PHYSICOCHEMICAL PROPERTIES AND ANTIOXIDANT ACTIVITIES OF HONEY FROM SOUTHERN NIGERIA

A. N. Ukom, I. O. Okereke, F. U. Ugwuona

Abstract


This study evaluated the physicochemical and antioxidant properties of honey from different locations in Southern Nigeria. All the parameters tested showed wide variability. Umuahia honey showed the highest acidity (pH 4.37), while Enugu and Exotic samples showed the least acidity (4.94). The electrical conductivity (EC) ranged from 0.64 (Umuahia) to 1.03 ms/cm (Enugu), which was above the standard limit (0.8 ms/cm). The colour ranged from 36.2 (Exotic) to 140.45 mmPfund (Umuahia). Exotic honey had the highest moisture content (18.86%) and lowest total soluble solid (TSS) content (93.23 °Brix), while Owerri honey had the least moisture content (13.66%) and highest TSS content (124.23 °Brix). The ash content ranged from 0.57 (Benin City) to 0.81% (Umuahia). Umuahia honey showed highest crude protein (1.21%) and reducing sugar (78.13%) contents, while Exotic honey had the lowest content of crude protein and reducing sugar (0.65% and 70.16%). The mineral contents showed that K was the predominant mineral and ranged from 30.78 to 49.12 mg/100g followed by P (7.78 to 12.64 mg/l00g), Ca (6.05 to 7.42 mg/l00g), Na (3.26 to 5.21 mg/l00g), Fe (1.03 to 3.02 mg/l00g) and lastly, Zn (0.43 to 1.02 mg/l00g). Umuahia honey had the highest mineral content while Exotic honey contained the least. Also, antioxidant compounds namely, total polyphenolic content (TPC'), total flavonoid content (TFC) and total ascorbic acid (TAA) ranged from 60.47 to 73.41 mg/GAE/g, 40.52 to 96.61 mgQE/g and 76.37 to 94.62 mg/mL. Antioxidant activity showed that FRAP assay ranged from 91.34 to 126.44 µmolTE/g, ABTS assay ranged from 72.02 to 93 µmolTE/g, DPPH Inhibition ranged from 70.61 to 85.64%, while the reducing power ranged from 43.03 to 54.03 mgQE/g. Umuahia honey possessed the highest antioxidant compound and strongest antioxidant activity. TAA and TPC showed strong linear correlation with DPPH and ABTS. The variations in the honey samples may be due to botanical origin, bee-keeping practice, handling and storage.

Keywords: Southern Nigeria, honey, physicochemical properties, antioxidant activities


Full Text:

PDF

Refbacks

  • There are currently no refbacks.


Chemical Society of Nigeria