Nutritional and antioxidant properties of avrils and rags from cempedak and nangka
摘要
Cempedak (C) and Nangka (N) are the commonly consumed species of Artocarpus in tropical countries but remained underutilized. This study aimed to determine and compare the nutritional, dietary fibres (DF) [total (TDF), insoluble (IDF) and soluble (SDF)] and antioxidant properties of avrils (A) and rags (R) of cempedak (C) and nangka (N). Nutritional composition was analysed using the standard methods, and DF employed the enzymatic gravimetric method (AOAC 991.43). Antioxidant content was determined by using Folin-Ciocâlteu and Aluminium Chloride Colorimetric methods, whereas antioxidant activity was determined by 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assays. Moisture ranged from 64.39 ± 1.35% to 71.87 ± 3.1%, highest in NR. Fat was highest in NR (6.03 ± 0.43%) but lowest in CR (1.85 ± 0.13%). Crude protein (5.43 ± 0.18% to 8.58 ± 0.18%) was highest in NR and lowest in NA. The highest carbohydrate was in CA (17.86 ± 0.76%) but lowest in NR (11.72 ± 1.51%), and ash ranged from 0.9 ± 0.05% (NA) to 1.65 ± 0.05% (NR) in samples. TDF was lowest in NA (9.95 ± 0.30%) and highest in CR (40.92 ± 0.85%). The IDF ranged from 5.45 ± 2.01% (NA) to 32.46 ± 0.69% (CR), while the SDF content ranged from 2.24 ± 0.48% (CA) to 9.42 ± 1.64% (CR). Rags exhibited higher antioxidant properties than avrils, except CA, which showed the strongest ferric-reducing ability. Total phenolic and total flavonoid contents were significantly (p < 0.01) correlated with DPPH but insignificant between total flavonoid content and FRAP. Results of the study demonstrated significant differences in the proximate, fibres and antioxidant properties of rags and avrils from cempedak and nangka. The rags exhibited higher antioxidants (especially NR) and fibres (especially CR) than avrils in most analyses, which indicates the potential of discarded parts from Cempedak and Nangka as sources for potent antioxidants, dietary fibres and macronutrients for dietary and functional properties. The data will be helpful in nutritional planning and functional ingredient development in the future.