Physico-chemical properties of Syzygium cuminii (L.) Skeels jam and comparative antioxidant study with other fruit jams

Abstract

Jamun, Syzygium cuminii (L.) Skeels commonly known as Indian blackberry is a widely distributed forest tree in India and other tropical and sub-tropical regions of the world. This fruit is a rich source of natural antioxidant, vitamins and minerals having good nutraceutical and medicinal value. Physical properties of jamun fruits were studied in order to facilitate its handling and processing. This work was intended to add value to these fruits in jam production. The corresponding processed jam were compared with other commercial fruit jams in terms of proximate composition, total phenolic content, antioxidant activity and viscosity to test its overall quality parameters. According to the experimental findings, the proximate composition of jamun jam was found to be equivalent with other jams and was the richest source of total phenol with 5.58 mg GAE/g. The antioxidant activities were also highest. The percent reduction of DPPH and ABTS radicals was 47.97 and 95.02, respectively and the FRAP value was 7.36 mM ferrous sulphate equivalent/g. Pseudoplastic behavior of the processed jam was determined with the help of rheometer to check its consistency which is due to the systematic trend of pH, pectin, total soluble solids and sugar concentration at the time of processing. Viscosity of jamun jam was found to be acceptable with other commercial variety jams. Results from this work revealed essential information that could promote the commercialization of jamun jam.