Techno-functional, antioxidant, and amino acid characterization of hydrolyzed bioactive peptides from coconut (Cocos nucifera L.) meal protein

Food Funct. 2024 Nov 11;15(22):11266-11279. doi: 10.1039/d4fo02741h.

Abstract

In this study, the techno-functional characteristics and nutritional value of coconut meal protein (CMP) and the obtained polypeptides by alcalase (H-Alc), trypsin (H-Try), pancreatin (H-Pan), and pepsin (H-pep) were investigated. The degree of hydrolysis was influenced by the enzyme type, where an order of H-Pan (37.5%) > H-Alc (33.2%) > H-Try (29.9%) > H-Pep (23.4%) was observed. Hydrolysates' solubility, emulsifying properties, foaming capacity, water-holding capacity (WHC), and oil-binding capacity (OHC) were substantially improved after hydrolysis. The techno-functional properties of CMP were affected by pH and the enzyme type. H-Pan and H-Pep samples exhibited the highest WHC (6.5 g water per g) and oil-holding capacity (OHC, 7.1 g oil per g). Different groups of functional amino acids, including essential (EAAs), antioxidant (AAAs), hydrophobic (HAAs), negatively-charged (NCAAs), and positively-charged (PCAAs), and the protein efficiency ratio (PER) in hydrolysates were influenced by the type of protease. H-Pan showed the highest antioxidant amino acids (AAAs = 125.3 mg g-1; NCAAs = 261.0 mg g-1) and nutritional value (with EAAs of 295.1 mg g-1; an EAA to total amino acid (TAA) ratio of 35.3% and a PER value of 2.4). Enzymatic hydrolysis, in general, led to a considerable enhancement in the antioxidant activity of hydrolysates compared to that of the primary proteins. Regardless of the type of antioxidant assay, the most enhanced antioxidant capacity was attributed to H-Pan hydrolysates with DPPH, hydroxyl (OH), ABTS+, and nitric oxide (NO) radical scavenging activities of 82.0%, 71.8%, 82.9%, and 49.8%, respectively. However, other hydrolysates did not show significantly different antioxidant activities (P > 0.05).

MeSH terms

  • Amino Acids* / chemistry
  • Antioxidants* / chemistry
  • Antioxidants* / pharmacology
  • Cocos* / chemistry
  • Hydrolysis
  • Hydrophobic and Hydrophilic Interactions
  • Nutritive Value
  • Peptides* / chemistry
  • Plant Proteins* / chemistry
  • Protein Hydrolysates / chemistry
  • Subtilisins / chemistry
  • Subtilisins / metabolism

Substances

  • Antioxidants
  • Amino Acids
  • Peptides
  • Plant Proteins
  • Protein Hydrolysates
  • Subtilisins