Open AccessFood functionality of protein isolates extracted from Yellowfin Tuna ( Thunnus albacares ) roe using alkaline solubilization and acid precipitation process
Author(s) -
Yoon In Seong,
Lee Hyun Ji,
Kang Sang In,
Park Sun Young,
Kang Young Mi,
Kim JinSoo,
Heu Min Soo
Publication year - 2019
Publication title -
food science and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 27
ISSN - 2048-7177
DOI - 10.1002/fsn3.793
Subject(s) - chemistry , yellowfin tuna , isoelectric point , casein , solubility , food science , chromatography , protein precipitation , nuclear chemistry , tuna , biochemistry , high performance liquid chromatography , biology , enzyme , organic chemistry , fish <actinopterygii> , fishery
Four types of roe protein isolates ( RPI s) were prepared through the alkaline solubilization and acid precipitation ( ASAP ) process, and their functional properties and in vitro bioactivities were evaluated. Higher buffer capacity in pH ‐shift range of 8–12 was found in RPI ‐1 ( pH 11/4.5), required average 94.5 mM Na OH than that of other RPI s to change the pH by 1 unit. All the samples of 1% dispersion (w/v) showed the lowest buffering capacity near the initial pH . The water‐holding capacities ( WHC ) of RPI s and casein as controls without pH ‐shift were in range of 3.7–4.0 g/g protein, and there were no significant differences ( p > 0.05). At pH 2 and 8–12 with pH ‐shift, WHC and protein solubility of RPI s were significantly improved compared to those of controls. Foaming capacities of RPI ‐1 and RPI ‐3 were 141.9% and 128.1%, respectively, but those of RPI ‐2 and RPI ‐4 were not detected. The oil‐in‐water emulsifying activity index of RPI ‐1 and RPI ‐3 was 10.0 and 8.3 m 2 /g protein, which was not statistically different from casein (7.0 m 2 /g), but lower than that of hemoglobin (19.1 m 2 /g). Overall, RPI s, casein, and hemoglobin exhibited lower food functionality at pH 4–6 near isoelectric points. Through the pH ‐shift treatment, the food functionalities of RPI s were improved over the controls, especially in the pH 2 and pH 8–12 ranges. RPI also showed in vitro antioxidant and antihypertensive activities. Therefore, it has been confirmed that RPI extracted from yellowfin tuna roe has high utility as a protein‐ or food‐functional‐enhancing material or protein substitute resource for noodles, confectionery, baking, and surimi‐based products.