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Abstract

Protein hydrolysates from skipjack tuna viscera prepared using Alcalase 2.4 L (VPH) with different degree of hydrolysis (DH: 10%, 20% and 30%) were prepared and determined for their antioxidative activity. VPH with 20% DH had the highest DPPH, ABTS radical scavenging activities and ferrous chelating activity (P<0.05). However, ferric reducing antioxidant activity of hydrolysates increased as DH increased (P<0.05). When VPH with 20% DH was determined for its pH and thermal stability, ABTS radical scavenging activity remained constant or slightly decreased in a wide pH range (2-11) and during heating (100°C) for 180 min. Functional properties of VPH (20% DH) at different concentrations were also investigated. The emulsifying and foaming properties were governed by its concentrations used. Hydrolysis by Alcalase at 20% DH increased protein solubility to above 91% over a wide pH range (3-9). Therefore, VPH could be used as a food additive possessing both antioxidant activity and functional properties.

Earthworm (Perionyx excavatus) Protein Hydrolysate: Hypoglycemic Activity and Its Stability for the Hydrolysate and Its Peptide Fractions

“…Nevertheless, the α-AIA and α-GIA stability of these samples gradually decreased as the pH shifted to very low or very high values (Figure 4). This could be due to the changes in the charges of peptides, particularly at the N-and C-terminus at high acidic and alkaline conditions [78], altering the electrostatic interactions and hydrogen bonds and transforming their secondary structures and solubility, resulting in the loss of bioactivity [79,80]. The change in the stability of these samples could be due to the impact of pH on one particular or more amino acids.…”

Characteristics and Properties of Acid- and Pepsin-Solubilized Collagens from the Tail Tendon of Skipjack Tuna (Katsuwonus pelamis)

“…The FRAP assays of ATC and VTC were not significantly different ( p > 0.05), but these two collagens showed a higher FRAP value than APTC ( p ≤ 0.05). The stronger reduction powder indicated that it could donate an electron to free radicals, resulting in a capacity to prevent or retard in the state of propagation [ 63 ].…”

Comparative study on the functional properties of the pearl oyster (Pinctada martensii) protein isolates and its electrostatic complexes with three hydrophilic polysaccharides

“…The emulsifying activity index (EAI) and emulsion stability index (ESI) were used to measure the emulsification of PPIs and PPI-polysaccharide complexes by the procedure described by Klomklao & Benjakul. [20] Arachis oil (3 ml) and sample solutions (1%, 9 mL, fresh samples) were homogenized (Model T25 basic; IKA-Labortecnik, Selangor, Malaysia) at a speed of 12,000 rpm for 1 min. The 20 μL emulsion was quickly taken from the bottom of the emulsion and added to a 0.1% (w/v, 5 mL) sodium dodecyl sulfate (SDS) solution and shaken well.…”

“…[26] The interaction between proteins and polysaccharides in food systems can show better performance than either used independently and can affect the flavor, nutrition, texture, and other qualities of the food system. [20] The solubility of PPIs and PPI-polysaccharide complexes is presented in Figure 2. The solubility of PPIs was (7.68 ± 0.54%), and compared to that of PPIs, the solubility of the complexes changed to different degrees.…”