Structure formation and rheological properties of pea protein-based gels

Abstract

Nutritional recommendations for the elderly, but also the general public, include incorporation of plant proteins in the diet, an increase in the intake of Ω-3 fatty acids and an increase in intake of dietary fibre. Protein structure and structuring behaviour of plant proteins differ from that of milk proteins. Therefore, the aim of the presented study was to characterise the structuring process and resulting structure of yoghurt-style gels containing 10% pea protein with and without addition of nutritionally recommended ingredients like rapeseed-oil and/or commercial oat fibre. Rheological measurements were combined with microscopy for sample characterisation. Generally, all studied formulations were able to form acid induced gels via fermentation. The acidification led to a two-phase gelation process resulting in thick gels that showed mainly weak rheological behaviour. Supplementation with oil and/or fibre resulted in an increase of the relative concentration of pea protein in the aqueous phase and led to a strong increase in the complex shear modulus |G*| as well as the maximum structuring velocity d|G*|/dt. These effects need to be considered when tailoring yoghurt-style gels with high consumer acceptance.

Enzymatic hydrolysis of pea protein: Interactions and protein fractions involved in fermentation induced gels and their influence on rheological properties

“…The slopes (dlogG'/dlogf) of G' from frequency sweeps (fig. 4a) were 0.13 which is slightly lower, but still similar to results found in previous work (Klost & Drusch, 2019) and can be ascribed to the high protein content of the gels. In amplitude sweeps (fig.…”

“…(Cheng, Thompson, & Brittin, 1990;Donkor, Henriksson, Vasiljevic, & Shah, 2007;Ferragut, Cruz, Trujillo, Guamis, & Capellas, 2009;Karleskind, Laye, Halpin, & Morr, 1991;Yazici, Alvarez, & Hansen, 1997), other protein sources such as oat (Brückner-Gühmann et al, 2019), lupine (Hickisch, Bindl, Vogel, & Toelstede, 2016) and pea (Klost & Drusch, 2019) have been less investigated so far but are believed to follow the general acid induced gelation process outlined above. With regard to pea proteins we previously described its ability to form fermentation induced selfsupporting gels and proposed a two-step gelation process that consists of the formation of an overall percolated network structure followed by condensation of smaller aggregates (Klost & Drusch, 2019). However, there is no specific knowledge on the type and ratios of interactions participating in the formation and stabilisation of these gels or on the influence of hydrolysis on gel properties.…”

Plant-Based Alternatives to Yogurt: State-of-the-Art and Perspectives of New Biotechnological Challenges

“…Protein-rich fractions from legumes were also used in YL formulation. Lupin protein isolate was used as the main protein source in a formulation including glucose and coconut oil [ 11 ] while recently, a pea protein isolate was used to prepare a PBYL, showing its ability to form gels after heating and fermentation [ 25 ]. Potato protein isolate was shown to be suitable to fortify a PBYL [ 24 ].…”

Pea Seed Proteins: A Nutritional and Nutraceutical Update

“…The plant protein can be used as substitute for animal protein for meeting nutritional need of lacto-vegetarians and thus can make the food healthier. Several researchers are working on partly or fully substitution of dairy proteins with pea protein and the impact on taste and structure of these products [86][87][88][89][90].…”