Product inspection in the food industry makes use of advanced technologies to aid in the detection of foreign objects in the product or weight irregularities that occur during and after the production and packing processes.
Metal detectors detect metal contamination, whereas X-ray systems detect a wide range of foreign materials, both metallic and non-metallic, such as glass, stone, and bone, and checkweighers ensure product consistency and regulatory compliance.
These procedures are critical for protecting consumer health, preserving brand reputation, and increasing operational efficiency by preventing external contaminants or defective items from entering the market.
Effective product inspection reduces the cost of recalls and guarantees regulatory compliance, promoting customer trust and the integrity of the food supply chain. Overall, identification of contaminants and precise weight control are critical components of a comprehensive food safety and quality assurance program.
Product Inspection Technologies
Metal Detectors
Metal detectors, which can identify ferrous, non-ferrous, and stainless-steel foreign objects, are an excellent choice for examining a wide variety of goods, from frozen meals to packaged snacks. Metal detectors measure the magnetic and conductive qualities of the packaged food under inspection.
Each inspected product contains intrinsic magnetic and conductive signals known as product effect, which vary depending on the type of product and packaging, for example, dry cereal has a low product effect, whereas wet foods such as canned soups have a significantly higher product effect due to their moisture and salt content.
A successful metal detector measurement ignores the product effect and responds solely to signals from impurities.
When a contaminant is discovered by the metal detector, it affects the product's magnetic and conductive signals, causing the detection system to activate a reject mechanism or stop the production line, depending on operational preferences.
In food manufacturing, the standard process involves processing incoming ingredients, combining them, cooking, molding, packaging, and storing. Contaminants such as debris from old blending blades or loose bolts and nuts can be accidentally introduced at any point during these processes.
To reduce contamination risk and achieve Hazard Analysis and Critical Control Point (HACCP) objectives for food safety compliance, metal detectors can be used at numerous stages of the process, from incoming raw material inspection to final packaging.
Metal detectors can be incompatible with metalized film wrapping due to the "package effect." Packages with metalized film pouches or metal containers might cause false rejects and interfere with the detection of contaminants because the signal produced by these packages overpowers the signal of tiny metal fragments.
As a result, metalized film packaging lends itself well to X-ray inspection. Additionally, environmental conditions can affect the performance of metal detectors during inspection of a product.
Magnetic fields from surrounding equipment, electrical interference from other machinery, and power supply variations can all affect the detector's sensitivity and accuracy. Finally, temperature and humidity conditions might affect the stability of the metal detector's electrical components, resulting in false rejects.
To mitigate these concerns, metal detectors should be installed in controlled surroundings, shielded from extraneous electromagnetic interference, and regularly calibrated to ensure dependable performance.
X-Ray Inspection Systems
X-ray inspection equipment creates an image of each package's contents, allowing for the detection of both metallic and non-metallic contaminants such as glass and rubber, as well as the identification of broken food pieces and missing parts.
Unlike metal detectors, X-ray inspection is unaffected by product or package effects, making it appropriate for a broader range of items and packaging materials, including those made of metalized film or aluminum foil trays.
Image Credit: Thermo Fisher Scientific – Production Process & Analytics
X-ray inspection devices can be used at all phases of the manufacturing process, from entering ingredients to final case packaging.
Given that food products are intended to provide a complete nutritional answer, they frequently contain a variety of nutrients and vitamins. This can further increase the possibility of diverse contaminants being introduced at any moment, from raw ingredients to final processing.
For example, imported meat may have metal shavings from prior processing stages conducted by the supplier, and vegetable harvests may unintentionally include stones and metal bits that could be overlooked before processing.
X-ray systems can serve a wide range of applications, but it is important to understand their limitations. One constraint is the product's density and thickness, which can impede X-rays and prevent the identification of very low-density impurities, such as thin glass, small glass shards, wood pieces, and thin plastics, among others.
For instance, if a product has the same density as a little piece of shattered glass, the X-ray equipment may be unable to identify the glass contaminant. Inconsistencies in packing shape might also impair the sensitivity and accuracy of detection.
For example, in a snack bag, the product distribution can move inside, resulting in false rejects owing to variations in package shape. High-speed manufacturing lines can also affect the resolution and accuracy of X-ray inspection, particularly due to shorter exposure times and motion blur in the image.
As a result, if the conveyor speed varies significantly, the same product may produce various detection results. Understanding these limits is critical when selecting X-ray systems for product inspection.
Checkweighers
Checkweighing, a complementary food quality method to foreign item identification, ensures that the weight reported on the product label corresponds to the actual weight of the package.
This prevents food manufacturers from underfilling packages, which can result in significant regulatory fines, or overfilling, which leads to unnecessary product giveaways.
Checkweighers are often placed after the portioning and packaging steps, with a final weight check often performed after case packing to ensure that the correct weight and packages were distributed.
Some checkweighers also offer feedback to operators on the filling process. For example, a manufacturer may specify a precise fill level or volume for a package, but with time, the filler may diverge from this target, resulting in overfill or underfill.
A checkweigher's capacity to assess data patterns, display how closely each fill coincides with the desired weight, and provide real-time feedback to the filling machine aids in production cost control.
This feature improves efficiency automatically while proactively assuring consistent product weight across time.
Environmental conditions and product buildup in the system are two potential limitations of checkweigher systems.
Checkweighers are susceptible to environmental variables such as vibrations, temperature changes, humidity, and airflow, which can impair weight measurement accuracy and necessitate mitigating methods.
Furthermore, material or product buildup on the weighing platform can lower the accuracy of weight measurements, but a cleaning operation can mitigate these impacts.
Quality Assurance and Regulatory Compliance
The food industry is essential worldwide and demands regulations appropriate to its size. Each country or region has its own regulatory authorities that ensure proper food safety protocols and public safety. A few of these entities are mentioned here to highlight their significance.
The Food and Drug Administration (FDA) in the United States and the European Food Safety Authority (EFSA) in Europe are two large authorities, among many others. These organizations prioritize safety and enforce the protocols that manufacturers must comply with to operate in certain locations.
In addition, some rules worth mentioning include the International Organization for Standardization (ISO), which has one of the most essential standards, ISO 22000: Food Safety Management System.
This sets the requirements for a food safety management system, in which an organization in the food chain must demonstrate its ability to handle food safety hazards so that food is safe for human consumption.1
The Hazard Analysis and Critical Control Point (HACCP) method is a systematic strategy used in the food industry to detect, assess, and control possible food safety hazards.2
These procedures ensure that food products are safe to consume and meet production standards. Product inspection technologies benefit the food sector by providing solutions for ensuring product safety and brand protection.
Product inspection can help businesses maintain track of both short-term and long-term data, assisting them with audits and tracking history.
Future Trends and Innovations
Product inspection manufacturers continually improve their systems to ensure industry and public safety. A noteworthy future trend is the combination of X-ray technology and Artificial Intelligence (AI) for sophisticated applications.
AI and X-ray systems are combined by applying modern algorithms and machine learning approaches to enhance the identification and analysis of faults and irregularities in food products, as well as facilitating complex computations and image processing.
Some applications include determining the correct orientation of a product within its packaging and categorizing/sorting different portions of a product. In addition, advances in X-ray image inspection are being made not only to detect inconsistencies in images, but also to examine segmented sections within a package for better analysis.
Conclusion
Product inspection technology, such as metal detectors, X-ray systems, and checkweighers, is critical for assuring food safety and quality.
Each plays an important function in identifying impurities, validating product weight, and improving overall quality. These technologies promote regulatory compliance and consumer trust by maintaining high safety standards.
References
- ISO (2018). ISO 22000:2018 Food safety management systems - Requirements for any organization in the food chain. (online) ISO. Available at: https://www.iso.org/standard/65464.html.
- Nutrition, C. for F.S. and A. (2020). HACCP Principles & Application Guidelines. FDA. (online) Available at: https://www.fda.gov/food/hazard-analysis-critical-control-point-haccp/haccp-principles-application-guidelines#execsum.
This information has been sourced, reviewed, and adapted from materials provided by Thermo Fisher Scientific – Production Process & Analytics.
For more information on this source, please visit Thermo Fisher Scientific – Production Process & Analytics.