Effectiveness of lemon juice and honey in shelf life enhancement of kunun zaki

Abstract

Kunun zaki, a refreshing non-alcoholic local beverage commonly consumed in Nigeria, has a short shelf life. This study was therefore carried out to determine the abilities of lemon juice and honey to improve the shelf life of the product. Traditionally produced kunun zaki was treated with lemon juice and honey in singles and in combinations at concentrations of 1.5, 2.0, 2.5 and 3.0 ml per 100 ml of kunun zaki. The treated kunun zaki samples together with the control (kunun zaki without preservative) were kept at room temperature (25±2 oC) for a period of five days during which physico-chemical characteristics and sensory qualities of the samples were monitored every 24 hours. Titratable acidity (TA) and pH were observed to increase and decrease respectively as keeping period increased. The observed changes became statistically significant (p< .05) after three days of keeping for most of the samples. At the end of the 5-day preservation period, the sample treated with 3 ml of honey recorded the lowest TA of 2.05±0.02 and the highest pH of 5.36±0.04. This sample also was the most accepted in terms of overall acceptability and other sensory parameters. It is concluded that the shelf life of kunun zaki can be improved using appropriate concentrations of lemon juice and honey but especially with honey (3 ml per 100 ml kunun zaki) which was able to preserve the product throughout the five-day period.