title: Influence of enzymatic hydrolysis and enzyme type on the nutritional and antioxidant properties of pumpkin meal hydrolysates.
abstract: Nutritional and antioxidant properties of pumpkin meal and their hydrolysates prepared by hydrolysis with alcalase, flavourzyme, protamex or neutrase were evaluated. The hydrolysis process significantly increased protein content from 67.07% to 92.22%. All the essential amino acids met the Food and Agriculture Organization of United Nations/World Health Organization (WHO/FAO) suggested requirements for children and adults. The amino acid score (AAS) of meal was increased from 65.59 to 73.00 except for flavourzyme (62.97) and protamex (62.50). The Biological Value (BV) was increased from 53.18 to 83.44 except for protamex (40.97). However hydrolysis decreased the Essential Amino Acid/Total Amino Acid ratio (EAA/TAA) from 32.98% to 29.43%. Protein Efficiency Ratio (PER) was comparable to that of good quality protein (1.5) except for flavourzyme hydrolysate which had PER1 = 0.92, PER2 = 1.03, PER3 = 0.38. The in vitro protein digestibility (IVPD) increased from 71.32% to 77.96%. Antioxidant activity increased in a dose-dependent manner. At 10 mg mL(-1), the hydrolysates had increased 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging activities from 21.89% to 85.27%, the reducing power increased from Abs(700nm) 0.21 to 0.48. Metal (Iron) chelating ability was improved from 30.50% to 80.03% at 1 mg mL(-1). Hydrolysates also showed better capabilities to suppress or delay lipid peroxidation in a linoleic acid model system. Different proteases lead to different Degrees of Hydrolysis (DH), molecular weight (MW) distribution, amino acid composition and sequence, which influenced the nutritional properties and antioxidant activities of the hydrolysates. Alcalase was the most promising protease in production of pumpkin protein hydrolysates with improved nutritional quality, while flavourzyme was best in production of hydrolysates with improved antioxidative activity among various assays. These results showed that hydrolysates from by-products of pumpkin oil-processing might serve as alternative sources of dietary proteins with good nutritional quality, and protection against oxidative damage.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, PR China.
authors.forename: Muhamyankaka
authors.initials: M
authors.lastname: Venuste
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Charles F
authors.initials: CF
authors.lastname: Shoemaker
authors.forename: Eric
authors.initials: E
authors.lastname: Karangwa
authors.forename: Shabbar
authors.initials: S
authors.lastname: Abbas
authors.forename: Patrick Eugene
authors.initials: PE
authors.lastname: Kamdem
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology; D002614:Chelating Agents / Q000378:metabolism; D002648:Child; D028464:Cucurbita / Q000737:chemistry*; D004044:Dietary Proteins / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D015227:Lipid Peroxidation / Q000187:drug effects; D062407:Meals; D008970:Molecular Weight; D009751:Nutritional Requirements; D009753:Nutritive Value; D018384:Oxidative Stress / Q000187:drug effects; D010447:Peptide Hydrolases / Q000378:metabolism; D010851:Picrates / Q000494:pharmacology; D010938:Plant Oils / Q000494:pharmacology; D011492:Protein Hydrolysates / Q000494:pharmacology*; D013381:Subtilisins / Q000378:metabolism; D014944:World Health Organization
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D001713:Biphenyl Compounds; D002614:Chelating Agents; D004044:Dietary Proteins; D010851:Picrates; D010938:Plant Oils; D011492:Protein Hydrolysates; C004931:1,1-diphenyl-2-picrylhydrazyl; D010450:Endopeptidases; D010447:Peptide Hydrolases; C412470:flavourzyme; D013381:Subtilisins