These days, plant-based alternatives to meat can be found on supermarket shelves and freezers, and in restaurants in many places in the world. Vegan burgers, sausages, nuggets, mince and a variety of other food types are common-place and modern biotechnology, food technology, and process engineering makes these products look, taste and smell remarkably similar to their animal counterparts.
However, it remains that proteins from animal muscle are very different from plant proteins and this inevitably impacts the chemical interactions between ingredients as well as some of the physical and mechanical properties once the plant protein enters the mouth.
In research published today by the American Institute of Physics, scientists from Germany – where consumers can choose from more than 1,200 different types of sausage – investigate the molecular function and effects of vegetable proteins of different origins to identify what makes plant-based meat substitutes different once they are being chewed.
“We use direct comparisons of meat-based, vegetarian with egg white, and pure vegan versions to show the differences in bite, chewing, mouthfeel, bolus formation, and associated enjoyment characteristics of the sausages,” said co-author Thomas A. Vilgis, from the Max Planck Institute for Polymer Research.
In particular, the researchers considered differences in tensile strength between the types of sausages. They say that muscle proteins emulsify fats and oils in a very different way to plant proteins and this makes plant-based sausages feel different when we bite and chew them.
“The ‘crunch’ or ‘crack’ of meat sausages is inevitably different than that of vegan sausages, simply because the molecular properties of the proteins are markedly different,” said Vilgis.
In addition, the researchers also tested the sausages in terms of their rheology (flow of matter), and tribology (friction) while in the mouth. This allowed greater insight into the differences between the three types of sausage than is gained from sensory comparisons alone.
“We’re looking much deeper than what is usually done in food technology, by taking into account the molecular properties of ingredients as much as possible,” Vilgis said.
“We are taking a closer look at the proteins as well as the sequence of amino acids, which we understand as a ‘code’ from which we can read certain properties to better understand the behavior of the sausages in the mouth when they are consumed. Thus, fundamental differences in the molecular structure and mouthfeel become immediately apparent.”
Building on the authors’ previous research of soft matter theory and theoretical polymer physics, the study represents an entirely new approach to experimental food science.
“We’re working directly at the interface between basic science and technological application,” said Vilgis. “With these methods, it is possible to make predictions in how the physical properties of an alternative sausage can be improved – and make targeted developments.”
The study is published in the journal Physics of Fluids.
By Alison Bosman, Earth.com Staff Writer