Storage Stability of Food Protein Hydrolysates—A Review

Abstract

In recent years, mainly due to the specific health benefits associated with (1) the discovery of bioactive peptides in protein hydrolysates, (2) the reduction of protein allergenicity by protein hydrolysis, and (3) the improved protein digestibility and absorption of protein hydrolysates, the utilization of protein hydrolysates in functional foods and beverages has significantly increased. Although the specific health benefits from different hydrolysates are somewhat proven, the delivery and/or stability of these benefits is debatable during distribution, storage, and consumption. In this review, we discuss (1) the quality changes in different food protein hydrolysates during storage; (2) the resulting changes in the structure and texture of three food matrices, i.e., low moisture foods (LMF, aw < 0.6), intermediate moisture foods (IMF, 0.6 ≤ aw < 0.85), and high moisture foods (HMF, aw ≥ 0.85); and (3) the potential solutions to improve storage stability of food protein hydrolysates. In addition, we note there is a great need for evaluation of biofunction availability of bioactive peptides in food protein hydrolysates during storage.

Particle Size of Milk Protein Concentrate Powder Affects the Texture of High‐Protein Nutrition Bars During Storage

“…As plasticization was lost during storage, the HPN bars hardened (Figure A‐C), lost adhesion (Figure D), and became more crumbly (Figure ). Conversely, protein hydrolysates, which have suppressed T gr , produce texturally stable HPN bars that maintain the rubbery state while stored at a temperature greater than their T gr (Rao and others , b). Protein T gr increases during HPN bar storage as water migrates to other components and as high molecular weight protein aggregates form (Zhou and others , b; Loveday and others ).…”

“…Whey protein concentrate (WPC) or isolate (WPI), specifically their hydrolysates, produce texturally stable HPN bars (McMahon and others ). Food protein hydrolysates advantageously possess lower glass transition temperature ( T g ) compared to their intact counterparts, which allows for better protein powder plasticization during HPN bar production and enables the resultant soft, rubbery state to be maintained throughout storage (Rao and others ). On a protein basis, MPCs concentrated from bovine skim milk contain ∼80% casein and ∼20% whey.…”

Extrusion modifies some physicochemical properties of milk protein concentrate for improved performance in high‐protein nutrition bars

“…Many scientific studies have looked at the effect of protein source on HPN bar texture and its time‐dependent changes assuming that different proteins are chemically and structurally disposed to perform better or worse in these applications . A common conclusion is that food protein hydrolysates produce soft, texturally stable HPN bars . Extruded and ground MPC80 made HPN bars with similar texture attributes, yet food protein extrusion is not known to hydrolyze proteins .…”

Instrumental and Sensory Texture Attributes of High‐Protein Nutrition Bars Formulated with Extruded Milk Protein Concentrate

“…It is well known that high‐protein nutrition (HPN) bars (20% to 50% protein w/w) and other shelf‐stable, intermediate moisture foods (IMFs; 10% to 40% moisture; 0.55 ≤ a w ≤ 0.90) problematically harden to unpalatable levels during storage (Loveday and others ; Imtiaz and others ; Rao and others ; Banach and others ). Reducing the average molecular weight of a protein by hydrolysis can soften HPN bars and slow their hardening by suppressing the system's glass transition temperature ( T g ) (McMahon and others ; Rao and others ). While enzyme hydrolysates have improved digestibility (Potier and Tome ) and reduced allergenicity (Verhoeckx and others ), they cost more to produce and taste bitter.…”