Meat croquettes are a typical Dutch snack. A croquette is a deep-fried product which consists of a provided ragout, which is coated with a thin layer of breadcrumbs. This breading layer consists of egg wash and breadcrumbs and ensures that the content of the croquette is held together during the deep-frying. Nowadays croquettes available in many variants, such as the potato croquette, goulash croquette and cheese croquette. The majority of these industrially manufactured croquettes are frozen.
According to the Dutch Commodities Act, croquettes may, in addition to water (62 to 72%), contain ragout, wheat flour (± 10%) and a maximum of 10% fat. In addition, the ragout has to contain at least 5 to 20% meat, depending on the croquettes quality indication. Only meat of high quality, with a low fat content and a very low collagen/protein ratio, is included when measuring the meat content.
Usually, South American frozen horse meat is used for the croquette filling. These blocks of meat are chopped into pieces and defrosted at a temperature of 4°C. The defrosting can take 1 to 2 days.
It is important that the egg wash mixture coagulates in the right way during frying, holding the breadcrumbs together, forming a coating around the ragout. Breadcrumbs may contain up to 12% moisture and must have a sufficiently voluminous grain structure so that sufficient moisture can be absorbed during cooking.
To prevent lumps from forming during the mixing of the flour and water, the flour is first mixed with melted fat or oil at a temperature of from 90 to 120°C. The roux has to form a homogeneous mass, because it determines the consistency of the final product. When this mixture is then mixed with a portion of the water phase, a better gelatinization of the starch will take place.
A broth is made from the meat with water. This is done at a temperature of between 70 and 95°C and can take up to 24 hours. Automated ragout boilers are often used for this process. The meat is then separated from the broth.
Grinding the meat
After a check on irregularities has been performed, the meat is reduced using a meat grinder. Ensuring that the meat is not made smaller than 0.85 mm, otherwise the meat does not count towards the meat content measured using a special method, in Dutch the so-called ‘pluis’ method. This method involves the croquette being stripped from its breadcrumb outer layer and the remaining part being cooked. Next, the whole, together with the hot water, is sieved through a sieve with a mesh size of 0.85 mm. Non-meat parts are removed and what is leftover makes up the coarse total meat content.
In a boiler with agitators, the broth is mixed with the roux preparation, making the roux fully absorb the broth. The mixture is then heated to 80°C, creating a viscous mass through the gelatinization of the starch. It is possible to lower the viscosity by continuing stirring for some time. Then, the meat, herbs, thickeners, and any pre-cooked vegetables added to the mixture.
In order to avoid a too strong reduction of the cooked meat, the post-mixing step must be as short as possible.
The ragout is then filled into flat stainless steel trays and placed to cool down to a temperature of 4°C in a cold storage room. The cooling takes at least 24 hours, allowing the ragout to develop its flavor. In addition, there is the possibility to fill the ragout in plastic casings and allowing them to cool in running water, after which they are further cooled down in a cold storage room.
However, it is better to cool the ragout using a scraping heat exchanger, preventing microorganisms from growing, and accelerating the process. During cooling, the viscosity increases because of retrogradation of the starch.
After cooling, ragout balls are formed using a portioning machine. The ragout balls fall on a treadmill and are formed into the croquette shape here. A vacuum filling machine can also be used to shape the croquettes. The molding plates are sprayed beforehand with water of 0°C, which will prevent the ragout from sticking.
The ragout shapes are floured. Flouring involves sprinkling the croquettes with wheat flour, after which part of the flour is blown off in order to remove the excess flour. Flouring limits shrinkage during baking and makes the egg wash attach better.
In order to make the breading layer stay in place and form a crispy crust, the croquettes are provided with a layer of egg wash. This wash consists of vegetable protein, starch and a thickening agent.
The outer layer of the croquette consists of a breading layer. The breading layer is made from fresh bread or biscuits and may differ in color and flavor. The fat absorption of the croquette during frying when using coarse breadcrumbs (> 0.5 mm) is higher than when using fine breadcrumbs. However, coarse breadcrumbs are used more often. Because they provide the croquettes with a crispier crust.
In order to increase the shelf life of the meat croquettes, they are frozen. One could choose to hand pack the croquettes before freezing them. The croquettes are put in boxes and stacked on a cart placed in a freezer room.
Nowadays the croquettes are generally frozen to -18°C or lower before packing. This can be done using a spiral freezer, or by the cryogen freezing. When using cryogenic freezing, liquid nitrogen, with a temperature of -196°C, is sprayed over the product. The warmed nitrogen vapors are then filtered off with suction. Using this method, the croquettes can be frozen to -18°C within 15 minutes. Due to the fast freezing, there is less loss of the water binding capacity of the proteins in the croquette.
After freezing the croquettes generally are hand-packed in cardboard boxes. a sheet of waxed paper can be put at the bottom and in between each layer of croquettes, preventing the croquettes from freezing together. To counter temperature fluctuations during distribution and storage, the croquettes are deep-frozen to -20°C and kept at this temperature.
Food Safety & Hygienic Design
Meat is an excellent environment for the growth of pathogenic microorganisms. It is therefore important to keep the temperature low. This applies for the product, but also for the environment. A temperature of 4°C is preferred.
If because of the operating personnel a higher temperature is set, for example 8 to 12°C, the tools and materials that come in contact with the meat have to be changed every 2 to 4 hours.
The ragout undergoes a heat treatment step, in which all the vegetative microorganisms are killed. When the product is at a temperature between 70 and 7°C, the equipment must meet the requirements of hygienic design - being cleanable to microbial level. A 4-hour cool-down time to 7°C will not cause any significant microbial growth.
If the croquettes are pre-fried, and then frozen, the risk arises that during the cooling process by air, microbial growth takes place in the air cooler, which will contaminate the product. This has happened with ‘frikadellen’, containing the S. aureus in high numbers, which were later killed off in the fryer, but the heat-stable toxin of this microorganism still caused food poisoning.
Soft Drinks Industry Winters
The rich history of Soft Drinks Industry Winters BV is now in its third century. Today, the bottling company is alive more than ever. With a flexible attitude and high quality standards it has become the largest Dutch soft drinks exporter. In addition, the lubricants of Shell Lubricants make the machines run optimally and food safe.
"You ask, Winters fills": that's the motto of Soft Drinks Industry Winters BV in Maarheeze (North Brabant, The Netherlands). The company is not directly known to the consumers: the company has never sold soft drinks under its own name. Still, it can look back on a long and rich history. When William Van Hooff laid the founding stone of his brewery on August 5, 1797, he could not have realised that it would become an international soft drink company in two centuries time. By inheritance to the next generations in the year 1873 Jan Winters came in charge. Since then, the brewery was known by his name. In 1918 the production of soft drinks started. Until 1958 Winters only had regional ambitions. Then the company expanded business and Winters became producer of world renowned branded as Seven-Up, Sunkist and Canada Dry. When the domestic sales of soft drinks stagnated, the sight was set on various foreign markets in the seventies. In 1978 the company became part of TLC Beatrice International Holdings. Together with the Belgian soda bottling Sunco, who belonged to the same group, it took over the French mineral water producer St. Alban in 1996. After a management buyout the holding company Sun Beverages Company emerged in 1998, comprising Winters, Sunco and St. Alban.
In 1989 the licenses for the production of Seven-Up and other branded products for the Dutch market ended. Since then all attention is directed to 'contract filling'. This is done on behalf of major international food companies, retailers and other commercial organizations. Winters fills cans for a range of soft drinks, energy drinks, mixed drinks, juices, waters and beers with well-known brands. Between 5 and 10% of production is destined for its own brands, such as Sun Cola and Orange, Party Cola and Orange, Provita multivitamin drink, Maresca mineral water and Megaforce energy drink. Nearly 95% of the volumes is exported worldwide and thus Winters is immediately the biggest Dutch soda exporter. Every year more than 500 million cans are filled, packed and logistically processed. Winters currently employs 120 people in permanent employment and dozens of seasonal workers. Production runs per working day in three shifts for 24 hours and during the peak season in a four or five shifts.
To realize such large numbers, Winters has three production lines. An important part of each line is the can sealing machine running at very high speeds. Two machines seal 1,200 filled cans per minute and the third will do another 625 units per minute. Frans Cox, head of utilities and engineering projects: "Such devices are very capital intensive. It is very important that they remain in good condition to produce an excellent product with a constant quality. "
For the reliability of the sealing machines the right food grade lubricants are essential. Some parts are lubricated with oil, others with grease. Oils are able to dissipate more heat and are regenerable by filtration. They are applied for the lubrication of (plain) bearings and gears. Fats are oils encapsulated in soap skeleton. They have less heat-dissipating properties, and can not be reused. The fats serve, inter alia, for the lubrication of bearings in hemming rollers. Incidentally, their lubricating frequency is lower than that of oils.
Until ten years ago, Winters used lubricants from various manufacturers. F. Cox: "However, the need hasd arisen to rationalise the diversity of products and providers. To get a better overview, we decided to give one person decision-making authority and to work with just one supplier. The result is that if there are questions, there is only one firm where you can go to the right person. That's an advantage, because of the high speeds the machines are very sensitive and, if necessary, you should be able to rely on a rapid intervention of your lubricant supplier."
Arjan Nieuwstraten, food sector specialist of Shell Lubricants, adds: "The material of a modern beverage can is much thinner than before and therefore the method of sealing is more critical. So you can imagine the tolerances to have to work with will be smaller than before. The importance of the lubrication is thus become much greater. "
At that time Winters already bought around 70% of its lubricants from Shell Lubricants and, partly by this collaboration this supplier was chosen. "The people at Shell were always coming into action directly when needed. They were also always ready for the start up of new equipment, switching to newer oils or fats, assistance in making lubrication schedules, etc. That's why we did not have to think long about who we wanted to go into business with", F. Cox continues.
In practice, there is now a 'gentlemen's agreement' between the two parties. "A synergy has grown between our companies, based on years of trust", A. Nieuwstraten confirms. "The collaboration with Shell Lubricants is closely aligned with the expectations that we have with respect to our suppliers", F. Cox adds.
Incidentally Shell offers Winters an additional service with the Lubriplan software. This lubrication management system provides an accurate overview of the inspection points for fats and oils in the machines and generates user-friendly instructions. So it is indicated where and with what frequency there has to be checked or lubricated and with what product that needs to be done. "Moreover Lubriplan builds up a history of the objects to be lubricated. It may sometimes appear that periodic lubrication at a certain location is needed less frequent than planned. Such cost optimisations we do proactively for Winters", A. Nieuwstraten continues.
In this industry, food safety is of paramount importance and it is essential that no contamination of the filled product occurs. The past decades mineral (engine) oils were used to lubricate can seaming machines. Because these are unfit and improper to come into contact with food, Shell Lubricants has developed a range of food grade oils and fats which are suitable for the lubrication of such equipment. They may be used in the food industry and meet the European standard and the US FDA NSF H1-H1. The FDA (Food and Drug Administration) considers incidental contact of these lubricants with the food product to be acceptable to a level of 10 ppm (parts per million). The lubricants are food safe without compromising on their lubricating properties.
Incidentally, there are two types of food grade products. In some sealing machines the lubrication takes place in a closed circuit: this process is called "recirculating oil '. For such systems Shell Lubricants has developed the synthetic oil 'Shell Cassida Fluid GLE' series. That series has excellent lubricating properties and is recognized by leading suppliers of sealing such as Angelus (USA), FMC FoodTech (Belgium) and Ferrum (Switzerland). A second process is that wherein the lubricant is used only once: the "total-loss system. For this, Shell introduced the food grade mineral oil 'Shell FM Gear Oil TLS 150'. That delivers outstanding performance, even in the presence of water, juice or beer. Moreover, this oil absorbs water, preventing rust.
Remarkable is that these Shell products were developed in cooperation with Soft Drinks Industry Winters. A. Nieuwstraten: "We gave attention both to food security and to the optimization of lubricant performance. At Winter we have gained a lot of knowledge about the lubrication of sealing machines with these products and numerous tests have led to the most sophisticated lubricants for this sector."
Large beverage producers that have known branded products manufactured through contract fillers not only value high the quality of the final product. Also, the extent to which the production process is controlled and hygiene risks are avoided, plays a major role for them. Winters has responded and holds international quality certificates according to ISO 9000, 14001 and HACCP (hazard analysis critical control points). In addition, the bottling company is certified to the BRC standard (British Retail Consortium). That standard contains guidelines which food producers have to meet in order to supply the large English supermarkets. Finally, for German and French retail chains Winters has the IFS certificate (International Food Standard).
With the high quality food grade lubricants of Shell Lubricants and the high quality standards of Winter the consumer profits.
Featured expert: Pieter Van de Schepop