Employing kiwifruit as a native proteolytic source to produce protein hydrolysate with enhanced nutraceutical properties

Kiwifruit known to support digestive health contain a high content of proteases. The present study aimed to employ these enzymes in the hydrolysis of edible bird’s nest (EBN) to improve its nutraceutical values. Our analyses revealed that EBN was efficiently digested by native proteases present in the kiwifruit juice. The antioxidant and anti-tyrosinase capacities of the resultant hydrolysate (IC₅₀ = 0.028 mg/mL and 0.220 mg/mL, respectively) were stronger than those of EBN (IC₅₀ = 0.091 mg/mL and 1.797 mg/mL, respectively) and a mixture of EBN with kiwifruit juice (IC₅₀ = 0.036 mg/mL and 0.440 mg/mL, respectively). Additionally, the content of free sialic acid, a key glyconutrient of EBN, was also increased by the treatment of EBN with kiwifruit juice (22.41 g/kg in the hydrolysate and 3.33 g/kg in EBN/mixture of EBN with kiwifruit juice). Our results offer a possibility to prepare a high-quality EBN hydrolysate that can potentially be applied in functional food products.