Course:VANT149/2025/Capstone/Science/Team29

Abstract

This study examines how storage temperature influences the pH and color stability of five fruit juices (orange, lemon, apple, pear, and strawberry) over time. Juices were stored at 4°C (refrigerator) and 40°C (hot environment) for 48 hours, and changes in pH and color were recorded every 12 hours. Results showed that orange juice, for instance, exhibited a pH increase from 3.5 to 4.0 within 48 hours at 40°C, while remaining unchanged at 4°C. Apple and strawberry juices experienced a pH drop of more than 0.5 units and significant browning under heat, while lemon juice remained relatively stable (pH shift from 2.2 to 2.5). Based on color and acidity changes, some juices became visually and chemically unacceptable after as little as 24 hours at 40°C, while they remained consumable for at least 48 hours at 4°C. These results suggest that storing juice in a refrigerator can extend acceptable shelf life by at least 4 times compared to room or high temperatures. This finding offers practical guidance on fruit juice storage in real-life settings, particularly in hot climates or during power outages.

Biographies

Person 1

Tangkun Liu is a 2024 student in Vantage Science program at the University of British Columbia. His research focuses on the effect of temperature on the pH levels of fruit. He is personally interested in this topic because how long can fruits be stored is often a controversial topic in his hometown, also this topic is closely related to daily life.

Person 2

Fengyu Jiang is a 2024 student in Vantage Science program at the University of British Columbia. His research focuses on the effect of temperature on fruit preservation and color. He is interested in this subject because temperature is important for the preservation and taste of juice, and this topic is closely related to daily life.

Person 3