Quality Attributes of Jams and Marmalades Produced from Some Selected Tropical Fruits

Abstract

Some selected tropical fruits such as mango, cashew apple, pineapple, guava, lemon, and sour-sop were processed and their pectin strength evaluated. These processed fruit samples were used in the production of jams and marmalades to study the physicochemical and sensory qualities of the products to ascertain their suitability and acceptability. The result showed that lemon (L) have high pectin strength, mango (M) and guava (G) have medium while pineapple (P), cashew apple (CA) and sour-sop (SS) have weak pectin strength. The proximate result revealed that moisture content of the jam samples ranged from 23.29%-45.21% for PJ and GJ, ash 0.19 MJ-0.82% SSJ, protein 0.20 PJ-0.73% SSJ, crude fat 0.02 LJ-0.44% CAJ and carbohydrate 53.64%-74.87% for samples GJ and PJ, respectively. Results for the proximate analysis of marmalades showed that moisture content ranged from 24.92%-49.02%, ash 0.24%-0.62%, protein 0.28%-0.86%, fat 0.08%-0.22%, and carbohydrate 50.03%-74.19%. Physical properties of the jam samples were 0.36 pa.S-2.57pa.S for viscosity, 2.30-2.75 for pH, sugar 52.80%-721% and total titratable acidity 2.60%-4.63% while that of marmalade samples were 0.17 pa.S-2.21pa.S for viscosity, pH 2.40-2.95, sugar 44.00-68.20°Brix and total titratable acidity 1.83%-3.54%. The results for sensory scores of the fruit jams showed that all the samples were acceptable by the consumers. Although, mango, pineapple, and cashew apple marmalade recorded the highest acceptability scores. Therefore, nutritious acceptable jams and marmalades can be produced using some Nigerian tropical fruits; hence, reducing their annual wastage.