## 3 Results and Discussion
### Application of Optimized Sample Preparation Method on Multi-Floral Honeys  
The optimized method was applied for the solubilization and determination of hydroxycinnamic acids in commercial multi-floral honey harvested in Cyprus. Multi-floral honey is the most widespread type of honey in Cyprus due to high plant diversity and the geography of the island. This is the first report describing the composition of Cypriot honey in terms of phenolic composition. Table 5 summarizes the amounts of each hydroxcynnamic acid in Cypriot honey collected from local supermarkets. Results showed that the most abundant hydroxcynnamic acid in Cypriot multi-floral honey was the \(p\)-comamatic acid; its content ranged from 0.35 mg kg\({}^{-1}\) to 2.59 mg kg\({}^{-1}\). A previous study on Serbian honey also demonstrated that \(p\)-comamatic acid was the major phenolic constituent in multi-floral honeys; they contain \(p\)-comamatic acid at a concentration between 0.40 mg kg\({}^{-1}\) and 9.97 mg kg\({}^{-1}\)[34]. Recently, [PERSON] et al. (2021) also reported that the major hydroxycinnamic acid in Polish multi-floral honeys was \(p\)-comamatic acid at a concentration of 1.39 mg kg\({}^{-1}\)[35]. Caffe acid was also found in all studied honey samples. Table 5 shows that the concentration of caffe acid in Cypriot multi-floral honey ranged from 0.46 mg kg\({}^{-1}\) to 1.22 mg kg\({}^{-1}\). The differences in the contents may be attributed to the diversity in flowering for the production of multi-floral honey [36]. This fluctuation agrees with international literature for multi-floral honey [37; 38; 39]; there are multi-floral honeys with no detectable amounts of caffeic acid and honeys with significantly high amounts (up to 20.9 mg kg\({}^{-1}\)) [40]. Chlorogenic acid, an ester of caffeic acid and quinic acid, was also detected in studied honeys. The median value of chlorogenic acid content in multi-floral honey produced in Cyprus was 0.63 mg kg\({}^{-1}\). Our findings are similar to published data [34; 37; 39]. However, an unusually high amount of chlorogenic acid (22.14 \(\pm\) 1.32 mg kg\({}^{-1}\)) was determined in one sample. [PERSON] et al. (2012) also  
Figure 2: Graphical representation of greenness for the optimum sample preparation method of hydroxycinnamic acids in honey using AGREprep software. Score values range from zero (considered a non-environmentally friendly approach) to one (the ideal greenest approach) and are accompanied by a color scale from red to green, respectively.  
described a similar high concentration of chlorogenic acid in multi-floral forest honey produced in Lithuania [41]. The high chlorogenic acid content is also correlated with honey that is produced from eucalyptus blossoms [42], thus it will be interesting to investigate the botanical origin of the sample. Rosmarinic acid was also quantified in all analyzed samples, but it is found at significantly lower concentrations. The presence of rosmarinic acid has been described in rosmary, mint, and sage honeys [43, 44]. Taking into consideration the plethora of native Lamiaceae plants grown in Cyprus, the detection of rosmarinic acid in Cypriot honey is reasonable. Finally, ferulic acid was detected in half of the examined samples at low levels. Its concentration ranged between 0.02 mg kg\({}^{-1}\) and 0.10 mg kg\({}^{-1}\) and it was the least abundant studied component in multi-floral honey. A comparable trend was observed in Sicilian honey, though it was not found in multi-floral honeys produced in China and Spain [37, 40]. Previous works reported that ferulic acid is distributed in acacia and heather honeys; these plants grow in Cyprus at areas of low altitude [41, 45]. Overall, the utilization of the developed ultrasound-assisted method was suitable for the analysis of hydroxycinnamic acids in multi-floral honey produced in Cyprus, providing, for first time, valuable information.