Contribution of Hydrolysis and Drying Conditions to Whey Protein Hydrolysate Characteristics and In Vitro Antioxidative Properties

Abstract

During the generation of functional food ingredients by enzymatic hydrolysis, parameters such as choice of enzyme, reaction pH and the drying process employed may contribute to the physicochemical and bio-functional properties of the resultant protein hydrolysate ingredients. This study characterised the properties of spray- (SD) and freeze-dried (FD) whey protein hydrolysates (WPHs) generated using Alcalase® and Prolyve® under pH-stat and free-fall pH conditions. The enzyme preparation used affected the physicochemical and antioxidative properties but had no impact on powder composition, morphology or colour. SD resulted in spherical particles with higher moisture content (~6%) compared to the FD powders (~1%), which had a glass shard-like structure. The SD-WPHs exhibited higher antioxidative properties compared to the FD-WPHs, which may be linked to a higher proportion of peptides <1 kDa in the SD-WPHs. Furthermore, the SD- and FD-WPHs had similar peptide profiles, and no evidence of Maillard reaction product formation during the SD processing was evident. The most potent in vitro antioxidative WPH was generated using Alcalase® under free-fall pH conditions, followed by SD, which had oxygen radical absorbance capacity and Trolox equivalent (TE) antioxidant capacity values of 1132 and 686 µmol TE/g, respectively. These results demonstrate that both the hydrolysis and the drying process impact the biofunctional (antioxidant) activity of WPHs.

Effects of Spray Drying and Freeze Drying on Physicochemical Properties, Antioxidant and ACE Inhibitory Activities of Bighead Carp (Aristichthys nobilis) Skin Hydrolysates

“…It was consistent with the result that the moisture content of freeze-dried chicken hydrolysate was higher than that of spray-dried [ 21 ]. In contrast, Kleekayai et al [ 23 ] observed that the moisture content of spray-dried whey protein hydrolysate was higher than that of freeze-dried whey protein hydrolysate. This may be related to the spray drying parameters employed, such as inlet and outlet temperatures, feed concentration, and airflow rate, which may affect the moisture content of SD powders [ 24 ].…”

Physicochemical characteristics and antioxidant stability of spray‐dried soy peptide fractions

“…In another study, the hydrolysates of stripped weakfish were microencapsulated in maltodextrin by spray‐drying, and it was found that the type of hydrolysate (with Alcalase or Protamex) influences the production efficiency (73–76%), moisture content (5.3–6.1%), and Aw (0.11–0.13) of the powders, and the hygroscopicity of the hydrolysates decreases from 30 to 16.1–17.1%, after encapsulation (Lima et al, 2021). It has been reported that the physicochemical, functional, and flowability characteristics of encapsulated hydrolysate powders are influenced by the composition of formulation (especially, type and concentration of hydrolysate and carrier) and the microencapsulation technique (e.g., spray‐ or freeze‐drying) (Akbarbaglu et al, 2019; Gan et al, 2020; Kleekayai et al, 2022; Sarabandi & Jafari, 2020).…”

“…Lima et al, 2021). It has been reported that the physicochemical, functional, and flowability characteristics of encapsulated hydrolysate powders are influenced by the composition of formulation (especially, type and concentration of hydrolysate and carrier) and the microencapsulation technique (e.g., spray-or freeze-drying)(Akbarbaglu et al, 2019;Gan et al, 2020;Kleekayai et al, 2022; …”

Antioxidant and α-Amylase Inhibitory Properties Generated from Chicken Head Proteins by Dual-Enzyme Hydrolysis

“…The highest value was found in CHP, while the lowest value was found in CHP3, namely protein hydrolysate using 0.75% bromelain and 0.25% papain. A decrease in pH after hydrolysis was also reported to occur in undersized crawfish minced meat hydrolysate (Bonilla et al, 2022) and whey protein hydrolysate (Kleekayai et al, 2022). The decrease in pH after hydrolysis may be caused by the release of carboxyl groups from protein chains during the hydrolysis process by proteases (Banjongsinsiri et al, 2016).…”