Solidification of concentrated pea protein–pectin mixtures as potential binder

Abstract

BACKGROUND Binders in plant‐based meat analogues allow different components, such as extrudate and fat particles, to stick together. Typically, binders then are solidified to transform the mass into a non‐sticky, solid product. As an option for a clean‐label binder possessing such properties, the solidification behavior of pea protein–pectin mixtures (250 g kg−1, r = 2:1, pH 6) was investigated upon heating, and upon addition of calcium, transglutaminase, and laccase, or by combinations thereof. RESULTS Mixtures of (homogenized) pea protein and apple pectin had higher elastic moduli and consistency coefficients and lower frequency dependencies upon calcium addition. This indicated that calcium physically cross‐linked pectin chains that formed the continuous phase in the biopolymer matrix. The highest degree of solidification was obtained with a mixture of pea protein and sugar beet pectin upon addition of laccase that covalently cross‐linked both biopolymers involved. All solidified mixtures lost their stickiness. A mixture of soluble pea protein and apple pectin solidified only slightly through calcium and transglutaminase, probably due to differences in the microstructural arrangement of the biopolymers. CONCLUSION The chemical makeup of the biopolymers and their spatial distribution determines solidification behavior in concentrated biopolymer mixtures. In general, pea protein–pectin mixtures can solidify and therefore have the potential to act as binders in meat analogues. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Pea protein–sugar beet pectin binders can provide cohesiveness in burger type meat analogues

“…High stickiness was also shown for a mixture composed of pea protein and sugar beet pectin [16]. Furthermore, it was found that this mixture transitions from a semisolid and sticky material into a non-sticky solid upon use of laccase inducing crosslinks between tyrosine in pea protein and ferulic acid in sugar beet pectin [16]. This resembles the above-mentioned transition of methylcellulose in vegan burger patties and the proteinaceous binder in beef burger patties upon heating [5,13,14].…”

“…As such, a concentrated mixture thereof could be used to adhere the aforementioned structured ingredients in a plant-based burger patty. High stickiness was also shown for a mixture composed of pea protein and sugar beet pectin [16]. Furthermore, it was found that this mixture transitions from a semisolid and sticky material into a non-sticky solid upon use of laccase inducing crosslinks between tyrosine in pea protein and ferulic acid in sugar beet pectin [16].…”

“…All burger patties lost their stickiness after the heat treatment caused by an increase in binder cohesion [12]. In the case of burger patties with pea protein-sugar beet pectin acting as binder, laccase induced crosslinks between the two biopolymers that led to solidification, i.e., higher cohesion [16]. Unexpectedly, the burger patties with no laccase addition also lost their stickiness, although no crosslinks could be formed between the pea protein and the sugar beet pectin.…”

“…The applied heat treatment of the burger patties at 45 °C was done to accelerate laccase action that crosslinks pea protein and sugar beet pectin leading to solidification of the pea protein-pectin binder as shown before [16]. Heating at 95 °C induces enzyme inactivation, which is a typical step in the food industry prior to selling [20], and also leads to a reduction of microbial contamination, thereby improving product shelf life.…”