Using the commercial protease Alcalase, researchers from the Centro de Investigacion en Alimentacion y Desarrollo produced hydrolysates from fish muscle that could substitute functional compounds such as bovine serum albumin and sodium caseinate.
"Results in the present study showed that hydrolysates produced from Pacific whiting (Merluccius productus) muscle can be used as food ingredients or additives to impart a desire characteristic to food products or increase food storage stability, acting as emulsifying, foaming or dispersing agents, in sausages, mayonnaise, salad dressings, beverages, creams, etc., all these in a broad pH range," wrote lead author Ramon Pacheco-Aguilar in the journal Food Chemistry.
The Mexican researchers used Alcalase to produce hydrolysates from Pacific whiting muscle with degrees of hydrolysis of 10, 15, and 20 per cent.
The functionality of the hydrolysates was then investigated in terms of solubility, emulsifying and foaming properties over a pH range of 4.0 to 10.0, and compared with bovine serum albumin and sodium caseinate.
Almost 100 per cent stability was reported in freeze-dried hydrolysates at all pHs studied. Moreover, the degree of hydrolysis did not affect the emulsifying properties, which were higher than sodium caseinate at pH 4.
Recent figures from Frost & Sullivan reveal emulsifiers, along with fat replacers, are leading growth in the food additive industry: since 2001 the market value of emulsifiers rose by some 5.6 per cent. Emulsifiers are used by food makers to reduce the surface tension between two immiscible phases at their interface - such as two liquids, a liquid and a gas, or a liquid and a solid - allowing them to mix.
While the hydrolysates did not exhibit a high foaming capacity, it was found to be "equal or even better than bovine serum albumin, except at pH 4.0," stated the researchers.
"Results suggest that hydrolysates from Pacific whiting muscle can be produced with similar or better functional properties than the food ingredients used as standards," they added.
Pacheco-Aguilar and co-workers called for further study to explore the potential of the fish protein hydrolysates in real food systems.
"The use of commercial enzymes for production of highly functional hydrolysates from marine species of low commercial value can be a feasible technology to make the most of a vast underutilized resource (such as the Pacific whiting) and use it as a food ingredient for direct human consumption," concluded the researchers.
Protein hydrolysates have many functions in the food industry, but one of the most commonly mentioned is as a water-holding agent in meat products to improve the moisture and succulence of the meat.
This offers the processed meat industry an alternative to phosphates, currently employed by the processed meat industry to maintain the "juiciness" of meat by binding water to the meat. Additives such as E450 (diphosphates), E451 (triphosphates) and E452 (polyphosphates) are commonly used.
Source: Food Chemistry
August 2008, Volume 109, Issue 4, Pages 782-789
"Functional properties of fish protein hydrolysates from Pacific whiting (Merluccius productus) muscle produced by a commercial protease"
Authors: R. Pacheco-Aguilar, M.A. Mazorra-Manzano, J.C. Ramirez-Suarez