Background: Processing of edible bird's nest (EBN) requires extensive washing to remove impurities and produces huge amounts of EBN co-products, which contain mainly feathers with glycoproteins attached, which are usually discarded. This study was conducted to recover the valuable EBN glycoproteins from the waste material. Enzymatic hydrolysis was applied to recover EBN glycopeptides from EBN co-products (EBNcoP ) and processed cleaned EBN (EBNclean ) was used as control, which were then freeze-dried into EBN hydrolysates (EBNhcoP and EBNhclean , respectively).
Results: The recovery yield for EBNhclean and EBNhcoP were 89.09 ± 0.01% and 47.64 ± 0.26%, respectively, indicating nearly 50% of glycopeptide can be recovered from the waste material. Meanwhile, N-acetylneuraminic acid, a major acid sugar in EBN glycoproteins, of EBNhcoP increased by 229% from 58.6 ± 3.9 to 192.9 ± 3.1 g kg-1 , indicating the enzymatic hydrolysis removed impurities and thus enhanced the N-acetylneuraminic acid content. Total soluble protein was more than 330 g kg-1 for all the samples. Colour parameter showed that hydrolysate samples have greater L* (lightness) values. Chroma result indicates the intensity of all the samples were low (< 11). Fourier-transform infrared (FTIR) spectrum displayed that the EBNhcoP exhibited similar functional groups with EBNhclean , indicating that the EBNcoP has similar functionality as EBNclean . Significantly higher (P ≤ 0.05) 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) activities were reported in EBNhcoP after the enzymatic reaction.
Conclusion: EBNhcoP were successfully recovered from low value EBNcoP with enhanced antioxidant activities. The findings of this work are beneficial for the EBN industry to reduce wastage and enhance economic values of EBN co-products, both economically and nutritionally. © 2020 Society of Chemical Industry.
Keywords: FTIR; N-acetylneuraminic acid; edible bird's nest; glycopeptide; recovery.
© 2020 Society of Chemical Industry.