Physciochemical variations in the honey produced by Apis dorsata from Punjab , Pakistan

A total of 24 samples was collected from three different localities (n= 3, Lahore, n= 10, Jhang and n=11, Kalar Kahar). These honey samples were analyzed for moisture content, pH, electrical conductivity, free acidity, lactone content, total acidity, proline and HMF content for quality evaluation of Apis dorsata honey. The average moisture content was 22.86%, 22.97% and 21.13% from Lahore, Jhang and Kalar Kahar, respectively. The pH values fell within the prescribed range of 3.42-6.1. The mean free acidity of all honey samples was well with international limits. Lactone content was 33.44meq/kg from Lahore, 15.53meq/kg from Jhang and 12.77meq/kg from Kalar Kahar. Total acidity calculated for honey samples of Lahore was 60.21meq/kg, 55.46meq/kg for Jhang and 50.36meq/kg for Kalar Kahar region. Proline content was estimated at an average of 5146.62mg/kg of honey samples from Lahore, 4328.44mg/kg from Jhang and 3554.68mg/kg from Kalar Kahar honey samples which were higher than minimum International Honey Standards limit. HMF content was measured as 36.41mg/kg from Lahore, 30.44mg/kg from Jhang and 89.93mg/kg from Kalar Kahar. The HMF Content was within the maximum International limit.


Introduction
Apis dorsata, the giant honeybee, is found in the tropical regions of Asia [1].It is also one of the native honeybee species of Pakistan commonly known as "dommna" and wild in nature.It's yellow in color with black stripes on each adnominal segment.It usually builds a single comb which is 1-1.6 m wide and 0.8-1.5mlong under the stout branchs of tall trees or buildings or water tower or cliff to protect their nests from top predators [2].The comb is formed by several layers of protective curtains of bees.These protective curtains keep a constant temperature for brood nest between 0-33 ºC.Apis dorsata seasonally migrates back and forth between low (10 m) and uplands (1100 m) to escape from harsh environmental conditions.When it migrates from low agriculture lands, they always aggregate in masses from 25-120 colonies (depend on nesting space availability).At this time of the year different types of honey crops are bloom.A single fully-grown nest may weigh over 20 kg including brood, honey, pollen and adult bee.However, in wet season they never aggregate in masses probably due to scarcity of food, strong wind, heavy rain fall, storms, and the low number of individuals in the colony [3].Although, physical properties and chemical composition of honey has been investigated by many workers [4, 5].However, it may vary with the bee species responsible for its production.In Pakistan commercial beekeeping is done by keeping A.mellifera (European honeybee species) hives and quality evaluation of honey in the country is mostly carried out by either buying or collecting honey available in local market or from beekeepers [6, 7].The composition of honey also depends on the type of plant source utilized by the bees as well as regional and climatic conditions [4, 8, 9].Honey is generally evaluated by a physicochemical analysis of constituents.Several of these constituents are of great importance to the honey industry as they influence the storage quality, granulation, texture, flavor and the nutritional and medicinal quality of the honey.The present study was aimed firstly to find Apis dorsata colonies on different floral sources and secondly to assess the physicochemical properties of Apis dorsata honey from Pakistan in order to increases the scientific knowledge about the honey produced by this honey bee species.A total of 24 samples were collected from three different localities Nankan Sahib, Faisalabad and Kalar Kahar.The predominant vegetation in these areas were Guava, Jaman Eucalyptus in Nankana Sahib, Citrus, Phulai, Mulberry, Neem, Guava, Eucalyptus, Peepal, Acacia in Faisalabad and Jojoba, Phulai, Neem, Mulberry, Citrus, Mango, Acacia, Sheesham in Kalar Kahar.

Materials and methods
Fresh Pakistani Apis dorsata honey samples were collected from different areas of Punjab, Pakistan: Lahore (Figure 1), Jhang (Figure 2) and Kalar Kahar (Figure 3) (Table 1).All these samples, after collecting, were stored in tightly caped jars under ordinary room temperature (25ºC -29ºC) in the laboratory until completely analysis.There was no sign of granulation in honey samples.No preservative or any heating was applied at any stage.Honey samples were diluted in distilled water at room temperature according to the requirements of the test.All tests were performed in triplicate at the Research laboratory of Zoology department of GC University, Faisalabad.The physicochemical methods used for the characterization of honey are those as recommended by International Honey Commission [10].The data was subjected to statistical analysis in which different physicochemical parameters were compared with international reference limits using student's "t" test

Total acidity
The total acidity calculated for honey samples of Lahore 60.21meq/kg (51.20 The present study showed that HMF content in Lahore and Jhang honey samples were within the limit of International honey Standards i-e 40mg/kg, but the HMF content of Apis dorsata honey samples collected from Kalar Kahar exceeds the maximum limit described for HMF Content by Codex Altimenterus.The reason of high HMF content might be that, all the three areas from where these honey samples were collected, have sub-tropical climate and according to [26] the honey produced in subtropical climate have high HMF value which may exceeds 40mg/kg.

Conclusions
The present investigations conclude that honey produce by Apis dorsata showed various quality parameters close to the International honey standards.Moisture content is beyond the Standard limits and seems to be specific in the honey produced by this honeybee species.

Table 1 . Samples collection sites of Apis dorsata honey S.No Nectar source (predominant) Locality No. of samples
1 Guava, Jaman Eucalyptus Lahore 3 2 Citrus, Phulai, Mulberry, Neem, Guava, Eucalyptus, Peepal, Acacia The moisture content in all samples of Apis dorsata are exceeding (Table 2) the limits of International Honey Standards and of Directive, 2001/110/EC from council of European Union, according to which water content of honey should not be more than 21%.This higher moisture content in Apis dorsata honey has also been recoded previously by [12] from four (

Table 2 . Comparison of physico-chemical characteristics of Apis dorsata honey from Lahore, Jhang and Kalar Kahar
(Bogdanov et al., 1999lues at 5% for different physicochemical parameters of Faisalabad, Nankana Shib and Kalar Kahar area.For moisture content p>0, 0.05, p>0.05 for pH, p>0.05 for EC, p>0.05 for free acidity, Lactone and total acidity, p>0.05 for proline content and HMF content.*Thesuggested values for proline content and electrical conductivity for new honey standards(Bogdanov et al., 1999) ** Council of the European Union.Council Directive 2001/110/EC of Dec. 20, 2001, relating to honey.