Pulp and by-products of indigenous and non-indigenous mangoes in Uganda: Physicochemical properties

Mango pulp and by-products are underutilized despite their application potential in the food systems. Our study assessed the physicochemical properties of pulp and by-products of 22 mango varieties to support their added value. We applied the methods developed by the Association of Official Analytical Chemists. The data were analyzed using descriptive statistics and non-parametric tests. Seven varieties had total soluble solids above the Codex Alimentarius threshold of 13.5°Brix, indicating their suitability for juice processing. Non-indigenous varieties exhibited higher titratable acidity and yellowness (b*), the traits desirable for juices and purees. Indigenous arieties had higher redness (a*) and lower acidity, which favor fresh consumption. Among by-products, the peel had the highest crude fiber content of 10.16 ± 1.76%. The seeds recorded the highest potassium and calcium concentrations of 354.90 ± 25.10 and 437.74 ± 35.81 g/100 g, respectively. The principal component analysis explained 87.62% of the total variation: principal component 1 (75.03%) differentiated varieties based on minerals, total soluble solids, and firmness, while principal component 2 (12.59%) accounted for differences in vitamin C and color. The principal component analysis and bootstrap hulls showed that varietal differences stemmed from the intrinsic traits rather than from the indigenous or non-indigenous classification. Kakule and Kapisa varieties appeared on the positive side of principal component 1, reflecting a higher mineral content. Apple mango and Boribo mangoes loaded positively on principal component 2 due to high vitamin C and color attributes. Kagoogwa, Takataka, and Tommy Atkins varieties clustered near the total soluble solids vector, indicating adequate soluble solids for juice processing. Our findings confirm that indigenous mango varieties in Uganda meet the industrial quality standards.