A portable measurement device for rapid food quality testing

A portable measurement device for rapid food quality testing

With the freshdetect BFD-100 portable measurement device, meat quality can be tested on site within a matter of seconds. The entire value chain benefits, from slaughter facilities and meat processors, to retailers, inspectors and laboratories, and more importantly consumers.

When microbiological food spoilage occurs, manufacturers and retailers suffer huge losses, consumers are exposed to serious health risks and vast amounts of food are wasted. In the age of the internet and social media, reports of food safety issues can spread like wildfire. Furthermore, slaughter operations and meat processors must comply with strict hygiene guidelines and requirements, by implementing reliable quality control measures stipulated in a wide range of government regulations. Businesses are also under pressure to ensure high product quality and a long shelf life, whilst avoiding excessive food waste.

To satisfy these numerous demands, slaughter operations and meat processors must be able to test the quality of their meat products as rapidly as possible – at every step of the processing chain, but this can be challenging using traditional methods.

To date, retailers and sellers have relied on sensory methods to test meat quality in the receiving area. This includes visual inspections, checking for odours and measuring the temperature. This is then followed by individual random samples that are extracted and sent to a laboratory to be analysed. Retailers typically have to wait several days to obtain the results, thus eliminating the possibility to react while the meat products are being handled. This leaves them with two choices: take proactive measures to dispose of potentially tainted products or accept the risk of low-quality products ending up in the hands of the customer. However, a portable measurement device could present a third possibility.

A need for rapid tests

Given that government-stipulated microbiological tests are too time-consuming and cumbersome, companies need a practical, reliable and cost-effective rapid test that can be utilised anywhere along the value chain. This type of test provides transparency and allows each step of the production process to be analysed and optimised.

The freshdetect BFD-100 portable measurement device satisfies these requirements by determining the quality of meat within a few seconds by means of the total viable count (TVC). This reliable and cost-effective portable measurement device is providing results with accuracy comparable to conventional microbiological tests in the lab. The BFD-100 is therefore, the first device to enable quantitative, comprehensive and preventative quality and process control measures, from the slaughter facility to the meat counter.

Retailers and sellers can now inspect all of the meat products on-site and if necessary, immediately remove any affected batches. The device can furthermore be used to analyse and optimise production flows, benefitting the company through lower production costs, extending the shelf life of the meat products and providing consumers better quality.

About FreshDetect

The BFD-100 portable measurement device was developed and produced by Munich-based FreshDetect GmbH, a developer and marketer of innovative measurement devices and solutions for rapid and tight quality control in the food industry. The people at FreshDetect are experts in the fields of spectrometry measurement technology and microbiology and boast extensive experience in the area of food processing technologies.

Company origins

In response to a series of spoiled meat scandals in Germany over the past decade, a research alliance was formed comprising the Fraunhofer Institute for Reliability and Micro Integration IZM, the Ferdinand Braun Institute, the Leibniz Institute and the Max Rubner Institute. The alliance was tasked with researching rapid test methods designed to avert such scandals in the future. The researchers eventually demonstrated a relative correlation between bacterial burden and the fluorescence signature.

An initial prototype portable measurement device was developed in a follow-up SME project. In 2013, the project resulted in a spin-off company, FreshDetect GmbH, which then developed the same-named de portable measurement device and readied it for production. The capability of the BFD-100 to measure the TVC and temperature of meat samples within three to five seconds with laboratory precision has meanwhile been scientifically validated.

The freshdetect BFD-100

The portable measurement device is a patented mini-lab, which detects the bacteria count by means of fluorescence spectroscopy. It is non-invasive, cost-effective, digital, simple to operate and can be used anywhere. Fluorescence spectroscopy can be used to immediately draw precise conclusions regarding the microbiological quality of food products in every step of the process with minimal effort. This opens up new opportunities for creating a tight network of measurements across the entire manufacturing process. This unprecedented volume of real-time data permits an end-to-end analysis of the manufacturing process for the first time, thus making it possible to optimise quality and costs.

The BFD-100 rapid test is simple to use. The measurement probe is placed on the surface of the meat for five seconds, after which the TVC, which is measured in CFU/cm2 or CFU/g, is immediately displayed and stored in the device. The device also records the temperature, date, time, (sequential) measurement number and other information. The data can be transferred to a PC via USB cable or directly to a management information system using a bluetooth interface. The portable measurement device is easy to operate, clean and calibrate.

The BFD-100 emits an intense blue light on the surface of the meat, which is then captured with a spectrometer. The signal contains fluorescence signatures that correspond to the surface bacteria and the meat matrix, including fluorescent porphyrin, which feature characteristic wave lengths in the ‘green-red’ range. The device then analyses the intensity and wavelengths of the light and determines the TVC, calculated in CFU/cm2 or CFU/g, using special algorithms. Referred to the calibrations sets, these algorithms correspond to a specific type of meat and packaging, two parameters that have a major influence on bacteria growth.

Creation of the calibration sets

The algorithms couple the measured fluorescence spectrum with the lab-based TVC measurement. Calibration thus requires capturing the fluorescence spectrum with the BFD-100 as a first step. The TVC of the same meat sample is then measured using the conventional, DIN 101061-compliant laboratory method. This step is repeated with further samples. The key is to collect a statistically-relevant amount of data – so that a basis is created that closely represents an average value. Prediction models are then developed from this data and are validated with additional samples.

Given that the freshdetect BFD-100 measurements rely on conventional microbiological methods as a reference, in theory, the forecast accuracy of an individual measurement cannot be higher than the error tolerance level of the microbiological reference method and because a significantly higher number of samples can be tested with the BFD-100 portable measurement device at no additional cost, an even more accurate analysis of the actual situation is possible.

Operating the device

If the BFD-100 is ready to be used, the user only needs to power it on and enter a PIN. A reference measurement then has to be performed, after which the start screen appears. This takes around five seconds and must be carried out once a day to calibrate the device. If the device is restarted, the reference measurement is not required.

Once the start screen appears, the user places the measurement probe on the sample and presses the measurement button. After three to five seconds, the TVC, calculated in CFU/cm2 or CFU/g, appears on the screen. The device also displays the sequential measurement number and the calibration setting for the product type, such as minced meat. Relying on experience or a defined threshold value, the user then knows if this measurement value is appropriate for the specific product, whether the meat has to be processed for a different purpose or disposed of.

To support more in-depth analyses or a series of tests, such as for process optimisation or supplier evaluation, the device can store up to 2,000 measurements, which can be exported in a file format like excel or transferred to an ERP system.

BFD-100 fields of application

The cost-effective, rapid and accurate measurement method makes the BFD-100 portable measurement device suitable for any application where detection of the TVC of meat is required. Slaughter operations and meat processors can use the device along the entire processing chain. In slaughter and cutting operations for instance, it can serve as a tool for drawing conclusions about hygiene conditions, or to substantiate hygiene analyses and management decisions. By utilising the BFD-100 in the receiving area, companies can immediately identify poor quality products that have to be rejected or to determine the best way to process the meat. With its minimal on-going costs, the BFD-100 is suitable for testing a large percentage of the delivered products. Apart from monitoring hygiene conditions, the TVC analysis also reveals packaging problems. And in the shipping area, it provides a quality guarantee when handing the product over to the customer. Slaughter and meat processors can thus determine the TVC at every step of the process and optimise their processes accordingly.

Because the BFD-100 is a portable measurement device, retailers have the opportunity to track the quality in the receiving area, as well as at the point of sale on a permanent basis. Waste and losses are minimised as a result. Apart from food retailers, restaurants can also use the BFD-100 to test food products upon delivery and immediately notify the supplier of any issues. Consumers thus enjoy guaranteed quality, in addition to protection against the health risks of contaminated or spoiled meat products.

Even laboratories can utilize the BFD-100, such as for analysing a selection of incoming samples. The rapid test results also allow labs to determine the most suitable dilution step for the microbiological analysis, thus saving time and money.

Food inspectors also benefit since the simple and rapid test method allows them to analyse a much larger number of samples compared to conventional tests. In a survey carried out by the University of Leipzig; food inspectors had a predominately positive stance toward the BFD-100 rapid tests, emphasizing its usefulness as a line of reasoning and for making on-site decisions at companies undergoing inspection.

Slaughtering and cutting

One concrete example that illustrates where the BFD-100 is useful in slaughter and cutting operations is when a production line is retrofitted or replaced. This is because it is difficult to ascertain how reworking a product line impacts product hygiene, costly measurements are required to ensure that the original best before date can be guaranteed. One option is to establish several “test days” quarterly in order to analyse the microbiological status of the products over the course of one production day. This would include a fixed number of measurements per hour. Relying on existing laboratory methods to determine the TVC quickly drives up costs, which can be significantly reduced by utilising the BFD-100.

Because meat can be contaminated by a variety of sources, slaughter operations maintain clear guidelines aimed at minimising the impact. Despite explicit instructions however, employees sometimes fail to observe these guidelines and whilst most contamination is not visible, it still exists. This makes it difficult to detect without microbiological analysis and increases the risk of the contamination spreading to the equipment, surfaces, hands and therefore across the entire production system.

An advantage of a portable measurement device such as the BFD-100 is that it can be used to detect contamination early enough to remove the affected products from the processing chain. If contamination has already spread, it can be used to pinpoint the initial source, thus revealing exactly which products are contaminated and at what step the contamination occurred.

Receiving

Analysing the overall quality of a palette, such as four sets of eight boxes, requires examining more than one box from the stack. Testing at least three boxes from three different levels of the palette provides a more accurate assessment for instance. The analysis should include an examination of the parameters defined in the specification, such as; fat content, the cut, unusual odours, freshness and adherence to microbiological thresholds.

If each of the boxes has 20 cuts of meat for example, the palette contains a total of 640 cuts (4 X 8 X 20). Three boxes then yield 60 cuts of tested meat, or roughly 10% of the total palette. At a cost of between €5 and €10 to test each sample, this leads to a total cost of between €300 and €600 to analyse one palette. If a truck delivers 15 to 32 palettes, the costs to analyse the microbiological quality of 10% of one shipment can run between €4,500 and €19,000. The vast majority of these costs can be avoided by using the BFD-100.

Storage and cooling

Cooling generates significant costs for companies in the meat industry. The BFD-100 portable measurement device can be used to determine how product quality is impacted when cooling temperatures are modified. Although microbiological tests can be utilised in this case, they come with high costs since multiple measurements are needed to develop a statistically-relevant assessment. By using the device however, the quality manager can perform continuous measurements to assess the impact of changing the temperature in the cooling storage, without delay and without the burden of additional costs. And because the BFD-100 measurements are non-invasive, the tested products maintain their value.

Cutting and processing

Products are taken from the production process several times a day and then analysed. The aim is to determine if the monitoring sensors still react properly to foreign objects or whether the requirements for temperature and packing conditions are being met. Since these samples cannot be returned to the processing chain without determining the bacterial burden, they are frequently collected and then discarded. Using the BFD-100, the company can verify the bacterial quality and continue to process those products deemed to be satisfactory.

Another scenario involves an unplanned expansion of production due to higher demand. The additional production time is taken from the scheduled cleaning window, which could result in bacterial plateaus on surfaces and increased moisture. Both of these factors can lead to an unplanned, higher bacterial burden – a scenario that was not taken into consideration when establishing the best before date. The quality manager must now decide if expanding production at the expense of the cleaning cycle is acceptable with respect to the hygiene conditions and what impact this situation has on the best before date.

Immediate test results using the BFD-100 allow the quality manager to determine the impact on the hygiene conditions in real-time, monitor the extra production shift and confirm adherence to the hygiene standards.

Packaging

One concrete example in the area of packaging is illustrated by the best before date of minced meat. A minced meat producer is competing for the business of a food retailer, where the best before date is an important aspect of the specification. In the retail food industry, roughly 10% of all food products are discarded because the best before date has expired.

Because there is no further room to adjust the price, management is planning to offer the potential customer a two-day extension of the best before date. The proposal would extend the normal seven-day sales period by 25%. This would have the effect of reducing the retailer’s volume of discarded meat by 7.5%. In the retail food industry, roughly 10% of all food products are discarded because the best before date has expired. A typical supermarket runs through around 750kg of minced meat a month. At a price of €4.50 per kilo, the retailer can then save around €1,000 per store. The only way to extend the best before date is to know the precise bacterial burden of the meat. The BFD-100 offers the opportunity to test all of the products before they are shipped, and to determine if the planned extension of the best before date can be guaranteed.

Optimising the process chain

The freshdetect BFD-100 portable measurement device is the first device to enable rapid detection – within seconds – of the TVC along the entire commercial meat processing chain with accuracy comparable to laboratory-based TVC tests and with nearly no on-going costs for the device.

This combination of immediate results, cost-effective measurements and high degree of accuracy provides companies new opportunities to optimise their workflows at every step of the process whilst creating a wide range of opportunities to reduce costs and ensuring better quality and safer food products.

Alternative methods

Conventional microbiological processes, such as the spatula and pour plate methods, require not only extensive effort, but also trained personnel – to ensure regulation-compliant execution of the tests. Although rapid methods such as impedance, bioluminescence-based ATP measurements and fluorescence-based flow cytometry provide automated measurements for the most part, high procurement costs and the on-going costs for the media and enzymes make these approaches unattractive. Furthermore, they destroy the products since they require extracting samples.

Fluorescence spectroscopy, in contrast, offers a non-invasive way to detect the bacterial density in real-time. In principle, it can measure through packaging films, whereas FT-IR-spectroscopy is not capable of that. Raman spectroscopy offers yet another alternative for testing through film packaging. The downside is that it’s unsuitable for measuring TVC on flat surfaces. With fluorescence spectroscopy and NIR hyperspectral imaging, researchers have demonstrated through a series of correlation models that it’s possible to estimate the amount of surface bacteria under lab conditions. To do that, various information has to be extracted from the spectra and analysed with algorithms.

The added value

Compared to conventional microbiological tests, the BFD-100 offers clear advantages for controlling the quality of meat products. By supplying measurement results within seconds, the device provides reliable information regarding product freshness and hygiene directly on-site, in effect leading to quality control measures that are integrated into the production process. Through this approach, companies conserve natural resources because they have the information they need to decide, during the manufacturing process, whether a product is ready for the retail shelf or more suitable for other uses. In situations such as disruptions to the cooling chain for instance, product returns or rejects no longer occur as a precautionary measure, rather only in cases where they are justified.

Consumers also benefit from access to safer products, this is because, in contrast to conventional tests, the BFD-100 permits a higher sampling rate. And by performing the measurements directly on the product to be sold without using expendable materials, companies contribute to a more sustainable environment and conserve their own resources. The advantages of the non-invasive measurements – even through packaging films – makes the BFD-100 an interesting proposition for health inspectors as well because they can determine the total viable count directly on-site, without waiting for the test results. This leads to a higher sampling rate whilst keeping the laboratory tests to a reasonable number. There are still other positive aspects of utilising the BFD-100. The rapid tests make it possible to objectively determine the best before date and to establish whether the meat is suitable for processing and consumption. This automatically leads to less food waste and other positive influences related to the climate, environment and society.

FreshDetect plans to expand its fields of applications to other food products, from fish and dairy products, to fruits and vegetables. The focus will include not only bacterial contamination, but the detection of pesticides, herbicides, origin, ripeness and other factors. It’s conceivable that a portable measurement device like the BFD-100 will one day replace the Petri dish for detecting the TVC, or even allow the consumer to test the quality of fresh foods directly in the store.

Oliver Dietrich, CEO
FreshDetect GmbH
+49 89 3249 39210
oliver.dietrich@freshdetect.com
https://www.freshdetect.com

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