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The study was conducted in Pandamatenga area, which is located in Chobe District at a distance of 821.2 km away from the capital city Gaborone. Chobe District is a semi-arid area, with hot and moist summer and dry/mild winter. This region is characterised by a relatively reliable growing season of 101-120 days (UNDP, 1968). Drought resistant crops such as sorghum can be grown without irrigation. The vegetation in Chobe District can be considered as a transition between the northern miombo woodlands and southern Kalahari savannas. Chobe is Botswana’s wettest climate zone with annual average rainfall levels of 640 mm, January and February being the wettest months. An aquic (geology of a soil, that has been saturated by ground water at some time in the past) moisture regime occurs in poorly drained parts of the lacustrine area. This region has clay, loam soil which cracks when dry. The following are the dominant tree species found in Chobe District: Acacia species, Baikiaea plurijuqa (teak), Beranemia species, Croton species, Combretum species, Cassia species, Sclerocarya birrea subsp. caffra (marula), and Ziziphus mucronata (UNDP, 1968).

A semi-structured survey was conducted in Pandamatenga in January 2020 in order to determine honeybee production practices, the major tree/shrub species used as bee forage in the area, their flowering season, honey harvest time, method of collection and handling of honey, use of honey, constraints and opportunities for production of honey in the area. A total of 25 individuals/households were selected purposively based on their experience and involvement in beekeeping and were interrogated through face-to-face interview techniques. Participants gave their informed consent prior to their participation in the study.

Two types of honey samples were collected from Pandamatenga area in Chobe District. One of the honey samples was collected from the wild (forest) and the other honey sample was collected from backyard hives of farmers in Panadamatenga. Three honey samples (each 250 g) were collected from each of the two locations (forest and backyard hives).

The honey samples were transported to the Botswana University of Agriculture and Natural Resources (BUAN) and kept in the refrigerator pending analysis. Analysis of the physico-chemical properties of honey was carried out in the Food Science Laboratory at BUAN and in the Chemistry Laboratory of the University of Botswana. Sensory analysis was conducted in the Food Processing Laboratory of the Department of Food Science and Technology at BUAN.

Determinations of moisture, reducing sugars, sucrose, hydroxymethylfurfural, acidity, pH and ash contents of honey samples were carried out according to the harmonized methods of the International Honey Commission (IHC, 2009) and the revised Codex Standard for Honey (Codex Alimentarius Commission, 1987).

Honey samples (i.e., honey collected from the wild and honey obtained from backyard hives of farmers) were served to 30 untrained panelists to evaluate how much they like the sensory qualities (grassy aroma, woody aroma, colour, thickness, sweetness and overall acceptability) of the honey using a 9-point hedonic scale (where 1=dislike extremely; 2=dislike very much; 3=dislike moderately; 4=dislike slightly; 5=neither dislike nor like; 6=like slightly, 7=like moderately; 8=like very much and 9=like extremely). Bread was used as the carrier and honey was spread on the bread and the samples were labelled with three-digit random numbers. After and in between evaluation of each sample, the panelists rinsed their mouth with water to avoid carrying over effect (Lawless and Heymann, 2010).

Descriptive statistics was used to present the results of the survey study. Comparison of the physicochemical properties and consumer acceptability of honey samples was made between honey samples obtained from the forest and honey samples obtained from backyard hives. The data generated was analysed using a T-test.

Demographic characteristics of the respondents interviewed in the Pandamatenga area is reported in Table 1. The results showed that the majority of the respondents (96%) were aged between 20-50 years, which indicates that most of the beekeepers were in their economically active and productive age group, and were actively engaged in beekeeping activities. All of the interviewed farmers were exposed to formal education (Table 1). Most of the respondents completed secondary education (56%), 28% went to tertiary institutions while only a few (16%) attended primary school (Table 1). The findings of the present study are in agreement with the findings of Kalayu et al. (2017) who reported that 59.9% of the respondents in Ethiopia who were involved in beekeeping were aged between 15-49 years, which is similar to the present study. According to Bareki et al. (2019), most of the respondents involved in beekeeping in Lerala village in Botswana were aged between 31 and 50 years in line with the present study. These researchers also indicated that most of the respondents in Lerala village completed secondary education. On the contrary, Beyene and Verschuur (2014) found out that 33.3% of the respondents involved in beekeeping in Waghimara Zone in Ethiopia were illiterate and they could not read and write.

Hive types, sources of honey and equipment used by respondents interviewed in the study area are reported in Table 2. Modern hive is the predominant type of hive used in the area for honey production. In the study area, honey is mainly produced using the backyard production system (76%); however, a quarter (24%) of the honey produced in the study area comes from the forest. In Russia in the Ural Mountains, the local people Bashkirs also practice ancient breeding style of a dark forest bee, Apis mellifera mellifera in the hollows of trees in the wild forests. However, the wild honey obtained from the forest accounts for only 1% of all honey, and honey obtained in apiaries is 99% (Ilyasov et al., 2015). The present observation is in line with the findings of Bareki et al. (2019) who reported that most farmers in Lerala village use modern hives for honey production. This suggests that beekeeping is slowly growing in the country and people are starting to move from traditional ways of keeping bees to modern apicultural practices.

Almost all the respondents use the same types of equipment for beekeeping in the study area. The major equipment used for beekeeping in the study area include smoker, brush, gloves, bee knife, bowl and protective clothing (bee suit) (Table 2).

Factors that determine choice of hive location, uses of honey and the quantity of honey harvested are reported in Table 3. According to the respondents, factors that determine the location of beehives in the study area include presence of shade, type of vegetation, supply of water, seclusion from human activity, indigenous plant species present in the area.

Honey is used for many purposes in the study area: honey is used for human consumption, used as body ointment, for wine making, used for medicinal purposes (wound healing) and as sweetener in drinks and food (Table 3). Honey promotes fast wound healing through its regenerative tissue growth and epithelization effects, with little or no scar formation (Molan, 2001; Al-Mamary et al., 2002; Bilsel et al., 2002; Chua et al., 2013). The average quantity of honey harvested per household per year in Pandamatenga villages was 20.7±10.74 L (Table 3). The amount of honey produced depends on the climate, availability of water and availability of forage for the bees (Molan, 2001). Jiwa (2013) reported that annual honey production per beehive in Tanzania varies from 4 to 17 kg with a mean amount of 9.66 kg.

The dominant vegetation, flowering season and honey harvesting season in the study area are reported in Table 4. The findings showed that the dominant vegetation used as forage or nectar in the study area include Helianthus annuus (sunflower), Sclerocarya birrea (marula), Citrus limon (lemon tree), Acacia nigrescens and Berchemia discolor (Table 4). Pandamatenga is a region where sunflower is grown at a large scale; hence it serves as the major bee forage in the area. The current results are in agreement with those of Bareki et al. (2019) who found out that sunflower, paw paw and citrus trees are used as bee forage in Lerala village. According to the respondents, honey harvesting season in the study area is February to June, which is different from the report of Bareki et al. (2019) who indicated honey harvesting time for Lerala village to be from November to May.

Moisture content is one of the important parameters that determines honey quality. Moisture content influences taste, viscosity and fluidity of honey (Salazar et al., 2017). The average moisture content of honey samples collected from backyard hives in the present study was 16.93% while the moisture content of honey samples collected from the forest was 24.87% (Table 5), which is in line with the findings of Ibrahim (1985) who reported moisture content ranging from 13.1-26.8% for honey samples produced in Sudan. The present finding is also similar to those of Terrab et al. (2004), Lazaridou et al. (2004) and Gobessa et al. (2012). However, according to EU Council (2002) and Codex Standard (Codex Alimentarius Commission, 2001), the recommended maximum moisture content of honey is set to be 20%. Variations in moisture content may be attributed to the floral source, temperature, relative humidity, method of extraction and storage conditions (Hussien, 2007).

The moisture content of honey samples collected from the forest was significantly (p<0.05) higher than the moisture content of honey obtained from backyard hives (Table 5). According to Salazar et al. (2017), moisture content may compromise the shelf life of honey since it directly influences water activity and microbial growth and it also leads to fermentation of the honey in the package. High moisture maybe a result of lack of good manufacturing practices at some harvest stages or it may be a sign of early harvesting which might have occurred when the honey was “green’’ or unripe (Salazar et al., 2017). Crane (1999) indicated that moisture content of honey depends on the temperature and relative humidity of the geographical region where the honey is produced. Terrab et al. (2003) reported that low moisture content helps promote longer shelf life of honey during storage.

The total ash content of honey samples collected from the forest was significantly (p<0.05) higher than the total ash content of honey obtained from backyard hives (Table 5). The average total ash content of honey in the present study was found to be 0.35% and 0.13% for forest and backyard honeys, respectively (Table 5). This result is in agreement with values reported in the literature. Ouchemoukh et al. (2007) reported that the ash content of honey from Algeria was found to be between 0.06-0.54%. The present observation is also in line with findings of Gobessa et al. (2012) who reported that honey produced in Homesha District in western Ethiopia ranged between 0.02-1.00%. The maximum ash content of honey allowed by the Codex standard (Codex Alimentarius Commission, 1987) is 0.6%. The values for ash content of honey observed in the present study are different from the findings of Terrab et al. (2004) who reported ash content of honey to range from 0.16-0.60%. According to Silva et al. (2009), ash content of honey gives an indication of the overall mineral content of honey. Vanhanen et al. (2011) indicated that ash is considered to be a quality criterion of honey which indicates possible botanical origin of the honey and also ash depends on the soil and climatic characteristics of honey origin.

Free acidity in honey is mainly due to the presence of organic acids particularly gluconic acid and it is an important parameter that is characterized by the presence of organic acids and some inorganic ions such as phosphates and chlorides (Moreira et al., 2007). Free acidity depends on the floral origin and storage conditions which can lead to variation in acidity of honey (Alves et al., 2013; Tornuk et al., 2013). Free acidity was found to be significantly different (p<0.05) for the two honey types (Table 5). The free acidity of honey samples obtained from backyard hives (11 mEq/kg) was significantly lower (p<0.05) than the free acidity of honey collected from the forest (67 mEq/kg). Honey with low acidity is a sign of good conservation as strong acidity promotes degradation of hexose to HMF (Finola et al., 2007; Ajlouni and Sujirapinyokul, 2010; Azonwade et al., 2018). The low free acidity observed in the backyard honey suggests that it is still fresh as compared to the forest honey. High free acidity can indicate fermentation of sugars and release of organic acids (de Silva et al., 2016) and it is related to deterioration of honey. Variation of free acidity among different honey samples can be explained by the blossom origin, the presence of different organic acids and inorganic ions, geographical origin and harvest seasons (Alves et al., 2013; Tornuk et al., 2013).

Similar observations were reported by Finola et al. (2007) and Ibrahim (1985) for free acidity of honey which were found to range from 11.9 to 29.4 mEq/kg and 6-171 mEq/kg, respectively. However, the values for free acidity of honey obtained in the present study are different from those of Terraab et al. (2004), Costa et al. (1999) and Serrano et al. (2004) who reported values ranging from 17.59-39, 81, 24.4-53.3 and 17.1-50.9 mEq/kg, respectively. According to Adgaba (1999), the national limit for free acidity of Ethiopian honey is 40 mEq/kg while according to Codex standard (Codex Alimentarius Commission, 2001), the maximum limit for free acidity of honey is 50 mEq/kg. Honey samples collected from the forest in the present study exceeded these limits. This may be because the forest honey samples might have been stored for a longer period after harvest, as storage affects the acidity of the honey.

The pH of honey samples obtained from the two sources (backyard and forest) showed significant (p<0.05) difference (Table 5). pH of forest honey (4.28) was significantly lower (p<0.05) than pH of honey samples obtained from backyard hives (6.67) (Table 5). The pH values of honey samples observed in the present study are in agreement with values reported in the literature. Terrab et al. (2004) reported that the pH of honey ranges between 3.56-4.79. Serrano et al. (2004), on the other hand, reported pH values ranging from 3.72-4.64 for honey, while Ouchemoukh et al. (2007) found pH value of honey to be 3.49-4.43. Moreover, Downey et al. (2005) indicated the pH of honey samples to be 3.75-4.61. All these values are in agreement with the pH of backyard hive honey observed in the present study. However, Pires et al. (2009) and Agbagwa et al. (2011) found very low pH values of 3.47-4.27 and 2.90-4.26, respectively for honey, which are different from pH values of honey observed in the present study. According to Terrab et al. (2002), honey is a naturally acidic food irrespective of the geographical origin which may be due to the presence of organic acids which contribute to flavor and stability against microbial spoilage. Acidity influences texture and is important in extraction process as it affects the honey as well as its stability and shelf life (Terrab et al., 2002; Terrab et al., 2014).

Carbohydrates in the form of sugars are major constituents of honey (Sato and Miyata, 2000). Solayman et al. (2016) reported that reducing sugars are reported to make up the largest portion of the sugars of honey. The average reducing sugars content of honey samples in the present study were found to be 56.60% and 56.93% for backyard and forest honey samples, respectively (Table 5). No significant difference (p>0.05) in reducing sugars was observed between the two honey samples (Table 5). The present results are in agreement with the findings of Gobessa et al. (2012) who reported a value of 42-71% for honey samples collected from western Ethiopia. However, the values observed in the current study are lower than the values reported for Indian honey (62.2-70.2%) (Kumar et al., 2013) and Pakistani honeys (57.7-70.5%) (Fahim et al., 2014) but higher than values (34.5-50.3%) reported for Algerian honey (Ouchemoukh, 2007). Feàs et al. (2010) reported reducing sugars content of 64.5-80.0% for Portuguese honeys. Variations in honey’s reducing sugar can be caused by many factors. According to Escuredo et al. (2012) and Tornuk et al. (2013), reducing sugar composition of honey depends on the honey’s botanical and geographical origin and is affected by climate and storage condition.

The sucrose content of honey samples collected from backyard hives and those obtained from the forest was 1.53 and 1.17%, respectively (Table 5). The sucrose content of backyard honey samples was significantly higher (p<0.05) than that of forest honey (Table 5). The sucrose content of honey samples assessed in the present study is in agreement with values reported in the literature. Serrano et al. (2004), Gobessa (2012) and Ouchemoukh et al. (2007) reported sucrose contents of honey to be 0.14-11.49%, 0.18-4.60%, 0.08-5.31%, respectively. Moreover, the values observed in the present study have not exceeded the recommended limit of 5% as stated in the Codex standard (Codex Alimentarius Commission, 2001). The present results are in line with the limits for (not more than 10%) Sudanese honey (SSMO, 2007).

Hydroxymethylfufural (HMF) is formed by decomposition of monosaccharides when honey is heated or stored (da Silva et al., 2016). HMF is also used to indicate the extent of heat applied on honey. Honey collected from backyard hives and the forest showed significant difference in HMF (p<0.05) (Table 5). HMF of honey samples analysed in the present study were 26.00 and 33.16 mg/kg for backyard and forest honeys, respectively (Table 5). These findings are in agreement with literature values, which state that honey should have HMF value of less than 40 mg/kg (Codex Alimentarius Commission, 2000; Gobessa et al., 2012). HMF is used to indicate the freshness of honey, hence it is present in trace amounts in fresh honey and its concentration is reported to increase with storage and prolonged heating of honey. HMF is an important parameter used to show honey purity and adulteration. Thus, both the honeys samples considered in this study were fresh. HMF can be influenced by many factors including, heating, storage conditions, pH of honey and adulteration of honey with simple sugars from external sources (Pasias et al., 2017).

The sensory acceptability of honey samples collected from backyard hives and the forest is presented in Table 6. The sensory attributes considered were colour, appearance, grassy aroma, woody aroma, sweetness, thickness and overall acceptability.

There was a significant difference (p<0.05) in the acceptability of the colour of the two honey samples collected from the forest and backyard hives in Pandamatenga (Table 6). The scores for the colour and appearance of the honey from backyard hives were liked significantly more than that from the forest honey. The difference in the acceptability of the colours and appearance of the honey maybe attributed to the source of forage, the type of trees (flowers) and the storage time after harvesting. Honey samples collected from the forest had dark brown colour while honey samples collected from backyard hives had light brown colour (Fig. 1). The difference in colour between the two honey samples might be attributed to the long time that the honey might have stayed in the hive in the case of the forest honey and the good management practiced in the case of backyard honey. The results are in agreement with the findings of Kaakeh and Gadelhak (2005) who reported a significant difference among 13 honey samples collected from Arab Gulf region for colour, smell, thickness, mouth feel (texture) taste, sweetness and aftertaste. However, Belay et al. (2015) found no significance difference in colour acceptance for honey samples collected from Harenna forest in Bale Zone of Ethiopia. They further explained that Harenna forest honeys had extra light amber and light amber colours. Colour is an indication of flavour concentration, usually a lighter colour indicates a milder flavour (Amril and Ladjama, 2013).

Fig. 1. 
Picture of forest (A) and backyard (B) honey samples collected from Pandamatenga village.

There was a significant difference (p<0.05) in the acceptance of the grassy aroma between backyard and forest honey samples (Table 6). Backyard honey had significantly higher acceptance scores (p<0.05) than the forest honey (Table 6). The panellists liked the grassy aroma of honey samples obtained from backyard hives than those obtained from the forest. The difference in the grassy aroma observed might be attributed to the location of the hives. According to Mousa et al. (2019), that aroma of honey is usually derived from the plant origin.

No significant difference was observed in the woody aroma between the honey samples (Table 6). Azenedo et al. (2003) and Alvarez-Suarez et al. (2010) stated that aroma and texture of honey vary with the flower nectar from which it was made. Honey can be made from a variety of different flowers including thyme, lavender, colver, alfalfa, heather and Acacia.

Sweetness is determined by the taste bud of the panellists. No significant difference (p>0.05) in liking of sweetness was observed between the two honey samples although backyard honey had numerically higher scores for sweetness (Table 6).

Similarly, no statistical difference (p>0.05) was observed between the two honey samples for thickness and smoothness (Table 6). Ndife et al. (2014) found out that honey from Nigeria scored 6.13-6.48 for smoothness which is in line with the present results for forest honey which scored 6.08 in smoothness. Backyard honey scored 6.76 for smoothness which is higher than that of the forest honey. Texture of honey is affected greatly by temperature and water content and to a lesser extent by the composition of honey (Durrani et al., 2011). Therefore, this may explain the reason why forest honey was liked less because of the high moisture content it had which might have attributed to the low scores.

Castro-Vazquez et al. (2010) and Alissandrankis et al. (2003) stated that variation of sensory attributes is generally a consequence of different types of honey, different geographical and botanical origin (floral change), chemical composition, weather conditions, and beekeeping practices. In general, there were significant differences (p<0.05) in colour, appearance and aroma between the two honey samples; however, there was no significant difference (p>0.05) in the overall acceptability, woody aroma, sweetness, smoothness and thickness of the two honey samples (Table 6).