Electrospinning Encapsulation of Chlorophylls Microwave-Extracted from Spinach Waste and Utilization as Coloring Agent in Yogurt

Natural colorants have become a developing market because of consumer preferences, and more cost-effective and stable production is necessary. In the present study, a natural green colorant was obtained via microwave-assisted extraction from spinach waste to produce affordable, environmentally-friendly, and innovative colorants. The extracts were encapsulated with zein via uniaxial and coaxial electrospinning techniques to overcome the stability issues associated with their natural green color. The encapsulation efficiencies of uniaxially encapsulated chlorophyll extracted from spinach waste by microwave were 63.50 and 57.18 for chlorophyll a and b, respectively. The efficiencies of chlorophyll a and b by coaxial electrospinning were found 49.53% and 88.58%, respectively. The microwave-assisted extraction and the addition of eumelanin may contribute positively to the antioxidant activity and thermal stability of electrospun samples. The stability test against light revealed that 61% of chlorophyll a could be preserved by uniaxial electrospinning. In addition, when chlorophyll-loaded nanofibers were incorporated into yogurt, a more stable green color was achieved during storage.