**1. Introduction**

Honey is an ancient natural product valued for its health benefits, medical characteristics and biological properties [1,2]. According to the definition of Codex Alimentarius [3] and a European Community Directive [4], honey is a natural substance produced by honeybees from the nectar of flowers without any added ingredients. Usually, the quality of honey is assessed by several parameters, including its moisture, sugar content, pH, total acidity, hydroxymethylfurfural (HMF) content and other factors [3,5,6]. The sweet taste of honey is primarily due to its high fructose content [4,6]. Consumers generally perceive it as a natural and healthier sweetening alternative to table sugar [7].

Due to its high price, honey is frequently adulterated [8]. It is ranked sixth amongst the food products subjected to fraud in Europe [9]. Therefore, strict monitoring and quality assurance are needed to prevent adulterated products from entering the consumer market. Adulteration is only one practice by which the quality of honey can be compromised. Other factors include, but are not limited to, the application of a heat treatment or the use of improper storage conditions [10,11].

**Citation:** Osaili, T.M.; Odeh, W.A.M.B.; Al Sallagi, M.S.; Al Ali, A.A.S.A.; Obaid, R.S.; Garimella, V.; Bakhit, F.S.B.; Hasan, H.; Holley, R.; El Darra, N. Quality of Honey Imported into the United Arab Emirates. *Foods* **2023**, *12*, 729. https://doi.org/10.3390/ foods12040729

Academic Editors: Liming Wu and Qiangqiang Li

Received: 6 December 2022 Revised: 24 January 2023 Accepted: 30 January 2023 Published: 7 February 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Due to the high variability in honey composition, the detection of adulteration is not an easy task. Honey adulteration can be carried out by adding water (dilution) or cheap sugar solutions, such as high-fructose corn syrup [12]. High-quality honey can also be mixed with honey of low quality, and sold at a higher price [13]. Adulteration may compromise consumer experience and expectations, which may lead to the reduced demand for honey and its products. Moreover, legitimate honey producers are often unable to compete with the low-priced adulterated honey. Consequently, there is growing interest in screening honey for adulteration and quality before market distribution.

Various methods have been developed to check for honey adulteration, with each method having its advantages [14]. Physicochemical analysis, such as of the sucrose content, the sum of glucose and fructose, moisture content, HMF, acidity, or diastase activity, are often used for this purpose [12,15]. Honey may be considered adulterated if one or more of these parameters does not meet international or domestic standards. Analysis of the sucrose content is also often used to identify honey adulteration. Authentic honey must not contain more than 5% sucrose [16]. Honey is mainly composed of glucose and fructose in varying concentrations (55 to 75 g/100 g), with a minimum acceptable limit of 60%. The second main component of honey is water (15 to 25 g/100 g), with an acceptable moisture level being below 17% [17]. HMF is an indicator of honey freshness and is commonly used in quality analysis. It is a compound formed during the acid-catalyzed dehydration of hexoses [18]. Generally, it should be present in very low amounts in fresh honey, with its complete absence being indicative of high-quality honey. As per the Codex Alimentarius honey standard [3] and the United Arab Emirates (UAE) standard, HMF content must not be higher than 80 mg/kg. The EC Council directive 2001/110/EC from the European community has set an HMF limit of 40 mg/kg, with an exceptional value of 80 mg/kg for honey coming from countries with tropical temperatures [4]. Honey with an HMF value of >80 mg/kg is characterized as being of very low quality. HMF quantities are affected by pH, heat treatment [19], and the conditions used for honey storage [20], with warm environments increasing the HMF concentration [21]. In addition, mixing honey with invert syrups can also increase HMF values [22]. Honey contains small amounts of different enzymes, and one of the most important ones is amylase (diastase). This enzyme is sensitive to heat and is, therefore, able to indicate the overheating of honey and its degree of thermal preservation [23]. Thus, diastase activity is considered to be a quality indicator used for the freshness of honey, set by Codex [3]. The diastase activity is usually expressed in Schade units, also known as the diastase number (DN), which is defined as the amount of enzyme that will convert 0.01 g of starch to the prescribed end-point in 1 h at 40 ◦C under the conditions of the test [24]. According to the Honey Quality and International Regulatory Standards, the diastase activity must not be less than or equal to eight, determined after processing and blending for all retail honey.

Besides the above stated parameters, free acidity is also used to identify fraudulent honey. The Codex Alimentarius [3] has set a permitted range of 50 meq acid/kg. A high value of free acidity in honey is an indicator that glucose and fructose fermentation by yeasts has occurred, converting the sugars to alcohol and carbon dioxide. In the presence of oxygen, alcohol is hydrolyzed to acetic acid, consequently increasing the free acidity [21]. On an obvious note, physical contaminants, such as hair and insects, are unacceptable. Recent research work has evaluated the quality of honey. A study by Kazeminia, Mahmoudi, Aali, and Ghajarbygi (2021) [25] assessed 43 honey samples collected from Qazvin province, Iran, and showed that the pH and acidity values conformed perfectly (100%) with the Iranian honey standard. However, 44.2% of the samples did not meet the acceptable quality level regarding HMF. For moisture content, 2.3% of the samples were above the acceptable limit. There was also a high percentage of samples that were not compliant with sucrose (53.5%), and glucose and fructose (25.6%) content requirements. Another study conducted by Gürbüz et al. (2020) [26] reported that all 68 honey samples collected from the Southeastern Anatolia region of Turkey were in compliance with the international standard in Turkey for sucrose content, the sum of glucose and fructose, moisture content

and free acidity. However, 20.6% of samples were non-compliant concerning diastase number. For HMF, 7 of 68, or 10.3% of honey samples, had a higher HMF content than the legally permitted EU maximum level of 40 mg/kg. A study conducted by Yayinie, Atlabachew, Tesfaye, Hilluf, and Reta (2021) [27] found that all 47 honey samples collected from different geographical areas within the Amhara region, Ethiopia, met the Codex Alimentarius [3] standard. Boussaid et al. (2018) [28] reported that all 9 honey samples collected from southern Tunisia met the standards of the Codex Alimentarius for pH, free acidity, water activity and HMF.

Since there has not been any investigation available that has examined the imported honey quality in the UAE, the present study was undertaken to assess the honey imported to the UAE via ports in the Dubai Emirates over a 5 year period.
