Impact of Storage on the Color of a Green Isotonic Beverage With β-Cyclodextrin/Chlorophyll Complexes

This study analyzes the stability of chlorophyll (Chl) from unsold spinach in isotonic beverages, comparing the pigment in its free form with that encapsulated in β-cyclodextrin (β-CD), after determining the inclusion ratio of 1:1. Stability was monitored for 14 days for the crude extract and 30 days for the lyophilized powder under different storage conditions (dark, natural light, and UV light, at 4°C and 25°C). The results prove that both exposure to light, especially UV radiation, and temperature affect the stability of Chl, but encapsulation significantly improves pigment retention. In lyophilized powder form, free Chl is characterized by a slower decline than the wet crude extract, mitigated by the presence of β-CD: After 30 days under the most critical conditions (25°C, UV light), the Chl/β-CD sample retains 30% of the Chl compared to 20% for the free molecule. In this condition, the degradation constant (k) of the encapsulated sample is lower than that of the unencapsulated one (0.0366 days^-1 vs. 0.0612 days^-1 for the powder and 0.399 days^-1 vs. 0.644 days^-1 for the crude extract). The color stability, evaluated using the parameter Δ E, is also improved by encapsulation, confirming the protective effect of β-CDs.