Ensuring Safety and Quality in the Production of Infant Formula
Across the dairy, food and beverage industries, food safety is of paramount importance, but nowhere more so than in the production of early life nutrition products for babies and young children. SPX FLOW has had a great deal of experience in working with manufacturers of infant formula and this article considers some of the critical factors to ensure quality and safety in this sensitive production process.
From experience, SPX FLOW knows that the best processing results are achieved through co-creation of production lines with its customers. This close partnership encourages the sharing of expertise and specialist knowledge; gives clear understanding of expected key performance indicators (KPIs), drives project efficiency, and offers the potential to exceed system performance expectations. The result is that everyone wins – the food manufacturer, the technology provider and the consumer.
Infant formula or other powder based early life nutrition (including baby milk, follow on milk and growing up milk) require the strictest food safety and quality standards. To meet the demands of this market place, producers want absolute certainty in hygiene and food safety while protecting the nutritional value of the product. Other factors that impact powder quality classification include the level of scorched particles, solubility index, color, structure and other functional parameters. These are important considerations in the design of a processing line and the final value of the infant formula.
Infant Formula Processing
There are many stages in a complete process line for producing infant formula and consideration needs to be taken for the type of ingredients, their quality and their application (liquid, powder in wet or dry compounding). Each stage requires careful design to ensure the highest quality and food safety are maintained and that the plant is efficient, flexible and reliable. SPX FLOW uses advanced technology with the experience it has gained over many years in serving this industry to optimize all aspects of infant formula production.
The first main step in producing infant formula is mixing. The quality of mixing has a big impact on end product quality and, where solids and liquids need to be combined, good dispersion is essential. To optimize quality and hygiene, SPX FLOW recommends the use of a vacuum mixer such as its innovative Flex-Mix Instant mixer.
There are many production benefits to a closed vacuum mixer including reduced mixing time, greater energy efficiency, reduced waste and easy maintenance; but for the purposes of this article let’s look at quality and safety issues it addresses:
During vacuum mixing, powder is sucked in from a closed powder hopper or bag system. Using the vacuum level in the tank, the powder is washed out directly into the circulating liquid below the liquid surface; ensuring dust is not released into the surrounding atmosphere. The wet and dry phases of the process are thereby completely separated, reducing the risk of bacteria formation. The use of a vacuum prevents air from entering the mixture, reducing undesirable effects such as oxidation, nutritional degradation and discoloring. The high shear pump is located at the side of the mixer which gives added ergonomic benefits including easy access and a safe environment for maintenance.
The Flex-Mix Instant creates high shear with a forced vortex which ensures fine emulsions that enhance product quality. It further offers a unique, patented valve arrangement that uses three valves at the powder inlet that automatically pulse the powder in using opening and closing sequences with delayed set points between the valves. This prevents any back flush of liquid into the powder supply line and ensures seats and seals are kept clean and dry for long periods; which not only reduces hygiene risks but also secures a stable process with extended lifetime, fewer blockages and less downtime.
The next main stage in the infant formula manufacturing process is an evaporation stage which is an energy efficient method of increasing total solids (TS) of the formula. An evaporator works by adding heat to the solution to a point where liquids turn into vapor and can be separated. The type of evaporator selected will depend upon local energy costs. Mechanical Vapor Recompression (MVR) evaporators use a mechanical compressor or fan to compress the vapor and need ample electricity supply. Thermal Vapor Recompression (TVR) systems use steam jets for compression and require a ready supply of steam to be available. The cost of steam versus the cost of electricity is, therefore, one of the primary considerations in selecting an evaporator for a particular plant.
The evaporator temperature is related to the evaporation pressure. System parameters are adjusted to optimize for product concentration and product quality as well as energy efficiency. Some plants select to use two evaporators which enable continuous production as one line is cleaned, the other is in operation; facilitating 24/7 production.
Using an evaporator reduces the energy required for spray drying and also helps extend the shelf life of the final product by removing occluded air from the fluid.
SPX FLOW Instant Infusion heat treatment technology is widely used for the production of Infant Formula because of the levels of food safety it offers while protecting nutritional quality. The process is a very gentle form of heat treatment that involves preheating to 75-85°C using plate and tube heat exchangers followed by rapid super-heating to around 140°C using steam infusion. The product is distributed in the form of thin strings into a chamber and is instantly heated by direct steam.
A short, accurate holding time in the range of 0.1-0.5 seconds avoids damage of essential amino acids, proteins and vitamins that can result in nutritional degradation, unacceptable flavor changes and the formation of burnt particles. The high temperature gives exceptional kill rate and eliminates even heat-resistant bacteria spores. This makes the process ideal for Infant Formula by protecting the quality and nutritional value of the product while ensuring the highest standards in food safety.
Optional Cavitation Stage
The SPX FLOW Cavitator™ uses a rotor with precisely machined cavities spinning in a liquid chamber that generates controlled cavitation. The process increases spray drying efficiency by reducing fluid viscosity and enabling an increase in solids level as well as adding microstructural conditioning that optimizes particle structure, size and distribution of solid components.
Combined High Pressure Pumping and Homogenization
Homogenizers are not complicated pieces of equipment but correctly designing and applying them requires skill and understanding. Homogenization helps with controlling final product quality, especially the levels of free fat which effect stability of the infant formula. The Homogenizer acts as a high pressure pump feeding the product to the spray dryer.
The main part of the latter processing stages for infant formula production involves a spray dryer. This process is vital to final product quality and gives complete control over characteristics such as density, moisture content, powder properties and sensorial aspects. As there is no further heat treatment, it is imperative that product contamination is not allowed. To this end, the air supply to the dryer uses HEPA filters and systems are designed for straight forward cleaning, to minimize the risk of cross-contamination and to maintain food safety.
The Anhydro Triple A spray dryer incorporates an internal fluid bed. This supports e forati of strong powder agglomerates before entering the external fluid bed which further dries and cools the formula ready for packing. This efficient cooling of powder helps maintain quality during storage.
Both internal and external fluid beds in the drying stages of the process are self-emptying. This helps minimize contamination at product changeover, reduces loss of powder in the system, and also ensures powder is out of the system for a more effective clean-in-place (CIP) cycle.
During spray drying the very fine powder and air is transferred to cyclones for separation. The powder fines can be returned to various positions in the process via a flexible fines return system which can further improve agglomeration.
Drying of infant formula powders also presents an explosion risk and comprehensive safety equipment is required to ensure protection of plant and personnel. Rupture chambers, vent ducts, firefighting systems, CO detection systems and suppression systems are all included in the design of a spray dryer. SPX FLOW also offers an early warning camera software system on its Anhydro spray dryers. This detects powder build-up on spray nozzles and gives a potential early warning to operators as there is a risk these may cause fire – enabling action to be taken to avoid emergency shutdown.
Automation is an important part of an infant formula processing line. Modern systems including the FactoryExpert™ automation solution help ensure reliability and optimized operating costs but they also add flexibility, traceability, assist with the control of quality and enhance overall operational safety of the system. Full integration with enterprise resource planning (ERP) systems accurately measures performance and provides real-time data to monitor product quality and need for proactive maintenance to keep the system running reliably and consistently.
The production of powder based nutrition involves many process stages, all which require careful integration and design to ensure the desired product quality and maximum food safety is achieved. To ensure all KPIs are met and high consumer confidence in a product brand, a close working relationship between processing companies and technology providers has been shown to yield the best results – offering efficiency, consistent quality and assured food safety at every stage of the processing line.
Each stage of the process requires understanding of the technology and the internal impact it has on the infant formula to maintain and control its desired characteristics. In SPX FLOW’s experience, achieving the highest standards of safety and quality does not mean manufacturers of infant formula need to compromise on production efficiency and flexibility. Systems are designed to meet the needs of today and the future, covering areas such as advanced powder nutrition for all life stages. Features and functions that provide food safety and plant safety are integrated into the plant throughout production stages, brought together with modern automation systems that help protect and control the whole process.