Comparative study of different drying methods regard to the phenols and flavonoids content of dried Citrus aurantium L. leaves

Abstract

Citrus Aurantium leaves contain compounds such as phenols and flavonoids that give it antioxidant properties. These properties can be affected by using any conservation method, such as drying. This study was carried out to determine the effects of different technologies of thermal drying on total phenols content (TPC) and the total flavonoids content (TFC) from the leaves of bitter orange (Citrus aurantium L.).  Solar drying was carried out under the open-air sun conditions and using two direct solar dryers; one with natural convection and the other with forced convection. TFC and TPC in equivalents of gallic acid (EGA) and quercetin (Q), respectively, of the ethanolic extracts of C. Aurantium were determined by using spectrophotometric techniques. The results showed maximum values of phenols for direct natural convection solar dryer (161.4 mg EGA/g MS) and minimum for shade drying (61.43 mg EAG/g MS). Regarding flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg QE/g MS), while in the open-air sun the lowest values were observed (11.72 mg QE/g MS). It is concluded, that the direct solar dryers are effective technologies to maintain the TPC and the TFC in the dry leaves of C. aurantium.Objective: To determine the effects of different thermal drying technologies on the total phenol and flavonoid contents (TPC) and total flavonoids (TFC) in sour orange (Citrus aurantium L.) leaves. Design/methodology/approach: Solar drying was carried out in outdoor sunny conditions using two direct solar dryers; one with natural convection, the other with forced convection. The total phenol and flavonoid contents in gallic acid equivalents (GAE) and quercetin (Q), respectively, of ethanolic extracts of C. aurantium were assessed with spectrophotometric techniques. Results: The results demonstrated maximum phenol values for the direct natural convection solar dryer (161.4 mg EAG/g MS) and minimum values for shade drying (61.43 mg EAG/g MS). As for flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg EQ/g MS), while the lowest was registered in the open air sun (11.72 mg EQ/g MS). Conclusions: Direct solar dryers are technologies effective for maintaining the phenols and total flavonoids content in dried leaves of C. aurantium.

Similar works

Full text

thumbnail-image

Revista Agro Productividad

redirect
Last time updated on 13/11/2021

This paper was published in Revista Agro Productividad.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.