Tomato ketchup

Tomato ketchup is a spicy sauce with tomato pulp as its main ingredient. In addition the sauce contains, vinegar, sweetener, salt and various herbs. The vinegar ensures preservation of the tomato ketchup and the herbs enhance the taste of the tomatoes. Moreover, starches can be added which swell during cooking and thus increase the viscosity. Because the quality of the tomatoes can vary, the recipe will sometimes need to be adjusted. The composition of the tomato ketchup may vary slightly per brand. Tomato ketchup can also be made on the basis of tomato puree instead of tomato pulp. In this case a tomato puree will have to be used, with which a comparable quality is obtained. In addition, the cooking process will have to be shortened.

Production tomato ketchup


With the help of water, the tomatoes are moved from the trucks to the factory. This prevents damage to the tomatoes and partially crops the tomatoes. After a short storage time, the tomatoes are washed for a second time. This time in rotating drums, after which the water is drained.


It is very important that the tomatoes are of consistent quality, which is why they are sorted using a sorting machine. The sorted tomatoes are reduced and pre-cooked in stainless steel barrels, so that the tomatoes are preserved and microorganisms are killed.

Make pulp

The reduced and pre-cooked tomatoes are made into pulp and stripped of seeds, skins and stems with the aid of a cyclone. After filtering the pulp and the tomato juice, the whole can be further processed.


The tomato pulp is boiled for 30 to 45 minutes in a combined mixing and cooking kettle until the correct concentration is reached. The temperature must be accurately controlled in order to promote the absorption of the ingredients and to prevent overcooking. Any foaming during cooking can be prevented by adding anti-foaming agents or compressed air. The herbs and the salt are added at the beginning of the cooking process. Any volatile herbs are added together with the vinegar at the end of the cooking process. Sugar can also be added later in order to prevent burning.

Refine - Homogenize

After cooking, a final refinement of the tomato ketchup takes place. The remaining fibers and particles are removed by filtration after cooking. One can possibly increase the viscosity of the sauce by homogenizing the tomato ketchup.


By filtering, air is struck in the tomato ketchup. For this reason, the tomato ketchup must first be deaerated before it can be filled to prevent bacterial growth, the formation of air bubbles and discolouration. In addition, any problems during the closing of the bottles are avoided. Venting can take place with the help of a vent or by keeping the tomato ketchup at 90°C for a certain period of time.


After deaerating, the tomato ketchup must be heated to at least 88°C to prevent post-contamination during filling. The tomato ketchup is filled in glass or plastic bottles. Due to the narrow neck, ease of use is increased and contact with air is minimized. After filling, the bottles are immediately closed.


It is important that the filled bottles are immediately cooled with cold air or cold water. If tomato ketchup is stored for too long at too high a temperature, flavour losses can occur.


After the bottles have been labeled with the necessary information and a check has taken place, the bottles are ready for transport. The boxes are often stored upside down to prevent browning in the narrow neck due to the presence of air in the headspace. Tomato ketchup can be stored at room temperature. However, after opening it is wise to keep the sauce in the refrigerator to maintain a good quality.

This production process can be carried out batch or batch continuously.


Content of Practical Guideline Hygienic compressed air in the food industry

Below you will find an overview of the content of the Practical Guideline "Hygienic compressed air in the food industry". To gain access to the complete guideline you need to create an account and indicate during the registration that you want access to the guidelines. That costs Euro 125, = per year excl. VAT. If you already have an account, you can email us and we will start the procedure to give you access. Publication in English will follow soon.

Working group members

René Bakker, Hago Food & Industrie.
Wouter Burggraaf, Burggraaf & Partners (chairman).
Maurice van Dam, Parker Hannifin (later succeeded by Michael Matthijssen).
Michael Evers, Niedax (secretary).
Jef Goossens, Boge Kompressoren B.V.
Christoph Illing, Parker Hannifin.
Edwin Lamers, Bürkert.
Koen Leeflang, Festo B.V.
Michael Matthijssen, Parker Hannifin.
Johan Nooijen, Geveke.
Norbert Rozemeijer, Ants Technology & Consulting – part of BT-Brammer Groep B.V.
Roy Schep, SMC Pneumatics BV (successor of Henk Klein-Middelink and Gert-Han Konijn).
Pieter van der Schepop, Fuchs Lubritech (ad hoc member).
Herman Steen, Synamic.
Martijn Visser, Adsensys B.V.
Mark White, Parker Hannifin (ad hoc member).

1 Scope

The practical guideline Hygienic compressed air in the food industry deals with the hygienic aspects of
- compressed air (from outside air to consumption point)
- including all conditioning, design, verification and monitoring
- including recommendations for energy consumption reduction
for application in the food industry.

Part of the guideline is a substantiation of the hazard and risk analysis.

2 Normative references (legislation and regulations)

There are three food safety laws that need to be considered in the EU:
- Hygiene regulation Reg. 852/2004
- Machinery Directive (2006/42 / EC)
- Materials regulations Vo1935 / 2004; Vo10 / 2011

And for (breathing) air (intensive contact with (pressurised) air)
- Directive on personal protective equipment

The FDA Code of Federal Regulations applies to the United States.

The standards for compressed air, driers, filters, appendages and hoses have been taken into account when drafting the guideline.
In addition, the other practice standards have also been considered: BRC v7, IFS v6, 3-A and more.   

3 Terms and definitions

Own definitions, concepts from guideline EN 1672-2 and zone classification.

4 Compressed air installation - Principles

Overview of the components that make up a compressed air system, with attention to the different principles and variants that can be chosen for a component: compressor or blower, oil-lubricated or oil-free, kind of separators, after-coolers, dryers, and filtering and separation steps.

5 Risk analysis

It discusses what can be significant hazards to the food, which can come with compressed air. This yields a number of sources that are treated individually:
- (aspirated) ambient air
- suction filter
- air compressor

After the compression:
- wet air buffer
- dryer
- filter

And finally:
- storage and distribution

The risks are discussed per source, such as
- water vapour and condensate
- particulate matter
- micro organisms
- environmental dirt
- hydrocarbons
- fragrances and flavours
- chemicals
- nutrients
- lubricating oil and grease
- dust formation by adsorbent.

Then recommendations are made for removing these hazards by source.
Where complete prevention of the hazard is not possible, the risks must be limited. It is indicated to which limits the compressed air must comply in terms of micro-organisms, moisture and the various contaminants.

6 Design requirements

In this chapter, the compressed air system is followed from intake to consumption point, and criteria and recommendations are given.

7 Verification & monitoring

Discussion of verifications of filters and of some quality characteristics of compressed air: residual moisture, residual oil, particles and microorganisms, and what measurement methods are available for this.

8 Recommendation

A brief overview where energy-saving measures are possible.

9 Working visits

The visits and discussions that the working group has held.

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  • Tomato
  • Oil - margarines & sauces
  • Sauces
  • Storage & transport
  • Washing
  • Homogenising
  • Cooking
  • Cooling
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