Juicy, Crunchy, Chewy:

A soggy potato chip. A mushy apple. Lumpy milk. For most people, food texture is not a conscious consideration – unless it’s significantly different than expected.

In haute-cuisine kitchens, this sensory incongruity is often used to surprise and delight, presenting foods that usually appear in one form in an unexpected manner: a foam of parmesan cheese, or a vegetable-flavoured ice cream.

But sometimes, rather than creating the most unexpected combination of flavour and texture, the challenge is doing the complete opposite: recreating precisely a food that people know, but from (completely) different ingredients.

Meat from plants, for example. Which raises the question: How does one make something made of plants feel like a burger?

This question is not one that’s gone unresearched – there’s a whole field called food rheology which studies the behaviour of food under specific conditions (i.e. in a mouth). There are countless machines and devices to measure everything from the stringiness of cheese on pizza to the tenderness of meat. There’s even a sub-field, psychorheology, that investigates the “sensory judgement of rheological properties”.

But measuring is something else than creating.

Survey have shown that for consumers aged 25 to 44, the texture of plant-based alternatives is the biggest reason to dislike it. The same survey noted that “cheese is the final frontier”, with consumers particularly unhappy about the taste and texture of plant-based cheese, lamenting the lack of creaminess.

Apart from texture, the slower uptake of animal-based food product alternatives can be attributed to perception of higher cost – which is no longer the case in some countries –, taste and the ‘clean label trend’, which sees consumers picking alternatives more readily if the foods are made out of natural ingredients rather than artificial or processed.

Consumer expectations for plant-based meat alternatives have evolved significantly over time. In 2018, the primary concern was that alt-meat burgers should maintain their structural integrity. However, by 2023, consumers have come to expect a level of juiciness comparable to traditional meat products.

The sensory experience plays a crucial role in consumer retention for plant-based foods. While initial adoption may be driven by health or environmental concerns, the taste and texture are key factors in ensuring repeat purchases. Research indicates that a significant portion of European consumers find dairy alternatives lacking in certain sensory aspects. The primary complaint is the absence of the rich, creamy, and smooth mouthfeel characteristic of cow's milk

To address these texture issues in plant-based dairy alternatives, typically, creaminess and mouthfeel is enhanced through the addition of natural ingredients and proteins, while undesirable flavors are masked, and flavor profiles are adjusted to match regional preferences for milk.

In the realm of plant-based meat analogues, recent years have seen considerable diversification and innovation, particularly in the burger category. As the market expands, consumer expectations for the performance of these alternatives have increased. For instance, plant-based sausages are now expected to replicate the bite of their meat counterparts, while analogue chicken pieces should exhibit improved juiciness and fibrous texture.

To meet these evolving demands, it's necessary to combine advanced texturizing technology with innovative ingredient solutions.

While the sensory experience of ‘crunchy’ or ‘chewy’ might be obvious to people, it’s slightly more complicated to measure those properties.

The focus extends beyond the measurement of texture properties, but also on the process that goes into making them, the safety of the end-product, the sustainability of the production process and the scalability of production.

Food can be understood as a disperse system in which one substance is dispersed within another substance. For example, margarine is a dispersion of fats or oils in a liquid-like structure, while chocolate is a solid emulsion in which cacao and sugar are suspended within solidified cocoa butter.

The size of the dispersed substance and the concentration of dispersion then lead to different properties of the system that allow for different parameters for quality. Taking chocolate, again, the size of the sugar particles determines the roughness (or smoothness) of the chocolate.

This understanding then allows for the development and application of technologies that can alter the production, extraction or properties of foods in desired ways. Take for example the relatively new application of a process called triboelectric separation, in which protein can be extracted from a source material using electric currents, with increased efficiency and low water-usage.

Another widely applied method is extrution, which is widely used in meat alternative production. Extrusion exists in a few different forms, but all amount to forcefully pushing a mixture of ingredients through a long barrel with a screw mechanism inside.

Roughly speaking, creating a plant-based alternative to an animal product requires mimicking the nutritional composition (fat, fiber, protein and carbohydrates, plus aromatic compounds, water and salt) from plant or microbe-derived sources, and then manipulating those to gain the correct rheological properties.