Texture Analysis in Plant-Based Dairy Product Development

In the nearly 40 years since soy milk was first introduced in the U.S. and Europe, the offerings for plant-based dairy alternatives have expanded significantly to include a wealth of options from nuts, seeds, legumes, fruits, grains and root vegetables. 

In fact, industry experts predict that by 2026, the market for dairy alternative products could reach $41.8 billion growing at a CAGR of 12.2%.

A variety of factors are contributing to the category’s growth, including dairy sensitivity issues, consumer perception that plant-based products are healthier for them, a desire to avoid hormones or antibiotics, and concerns about animal welfare.

Texture Analysis: A tool for developing new food packaging from byproducts (waste)

By-products and waste generation are having an impact on environmental, economic, and social sectors. 

 

To the environment, these contribute to GreenHouse Gas (GHG) emissions. Many of these biomaterials are not utilised and end up in municipal landfills where they create serious environmental problems due to microbial decomposition and leachate production. In some cases, the by-products are burned to remove fungi and parasites. From the economic point of view, the adverse impact is due to the costs related to the handling of solid waste in landfills. Moreover, the management of large amounts of different degradable materials poses a challenge.

 

However, there is an increasing need for biodegradable, environmentally friendly and functional food-packaging materials. In this regard, proteins obtained from agri-food industry by-products may become a promising and sustainable (less impact, valorisation) source of such materials.

 

Measuring the crispness of fried vegetable products

Cooking in oil is widely used in the production of snack foods of various kinds, and results in drastic changes to the structure of the food.

Penetration of oil is particularly important for structure development in products such as potato chips, tortilla chips and potato crisps. In products which become totally hard and crisp, the oil first coats the surface and begins to move into the chip. As the heat builds up inside, moisture turns to steam and exits the chip, leaving a sponge-like network of tunnels which fill with oil.

This process occurs within the first 20 seconds of frying. Starch granules gelatinise inside the chip, but not at the surface. The interior becomes smooth and plastic as protein, starch and lipids interact to form a continuous phase which hardens upon dehydration.

Tofu texture

In the Far East, tofu is the most popular soybean food whilst in the West, tofu is gaining in popularity.

Tofu is very similar to cheese in appearance, texture, and chemical composition. By controlling the amount of coagulants and pressure applied during moulding, the texture of the tofu may be varied from extra firm, firm, soft, to silken.

Measuring the consistency of vegetable purées

Purées are very thick and viscous slurries made from processed vegetables that are often concentrated and include fibrous material or fruit pieces that adds structure. 

They are commonly used in fillings for pies, ketchup or baby food. Additional ingredients are usually added to manipulate consistency and processing properties.

For the measurement of consistency, a Back Extrusion test can be carried out by fixing a suitable diameter disc to the TA.XTplus texture analyser: the disc moves down into the vessel with good clearance between the vessel and disc so as not to produce erroneous increase force readings due to ‘side effects’.

Testing the overall firmness of a weight or quantity of cooked vegetables

Processed root and tuber products

Thermal treatment is one of the most important processes in the manufacture of storable and ready-to-serve food products of agricultural origin.

During thermal treatment, many desirable and undesirable reactions take place; components such as vitamins and colour components, for example, and also physical properties, such as texture, may be changed.

Cooking just to the point of softness produces vegetables with optimal texture which is where texture analysis plays a major role in determining processing times.

Testing cooked individual vegetable texture

Most vegetables are cooked before consumption, a process that softens their texture (unless there is a lot of lignification) and gelatinises the starch deposited as food for the plant. 

 

Starch and protein deposits are particularly abundant in beans, peas, and corn picked at maturity. A sugar to starch equilibrium reaction occurs during the storage of some vegetables, and this can affect their texture.

Sweetcorn and sweet peas when picked immature have much sugar and a succulent texture. Within hours the texture of sweetcorn can become tougher and drier due to sugar conversion to starch.

Testing fresh individual vegetable texture

As opposed to fruits, which are generally picked when mature but unripe, many vegetables (apart from legume seeds, tubers, bulbs and roots) are picked and consumed when still immature, tender and succulent.

 

This is largely due to the fact that while fruits generally soften on maturation and storage, young vegetables become tougher when they age. This toughening is due to the lignification of the primary cell wall and formation of the secondary cell wall. When cucumbers are stored below 7°C, their texture breaks down due to excessive softening and exudation of liquid as tissue undergoes a structural collapse. Tomatoes are also susceptible to low-temperature injury.

Many of the form, structure and physiological considerations discussed in connection with fruit texture also apply to vegetable texture. The main difference is that, while on maturation the fruit tissue stops growing and suffers enzymatic degradation, the vegetable tissue proceeds to differentiate and cell growth and enlargement continue. The amount of fibrous tissue increases. Toughening may reach the point where the vegetable is no longer suitable for human consumption.