Lekker en gezond

Las fresas frescas son muy saludables porque son ricas en vitamina C y bajas en calorías. Las fresas se pueden conservar por pasteurización en una lata o en una jarra. Después de la cosecha, las fresas son clasificadas, lavadas y enlatadas. Durante el proceso de enlatado se añade un jarabe y después de esto las latas y frascos cerrados se someterán a un tratamiento térmico.

The Strawberry (Fragaria) belongs to the rose family (Rosaceae) and is one of the most popular summer fruits. There are more than twenty kinds of strawberry plants. Crossing strawberries from California, which have a hard fruit, with the softer European strawberries, resulted in sturdier varieties that could be exported over long distances.

Strawberries are so-called false fruits. The ovary, seed and bottom of the flower contribute to the fruit forming. A strawberry is a swollen receptacle of the strawberry flower with yellow seeds on the outside. The strawberry plant produces stolon or ‘runners’ to propagate itself.

Fresh strawberries are very healthy because they are rich in vitamin C and low in calories. The smaller the strawberry, the sweeter it tastes. Homegrown strawberries taste best, because strawberries will quickly lose their flavor because of the long supply lines.
Strawberries are often used as a flavor enhancer in for example yoghurt because of their strong aroma. Strawberries are also often made into jams.

Canned Strawberries

Strawberries can be preserved by pasteurization and are sealed in a can or in a jar. After the harvest, the strawberries are sorted, washed and canned. During the canning process a syrup is added and after that the closed cans and jars will undergo a heat treatment.

The canned strawberries are different from strawberry jam. Strawberry jam is made by boiling the strawberries, sugar and a gelling agent, after which the mixture is put into jars and is pasteurized.

An alternative process to give strawberries a longer shelf life is freezing. By using the IQF method (individually quick frozen), the strawberries’ flavor and texture are better preserved. The final product is meant for frozen distribution.

A second alternative is pasteurizing the strawberries under pressure. Using this technique, the texture and flavor remain closest to that of fresh strawberries.


Strawberries are put in syrup in order to preserve their taste. The syrup contains a mix of sugar and water, with the possible addition of glucose or glucose syrup.

Strawberries in syrup are divided into three classes:
- In light syrup: a sugar-content in the liquid part of 11% and a total of 18°Bx (Brix)
- In heavy syrup: a sugar-content in the liquid part of 13% and a total of 21°Bx
- Extra heavy syrup: a sugar-content in the liquid part of 15% and a total of 24°Bx

There are special varieties of strawberries used for industrial processing which easily let go of the green stem on top of the strawberry, also know as the crown. In addition, sturdy strawberries which are not too large, fully ripened, with an intense red color, good flavor and aroma are preferred.

Production process strawberries in syrup


Strawberries in the Netherlands are grown directly into the garden soil covered by plastic or glass. Strawberries can be grown in many types of soil, provided that the soil can retain sufficient water, contains humus and has a low pH. Materials to cover the soil, such as black plastics or straw ensure that there is less weed growth and enable the soil to retain the water better.

When the flower buds are removed from a strawberry plant, the plant will immediately switch to a vegetative state. This will create stolons (runners), which will develop into new young strawberry plants.

Because the strawberry plant is self-pollinating, there is no need for cross-pollination to take place. Wind and insects are crucial to the pollination process of the strawberry plant.

Normally, strawberries are planted in August, so they can be harvested the following year in June. Through acceleration of the growth process by covering the strawberries with perforated foil, straw or by using refrigerated plants the strawberry harvest can take place from late December to late February. The strawberries are harvested when they are not fully ripe yet, because they will ripe further after picking.
The strawberries are harvested by hand by taking the strawberry carefully and twisting the stem perpendicular to the strawberry, so it will break off. The strawberries are sorted immediately after picking.


Processing of the strawberries is done in during the period from mid June to mid July. After harvesting, the strawberries must be processed or stored cold as quickly as possible. Strawberries are very sensitive to temperature and relative humidity, which both control the breathing activity, and thus have an impact on regulating the degradation of sugars and flavorings. A rapid development of micro-organisms can cause the consistency and structure of a strawberry to deteriorate. When strawberries are stored at a temperature between 0 and 5°C and kept in an area with a relative humidity of 90% they will expire within two days.


Before the refrigerated strawberries are washed, the mouldy and rotten strawberries and contaminants are removed by sorters from a sorting belt. Strawberries that have not fully ripened yet are kept aside to later be processed to pulp.


After being carefully sorted using the sorter belt, the strawberries are transported to a Hermes Washer, or a so-called double washer. In this machine, the strawberries are presoaked, were with rising air bubbles sand and other contaminants, like the heat-resistant fungus Byssochlamys Fulva are removed. In order to make sure that the strawberries used for syrups do not contain more than 50 mg of sand per kg of the finished product, the strawberries are put on a mesh belt and washed down with water. After the cleaning the fruits are given time to drain. The process of washing the strawberries should not take too long, because it will make the the flesh of the strawberries soft making them fall apart easily. The water used for cleaning the strawberries should be of good quality and decontaminated with ultraviolet light or chlorine.


Before the strawberries are pasteurized they are put in cans. By using a filling table continuously vibrating cans are being filled up with strawberries. 550 to 700 grams of strawberries are needed to fill a container of a liter, so there will be sufficient strawberries left after the shrinking of the strawberries that happens during the pasteurization process. Subsequently, the content of the cans is put under a vacuum, to prevent unwanted oxidation reactions or deformations of the cans. After closing the vacuum pump, hot syrup is added. The concentration of the sugar solution depends on the type of syrup and the sugar-content of the strawberries. To lower the pH citric acid or lactic acid may be optionally added. Legally permitted food dyes can also be added. After the hot syrup is added the cans are sealed before pasteurization.


The cans are pasteurized at a temperature between 85 and 95°C, to have a temperature of 80°C at the can’s core. After pasteurization, the cans are cooled down immediately to about 30°C. The high sugar content, low pH and pasteurizing contribute to complete conservation of the product.


The cans are labeled and packed in boxes, after which they can be stored for a long period of time outside of the refrigerator.

Food Safety & Hygienic Design

On relatively acidic products (pH<4.6) microbial spores can not develop into vegetative (alive) micro-organisms, which could potentially spoil or severely contaminate a product. Sterilization or deactivation of spores is therefore unnecessary. The milder pasteurization technique is sufficient to kill vegetative cell and has less of an impact on the flavor.

The acidity of the strawberries can be critical. This is the reason that strawberries are put in heavy syrup.

The production equipment and machinery must be of of a GMP-class. This means that the machinery and equipment must be visibly clean before use. In case that the machinery cannot be emptied fully (and is clean and set aside dry), the machinery has to be thoroughly cleaned and disinfected before the production process can start again. Cleanable to a microbial level (hygienic design) is not necessarily required for this process. A light microbial contamination should not be a problem.

Even though the product undergoes a heat-treatment after being sealed, does this not give a license to clean less frequently or not fully clean the machinery and equipment. Large amounts of heat-stable toxins, originating from micro-organisms, can remain toxic even after pasteurization and will keep posing a threat to the health of the consumer.


Bebidas Industria Winters (EN)

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 (taken over by Fuchs 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.

Contract filling

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.

One supplier

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.

Food safety

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."

Quality Systems

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.

FUCHS LUBRICANTS GERMANY FUCHS es un grupo global de …
Company profile

Featured expert: Pieter Van de Schepop

toggle editorial
  • Pasteurización - esterilización
  • Lubricación de calidad alimentaria