Based on the total phenolics and flavonoid contents one can consider that goji fruit (Lycium barbarum) has high antioxidant activity.
The results of our study provide detailed information regarding the antioxidant activity, physico-chemical and sensorial stability of Goji fruits jam and jelly. Experimental data have indicated high antioxidant activity of jam and jelly, the highest values recorded at goji fruits jam.
Storage at 4°C did not induce changes in the physico-chemical parameters of goji fruits jam and jelly. Sensorial quality was well preserved under the investigated storage conditions.
The information obtained in the present study finds its practical application because it showed the behavior of the goji fruits jam and jelly during storage in refrigeration conditions. It can be observed that the storage in refrigerated conditions of the analyzed samples did not lead to significant changes of physico-chemical properties and antioxidant capacity.
The total acidity is one of a number of physico-chemical parameters which affect product quality; to a large extent, acidity protects against the development of microorganisms. The storage time of the analyzed samples was not enough to cause significant decreases in pH and therefore increase of total acidity. Total soluble solids are primarily D. Istrati et al. / AUDJG – Food Technology (2013), 37(2), 100-110 represented by sugars, with acids and minerals contributions.
According to the Codex standard for jams, jellies and marmalades (CODEX STAN 296-2009), the soluble solids content for jam shall be between 60 to 65% or greater and in the case of jelly the soluble solids content shall be 40 – 65% or less. The changes in the total soluble solid values found in this study at different storage time were within the limits imposed by the standard and in agreement with the values reported by Ferreira et al. (2004) for quince jams and Touati et al. (2014) for apricot jams.
Experimental data indicated good antioxidant activity of goji fruits jam and jelly. The highest values of antioxidant activity were recorded at goji fruits jam as compared to the goji fruits jelly. This difference was due to different quantities of goji berries used to produce finished products. Large quantities of fruits goji resulted in obtaining products which recorded higher values of antioxidant activity.
Other fruits to consider: