test & measurement supplement
Non-destructive testing A food waste reduction opportunity?
Food waste reduction is a key objective for consumers, businesses and governments seeking to save money, improve food production efficiency, lower greenhouse gas emissions, reduce packaging waste and protect the environment. Such issues have enjoyed a high profile in recent years but in the following article Dr Abdel Ezbiri from the technology company Cerulean will discuss the waste that results from the temperature testing of fresh and chilled foods, and outline the success that some food processors have achieved in adopting non-destructive testing (NDT) technology
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nder food hygiene regulations, the safety of a wide variety of foods is dependent upon the maintenance of
correct temperature conditions in compliance with the principles of Hazard Analysis and Critical Control Point (HACCP). Generally, temperature is the main factor affecting the prevention of microbial food spoilage. In addition to temperature and storage time, the speed and extent of spoilage is affected by the type of food product, its composition, methods used during processing, contamination during processing and the nature of packaging. Temperature testing therefore performs a vital role in the protection of consumers and in compliance with food hygiene regulations relating to sandwiches, snacks, ready meals, prepared foods, and both chilled and frozen foods.
TEmpErATurE TESTiNg TEChNiquES Traditional methods involve the insertion of a metal probe into the food product in order to determine the temperature of the food; usually at the probe’s tip. In order to check the temperature of a food product, the probe is inserted so that the tip is in the centre of the food (or the thickest part) and left in place until the reading stabilises. After the reading is taken, the probe must be thoroughly cleaned and disinfected to avoid cross-contamination between samples. Crucially, if the food sample is affected by the
testing process (for example, if the packaging seal has been broken) it is no longer suitable for consumption and must be discarded. There are two main types of non-destructive
testing methods – remote infrared cameras and microwave thermometry. Infrared cameras are able to accurately measure the surface temperature of objects remotely. Their advantages are that they are non-destructive and fast, but their main disadvantage is that they
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measure the surface temperature, which is not necessarily the true temperature of the food, especially if the sample is within packaging. Instruments that employ microwave
thermometry have the major advantage of testing the whole product, producing an average temperature for the entire sample, quickly and accurately. Cerulean is the only manufacturer of commercially available instruments employing this technique for food testing, and the feedback from users of this equipment (Celsius range) is provided in the case studies that follow. New versions of this technology are being developed to improve efficiency and reduce payback periods even fur ther.
WASTE From iNvASivE TEmpErATurE TESTiNg The amount of waste resulting from invasive temperature testing depends on a number of factors. Firstly, the volume of food products being tested will vary according to the type of food and the individual process. Operators will need to be able to demonstrate that the frequency of testing is appropriate and that the samples being tested are representative of a batch. Consequently, the proportion of food going to waste following temperature testing varies considerably between different processing plants. Once a tested food product is discarded it can be dealt with in a number of ways. It may go
May 2019 Instrumentation Monthly
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