Search

The swiftlet’s nest is an edible bird’s nest (EBN) produced from dried gelatinized saliva secreted by swiftlets during the breeding season. It is widely used in industries for its high nutritional values and health benefits. However, the utilization of ESN is restricted due to its physicochemical properties, such as insolubility. The recently invented bioactive ESN hydrolyzate is reported to improve the ESN’s solubility, functional and nutritional properties to broaden its application. This study has produced bioactive ESN hydrolyzates with different hydrolysis periods to investigate the optimum conditions to achieve maximized degree of hydrolysis (DH) and to compare the physicochemical differences. The result revealed that optimum ESN hydrolysis was at 90 minutes, in which the DH and enhanced solubility (three folds) indicated a complete breakdown of glycoprotein into bioactive glycopeptide. This result is in line with the physicochemical analyses result. The hydrolysis has significantly decreased (p ≤ .05) the ESN protein content, while the levels for peptide, glycopeptide, polysaccharides, and sialic acid showed the opposite. Interestingly, the amino acid from raw ESN and hydrolyzates in all incubation periods showed no significant difference (p ≤ .05). This result suggests that the ESN biological properties remained unchanged with alcalase hydrolysis. Therefore, the findings in this study confirm the feasibility of bioactive ESN hydrolyzate as a versatile product suitable for various industries in utilizing ESN in whole instead of as extracts.

Edible bird’s nest (EBN), the swiftlet’s nest, has been consumed for centuries as a tonic or health food. The information upon the usage and benefits of the EBN are largely based on historical and observational reports since its discovery, until some were proven scientifically at recent times. Studies have been conducted on the major components of the EBN, i.e. glycoprotein, in attempts to elucidate the roles of the glycoprotein in terms of functionality toward health improvement. This article presents a review of the physicochemical and nutritional composition of EBN from different harvested locations and its functional properties. The conversion of EBN glycoproteins to glycopeptides via suitable hydrolysis methods to produce bioactive EBN glycopeptides was demonstrated, and it showed improvements in the functionality and nutritional values of EBN. Some applications of EBN glycopeptides into the new development of food and beverage products showed positive results, implicated to the bioavailability of the EBN glycopeptides. The combined information in this review will benefit the scientific communities, EBN manufacturers, and nutraceutical industries.

Inhibition of Angiotensin Converting Enzyme (ACE) reduces blood pressure and gives an anti-hypertensive effect. Chicken skin is an undesirable by-product of the poultry industry, disliked by consumer because of the high fat content. The aim of this research is to determine the effect of molecular weight reduction on ACE inhibition activity in chicken skin hydrolysate. Chicken skin is prepared by manually defatting, soaked in acetone and in 0.1M phosphate buffer. Sample hydrolysis is carried out using alcalase enzyme for a duration of 4 hours at 60˚C and pH 9.5. The best degree of hydrolysis (DH), at 4th hour, with value of 49.54 ± 0.79 %, is ultrafiltrated and used in ACE inhibition activity detection. The sample weight ≥ 10 kDa , 3 – 10 kDa and ≤ 3 kDa contains 5.63 ± 0.01 g/L, 2.84 ± 0.06 g/L and 1.07 ± 0.18 g/L peptide content respectively whereas soluble protein content is 0.51 mg/mL for sample weight ≥ 10 kDa, 0.27 mg/mL for sample weight 3 – 10 kDa and 0.23 mg/mL for sample weight ≤ 3 kDa. The ACE inhibition activity in sample weight ≤ 3 kDa is highest with value of 80.38 ± 2.69% followed by sample weight 3 – 10 kDa with a value of 49.40 ± 2.63% and sample weight ≥ 10 kDa with value of 42.73 ± 5.08%. Significant differences ( P ≤ 0.05) exist between sample weight ≤3 kDa and > 3 kDa. This research shows that molecular weight reduction increases ACE inhibition activity.

Gelatin hydrolysate is derived from a hydrolysis of gelatin (denatured collagen) to expose the functional properties of the hydrolysate obtained. This study was carried out to determine functional properties of gelatin hydrolysate from salmon skin as influenced by the degree of enzymatic hydrolysis. Aqueous extraction of gelatin from salmon skin was done at 45oC for 60 minutes. The extracted gelatin was then hydrolysed using 1% alcalase at 54.5oC and pH 8. The functional properties determined were molecular weight, solubility, foaming capacity and stability, emulsifying activity and stability index were analysed. It was found that different time of hydrolysis (5, 15, 45 and 180 minutes) resulted in different degree of hydrolysis (DH) (10, 20, 30 and 40%, respectively). The gelatin hydrolysate at 40% DH showed the highest solubility (p<0.05). However, the foaming and emulsifying properties were the highest at 10% degree of hydrolysis (p<0.05).