Effect of Temperature and Packaging Method on Bioactive Compounds of Freeze-dried Red Beet Powder during Storage

In this study, the effect of two different storage temperatures (4 and 25°C) and two different packaging techniques (normal atmosphere (NAP) and modified atmosphere (MAP)) on some quality properties of freeze-dried red beet powder during storage for 28 days. Color, total phenolic content, total antioxidant activity and betanin analyses were performed weekly during storage. The L*, a*, b*, chroma and hue angle values of all samples stored at low temperature and room temperature decreased during storage while their ΔE values increased. At the end of the storage, a loss between 1.20 and 2.30% occurred in the total phenolic contents of powder samples. The highest antioxidant activity value was determined in MAP samples stored at low temperature, and the lowest antioxidant activity value in NAP samples stored at room temperature. Losses in the betanin contents of NAP and MAP samples stored at room temperature were 12.02 and 10.14%, respectively. In samples stored at low temperature, their loss rates were 2.03 and 0.81%, respectively. In general, the storage condition in which the bioactive compounds of freeze-dried red beet powder suffered the least loss was at low temperature and in samples packaged with a MAP technique.