Effect of Ripening Stages and Oven Drying on the Carotenoid Composition of Goji Berry(Lycium barbarum L.) Fruits

Abstract

In this study firstly, pH, titratable acidity, water soluble solid (°Bx) and carotenoid content of goji berryfruits in three different ripening stages (mature green, intermediately ripe, fully ripe) were determined.Secondly, the fully ripe goji berry fruits were dried at 50, 60 and 70 °C in an oven drying and the changes incarotenoid composition and kinetic parameters were investigated. Thermal degradation of carotenoids in gojiberry fruit fitted to the first order reaction model and k, t1/2, Q10 and Ea values were calculated. Changes in thecarotenoid composition were observed as a result of the ripening of the fruit. Lutein was found as thepredominant carotenoid at mature green goji berry fruit, while zeaxanthin dipalmitate was at intermediatelyand fully ripe goji berry. Chlorophyll a and b were detected in the mature green fruit but not in theintermediately and full ripe fruit. The results demonstrated that drying temperature is an important factoraffecting carotenoid degradation in goji berry fruits and different ripening stages have important effect on thecarotenoid content of goji berry.