EVALUATION OF SOME MULBERRY SPECIES AND THEIR SUITABILITY FOR PROCESSING JAMS

Three species of mulberry fruits namely white mulberry (Morus alba L.), red mulberry (Morus rubra L.) and black mulberry (Morus nigra L.) cultivated in Egypt as well as the comparison between the antioxidant activity of fresh fruits and jams prepared from selected species were evaluated. Results showed that protein content was 1٫38, 1٫2٤ and 1٫1٥٪, total sugars 12٫7٥, 1٥٫2٥ and 1٦٫03٪ in black, red and white mulberries, respectively. Reducing sugars varied from 11٫32 to 1٤٫00٪ in black, red and white mulberries and total lipids ranged from 1٫08 and 1٫7٥٪ in black and red mulberry fruits. Also, crude fibre was 1٫٦0, 2٫17 and 2٫28٪ in three mulberry species while pH value ranged from ٥٫٤9 and ٥٫80. Results also indicated that black mulberry had the highest content of total phenolics, total flavonoids and anthocyanins content otherwise white mulberry had the lowest content. Fractionation of phenolic compounds in all mulberry species represented the highest content of protocatechuic meanwhile both red and white mulberries had moderate contents of p.hydroxybenzoic acid. The mineral analysis showed that potassium was the most abundant element in all three mulberry species. Both black and red mulberries had high calcium content followed by sodium and magnesium. At the same time, red mulberry had the highest content in iron and zinc compared with the other two species. Results also showed that BHT had the highest antioxidant activity compared with fresh mulberry fruits or jams prepared from these fruits (92٫9٥٪). Fresh black mulberry had the highest antioxidant activity (8٦٫٤٦٪), while fresh red and white mulberries recorded ٦0٫3٥ and ٥٥٫31٪, respectively. Jams prepared from three mulberry species gave the lower antioxidant activity. The sensory assessment indicated that jam prepared from black mulberry recorded the best sensory properties followed by red mulberry jam while the lowest score for taste, odor and texture was observed in jam prepared from white mulberry.