Dragon Fruit or Pitahaya is a tropical fruit that belongs to the genus Hylocereus from the family Cactaceae. This fruit is cultivated in the US, Australia, Mesoamerica, Southeast Asia and throughout tropical and subtropical regions of the world. The dragon fruit must be peeled for consumption to expose the flesh while the skin is not consumed and will be wasted. This waste of peel is usually used as fertilizer. Tenore et al. (2012) and Faridah et al. (2015) studied that dragon fruit peels have high beneficial compounds includes phytochemicals (betacyanins) and dietary fiber (pectin). So this food is must be considered as a good material for the development of functional foods.Peel of the dragon fruit also has another beneficial compound named’Betacyanin’. This compound is used as a natural red pigment color and has some protective effects on chronic illnesses. Thammawong et al. (2019) and Faridah et al. (2015) informed that during food processing, the steadiness of betacyanin could be affected by oxygen, heat, light, moisture, and pH because changes in these factors causes discoloration of this pigment.
‘Jam’ is a pectin derivative product that has a long shelf life due to its high sugar content. It is a thick sweet spread made by cooking crushed or chopped fruits with sugar. Jam production requires the accurate proportions of based fruits; pectin and sugar to get the desired result that is acceptable for consumers. Response surface methodology (RSM) is an applicable approach that is used to optimize food industry processes. Basically, RSM clarifies the aspects affecting the desired response if there are many factors and interactions in the study of food production.
The research was carried out by Faridah et al. (2020) published in the Pakistan Journal of Nutrition to design an optimized recipe for the production of functional jam derived from the peel of the dragon fruit. The researchers found that the quantity of peel of dragon fruits follows by sugar content and processing time have a strong tendency to affect the quality of produced jam which subsequently will affect the consumer’s acceptance.
The peel of dragon fruit has potential as raw material for the production of a consumer’s acceptable as a functional food. The researchers recommended conducting further studies to optimize the dragon fruit jam recipe that affect phytochemical characteristics.