Real-Time Process Monitoring in Food and Beverage Manufacturing

As a result of 2016 planned amendments to the FDA’s Food Safety Modernization Act (FSMA), the food and beverage industry is facing many challenges. Chief among them is the need to implement cost-effective preventative controls to ensure consumer safety. These regulatory changes, along with consumer pressures, require a fresh look at food safety and shelf-life management, product quality, process control and product traceability.

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As a result of 2016 planned amendments to the FDA’s Food Safety Modernization Act (FSMA), the food and beverage industry is facing many challenges. Chief among them is the need to implement cost-effective preventative controls to ensure consumer safety. These regulatory changes, along with consumer pressures, require a fresh look at food safety and shelf-life management, product quality, process control and product traceability.

Increased LED adoption improves real-time monitoring applications

Spectroscopy is a proven analytical technique for process monitoring to ensure food quality and safety while providing the added benefit of manufacturing optimization. Spectroscopic analysis is fast, safe, and non-destructive, providing data with fewer errors while maintaining sample integrity. These sensors are less costly than other types of instruments, such as those based on chemical analysis, with light source replacement the only recurring cost.  Spectroscopic sensors are typically used for inline monitoring, where devices are mounted directly in the process flow, because of their compact size. This eliminates the sample wastage of other monitoring methods where process flow is diverted into special piping and provides cost savings and productivity gains over grab sampling where samples are manually collected and taken to the lab for testing.

The specific spectroscopic method used—UV-Vis, FTIR, Raman—is determined by the sample characteristics. The widest application range is covered by UV-VIS spectroscopy, which is ideal for the quantitative and qualitative analysis of samples in absorption, transmission and reflection measurement modes. Many of these measurements are taken with the deep UV, or UVC, wavelength range from 200 nm – 280 nm. Traditional UV-Vis equipment uses deuterium or xenon flash lamps, which provide adequate light in the UVC wavelengths, but require costly filters and bulky power supplies. Leading sensor manufacturers are seeking alternative light sources, such as UVC LEDs to satisfy miniaturization and cost reduction requirements from the industry.

Ensuring ingredient quality

Most food and beverage producers require a Certificate of Analysis (COA) for ingredients, but one key component that is often overlooked is water. Water supplies are known to vary over time with regard to taste, odor, chemistry, and the presence of microbes, which can potentially alter the desired final product. Food and beverage producers assume the municipal water they use in their processes is adequately monitored, analyzed, and determined to be safe. However, as food processing expands to a multi-national footprint, monitoring water quality at the plant becomes more important for product consistency. In many countries, local water utilities have limited monitoring capability or employ unreliable analytical techniques. In addition to the incoming water quality, it is common for the process water to become loaded, or contaminated, with organics during manufacturing. Total Organic Carbon (TOC) analysis is a basic test that can determine the quality of water through the entire manufacturing operation.

TOC can be measured by chemical methods or by absorption spectroscopy at 255 nm. However, chemical methods based on persulfate oxidation are expensive, require more time between measurements, and have high consumable costs. Consequently, UV spectroscopy using xenon flash lamps has become the preferred method of monitoring. Although these high-quality instruments offer precise, accurate measurements of multiple parameters of water quality, they provide more functionality than what is required for a typical manufacturing plant.  By switching to LEDs, TOC sensor costs can be further reduced.  Engineers can achieve the same benefits of xenon flash lamps for a subset of parameters by using UVC LEDs, along with a less costly detector and power supply. High-performance UVC LEDs offer linearity of measurement* that matches the performance of expensive xenon flash lamps, at 40 - 80% of the cost.

*Linearity of measurement refers to the correlation between the optical methods of water-quality measurement with a reference method, typically a chemical measurement in the lab.

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UV spectroscopy can perform inline quality control for other ingredients in food and beverage, such as protein or caffeine. Understanding these levels ensures that products meet regulatory requirements and can, in some cases, impact the bottom line. Protein content in raw milk can vary significantly and is dependent on a number of factors such as season, stage of lactation, breed, and cow diet. As powdered milk is priced based on protein levels, accurate measurements can significantly impact revenue. In addition, by knowing the protein content of raw milk,  dairy producers can decide if the milk is fit for producing high protein—and high margin—products such as cheese and increase processing yields. Absorbance measurements at 280 nm can be used to determine the quantity of protein in milk in-line and eliminate the need for grab sampling, sample transport and preparation, and analysis.  

Ensuring food safety

Clean in place (CIP) systems make food safe through the effective washing and rinsing of equipment. Closely tracking the amount of chemicals used in the process can positively impact operation costs and ensure consumer safety. Overdosing can result in corrosion and increased cost, while too little disinfectant can lead to contamination and jeopardize food safety. By measuring bacterial concentration with UV spectroscopy, operators can verify effectiveness of cleaning between manufacturing runs.

Bacteria concentration in the rinse water can be measured using UV fluorescence spectroscopy, a method that is as much as 1000 times more sensitive than absorption spectroscopy. This method is capable of detecting concentrations in the part-per-billion levels. UVC LED-based instruments can measure the tryptophan signal to validate CIP systems to control the duration of cleaning, ensuring the right amount of chemicals are used—not too much, not too little.

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As consumer and regulatory pressures increase around food safety, the list of tracked compounds and their allowed concentration levels is expected to be controlled more stringently in the future. UVC LED-based sensors can provide system configurations with lowest detection limits and highest precision over other non-optical methods. This new class of sensors will help the food and beverage industry monitor processes in real-time, and thus maintain food safety, improve quality, and optimize manufacturing for the best return on assets.

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