抄録
Hot beverages packaged in PET bottles or cans are typically consumed after being held at medium temperatures (50–60 °C) for extended periods. Sucrose is commonly used as a natural sweetener in these beverages. While the degradation of sucrose at high temperatures (e.g., above 100 °C) under weak acidic conditions is well-documented and utilized in the production of “invert sugar,” information on sucrose degradation at medium temperatures over prolonged periods is limited. This study aimed to investigate the effects of storage conditions on sucrose degradation and changes in taste quality in hot beverages. Commercially available hot beverages were stored at various temperatures and sampled periodically to assess changes in sugar concentration. The results indicated that sucrose degradation occurred more rapidly in weakly acidic beverages at higher temperatures and with longer warming times. The half-lives of sucrose at 60 °C were calculated as 4 days for lemon tea (pH 3.6), 1 day for hot lemonade (pH 3.3), and 19 days for black tea (pH 4.6). Little degradation was observed in milk tea (pH 6.5). Sensory evaluation revealed that long-term warming of lemon tea (60 °C, 10 days) led to noticeable taste changes. Additionally, model hot beverages with pH values ranging from 3.2 to 4.8 were prepared and stored at 45–65 °C for up to 7 days. The results demonstrated that the rate of sucrose degradation varied significantly with minor changes in pH and temperature, with a more pronounced effect observed in acidic beverages with a pH below 4.0.
