Electrically assisted ionic gelling encapsulation of enzymatically extracted zinc‐chlorophyll derivatives from stinging nettle (Urtica urens L.)

Abstract

This study evaluates the effect of four different encapsulation techniques. Zn‐chlorophyll derivatives obtained by enzymatic extraction with 26.80% yield compared to nonenzymatic extraction from stinging nettle were encapsulated with (i) ionic gelling, (ii) ionic gelling + chitosan coating, (iii) electrically assisted ionic gelling (iv) electrically assisted ionic gelling + chitosan coating methods. The decrease in total chlorophyll content at the end of the 8 weeks storage in the capsules according to the initial amount was found to be 17.32, 44.97, 4.18 and 26.52%, respectively. Depending on the total chlorophyll content, the decrease in a* value in the capsules according to the initial amount was found to be 30.00, 68.63, 8.16 and 53.04%, respectively. The capsules prepared by the electrical method provided the highest protection of chlorophyll during storage. Chitosan application as a second layer to capsules resulted in an increase in chlorophyll decay in both ionic gelling and electrically assisted ionic gelling methods (p < 0.05). It has been determined that the application of chitosan in chlorophyll encapsulation is not appropriate due to the poor color and malodor effect. Practical applications Natural colorants are food additives that are widely used to increase the acceptance of products in the food industry. Nowadays, the demand of consumers for natural products has increased the studies on this subject and the search for solutions to problems. The most important problem of natural colorants is their low stability. The development of natural colorants with high stability requires different techniques such as encapsulation or innovations in the molecular structure. With the applied techniques, the stability of natural products can be increased as well as innovative forms of the products obtained can find market share in the industry.