Enzymatic treatment of soy protein isolates: effects on the potential allergenicity, technofunctionality, and sensory properties

Abstract

Soybean allergy is of great concern and continues to challenge both consumer and food industry. The present study investigates the enzyme‐assisted reduction in major soybean allergens in soy protein isolate using different food‐grade proteases, while maintaining or improving the sensory attributes and technofunctional properties. SDS‐PAGE analyses showed that hydrolysis with Alcalase, Pepsin, and Papain was most effective in the degradation of the major soybean allergens with proteolytic activities of 100%, 100%, and 95.9%, respectively. In the course of hydrolysis, the degree of hydrolysis increased, and Alcalase showed the highest degree of hydrolysis (13%) among the proteases tested. DSC analysis confirmed the degradation of major soybean allergens. The sensory experiments conducted by a panel of 10 panelists considered the overall improved sensory properties as well as the bitterness of the individual hydrolysates. In particular, Flavourzyme and Papain were attractive due to a less pronounced bitter taste and improved sensory profile (smell, taste, mouthfeeling). Technofunctional properties showed a good solubility at pH 7.0 and 4.0, emulsifying capacity up to 760 mL g−1 (Flavourzyme) as well as improved oil‐binding capacities, while the water‐binding properties were generally decreased. Increased foaming activity for all proteases up to 3582% (Pepsin) was observed, whereas lower foaming stability and density were found. The hydrolysates could potentially be used as hypoallergenic ingredients in a variety of food products due to their improved technofunctional properties and a pleasant taste.

Improvement of techno-functional properties of edible insect protein from migratory locust by enzymatic hydrolysis

“…According to the DH value, the most effective protein degradation among the single enzyme hydrolyses was achieved after treatment with Alcalase (31.1%) followed by Neutrase (26.2%), Flavourzyme (24.1%) and Papain (20.6%) at highest E/S ratio (1%) and longest t H (24 h). A similar trend was already reported by Meinlschmidt et al [51] for the hydrolysis of soy protein isolate. Studies regarding enzymatic degradation of insect protein are rather scarce.…”

“…The bands at 45 kDa and 37 kDa were gradually decomposed and completely eliminated only after 24 h. The slower decomposition of the proteins by Flavourzyme was also demonstrated by the lower increase of the intensity of the predominant low molecular weight bands (10-15 kDa). Similar observations were reported by Meinlschmidt et al [51] and attributed to the fact that Flavourzyme contains exoproteases, which cleave small peptides fragments at the end of proteins, hence leading to a slow, step-wise protein decomposition.…”

“…This divergence was similarly observed by Meinlschmidt et al [51] and might be ascribed to the weak, unstable fluorescent product build by the reaction of o-phthaldialdehyde and cysteine residues released during enzymatic cleavage with Papain [57].…”

“…An increase in emulsifying capacity was similarly found after comparable hydrolysis treatments of tropical banded crickets [33]. However, some hydrolytic settings were also shown to reduce emulsifying properties due to excessive protein degradation which negatively affects interfacial adsorptivity and molecular rearrangement at the surface [29,33,51].…”

“…Foam stability between 30-40% at pH 5 and pH 9 was observed for the untreated control while FS was not assignable (na) at pH 3 and pH 7. Initial foam stability of untreated MLPF is considerably low in comparison to conventional food proteins such as soy protein isolate (5% w/v) or rapeseed albumin solution (1.5% w/v) exhibiting an FS of 90% and 76% after 60 and 30 min, respectively [30,51]. Enzymatic hydrolysis resulted in a sharp increase of the foam stability at pH 7 (72%) and a limited improvement at pH 9 (82%).…”