color, all honeys received high average scores (≥9.2). The smell was rated high for honey enriched with distilled oils at a concentration of 0.1%, and increasing the concentration caused too intense a smell, which was not appreciated by the assessors. The smell of honey with the addition of commercial oils, especially clove, was rated lower, where the smell was described as too sharp. In terms of taste, honeys with distilled oils were rated similarly, and the ratings were higher than honey with the addition of commercial oils. The introduction of essential oils slightly worsened the consistency of honey in the consumer assessment; the honey was described as slightly “runny”. In general, the idea of honey with the addition of essential oils was positively assessed by the evaluators, with a lower share of self-distilled oils being indicated as optimal.

In the case of creamed honeys with plant additives, consumer acceptability is of particular importance. It determines whether the developed product has a chance of success on the market. The attractiveness of honeys with various spice and fruit additives, including cinnamon, was studied by Predanocyova and Šedik [39]. The evaluators indicated features that positively distinguished individual products: color in the case of honey with raspberries, and taste for honey with cinnamon, hazelnuts and cocoa. Honey with cinnamon was generally rated the highest among those examined. Similarly, honey with cinnamon was the most accepted by consumers in another study, ahead of honeys with cardamom and ginger [1]. So far, honeys with the addition of essential oils have not been assessed in this way; there are only reports on the evaluation of honeys enriched with chokeberry extracts, for which it was found that the optimal sensory content of the additive is 0.3–0.4% [9].

4. Conclusions

A new type of product produced by admixing cinnamon or clove EOs to rapeseed honey was proposed. The flavored honeys obtained in this way were positively assessed in terms of organoleptic properties, and a strong enrichment of rapeseed honey in volatile substances from essential oils was also confirmed by GC-MS. Depending on the type of oil (available commercial or self-distilled), the composition of volatilome was strongly dependent on the composition of EOs used. A multiple enhancement of antioxidant properties was obtained in comparison with the control initial honey. To sum up, it seems optimal to add no more than 0.1 v/w of essential oil, and it should be of high quality. Further testing of such products seems justified, especially in terms of expected enhanced antibacterial activity.