Impact of storage temperature on quality changes in mashed potatoes

Abstract

This study investigates the impact of storage temperature on the quality changes of instant mashed potatoes over a 40-day period. Instant mashed potato samples were stored at three different temperatures: 2 °C, 5 °C, and 8 °C. Various quality parameters, including pH, total acids, reducing sugars, starch, protein, and lipid contents, as well as microbiological indicators such as Coliform, total yeast, and mold counts, were monitored. Results indicated minimal fluctuations in pH levels, with values ranging from 5.12 to 5.24 across all temperatures. Total acid content increased slightly over time, with higher levels at warmer temperatures. Reducing sugars and starch decreased significantly, with the smallest reduction observed at 2 °C. Protein and lipid contents also decreased but to a lesser extent. Microbiological analysis showed that while Coliform and yeast and mold counts were below permissible limits initially, significant growth occurred, especially at 8 °C. By the 40th day, Coliform counts exceeded allowable limits at 8 °C, indicating spoilage, while 2 °C and 5 °C maintained acceptable microbial levels. Overall, storage at 2 °C proved to be the most effective in preserving quality. These findings suggest that lower storage temperatures can better maintain the quality and safety of instant mashed potatoes.