Texture Analysis: A tool to help the development of new food products from byproducts

In a linear economy we ‘take’ raw materials from the environment, ‘make’ something, ‘use’ or don’t use it, and finally ‘dispose’ of it. 

 

For example: in a supermarket, food that is still good but needs to be removed from shelves – often due to inventory or overstock reasons – typically heads to the landfill. We need to adopt a new approach to avoid this wasteful situation that challenges economies across the globe. A circular approach – reuse, recycle, remake, redistribute – aims to ensure zero food waste in the food chain. 

 

Aside from the waste associated with retailers and consumers there is a growing interest in the potential use of food manufacture by-products and how they can be reintroduced into the manufacture of new products. This would not only reduces waste but also provides a nutrient recycling opportunity and establishes a more efficient and sustainable food supply chain.

Effect of storage on Texture: Meat

Texture is the main quality characteristic of meat, affecting price and consumer acceptance.

Tenderness and juiciness are the main textural parameters that affect a consumer’s enjoyment in general. 

Tenderness refers to the force needed to yield the meat during chewing, and the energy needed to masticate it to the point of swallowing. Juiciness refers to the type and amount of liquid released during mastication. Some specific meat products have a different textural priority, such as the chewiness exhibited by beef jerky.

A large amount of research has been dedicated to understanding the texture of meat. However, the detailed mechanism of tenderisation is still not fully understood. Tenderness is known to be influenced by properties of the raw material, such as animal breed and age, muscle contraction, amount of connective tissue, ripening and its cooking method.

Effect of storage on Texture: Vegetables

From the point of view of texture, vegetables represent a very diverse group of products.

 

They can be consumed in many different textural forms. For instance, cooked asparagus is soft, fibrous and pulpy, cucumber is crisp, firm and juicy, raw carrots are hard and crisp, and cooked peas are soft and mealy. The tissue structure in each case determines the texture as received by the consumer.

Fresh vegetables

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.

Why we need controlled failure

We live in a world obsessed by perfection.  Everything is supposed to be better if it’s shiny, defect-free and stronger than a Sherman tank. 

But be careful what you wish for, because a flawless world wouldn’t work nearly as well. Imperfections are tools, and we would be lost without them.  

Of course, flaws are not always convenient.

Imagine bending a long thin object, like a bar of chocolate. If the chocolate has flat surfaces, each side is stretched evenly. It’s hard to break, but if you put a notch in it the section of chocolate just underneath also has to do the job of the bit you’ve taken out. The chocolate will break at the notch. It’s not because it’s thinner at that point but because the sharp point of the notch concentrates the force in a very small area.

In a flawless object the stress you put on a material by pushing, stretching, bending and twisting is relatively evenly spread. Features like notches, voids and tiny cracks make the pattern of stress more complicated, concentrating the stress in some bits and relieving it in others. If you could see stress as colours, every object you pushed on would suddenly light up with bands of colour and the flaws would be tiny pinpoints of dazzlingly bright light. Those pinpoints are vulnerable, overloaded already, they can’t take much more.

Effect of Storage on Texture: Baked Goods

Bread

When bread goes stale, the major factor that puts a consumer off is the change in texture, although flavour changes also occur. 

 

The textural changes during bread staling, and the processes that drive them, have been outlined in detail in a previous series of blog posts. The exact process of staling is not well understood despite a large amount of research into this topic.

Staling begins as soon as baking ends, and it becomes detectable to the consumer as early as a few hours after baking. Bread staling presents itself as reduced springiness and reduced crumb softness, both of which can be measured using a firmness measurement with a cylinder probe on a TA.XTplus Texture Analyser.

 

Additionally, the mouthfeel of both dryness and crumbliness increases, and the crust becomes tougher and less crisp. This change occurs due to moisture movement from the crumb to the crust, but changes to the contained starch molecules are also a major cause.

Effect of storage on texture: Fruit

When a food product is stored, its texture will change in any number of ways, almost always decreasing the product’s quality. 

 

A high shelf life is useful in the eyes of the manufacturer, and understanding the processes behind food degradation in storage is key to improving this shelf life, where possible.

Texture has its roots in the structure of food, from the molecular to macroscopic levels, and understanding the changes to the food on each of these levels helps to explain the texture changes that occur during storage.

Paper and Cardboard Testing with a Texture Analyser – Part 3

Reliable Testing for Packaging and Print

Tensile Test
Example standard: ASTM D828

Tensile testing is applied to paper products for various reasons to assess strength in use; standards such as ASTM D828 cover the methods required to measure the tensile properties of paper and paperboard. Tensile tests are used for combined corrugated board but not as frequently as bending, compression and puncture.

Paper and Cardboard Testing with a Texture Analyser – Part 2

Reliable Testing for Packaging and Print 

Pin Adhesion Test
Example standard: TAPPI T821

Another factor that controls the quality of corrugated board is the strength of adhesion between the corrugating medium and its facings. This adhesion can be measured directly using a ‘pin adhesion test’, where pin adhesion is the force to separate the two components. In this test, pins are inserted between the facing and fluted medium, then attached to rigs connected to the loading arm and base. The rigs are pulled apart at constant speed until the facing is separated from the flute tips. Separation of all bond lines is not necessary. This test assesses the quality of the bond formed when the board was combined, and can be used to detect some manufacturing defects such as poor adhesive penetration and spotty adhesive application.