Preparation of Jam Pitaya

摘要

This article is dealing with the study of the process technology of the pitaya jam with the pitaya with red skin and white meat as raw material. The experimental result showed that the jam has the best liquidity and spreadcability when taking xanthan gum: 5% and the agar: 95% as thickening agent. The best formula of the pitaya jam, through the orthogonal test, is A2B3C1D2, say, the pitaya jam: 40%, sugar: 10%, thickening agent: 0.02%, citric acid: 8%. Using this formula, the pitaya jam will gain such properties as special faint scent, moderate sour-sweet taste and uniform texture. The pitaya, also called the dragon fruit or pitahaya, is a famous fruit native to the tropical and subtropical zones. Currently, pitaya trees have been planted in China on quite a large scale~([1]). Unique in healthcare functions and rich in such nutrients as sugar, organic acids and dietary fiber, pitaya meat has a content of dietary fiber (2.33%) and protein (1.12%),much higher than that of apple and sweet orange. Pitaya contains eighteen types of amino acids, including eight types of essential amino acids that total 34.9% of the total amino acids. Beyond that, the pitaya has multiple mineral, especially K, Ca, Mg and Ph~([2]). Currently, the study on pitaya processing technique primarily focuses on such fields, for example, extraction of juice~([3]), and making fruit wine~([4]), vinegar~([5]), candy~([6]), yogurt,~([7]), ice cream and tinned food. However, there is little study on pitaya jam making. This paper deals with pitaya jam making with the purpose of providing a reference to developing more pitaya products and jam products.