Quality Assurance and Food Safety of Powdered Ingredients

Although there is still much to learn about the process of mixing solid particles, designers of industrial plants often fail to take advantage of available knowledge so that the best possible results can be achieved. The operation of a mix[1]er must be regarded as producing equilibrium between mixing and segregation; those mixers being used can be classified as either segregating or non-segregating. Components—or mix ingredients—to be used can be similarly classified. In addition, the selection of the mixer for a particular duty should be based on how materials tend to segregate; those that do should not be put into a segregating mixer. Further, care must be taken in the handling of a mixture to avoid segregation. In regard to powdered foodstuffs, we can distinguish three main “actors”: ingredients, mixers, and handling or materials management.

Role of Quality Assurance:

Quality assurance (QA) systems take a much wider view of what is involved in satisfying customer and production needs, focusing on the prevention of problems, not simply on their cure. Curing problems is expensive; quality cannot be “inspected into” a product.

A QA approach, therefore, includes the whole production and distribution system, from the suppliers of raw materials through management to the customer. QA systems should be documented in a simple way to show who has responsibility for doing what and when. The QA focus on prevention should mean that action is taken to meet a specification and prevent failures from occurring a second time. This is done by planning, management action, and agreements with key suppliers and other people in the distribution chain.

QA requires that staff is well trained and motivated. Workers are normally well aware of the causes of most problems, and when QA is used properly, they can resolve most quality problems within their control. It is the responsibility of business owners to ensure that the QA system together with any necessary equipment and information are available to the workers to allow them to exercise this control. Then the importance of QA becomes obvious when food safety is concerned.

Why Use a Powder?

The major reason for production in powdered form is simply to prolong the shelf life of the ingredients by reducing water content; otherwise, the ingredient will be degraded. Thus, the major function of the powdered form is to maintain the stability of the ingredient’s functionality until it is required for use, which is eventually in some sort of wet formulation.

Food safety and QA must be concerned with those manufacturing hazards affecting foods.

When dealing with powdered beverages, in most cases, the hazards—if the raw materials have been handled properly—are primarily physical in nature because such ingredients, due to their low water activity coefficients, do not allow for microbiological hazards.

The food industry still has processing problems and requires further basic research to understand processes and handle powdered foodstuffs, which means food safety and QA programs should be integrated into research for such developments.

For example, different product groups can be distinguished in the following ways:

Powdered products: 

• Powdered beverages (no fat)
• Soups (powder and garnishes, low in fat)
• Sauces and gravies (powder; sometimes garnishes; low in fat and often high in starch)
• Recipe mixes (low in fat, spices)
• Ready-to-serve dishes (cup products, pasta and rice preparations, big pieces)
• Powdered bouillon (high in salt)
• Seasonings (high in salt and glutamate) 

Agglomerated and granulated products:

• Vending soups (agglomerated powder)
• Food service sauces and gravies (agglomerated powder; high in starch)
• Granulated or agglomerated seasonings
• Instant bouillon (agglomerated or granulated powder, high in salt)

Tabletted and compacted powders:

• Bouillon tablets (hard and soft bouillon, high salt content, medium to high fat content)
• Sauces (tabletted sauces; high in salt, fat, and starch)

Powdered beverages are a group within the powdered products category that have simpler formulations to control because they lack fat ingredients, similar to other powders like spices. This condition raises fewer concerns with regard to their manufacturing and distribution than those where fat is involved. Mixes containing powdered and coarse particles, which often have different densities and shapes, tend to segregate during production and transport; this phenomenon must be viewed differently if the powdered formulations include fat. In cases where no fatty ingredients are used, mixing time becomes an important issue, such that the added mixing time and further handling of the different dry components allow additional segregation, and very often the homogeneity of the mix decreases.

Powder Components and Characteristics:

Powdered foods, including powder milks, dry-mix fruit drinks and juices, gelatin dessert mixes, starch-based pudding, tapioca-based desserts, “energy” mixes, and other sugar- and starch-based powdered formulations, tend to have diverse components, many of which with substantially different particle sizes and flowability characteristics. Please note that the above examples are products that are essentially fat-free. The reason for this segregation is due to the different mobility of the articles in the bulk state. However, there is no standardized and accepted method to simulate this segregation behaviour depending on the real movement of the powder during production and transportation, making any kind of measurement difficult. This situation creates a QA concern that must be approached individually in each product case, making the setting of quality control parameters—and testing methods—very difficult.

Measuring uniformity of a mix requires experience and must be specific to the product and manufacturing piece of equipment. Furthermore, a clear rule or processing procedure is needed for how to design the product and its production to avoid this segregation.

Formulation Innovations:

The powdered drink category is undergoing rapid changes, driven by exciting product innovations; technology exists to help overcome challenges in formulating with functional ingredients, and encapsulation technology is available to protect vital flavor components from degradation. Whether the products are powdered soft drinks or high-performance nutritional powders, they all must be hydrated prior to consumption, and their presentation (to the consumer) must be taken into consideration in any QA program. It is easier if individual servings are packaged for consumer use; the instructions on the packet will indicate the need to use the total amount of powder in the package to prepare the drink. Thus, if actual segregation of the ingredients does occur, this will not affect the finished drink. Yet, if the powdered beverage is being sold in a canister or jar, and in order to prepare a drink, water or milk must be added to x number of teaspoons (or other solid measurement) of powder, then the homogeneity of the product in the canister or jar becomes paramount. These conditions require a much “tighter” QA program, which begins with tighter raw material specifications and mixing times, and involves additional ingredients, climate control, and mixer designs, as well as manufacturing and packaging specifications. Only in this way will the proper ratios of powder to liquid be assured when and if instructions for preparation of the drink are followed. One other example that often occurs, especially if a child is preparing his/ her own chocolate milk using a powdered mix: The excessive amount of the powder in a glass of milk can result in a lack of dissolution of the powder, an over sweetened drink, an intensive chocolate-flavored (or other flavor) drink, etc.

Food ingredient powders will eventually be utilized in some sort of wet formulation. For powdered beverages, that functionality will depend on the powder particle and its interaction with water. Air is the cheapest food ingredient, followed by water, and many ingredients are applied to entrap more air and water by utilising their aeration and gelation properties. Such characteristics have been appearing in new dry beverage powders to show foam and/or similar characteristics upon the final preparation of the product.

What about Powdered Food Safety?

Food safety of dry powders is not given much attention because of their characteristic low water activity yet requires much more attention, especially because of the sourcing of materials and complexity of dry product handling.

Finally, because of the complexity of the total powdered foodstuff manufacturing process and the lack of a formal education for practicing engineers and food scientists, college-level courses must be established. Meanwhile, some courses are available, conducted mainly by industry consultants and certain academic institutions. The final question is: If there is a need for more educational opportunities, when are the educational institutions going to meet it? There is a potential for a worldwide distance learning program dealing with aspects of powder science and technology, which should include specific food safety and QA concerns.

Establishing an adequate food safety and QA program for powdered food products requires it to be specific to the product (formulation considering available specifications of the ingredients), its manufacturing (handling, mixing, and packaging equipment), its distribution, and its ultimate use by the consumer. The needs and controls required cannot be generalized.

The complexity of the overall processes of manufacturing and distributing powdered foods is not typically science- or technology-based, mainly because of a lack of formal educational courses. The process has been conducted more as an art, with experience and hands-on learning. There thus exists an opportunity for more research and development with the objective of technologically improving the process. Consequently, inclusion and updating of food safety and QA procedures in manufacturing must constantly be stressed.

Powders in the Food Market:

The powdered beverage market has grown beyond traditional sugar-based drinks, basic protein shakes, and sports energy beverages. Functional beverage and food marketers see powders as a new opportunity to expand their delivery formats and offer convenience, better value, and an environmentally friendly solution to ready-to-drink options. Supplement marketers offer increased value by adding flavor, function and hydration components, creating delicious powdered drinks for consumers to enjoy. However, crossing over to powders has its unique design and development considerations. Expert powder manufacturers use a host of technologies to meet the functional and sensory expectations of both clients and consumers. These technologies include unique food safety and QA considerations to ensure the uniformity of the finished product as it is consumed.

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