PREPARATION AND STUDY ON STORAGE STABILITY OF MIXED RTS BEVERAGE OF DRAGON FRUIT AND PINEAPPLE INCORPORATED WITH MINT

Abstract

The main aim of this research was to prepare mint incorporated dragon fruit based RTS blended with pineapple and study its storage stability. Dragon fruit (white variety), pineapple and mint were obtained from local market. After preparation of their respective juices, optimization using Design-Expert 13 software resulted in seven dragon fruit to pineapple ratios; A(50:50), B (62.5:37.5), C (66.67:33.33), D (75:25), E (83.33:16.67), F (87.5:12.5) and G (100:0). Sample A with 50:50 blend was identified to be the best through sensory evaluation. This blend further served as the control for further experiment. Mint juice was then added to the RTS in varying ratios; A (94:6), B (95.5:4.5), C (96:4), D (97:3), E (98:2), F (98.5:1.5) and G (100:0). Sample A with 96:4 blend was determined to be the optimal choice through sensory evaluation. The selected blend then underwent pasteurization at 80°C for 30 s and was stored for 45 days at three different temperatures (room, refrigeration, and frozen temperature) in pre-sterilized PET bottles. Analysis at 15-day intervals showed significant changes in TSS, titrable acidity, reducing and non-reducing sugars, pH, and vitamin C during storage. Statistical analysis using one way and two-way ANOVA demonstrated the significant effect of the storage period on these parameters (p<0.05). The study also provides insights into the chemical and microbiological changes during a 45-day storage period, emphasizing the significance of storage conditions on the product's quality. The production cost for a 250 ml bottle of the final product was determined to be NRs.73.