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Abstract.- The sidder or ber honey of Pakistan can be stored for one year without seriously compromising with its quality. Although the values of various quality criteria had altered over a period of one-year; but they remained within the permissible limits. After one year of storage the pH varied between 7.4 and 6.8 for Bannu ber honey, 7.2 and 6.9 for Karak ber honey and 5.6 and 4.9 for Chunian ber honey.
Similarly free acidity ranged between 6.5 and 29 meq/kg, 5.5 and 17meq/kg, 16 and 36.5meq/kg, lactone 0-2.7meq/kg, 1- 7.5meq/kg, 0-2.5meq/kg, total acidity 6.5- 31.7meq/kg, 6.5-24.5meq/kg, 16-39meq/kg, Electrical conductivity between 0.53- 0.61mS/cm, 0.51-0.56mS/cm and 0.22- 0.40mS/cm, HMF content between 2- 11.2mg/kg, 1.7-10.5mg/kg, 4.6-26.9mg/kg, Proline content between 608.4-341.2mg/kg,2800-476mg/kg, 621.2-147.3mg/kg, Diastase number between 33-23.4DN, 31-23.8DN, 42-27DN and Invertase number between 72.2-50.1, 68.7-52.9 and 90.27-44.7 for Bannu, Karak and Chunian ber honey, respectively.
Key words: Shelf life, ber honey, physicochemical characteristics of honey, proline content, HMF content, diastase number, invertase number.
Honey is susceptible to physical and chemical change during storage. It tends to be dark and loses its aroma and flavors (www.nhb.org). Honey is generally evaluated by a physico-chemical analysis of its constituents. Several of these constituents are of great importance to the honey industry as they influence the storage quality, granulation, texture, flavors and the nutritional and medicinal quality of honey. The International Honey Commission (IHC) has, therefore, proposed certain constituents as quality criteria for honey (Bogdanov et al., 1999). These include: moisture content, electrical conductivity, reducing sugars, amount of fructose and glucose, sucrose content, free acidity, total acidity, proline content, hydroxymethylfurfural (HMF), diastase activity, invertase activity and specific rotation. In the present study standard methods were used for determination of quality of honey.
The purpose of the present study was to assess the effect of shelf life on physicochemical characteristics of sidder/ ber honey samples stored at ordinary room temperature for one year.
Materials and methods Fresh Pakistani sidder honey samples were collected from Karak, Bannu and Chunian areas for study and stored under ordinary room temperature (25-29°C) in the laboratory until completely analyzed. There was no sign of granulation in honey samples. No preservative or any heating was applied at any stage.
All physicochemical determinations were essentially carried out according to the European...