Effect of passion fruit juice and pectin on characteristics of Purple Yard Long Bean jam

Abstract

The present study aims at studying the amounts of passion fruit juice (21.1, 23.3 and 25%) and the amounts of pectin (0.5, 1 and 1.5) optimum to produce Purple Yard Long Bean jam (Vigna unguiculata subsp. sesquipedalis) cv. Sirindhorn No.1. The results showed that jam with 21.1% of passion fruit juice and 0.5% of pectin had the highest pH value and the lowest Rupture Strength. The water activity value and total soluble solids of 3 formulas jam were not statistically different. Jam with 25% of passion fruit juice and 1.5% of pectin had increasing of L∗ value and decreasing of a∗ value. Sensory evaluation showed that the jam with 21.1% of passion fruit juice and 0.5% of pectin gained the highest hedonic score in terms of odor, taste, texture, spreadability and overall preference. Purple Yard Long Bean jam with 21.1% of PJF and 0.5% of pectin had with higher fiber content than in commercial products.