Optimization of process conditions for production of jam from honeydew (cucumis melo I) skin

Abstract

Honeydew melon fruit (Cucumis melo I) is one of Malaysian's favourite fruit. This type of melon is rich in potassium, vitamin C and sodium. Almost 30 percent part from honeydew fruits are thrown away as waste, which leads to additional environmental problem. Nowadays, utilization of fruit or food waste into valuable products is becoming the main concern of research by the food scientists. This study has been divided into three parts, which were [1] pectin detection and jam making from melon pulp and melon skin, [2] optimization of product ingredients and [3] study of some physicochemical parameters. Alcohol precipitation has been used to detect the availability of the pectin in the fruit pulp and fruit skin before jam spread were produced from both parts. Pectin found in fruit skin was higher compared to fruit pulp, which were 0.503% and 0.088% respectively. In addition, jam spread of honeydew skin without additional commercial pectin received positive response from the sensory panelists. Thus fruit skin can be utilized to produce commercial pectin or jam spread. Later, optimization of the ingredients for jam spread of honeydew skin was conducted by using FCCCD under RSM. The independent variables were amount of sugar, amount of acid and amount of pectin. Twenty samples were evaluated by 20 trained students of IIUM in terms of appearance, aroma, taste/sweetness, texture and overall acceptability. The optimum formulation for jam spread of honeydew skin was 70% of sugar, 1.13% of pectin and 0.81% of acid. At the end of the study, moisture content and ash content were determined. Percentage of moisture and ash contain for sample with high sugar contain (64%) were 25.84% and 1.07%, respectively. While percentage of moisture and ash contain for sample with low sugar (58.63%) was 43.26% and 0.793%, respectively. Sample with more sugar can last until 6 month in the fridge. In contrast low sugar jam already yields a mould at the same time. The regression coefficient (R2) came out from experimental and predicted result was 86.16%.