Rapid measurement of food quality
A food industry that is looking to the future carries out automatic measurements of food quality on or close to the production line. Several scientists and experts working at Nofima have comprehensive knowledge of the rapid measurement of food quality.
We develop rapid, reliable and non-destructive measurement and control methods that can simplify operating procedures for the food and fishing industries. The food products can be measured directly on the production line or in its immediate vicinity. Many parameters of a food product can be measured at the same time, such as the amounts of fat, water, protein, connective tissue and carbohydrates. Other parameters are fat composition, colour and freshness. This gives unique possibilities for documentation, quality sorting and the optimal use of raw materials.
Most of the methods developed by Nofima are based on spectroscopy. Modern spectroscopy instruments can measure in two dimensions, and some can measure in three. This gives new possibilities for detailed analysis of processes and products. The instruments are constantly improving, with higher speeds, greater accuracy, and higher sensitivity and specificity. This means that we can measure molecular structures and components that were, until recently, impossible to measure without using time-consuming chemical analyses.
Our scientists develop, adapt and test spectroscopy techniques used for problems related to food quality, process understanding, process surveillance, process optimisation, documentation of raw materials and products, and the understanding of structures and molecular interactions. These techniques give rapid replies, which means that they are being used to an increasing degree in process development.
Nofima has expertise in a broad wide variety of of spectroscopy techniques:
NIR and VIS spectroscopy
NIR (near infrared) and VIS (visible) spectroscopy are techniques in which light is passed through a food product to measure how much light is absorbed in the product at various wavelengths. These are rapid measurement methods that are suitable for quantifying various properties of food. Fat, water, protein, carbohydrates and pigments are some of the chemical components that can be measured with NIR and VIS.
NIR is the most widely used online and at-line technique used in the feed and food industries. Nofima has developed several measuring instruments with a variety of applications such as determination of freshness, the blood content of fresh and smoked fish, the water content of dried and salted cod, the levels of fat, carbohydrates and pigment in fillets of salmon, the levels of fat and water in fillets of meat, the formation of acrylamide in potato crisps, and the amounts of health components of barley.
Fluorescence spectroscopy is a highly sensitive spectroscopy method that can be used analytically in the lab and online in processes. It is based on illuminating the sample with ultraviolet (UV) light such that some molecules emit fluorescence. The measurements can be made on fluids and directly on food products, including food product that are sensitive to light. The method can be used, for example, to measure connective tissue in meat, riboflavin (vitamin B₂) in dairy products, and the oxidation (rancidification) of products such as fish, meat and cheese in a few seconds.
FT-IR (Fourier transform infrared) spectroscopy
FT-IR spectroscopy has been used to analyse biological material since the 1980s. The technique is simple to use, rapid and cost-effective. Scientists at Nofima have worked with the development of FT-IR as a rapid screening tool for the documentation of, among other things, the levels of fat and proteins in milk and the levels of carbohydrates in juice. We have also used it to monitor bacterial fat production and the enzymatic breakdown of proteins. The method is also used for the rapid characterisation of micro-organisms, to study changes in protein structure in muscles, and how this structure influences the mobility of water in various process conditions.
Raman spectroscopy is related to NIR, VIS and fluorescence spectroscopy, but it can measure other compounds. It also makes it possible to take samples both from solid and liquid products. Raman spectroscopy is mainly used at Nofima for detailed structural studies of various types of molecules. The rapid characterisation of fatty acids in food, such as parameters related to the degree of unsaturation, is one interesting possibility.
Images of a food product are created in imaging spectroscopy in which each point (pixel) in the image is presented as a light spectrum. This can be used to create a two-dimensional map of properties. Imaging spectroscopy can be used to measure many chemical components at the same time, in what can be regarded as chemical “fingerprinting”. Nofima has participated in the development of high-resolution online instruments that can be used at the speeds used by conventional transport belts, and in the TOMRA Qvision online system, which uses hyperspectral imaging at visible and NIR wavelengths.
Nofima has built up an online system for colour measurement, based on the use of transport belts, diffuse illumination and a colour line scan camera. The system has been developed to examine capture damage to fish and to document product colour.
Nofima has contributed to industrial solutions using radiology and the analysis of radiology images from food production. We have developed, among other things, commercial production equipment (SensorX) to detect pin bones in fish and bones in chicken fillets.