Making coated foods demands process control

The modern consumer shows a clear preference for convenience. It combines the obvious demand for safe, healthy and tasty food with easy to prepare and variation. Food processors responded by providing a wide range of choices, including products that were given an extra flavour and a mouth-watering appearance by means of a coating. Product differentiation often increases sales but can be a burden for the food manufacturer. It demands a high level of efficiency, flexibility and above all process control.

By Wiebe van der Sluis, Doetinchem, the Netherlands

It is widely known that edible coatings can improve the quality of fresh or frozen processed meat, poultry, and seafood products. Coatings first of all create a typical taste and texture. But they also slow down moisture/weight loss, reduce lipid oxidation and discoloration, and enhance product appearance in retail packages. Furthermore they eliminate dripping, seal in volatile flavours, and function as carriers of food additives such as antimicrobial and antioxidant agents.

Food processors appreciate these positive characteristics and can choose from a long list of coatings to prepare a wide range of foods, including meat, poultry, vegetables and meat replacers such as Valess and Tivall. These coated products are in high demand by caterers, restaurants and food retailers. They prefer large, often frozen, volumes of palatable and easy to prepare products with a highly standardised structure, size and weight. In addition, the consumer of tomorrow demands safe and healthy food, but also wants convenience since the busy lifestyle does not include spending many hours on preparing lunch or dinner. Coated food can meet all those desires.

Fresh and frozen production
The many coating options available today generate opportunities for food processors to distinguish themselves from their competitors by creating unique products of top quality.

Numerous food companies have taken on this challenge and choose either to specialise in the production of (deep frozen) bulk products at high capacity and or the production of lower volumes of fresh/chilled products with the possibility for fast reaction to a change in consumer preferences.Fresh and chilled food producers frequently deal with high product features at lower volumes for a wide range of products. They face a short response time when market demands change. This usually necessitates flexible production lines with capacities ranging from 500-2000 kg/hr. Formed or natural substrates have to be of top quality and when using a coating it has to be appetising and supporting the look of the end product. Producers therefore have to make use of a high quality batter and end-coating.

Bulk producers mainly focus on the frozen food markets both in retail and food service and usually choose for a less flexible line to deliver just a few commodity foods, like formed chicken fingers or tenders, that can be kept for quite some time in stock. Further differentiation between processing line solutions is determined by the market segment the producer delivers to. Markets asking for a low margin bulk product with less critical product quality require a maximum cost focus and maximum production efficiency. This usually results in a less flexible high capacity line in a traditional form-coat-fry-cook set-up. Such a simple line can operate with maximised line output and allows using relatively low cost coatings. All what counts here is high speed (at a capacity of up to 6000 kg/hr) and maximum utilisation of the machines.

Markets however that ask for high product quality and distinct product differentiation, may require a more complex line that is called innovative line set-up. In this type of line, the cooking step is moved in front of the frying step with an additional pre-dust step to bring in a stronger bridge between substrate and batter. This results in an improved texture and moisture of the substrate, more crispy coating and moreover an improved product yield of 2-5%. Counter side of this line is that the product loading and line transfers are more critical, capacity utilisation is a bit lower and it requires a specific high quality pre-dust step resulting in a higher cost price of the coating.

Flexibility in production lines
Focusing on flexibility, optimising substrate and coating use as well as uniformity in weight, size, taste and colour of the end product is of utmost importance, especially for companies that operate in the top segment of the food market. CFS (Convenience Food Systems) aims to offer producers the tools to prepare and know the characteristics of the substrate before it can be covered with the right amount of pre-dust, batter and top coating.

Pre-dust and batters play an important role in reducing fluid loss, holding the end-coating and oil absorption during frying. Knowing the specifics of the substrate and coatings prior to and during production is important for process efficiency and the quality of the end product. Current production lines therefore make more and more use of process and product control systems to ensure a uniform high quality end product at the highest productivity level.

Product differentiation includes a frequent change in products and production processes. The desired flexibility has to go with a perfect plant infrastructure and layout, as well as the availability of handy machines that can quickly be cleaned and changed for other applications. Within a coating line this means that machines have to be easy to manage, can deal with a wide range of coatings and can run at high capacity for various applications. The CFS OptiFlour is one of those machines. It is very easy to operate and all process settings can be adjusted from outside the machine, even during operation. The control panel provides all-important information.

The coating supply is controlled by an adjustable top and bottom belt-drive system which runs with seasonings, fine pre-dust flour, fine- and medium crumbs, and sticky seeded flours. Attention has to be given to accessibility and easy cleaning. The closed construction minimises dust production and allows the connection with the factory’s existing exhaust system. This creates a dust free working environment and puts an end to the inconvenience of blocked blower pipes and minimises cleaning the room after production. The dust taken with the air is separated and can be re-used without interrupting production. An important feature of this machine is that it can be used for bulk as well as speciality products.

Minimising down time losses
In order to remain competitive both bulk and fresh/chilled producers have to take care of the overall efficiency inside their plant. At the end the only thing that matters is the cost per kg/pack produced. This puts the pressure on them to look at the logistics inside the plant and the capabilities of their machines. Nobody wants to loose the battle due to low machine capacities to many down time hours while switching products or product losses from rest product in machines or uneven distribution of the coating.

Down time and product loss is always a critical element in the production of any product. This forced food processing machine manufacturers to always look at these issues when designing new systems. CFS made it even one of the main goals of their operation. Their “Lifecycle Performance” approach is meant to increase their customer’s performance over time and initiated the development of new production and control systems. It allows them to assist customers in improving their performance.

Full process control
Modern food producers always have to think about process efficiency, minimising costs, maximising product quality and optimising the environment for the workers. This requires full control over the production process and the costs involved. Straight through processes have their difficulties and need dedicated solutions. More complex operations, especially those with frequently changing product flows and machine use, may run into complicated calculation models, which may not provide quick answers when a problem occurs. The availability of intelligent electronic calculation and monitoring programs may mitigate the problem.

CFS recognised this and assured that the electronic systems present at all their machines can communicate with each other in the same language (Common User Interface). This allows users of any flexible production line, assembled of their machines, to get an immediate insight in the performance of the line. Products can be followed from the beginning until the end, so producers have all product details available even before the product leaves the plant. Such information is important for the running business but also in case of an emergency. It can be used for tracing and tracking too.

In conclusion, one can state that the availability of these flexible and easy to control systems helps food processors, no matter what their product range, to improve the efficiency of their operation. They meet the demands of producers that serve niche markets and opt for flexibility and process utilisation while producing a wide variety of high quality products. Producers that choose to serve the market with coated foods produced in large volumes too can make use of these systems to maximise their yield through savings in costs and optimising process control.

Coating history
Coating is known to contribute to product quality and taste. It is unknown what the origin of coating is, but there are stories about coating which go back to the fifteenth century and even earlier. Some of the stories refer to holy days when Catholics avoided meat and ate fish and vegetables instead. To add some more flavour to their dishes they sometimes dipped the fish and vegetables into a batter before frying. Originally the batter was made of cold water and wheat flour, but soon eggs, salt and spices were added. Such a batter is, relatively spoken, the cheapest part of a coated product and therefore stimulated cooks to use small batches of meat, fish or vegetable pieces as substrate in a batter. They quickly discovered that when using cold batter, lumps in the mixture would stick to the substrate resulting in a unique fluffy and crispy product when cooked at a very high oil temperature. Portuguese missionaries and traders introduced this technique in the mid-sixteenth century to Japan where it received the name “tempura”.