Optimization of the levels of ginger extract, palm oil and glucose syrup on the sensory quality of ginger yema

Abstract

Ginger yema is a product of Guio-ang MPC cooperative of Guindolman, Bohol, Philippines. Yema may also be called a custard candy as it is mainly made of egg yolk, sugar and milk. The yema product made by Guio-ang MPC cooperative uses these same common ingredients with added ginger extract and glucose. To improve and enhance the sensory quality of the aforesaid product, an optimization study on the ingredients namely ginger extract, palm oil and glucose syrup was conducted. Response Surface Methodology (RSM) was used to determine the effect of the different levels of ingredients on the product’s sensory quality. Statistical analysis revealed that the linear and quadratic term of palm oil and glucose syrup levels significantly affect the color, hardness, chewiness and general acceptability of ginger yema. The quadratic term of ginger extract and palm oil significantly decreased the oiliness acceptability. Significant reduction in toothpacking acceptability was observed in the linear term of the glucose syrup level. The interaction of palm oil and ginger extract had a negative significant effect on the color, while the interaction of glucose syrup level and ginger extract significantly affected the hardness and toothpack. The interaction of the glucose syrup level and palm oil significantly affected the product’s hardness, chewiness and general acceptability as well. The superimposed contour plots of all responses revealed the optimum result for color, hardness, chewiness and general acceptability at 14.75% w/w ginger extract, 12.00% w/w palm oil, and 12.20% w/w of glucose syrup.