ORIGINAL ARTICLE
Physicochemical Properties and Antioxidant Capacity of Tryptic Hydrolysates of a Pea Protein Isolate: Influence of the Degree of Hydrolysis
			
	
 
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				1
				Team of Chemical and Physical Properties of Food, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Trylińskiego 18 Str., 10-683 Olsztyn, Poland
				 
			 
						
				2
				Institute of Food Science Research (CIAL), CSIC-UAM, C/Nicolás Cabrera 9, 28049 Madrid, Spain
				 
			 
										
				
				
		
		 
			
			
			
			 
			Submission date: 2025-09-20
			 
		 		
		
		
		
			
			 
			Acceptance date: 2025-10-28
			 
		 		
		
		
		 
	
							
					    		
    			 
    			
    				    					Corresponding author
    					    				    				
    					Magdalena  Karamać   
    					Team of Chemical and Physical Properties of Food, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Trylińskiego 18, 10-683 Olsztyn, Poland
    				
 
    			
				 
    			 
    		 		
			
												 
		
	 
		
 
 
 
 
KEYWORDS
TOPICS
ABSTRACT
Enzymatic pea protein hydrolysates offer potential health benefits because of their content of bioactive peptides, which have been released from the protein by the action of proteases. This study examined how the degree of hydrolysis (DH) of pea protein with trypsin influences physicochemical parameters and antioxidant capacity of the resulting hydrolysates. The molecular weight (MW) distribution of a pea protein isolate and its hydrolysates at the DHs of 2%, 5%, 8%, and 12% was determined using size-exclusion chromatography. Surface hydrophobicity was evaluated by two fluorescent probe assays, namely 8-anilino-1-naphthalenesulfonic acid (ANS) and cis-parinaric acid (CPA). Antioxidant potential was assessed as ABTS•+ scavenging capacity, oxygen radical absorbance capacity (ORACFL), antioxidant capacity of water-soluble and lipid-soluble compounds in the photochemiluminescence assay (PCL-ACW and PCL-ACL, respectively), and the ability to inhibit the oxidation of β-carotene-linoleic acid emulsion. With increasing DH, the contribution of fractions with MWs of 2–4 kDa and 4–7 kDa in the hydrolysates increased. However, the relative content of peptides with MWs less than 2 kDa remained below 10% in all of them. The ABTS•+ scavenging capacity and ORACFL also increased with DH, and the highest values, 0.111 and 0.320 mmol Trolox equivalent/g, respectively, were obtained for the hydrolysate at a DH 12%. Surface hydrophobicity increased only to DH 5%. Hydrolysates at DHs of 8% and 12% were characterized by gradually lower values. The trend of surface hydrophobicity changes was consistent with that of PCL-ACL. Additionally, principal component analysis showed an association between surface hydrophobicity and antioxidant capacity in the model emulsion. Overall, tryptic pea protein hydrolysates had improved antioxidant properties compared to the isolate, and the degree of hydrolysis was a parameter that allowed optimizing these properties under different conditions of antioxidant action.
		
	
		
    
    FUNDING
    
    	The study did not receive any external funding.
     
    
    CONFLICT OF INTEREST
    
    	The authors declare that they have no conflict of interest.
     
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