Effect of Incorporation of Potash from Ficus carica Fruit Peel Waste into Potash (Nikkih) from Plantain Peel Waste as Emulsifiers on the Physico-Chemical, Functional Properties, and Acceptability of Yellow Achu Soup

Abstract

Yellow Achu soup used to eat achu is an emulsion composed primarily of red palm oil and water stabilized by potash as an emulsifier, is regarded as one of the prestigious traditional foods in Cameroon. However, the yellow achu soup faces a problem of stability due to the inability of the potash from plantain peel alone, commonly called Nikkih, to emulsify and stabilize it. This study was therefore aimed at investigating the effect of incorporation of potash from Ficus carica fruit peel to potash from plantain peel, Nikkih, on the emulsification, emulsion stability, and acceptability of yellow achu soup. To this effect, ashes obtained from plantain peels and Ficus carica fruit peel were extracted with water to get their respective crude extracts, potash, with concentrations of 0.07g/ml or 1g/15ml. A mixture experimental design was used to mix different proportions of the plantain peels to Ficus carica fruit peel potash to get 7 samples of the emulsifier, ranging from 100:0, 80:20, 70:30, 60:40, 50:50, 30:70 0:100 denoted as IKM, KIM, MKI, IMK, MIK, KMI, and KKI respectively. The yellow achu soup obtained thereafter was prepared by mixing thoroughly 20ml of partially bleached palm oil, 10ml of emulsifier solution, and 70ml of water at 800C. The pH, emulsification index, foaming capacity, and foam stability of the resulting soup were analyzed followed by an evaluation of its acceptability. The pH of the mixture varied from 11.75 to 11.01, with a pH of 11.53 obtained for the plantain peel crude extract, IMK, and the lowest pH of 11.01 ± 0.01 obtained from the Ficus carica fruit peel ash extract, KKI. The highest alkalinity of 11.75 ± 0.02 for the mixture was obtained at a mixture ratio of 60:40 for sample IMK. The pH of the resulting yellow achu soup decreased as the incorporation ratio increased, with the highest pH of 11.49 using only the plantain crude extract, IKM, to the lowest pH of 10.58 using only the Ficus carica fruit peel ash extract, KKI. The foaming capacity of the yellow achu soup varied from 10.76 ± 2.78% representing the highest for sample IMK while the lowest value was 5.36 ± 0.18% using sample KIM. The foam stability varied from 11.89 ± 2.34% for sample IMK to 4.67 ± 0.79% for sample KIM. Sample MIK displayed the highest emulsifying activity with a value of 65.15±0.30% and 58.79±8.70% after 24 hrs and 48hrs respectively, while KIM had the lowest emulsifying activity of 34.21±0.54% after 24 hours and 34.17±0.23 after 48hours. Out of the ten panelists involved in the sensory evaluation, 50% generally accepted sample MIK, 20% accepted IMK and KMI while 10% preferred MKI. The incorporation of the Ficus carica fruit peel potash to Nikkih serves as a good strategy to improve on the functional properties and acceptability of yellow achu soup.