Antioxidant activities and functional properties of enzymatic protein hydrolysates from defatted Camellia oleifera seed cake

Abstract

Seed cake protein (SCP) from Camellia oleifera was hydrolyzed by five commercial proteases (Flavorzyme, Trypsin, Neutrase, Papain, Alcalase). Amino acid composition, molecular weight distribution, antioxidant activity and functional property of the seed cake protein hydrolysates (SCPH) were investigated. Enzymatic hydrolysis improved protein solubility significantly but impaired the foaming and emulsifying property. Hydrolysate generated by alcalase had the highest hydrolysis degree (DH) and antioxidant activity, and displayed excellent protein solubility over wide range of pH, while hydrolysate prepared by flavorzyme showed better copper chelating capacity and emulsifying stability with low molecular weight distribution. Trypsin-treated SCPH showed better foaming property than original protein. The results indicated that enzyme type greatly influenced the molecular weight, functional property and antioxidant activity of SCPH. It was also found that electing appropriate protease and controlling the DH could be enhanced or reduced functional property according to actual applications.

Antioxidative and Functional Properties of Kariya (Hildergadia barteri) Protein Hydrolysates Obtained with Two Different Proteolytic Enzymes

“…According to Chobert et al (1988), the high solubility of protein hydrolysates has been attributed to the enzymatic release of smaller polypeptide units and reduction of the secondary structure of the protein. Previous studies on C. oleifera seed hydrolysates as reported by Li et al (2015) showed that the highest solubility occurred at strongly basic pH which is also comparable to the result obtained on KPH. The high peptide solubility of KPH indicates potential applications in food industry.…”

“…The proximate analysis showed that kariya kernels contain 17.5, 37.5, 2.8 and 6.5% crude protein, crude fat, ash and crude fiber, respectively (Ogunsina et al 2011). The crude protein content of kariya falls within the range of 15-25% for bambara groundnut (Murevanhema and Jideani 2013) and 14-20% for C. oleifera seed (Li et al 2015) but less than 20-24% for conophor nut (Gbadamosi et al 2012).…”

“…According to (Ajibola et al 2011), mammalian body needs additional antioxidant to protect the body against oxidative damage that cannot be sufficiently protected by the body's physiological defense mechanism during severe oxidative stress. Several in vitro antioxidant evaluation systems such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), metal chelation and ferric reducing power have been used in the evaluation of antioxidant activities of enzymatic hydrolysates from plant-derived proteins, such as hemp seed (Girgih et al 2011), pea seed (Pownall et al 2010) and Camellia oleifera seed (Li et al 2015). Some of the factors that influence the antioxidant properties of these hydrolysates include the type of native protein and the operational condition applied to isolate the protein, specificity of the protease used for hydrolysis, degree of hydrolysis (DH), peptide structure, amino acid composition of the peptides and molecular weight of the peptides (Tang et al 2009;Udenigwe and Aluko 2011).…”

Functional Properties and Protein Digestibility of Protein Concentrates and Isolates Produced from Kariya (H ildergadia bateri ) Seed

“…The crude protein content of kariya falls within the range of 15–25% bambara groundnut (Murevanhema and Jideani ), 14–20% Camellia olifera seed (Li et al . ) and 20–24% for conophor nut (Gbadamosi et al . ).…”

“…The proximate analysis showed that kariya kernels contain 17.5% (Ogunsina et al 2011) and 28.68% (Adebayo et al 2013). The crude protein content of kariya falls within the range of 15-25% bambara groundnut (Murevanhema and Jideani 2013), 14-20% Camellia olifera seed (Li et al 2015) and 20-24% for conophor nut (Gbadamosi et al 2012). With this protein content, the functionality of kariya protein concentrate (KPC) and isolate (KPI) can be explored in food applications.…”