WO2008098822A1

WO2008098822A1 - Process to prepare a tomato product

Info

Publication number: WO2008098822A1
Application number: PCT/EP2008/050797
Authority: WO
Inventors: Gino Berninzon Di Domenico; Sander Dubbelman; Cristiane Fozzatti
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Unilever Limited
Priority date: 2007-02-16
Filing date: 2008-01-24
Publication date: 2008-08-21
Also published as: AR065343A1

Abstract

Process for the manufacturing of a processed tomato product, comprising the steps of: a. providing tomatoes from plants from a determinate tomato variety, b. comminuting said tomatoes, c.optionally performing a breaking step on said comminuted tomatoes, d.optionally concentrating at least part of the product resulting from step (b) or (c), e.optionally adding additional ingredients to the product resulting from any of steps (b)to (d), f.packaging the product resulting from any of the steps (b)to (e), g.performing a preservation step to the product, characterised in that said plants are cultured using a structure that protects the tomato plants from rain,

Description

PROCESS TO PREPARE A TOMATO PRODUCT

This invention relates to a process for the manufacturing of a tomato product and the tomato product produced according to this process.

Terms and definitions

The following terms are specified to indicate their meaning in the context of the present patent application.

Bostwick: measurement to determine the consistency of a viscous material by determining how far the material flows under its own weight along a surface in a given period of time. Hereto a Bostwick consistometer is used. A detailed description can be found in US 20030134026A1

Brix: Degrees Brix (symbol ⁰Bx) is a measurement of the mass ratio of dissolved sucrose to water in a liquid. It is measured with a sacchahmeter that measures specific gravity of a liquid or more easily with a refractometer, e.g. a Bellingham Stanley RFM 342 Refractometer. A 25 ⁰Bx solution has 25 grams of sucrose sugar per 100 grams of liquid.

Tomato pulp: inhomogeneous mass of chopped tomatoes comprising chunks of fruit flesh, fibres, seeds and skins which may be pumped.

Tomato juice: Chopped and sieved tomatoes, Brix level ca. 5, according to the Standard of Identity as defined in 21 CFR 156.145 of the FDA (Revision 1^st of April 2006).

Tomato puree: Tomato juice concentrated to Brix level of 8 to 24, according to the Standard of Identity as defined in 21 CFR 155.191 of the FDA. (Revision 1^st of April 2006). Tomato paste: Tomato juice or puree concentrated to a Brix level higher than 24, according to the Standard of Identity as defined in 21 CFR 155.191 of the FDA (Revision 1^st of April 2006).

Tomato particulates: inhomogeneous tomato product comprising pieces of e.g. at least about 1 and less than about 19mm, preferably of at least about 5 mm and less than about 10mm. (measured at the longest axis).

FDA: Food and Drug Administration (United States).

Background of the invention

Tomatoes are grown around the world for basically two applications. Either to be sold to the end consumer as fresh fruit or to be used in food processing industry to prepare various processed tomato products. Examples of these processed tomato products are e.g. sauces, passatas, ketchups, tomato dices, crushed tomatoes, whole peeled tomatoes, purees or pastes. Important tomato producing countries have Mediterranean or tropical climates such as in Brazil.

In general, tomatoes that are sold fresh to consumers differ from those used for the production of processed tomato food products. Freshly sold tomatoes are relatively juicy and soft. The plants are in general from a variety of the 'indeterminate' type. This means that the plants do not flower at the same time and fruits are not ripe simultaneously. Hence, a plant may contain unripe green fruits and ripe fruit at the same time. During culturing, 'indeterminate' plants generally grow at a cordon and grow during an extended period of e.g. 9 to 12 months. Growing tomato plants on stakes is a labour intensive way of growing tomatoes, and therefore not preferred for industrial purposes. When the climate conditions are poor, the plants may be cultured in greenhouses or tunnel structures, to provide climate conditions suitable for growing tomato plants. Growing these tomato plants in greenhouses may result in a cost increase up to twenty fold. For example, the price for tomatoes for industrial purposes is about 50 euros per ton and that of freshly sold tomatoes about 1000 euros per ton. For freshly sold tomatoes, the relatively high costs are not considered a major problem by the consumer.

For industrial purposes, tomatoes should fulfil specific requirements, and therefore differ from tomatoes sold as fresh fruit. Tomatoes sold fresh to end consumers are in general too soft for industrial processing. Industrial tomato varieties are generally of the 'determinate' type. This means that the plants flower at the same time and that the tomatoes are ripe at the same time. When referred to "the same time", it means that at least 80%, preferably at least 90%, of the plants transplanted on the same moment have their flowers on the same moment and at least 80%, preferably at least 90% of the tomatoes on a plant are ripe during the moment of harvest. 'Determinate' plants have a clearly defined growing cycle of less than 150 days from transplanting the small plants until harvest. This enables to harvest the whole plant at once. The harvesting can be done manually or mechanically. "Determinate type" and "Indeterminate type" are well known terms in the field of tomato breeding.

From the prior art, in general two processes are known to produce a processed tomato product, referred to here as 'intermediate paste process' and 'fresh pack process'.

Intermediate paste process

The 'intermediate paste process', known to the skilled person, comprises a 'primary process' and a 'secondary process'. In the 'primary process' a (mainly) intermediate product is produced. This intermediate product may be a tomato puree, a paste or particulates. This intermediate product is preserved and stored for later use. The intermediate product may then be processed further in a 'secondary process' to a further processed food product. This product is ready to be sold to the consumer. The primary and secondary process comprise the following steps respectively:

Primary Process Comminuting step

Harvested tomatoes are subjected to a comminuting step. When a tomato paste or a pulp is prepared, comminuting involves chopping the tomatoes into an inhomogeneous mass comprising chunks of fruit flesh, fibres, seeds and skins. When tomato particulates are prepared, comminuting involves cutting and/or crushing the tomatoes into pieces of e.g. at least about 1 and less than about 19mm.

Breaking step

After the comminuting step, the tomato pulp or particulate mass undergoes a breaking step. 'Breaking' is a term the person skilled in the art understands as being a common processing step in the tomato industry that involves heating the comminuted tomatoes. Depending on the temperature, this breaking step may be referred to as either a hot-break or a cold-break step. During a hot- break step (see e.g. W.A. Gould, Tomato Production, Processing and Technology, 3^rd Ed., pp. 202-204), pectinase enzymes as PME (pectin methyl esterase) and PG (Poly Galacturonase) are inactivated by application of temperatures higher than about 9O⁰C. Pectinase enzymes are involved in the breakdown of pectins which contributes to a more solid viscosity of the tomato product. The hot-break step has the advantage that enzymes are inactivated quickly, thus giving products with a good (thick) consistency. However the high temperatures of the hot-break step are detrimental to flavours and colour. Alternatively, a cold-break step can be applied wherein said enzymes are not inactivated. Temperatures for this process are less than 82°, with preferred temperatures between 60 and 66°C. The cold-break process retains the tomato flavours and colour better, e.g. the enzyme lipoxygenase, contributing to a good flavour, remains intact, but enzymes are not fully or quickly inactivated, which may lead to break down of pectin and as a consequence a thinner consistency. Typically, a puree or paste produced by a process comprising a hot break step has a Bostwick value of from 3 to 5 cm and a puree or paste produced by a process comprising a cold-break step has a Bostwick value of from 8 to 12 cm at 12°Bx. Depending on the desired product, either the hot- break or the cold-break step may be used. Generally, tomato particulates do not undergo a hot-break step. Especially the poly-galacturonase enzyme shows limited degrading activity when still present in the particulate and not exposed to the outside. However, the enzymes may be inactivated during a later preservation step.

Sieving step

When a tomato paste is prepared, the tomato pulp is sieved after the breaking step (hot-break or cold break). Sieving results in a substantially homogenous product, referred to here as tomato juice (see definitions). The tomato pulp is sieved using sieves with holes ranging from 0.6 to 2.5 mm. Depending on the application, a smaller size or a bigger size might be chosen. For obvious reasons tomato particulates are not sieved in this way.

Concentration step

Especially when a tomato paste is prepared, the tomato juice is concentrated using heat. Tomato particulates are not concentrated or only in a moderate way. Such a concentration may be performed in e.g. a multiple effect evaporator whereby the temperature is raised to e.g. 5O⁰C to 9O⁰C. A tomato paste is obtained that may be six times more concentrate than the original tomato juice. Alternatively, the tomato juice may be concentrated to a lower degree (e.g. two times or three times), to provide a puree (see definitions). Pasteurization or Sterilization step

The concentrated tomato paste or the tomato particulates are pasteurized for 5 minutes at minimum 90.5⁰C (194°F) or sterilized for 3 minutes at minimum

121.1⁰C (250⁰F).

Tomato particulates have a relatively weak structure. To protect their integrity, in or before this step, tomato paste, puree or juice resulting from the paste production may be added to the particulates, in order to facilitate the transport of the tomato particulates along the heating elements used for providing the temperatures mentioned above.

Cooling step

After the pasteurization or sterilization step, the product is cooled to a temperature of ca. 3O⁰C. This is preferably done in an aseptic system.

Packaging step

After cooling, the tomato paste or particulate product is packaged in a pack to be stored for further use. This is preferably done in an aseptic pack. For this reason, it is referred to here as 'intermediate product'. Such a packaging may comprise typically a 'bag-in-box'-system, containing e.g. 300 gallons (1135 litres), or a bag-in-drum system, containing typically 230 litres, of intermediate product.

Storage

The intermediate product may be stored from the end of the 'local tomato season' until 9 months later, before the next season is started or even longer. For understanding the importance of the present invention, it should be mentioned that such storage is generally carried out at ambient temperatures, as cooling conditions often may not be present or provided, especially due to the excessive cost of cooling a large volume of intermediate product over a long period. Ambient temperatures may rise far above 3O⁰C in tropical climates like in Brazil.

As tomatoes are available only in the 'local tomato season', it will be understood that the 'primary process' is only carried out during the 'local tomato season'. In the present specification, 'local tomato season' indicates the period wherein tomatoes are harvested in a specific area.

Secondary process

During the entire year, i.e. also outside the 'local tomato season', a processed tomato product can be produced from the stored intermediate product (either the tomato paste or the particulates) in a process called 'secondary process'. When the tomato product is prepared from the intermediate paste product, the tomato paste is diluted by e.g. water. Several ingredients may be added to the diluted tomato paste or to the particulates. Such ingredients may e.g. comprise salt, other vegetables, sugar, and herbs, like e.g. basil or garlic. Following the preparation of the processed tomato food product, the product is pasteurized e.g. for 5 minutes at minimum 90.5⁰C (194°F) or sterilized e.g. for 3 minutes at minimum 121.1⁰C (250⁰F) and filled into a pack like e.g. jars, cans, pouches or bags. The packaged tomato products can then be shipped for retail.

Fresh pack process

An alternative process used in the state of the art to prepare processed tomato products on industrial scale is a process wherein an intermediate concentration to a paste, followed by pasteurisation or sterilisation and an elongated storage period of the intermediate product is absent. Tomato juice or tomato particulates are immediately further processed towards a processed tomato product, in a way as described above. Alternatively the tomato juice is slightly concentrated to form a tomato puree with the right consistency for application in a processed tomato food product. Also here, the finished products are pasteurized or sterilized and filled in a packaging and sold. This alternative process is commonly referred to as 'fresh pack process'. As the tomato product is in a lesser extent exposed to relatively high temperatures, the quality is better than that of product resulting from the 'intermediate paste process'.

Chronologically, first the 'fresh pack process' was applied for producing tomato products on industrial scale. A disadvantage of the 'fresh pack process' is that it is confined to the 'local tomato season'. This results in an inefficient factory organisation, as there is no constant supply of tomatoes. The processed tomato products produced by the 'fresh pack process' have to be stored for the rest of the year, until the start of the next tomato season or even longer. This relatively long storage period negatively affects the quality of the processed tomato product. For example, when the 'local tomato season' lasts from July to September, products sold in June to the consumer were produced the year before in September. This means that the product is already 9 months old. Though this process only uses fresh tomatoes, the consumer may not experience the product resulting from this process as fresh, since it was produced already e.g. nine months ago. Moreover, when the processed tomato products have to be stored, high costs for a storage facility become inevitable.

To provide a constant factory supply, the tomato processing industry switched from the "fresh pack" process to the 'intermediate paste process' . The 'intermediate paste process' enables a constant supply of tomato paste or particulates and an efficient working schedule in the factory. However, a problem observed with the 'intermediate paste process' is that it does not provide products with an optimal quality. The breaking step (hot-break step), concentration, intermediate pasteurization/sterilization, storage under relatively high temperature conditions of the intermediate product, which may last up to 9 months, or indeed even longer, final pasteurization/sterilization, and storage on the shelf may have a negative influence on the taste, aroma and/or texture of the final product.

Loss in quality may be reflected in e.g. a change in colour, e.g. browning due to a e.g. a loss in carotenoids, like beta-carotene and lycopene, or due to Maillard reactions, a poorer flavour due to e.g. formation of off-flavour compounds, such as aldehydes, epoxydes and carbonylic compounds and due to e.g. the loss of volatile compounds involved in the experience of freshness, like e.g. hexanal, Z-3-hexenal, E-2 hexanal, 6-methyl-5-hepten-2-one and 2-isobutylthiazole, a loss of consistence, that may be due to loss of pectin, protopectin, and a loss in healthfulness, due to e.g. a loss in e.g. vitamin C (Radhika et al. 2001 , Journal of food processing preservation 25, p431 -445, p432).

US 3,172,770 describes a process to provide a better quality tomato product, while using an 'intermediate paste process'. The process comprises a separation of the juice from fresh tomatoes, dividing said juice into a plurality of fractions, one of said fractions containing substantially all of the insolubles in said juice and the other of said fractions containing substantially all the solubles in said juice, cooling and freezing said fraction containing substantially all of said insolubles and concentrating said fraction containing said solubles to a volume of approximately one-tenth of its original volume (by e.g. low temperature evaporation processes or freeze evaporation processes), and salting said concentrated fraction to a salt concentration of approximately 80% saturation of the free moisture therein.

US 3,172,770 provides a solution for the inferior taste of tomato products which are produced using the 'intermediate paste process'. However, the costs for cooling and freezing the intermediate product during processing and storage render this process not interesting for tomato processing on an industrial scale. Moreover, deterioration of quality of the flavours even occurs in frozen fractions during storage (Calligaris, S. et al. Journal of Food Science, Vol. 67, nr. 6, 2002, p2432-2435).

Accordingly, it is an aim of the present invention to provide a process to prepare a tomato product, the process providing a more efficient production in the factory, lower production costs and still providing tomato products of high quality.

Summary of the invention

Accordingly, to solve at least one of the problems mentioned above, the present invention provides a process for the manufacturing of a processed tomato product, comprising the steps of: a. providing tomatoes from plants from a determinate tomato variety, b. comminuting said tomatoes, c. optionally performing a breaking step on said comminuted tomatoes, d. optionally concentrating at least part of the product resulting from step (b) or (c), e. optionally adding additional ingredients to the product resulting from any of steps (b) to (d), f. packaging the product resulting from any of the steps (b) to (e), g. performing a preservation step to the product, characterised in that said plants are cultured using a structure that protects the tomato plants from rain,

Detailed description of the invention

The present invention relates to a process to produce a processed tomato product. The processed tomato food product may have several forms, such as tomato puree, juice, paste, tomato sauce, passata, whole peeled tomatoes, diced tomatoes, crushed tomatoes, catsup etc. In the first step (a) of the process tomatoes are provided. Tomato plants used for industrial purposes are preferably grown as a bush on the ground (not on a cordon). The process is conducted using tomatoes of a determinate variety. A determinate variety is suitable for industrial processing, because it enables a cost efficient production as all fruits ripen simultaneously.

After growing of the tomatoes, the tomatoes are harvested from the tomato plants. Harvesting is done as described above, preferably when >90% of the fruit is fully ripe. In a preferred aspect of the invention, the yielded tomatoes are red. During harvesting, the entire plant can be removed from the soil, and ripe tomatoes do not have to be picked by hand but may be removed by shaking the harvested plants until the ripe tomatoes drop to the ground. This greatly reduces costs. After harvesting, the tomatoes are subjected to washing, which is suitably done in a water bath.

After harvesting and washing, the tomatoes are comminuted, (step b). When a puree is produced, the comminuting step (b) comprises the preparation of a pulp. A pulp is an inhomogeneous mass comprising chunks of fruit flesh, fibers, seeds and skins. This mass may be pumped. Chopping may be done by chopping the tomatoes, using e.g. a chopper machine and/or rotating knives. When tomato particulates are produced, the comminuting step comprises cutting and/or crushing the tomatoes into particulates..

After the comminuting step (b), an optional breaking step (step c) may be carried out. This may be a hot-break or a cold-break step. When a tomato paste is produced, usually a breaking step is carried out, and the breaking step may be a hot-break step or a cold-break step, using the temperatures mentioned above. Normally tomato particulates do not undergo a hot-break step, but this might be done optionally. Tomato paste, puree, juice can be made using cold break or hot break. Tomato particulates normally do not undergo a break. In case of particulates, enzymes may be inactivated during a preservation step (g) using heat. In the context of the present invention, heating as applied during breaking, concentration and/or preservation steps (see below) may preferably be performed using steam. Preferably, the steam has a temperature of 100⁰C or higher. Therefore, according to a preferred aspect, the invention relates to a process wherein steam is used for any heating step.

In case a tomato juice or a puree is prepared, after the breaking step, the tomato pulp is sieved using a screen with holes ranging from 0.6 to 2.5 mm. Sieving of the tomato pulp results in a tomato juice (see definitions). Sieving may preferably be done using an extractor comprising rotating blades, such as e.g. known from patent application WO 2004/045318. The rotation speed may be e.g. 800 to 1000 rpm. During sieving, skins and seeds of the tomatoes are separated from the surrounding flesh and moisture. Seeds and skins comprise a fraction of from about 0.8 to 5 wt.% of the initial tomato pulp. In case tomato particulates are produced, a sieving step may be carried out using a vibrating sieve, to separate part of the moisture, skins and seeds from the particulates. Therefore, according to a preferred aspect, the invention relates to a process wherein the process further comprises a sieving step carried out after step (b) or (c), wherein an extractor comprising rotating blades or a vibrating sieve is used. Preferably, sieving is carried out such that the skins and seeds removed comprise less than 5 wt% by weight of the initial tomato pulp.

At least part of the tomato juice or of the tomato particulates may optionally be concentrated slightly until the desired consistencies reached for application into a processed tomato food product (step d). Preferably this is done under gentle conditions in order to maintain the quality attributes of the fresh tomatoes. Gentle conditions are typically temperatures less than 70⁰C and a maximum concentration level of 17°Bx. A severe concentration, as applied to prepare a paste, is preferably not used, as this is detrimental to the flavours. Concentration is preferably carried out under a vacuum. In the present context, vacuum is intended to mean 5066.25 to 81060 Pa (0.05 to 0.8 atm.) below the ambient pressure. Therefore, according to a preferred aspect, the invention relates to a process wherein the optional concentration step (d) is carried out using a vacuum of 0.05 to 0.8 atm. below the ambient pressure.

After the optional breaking step (c), the optional sieving, or the optional concentration step (d), additional ingredients may be added to the tomato pulp, juice, puree or particulates (optional step e), to complete the recipe of an end product. Such ingredients may preferably comprise vegetables, like onions, extracts of vegetables, herbs, like e.g. basil or parsley, extracts of herbs, salt, monosodium glutamate, meat, and other ingredients that the person skilled to prepare tomato sauces or pasta sauces is familiar with or a combination thereof. The product, however, may also be produced without further additional ingredients.

After the optional addition of the additional ingredients, the tomato product is packaged in step (f). The packaging may be performed in a packaging suitably used to package processed tomato products, such as e.g. jars, cans, pouches or bags.

After packaging, the product undergoes a preservation step (step g). This step may be carried out by e.g. heating the product. The person skilled in the art will understand which temperatures and times are suitable for a pasteurisation step or a sterilisation step. A suitable temperature may be e.g. 93.3°C for pasteurisation during 5 minutes or 121⁰C during 3 minutes for sterilisation. Other combinations of times and temperatures can be chosen as long as the integrated thermal treatment, i.e. the combined effect of time and temperature, is equal to or higher than the values stated above. Also other techniques may be used for preservation, using e.g. magnetic fields, radiofrequency, irradiation, cooling or freezing or a combination of these techniques. Steps (f) and (g) may be carried out in a reversed order when desired. According to the invention, during step (a) of the process the tomato plants are grown in a structure that protects the plant from rain. This may preferably be a tunnel structure. Tunnel structures suitable for the present invention are known from the art, e.g. from American patent application US 2005/0268544. US 2005/0268544 describes the use of a tunnel system to cultivate garden plants from frost and other environmental hazards. The enclosure consists of support arches over which a protective cover is deployed. The cover is held in place by elastic hold-downs strung across the outside of the cover at each arch. Each arch presents to the hold down a concave shape that receives and stabilizes the hold-down. The cover is translucent to sunlight and may include two types of material, one impervious to wind and rain, the other a mesh transparent to wind and rain. The cover or portions of it may be polarized to enhance or retard the pass-through of certain spectra of light. Access to plants is gained by lifting and bunching up the side portions of the cover, which is easily placed in a closed position again when access is no longer necessary.

For the present invention, the tunnel structure may comprise steal, preferably a galvanized steal. The dimension may comprise a length of e.g. 60m to 100m, a width of e.g. 4.5 m and a height of e.g. 1.5 to 2.5m. Industrial cultuhng commonly results in tomato plants with a height of approximately 50 to 75 cm. According to a preferred aspect of the present invention, the distance between the top of the plants and the roof of the tunnel structure preferably is at least between 0.75 and 2.25 m, more preferably between 1 m and 2 m. The height and width of the tunnel structure are not that critical for the scope of the invention and should be regarded as indications.

According to the invention, the structure applied in the process according to the invention comprises a semi-open structure, showing e.g. openings. The openings may be lateral openings. The presence of openings contributes to a better control of temperature and/or humidity inside the tunnel. The open area may be located up to a height of e.g. about 50 cm from the ground. For tunnels in the shape of greenhouses, the openings can have a height up to 150 cm from the ground. In a preferred aspect of the present invention, the openings have a height comparable to the height of the tomato plants, in this way providing optimal temperature and/or humidity control for the plants.

Glass houses and tunnel structures are used to create a micro-climate. Glass houses trap heat and humidity in temperate climates where it is too cold or too dry to culture tomatoes. It may be commonly expected that by the application of the tunnel structure, temperatures inside the tunnels would increase to such an extent, that the cultuhng would not be possible anymore, especially in tropical areas, e.g. higher than 4O⁰C. In addition, it might be expected that the humidity of the environment inside the tunnel structure would rise up to levels unsuitable for tomato culturing, e.g up to almost 100%. According to the average skilled person, the use of glass houses and tunnel structures results in a lower yield, as the individual tomato fruits remain smaller than when cultured outside. These presuppositions might be reasons that, to our knowledge, nobody ever applied the use of tunnel structures for the culture of determinate tomatoes for industrial purposes. To the surprise of the inventors, it was found now that the temperatures within the tunnel structures were comparable with those of the open field, and increased only with about 5⁰C (example 1 ). This temperature increase was only observed at the warmest period of the day, also depending on the presence of clouds or occurrence of rain. Surprisingly, the humidity is even lower than in the open field.

Unexpectedly, application of a tunnel structure resulted in a culture environment that appeared highly suitable to culture determinate tomato plants. Even more surprisingly, application of a tunnel structure resulted in a significantly increased yield. The yield per plant increased to at least 4 and less than 10 kg of tomatoes per plant, preferably, at least 5 and less than 8 kg of tomatoes per plant. Typically, the yield of tomatoes grown in an open field is in the order of 3 to 5 kg/plant. Example 2 shows the increase in yield per plant using the process of the present invention, compared to the average yield per plant during the standard (dry) season.

In a preferred aspect of the invention, the determinate tomato variety of step (a) of the process of the invention is a determinate tomato variety producing relatively firm fruits. A majority of the determinate varieties produce tomatoes that are relatively firm. These tomatoes are firmer due to higher fibre content resulting in a hard compact flesh. The firmer structure proves advantageous in industrial processing steps that may be relatively rough, like harvesting, washing and further processing into tomato food products. In addition, relatively high fibre content may contribute to a higher viscosity of the processed tomato product, compared to a processed tomato product resulting from tomatoes commonly destined to be sold fresh. The higher viscosity is reflected by the Bostwick levels of pastes or purees (see definitions) derived from the respective tomatoes. The Bostwick level of a tomato paste or a puree resulting from a determinate tomato variety as used in the process of the present invention is in general less than 12 cm, measured at 12°Bhx. This higher viscosity is considered highly advantageous during the preparation of processed tomato products. In contrast, the Bostwick level of a puree or a paste of tomatoes that are normally used for fresh consumption show a Bostwick level that is in general more than 12 cm, measured at 12° Brix. Therefore, according to another aspect, the invention relates to a process wherein the determinate tomato variety is a variety producing fruits that after processing result in a tomato puree with a Bostwick level of less than 12 cm, measured at 12° Brix. For example, the following varieties are suitable to be used in the process according to the invention. Their respective suppliers have been indicated in brackets. N335 (Nunhems), Design (Nunhems), C232 (Unilever), H9992 (Heinz), C871 (Unilever), AP865 (Seminis), C875 (Unilever), H9205 (Heinz), H9997 (Heinz), N147 (Nunhems), C205 (Unilever), C285 (Unilever), ISI 29616 (Agristar), Hypeel 108 (Seminis). Information on these tomato varieties can be found in e.g. SERVIQO NACIONAL DE PROTEQAO DE CULTIVARES of the Ministry of Agriculture of Brazil. The varieties SVR 025 10 566 (Seminis), HMX 4798 (Agristar), SVR 025 40 264 (Seminis), SVR 025 00 000 (Seminis), D038 (Unilever), PX 023 13 755 (Seminis), Dracula (DeRueters), Tiziano (DeRueters) are also suitable to be used in the process according to the invention. Especially preferred varieties are Design, PX755, Hypeel 108, AP865, Tiziano and Dracula. These varieties have a very pleasant taste and/or a deep red colour and/or they give a high yield of tomatoes per plant. Therefore, in a further aspect, the invention relates to a process according to the invention, wherein the tomato variety is one of the following: Design; Hypeel 108; AP865; according to the register of the SERVIQO NACIONAL DE PROTEQAO DE CULTIVARES of the Ministry of Agriculture of Brazil, Tiziano (supplier: DeRueters); Dracula (supplier: DeRueters); PX755 (supplier: Seminis). It is understood by persons skilled in the art that other industrial tomato varieties can be employed without departing from the scope of the invention.

In a preferred aspect of the invention, the determinate tomato variety of step (a) of the process of the invention is a hybrid variety. A hybrid variety is the result from parent plants from different varieties. The advantage of a hybrid variety is that the seeds are infertile. There is no risk of cross pollination, open pollination in the surrounding area or theft of seeds. But, perhaps even more important, a constant quality of seeds may be produced. Therefore, the present invention preferably relates to a process, wherein the determinate tomato variety is a hybrid variety.

In a preferred aspect of the invention, advantageously the process may be carried out outside the local tomato season. The person skilled in the art will understand what period is defined with 'local tomato season'. The 'tomato season' may be different in different areas in the world. The 'tomato season' is commonly defined as the period from the first day of the harvest to the last day of the harvest. For the skilled person, it is clear that tomato plants should be transplanted already four months earlier, to harvest during the 'tomato season'.

Temperature, rainfall and humidity are important parameters that may determine the 'tomato season'. A too high humidity results in e.g. rotting of the fruits or mould on the plants. Especially bacterial leaf spot is a serious disease which will normally result in the death of the tomato plant when relatively high humidity continues for an extended period of e.g. 3 days. This relatively high humidity may be e.g. a humidity of more than 80%. Moreover, the machines used for harvesting can sink away in the soil when this is too wet. During the 'local tomato season' the relative humidity of the ambient averaged over a calendar month is lower than 85%, preferably lower than 75%, more preferably lower than 65%. Therefore, according to another aspect, the invention preferably relates to a process wherein the process is carried out in the period when the monthly average relative humidity of the ambient is more than 65%, preferably more than 75%, more preferably more than 85%. The relative humidity of the ambient is intended to mean here the relative humidity as present outside of the tunnel structure. For example, the 'local tomato season' generally lasts from June to October in the state of Goias in Brazil and from July until October in the Sao Joaquim valley in California, USA.

In a further aspect, the invention relates to a process wherein the process is carried out in the 'local rain season'. It is known to a person skilled in the art, when the local rain season takes place. Preferably, the process is carried out in the period wherein the monthly average rainfall is higher than 180 mm. preferably higher than 200 mm. In the present specification, 'monthly' is intended to mean 'per calendar month'. Another way of defining the tomato season is via the incidence of bacterial leaf spot. The tomato season is the period in which tomatoes can be grown with a low incidence of bacterial leaf spot, resulting in yields of more than e.g. 50 000 kg/10 000 m²(50 ton/ha).

In a preferred aspect, the process according to the invention is carried out in a structure that protects the tomato plants from rain, wherein said structure has the shape of a tunnel or a greenhouse. Preferably, said structure is a semi- open tunnel structure.

According to yet another aspect, the present invention relates to a process, wherein the tomato plants are cultured in soil and said soil is covered with plastic mulches. In this way, contact of the plants with the soil is avoided. The reason for this measure is to reduce the incidence of bacteria, thereby improving the health of the plants. For the same reason, the plants may be watered by a drip-irrigation system, contributing to keep the leaves dry. The mulches preferably are white, as the white mulches reflect the light, in this way keeping the soil relatively cool and keeping the environment clear.

According to yet another aspect, the present invention relates to a process, wherein the structure that protects the tomato plants from rain comprises a covering of polyethylene material. The covering may be adapted to the light intensity of the climate zone, and may be diffusive or comprise an UV- protection. The covering may be more transparent to specific wave lengths that favour the growth of tomato plants. Such wave length may e.g. be infra red. In a preferred embodiment, the covering comprises a specific type of polyethylene, called diffuser polyethylene. Diffuser polyethylene distributes the light evenly in all directions, in this way providing all plants with a similar amount of light. In yet another aspect, the present invention relates to a process wherein the structure that protects the tomato plants from rain comprises means to prevent entrance of insects. These means may be present on the covering of the tunnel structure. Preferably, the (lateral) openings of the tunnel are equipped with anti-insect nets.

In this way, industrial tomatoes can be grown in an environment that is susceptible to insect-borne diseases. One example is the incidence of Gemini- virus in Brazil and other tropical countries that is transferred by the white fly to the tomatoes. Indeed, the incidence of white fly is higher in the rain season than in the dry season.

In a further aspect of the invention, the invention relates to a processed tomato product obtainable by a process according to the invention. Preferably, the processed tomato product according to the invention comprises a sauce, passata, ketchup, tomato dices, crushed tomatoes, whole peeled tomatoes, tomato juice, puree or paste or a combination thereof.

In summary, the process according to the invention provides significant advantages. Using this tunnel structure, according to the invention, the tomato plants can grow the entire year. Culturing of tomatoes is not confined anymore to the 'tomato season'. Consequently, no stock of an intermediate product and hardly any stock of the end-product need to be produced. This results in a constant supply chain and a better efficiency of the processing plant, that can be active the entire year as fresh tomatoes are available the entire year. Indeed, using the process of the present invention, two or even three growing cycles per year of tomatoes become possible. In addition, the intermediate pasteurization/sterilisation step becomes redundant by the process according to the invention. The reduced need for storage and reduction in heating steps results in lower conversion costs (e.g. ca. 15 times lower for particulates produced according to the 'fresh pack process' compared to particulates produced according to the 'intermediate paste process') and hence a lower price of the processed tomato product (up to 30% lower). The production of fresh packed processed tomato food product becomes possible during the entire year. This enables the marketing of 'fresh pack' products with a fresh appearance and taste during the entire year. The use of the process to produce a tomato product according to the invention is exemplified in Example 1.

EXAMPLES

Example 1 : Growing tomatoes inside tunnel structures during the rain season in Goiania, Brazil (16°S,49°W).

Tomatoes of varieties C285, C232 and H9992 were transplanted inside one tunnel each on 4^th of November 2005, i.e. during the rain season. The average climatic conditions in Goiania, Brazil can be found in e.g. www. Worldclimate.com. The arcs of the tunnels were made from galvanised steal. They were fixed to the ground in concrete footings. The tunnels were covered by a diffuser poly-ethylene with UV protection. The tunnels were 4.5 meters wide and 65 meters long and had lateral openings on each side of the tunnel. Two rows of tomato plants comprising 4 plants per meter were planted inside the tunnels. The plants were protected from the soil using white mulch. In total 480 plants per variety were transplanted. Harvesting took place between 8^th and 20^th of February, i.e. during the rain season. The length of the growing cycle was between 108 and 124 days. The temperature and humidity inside and outside the tunnels during this period were measured using a Log Box from Novus. The temperature and humidity sensors were installed at a height of 1.5 m above the ground in the shadow of a wooden cage). The average daily temperature as averaged over the time of the growing cycle was only slightly higher inside the tunnel structures (0.78⁰C). The daily relative humidity as averaged over the time of the growing cycle was 83.05% inside the tunnel structure, whereas outside the tunnel structure, this was higher, being 88.43%.

Also, rainfall was measured using a pluviometer from SoilControl Taylor. The total amount of rainfall in the period from 4^th of November 2005 until 7^th of March 2006 was 1354 mm with 17 days with more than 30 mm of rainfall.

The yield of fully ripe red tomatoes was on average 6 kg per plant. It should be mentioned that hardly, if any, yield was observed from tomato plants that were grown at the same time outside the tunnel structure.

The tomatoes were washed rigorously and then comminuted by chopping in a chopper pump to form a pulp. Next, a hot-break step took place in which the tomato pulp was recirculated through a shell-and-tube heat exchanger until a temperature of 95^°C was reached. After this, recirculation continued for another 5 minutes. Next, the tomato pulp was passed through a 1.4 mm screen. The resulting tomato juice was transferred to a single-effect forced recirculation evaporator and concentrated at a temperature between 65 and 70⁰C until the concentration level reached approximately 14°Bx. The resulting puree was heated until 90⁰C, put into cans and pasteurised for 10 minutes in a water bath of a temperature of 97°C. Next, the product was cooled down by flowing tap water for a period of 25 minutes over the cans. Next, colour using a colorquest 45/0 from Hunterlab and Bostwick of the resulting tomato puree were measured. The Bostwick level at 12°Bx was on average 2. Example 1 shows that regardless of the rain season, the process according to the invention provides a novel method of preparing a processed tomato product with excellent quality and with lower costs compared to the 'intermediate paste process'. Example 2: Growing tomatoes during the dry season in tunnel structures and in the open field in Goiania, Brazil (16°S,49°W)

Tomatoes of varieties HMX 4798, SVR 025 40 264, H9997, N 147, C901 , SVR 025 00 000, ISI 29616, SVR 025 10 566, C871 , Design, C877, H9205, H9992 and C232 were transplanted on 2^nd of May 2006 inside the tunnels. The tunnels were covered with diffuser poly-ethylene with UV protection. The tunnels were 4.5 meters wide and 65 meters long. Two rows were planted inside the tunnels and 4 plants per meter were transplanted. The plants were protected from the soil using a white mulch. The same varieties were transplanted on 16^th of May 2006 in the same field (i.e. the same soil conditions) outside the tunnels for comparison. Harvesting took place about 120 days after transplanting (i.e. 29^th of August and 12^th of September respectively). Total rainfall in this period was 35 mm. The daily average temperature averaged over the time of the growing cycle was slightly higher inside the tunnel structure compared to ambient (0.68⁰C). The daily relative humidity as averaged over the time of the growing cycle was 61.63% inside the tunnel structure, whereas outside the tunnel structure, this was higher, being 63.19%.

Of each variety, a pulp was prepared by washing the tomatoes and comminuting them by homogenisation in a kitchen blender. Colour a/b ,Brix and concentration of the nutrients Vitamin C, Vitamin E, Lycopene and β-Carotene were compared for varieties grown in a tunnel structure and grown in the open field. Growing in a tunnel structure did not have a negative effect on these parameters or at least showed a comparable value.

The tomato juice as described above is further processed as in Example 1 described above, resulting in a processed tomato product. To the surprise of the inventors the yield of plants cultured in a tunnel structure in the conventional tomato season is significantly higher than that of plants cultured outside despite the fact that the daily average temperature was only 0.68⁰C higher inside the tunnel than outside the tunnel. All tested varieties showed an increase in yield of red tomatoes per plant in kg when cultured inside a tunnel compared to the same varieties cultured in the open field. The yield increased up to an amount of 63%.

It is clear from example 2 that application of the process according to the invention results in a higher tomato yield, contributing to a cost saving of the production process of preparing a processed tomato product and hence to a reduction of the costs of the processed tomato product. Using the process of the invention, the reduction of the price of a processed tomato product is at least 15% and will reach about 30% when the increase in yield is taken into account.

Example 3: recipe of a pasta sauce comprising the processed tomato product.

A sauce was made using variety H9992 according to the formulation below.

A tomato sauce was prepared according to the process of the invention. In step (e) of the process, additional ingredients as indicated in the above table were added. This resulted in a tomato sauce.

Claims

1. Process for the manufacturing of a processed tomato product, comprising the steps of: a. providing tomatoes from plants from a determinate tomato variety, b. comminuting said tomatoes, c. optionally performing a breaking step on said comminuted tomatoes, d. optionally concentrating at least part of the product resulting from step (b) or (c), e. optionally adding additional ingredients to the product resulting from any of steps (b) to (d), f. packaging the product resulting from any of the steps (b) to (e), g. performing a preservation step to the product, characterised in that said plants are cultured using a structure that protects the tomato plants from rain.

2. Process according to claim 1 , wherein the determinate tomato variety is a variety producing fruits that after processing result in a tomato puree with a Bostwick level of less than 12 cm, measured at 12° Brix.

3. Process according to claim 1 or 2, wherein the determinate tomato variety is a hybrid variety.

4. Process according to anyone of the preceding claims, wherein the process is carried out in the period when the monthly average relative humidity of the ambient is more than 65%, preferably more than 75%, more preferably more than 85%.

5. Process according to anyone of the preceding claims, wherein the process is carried out in the period wherein the monthly average rainfall is higher than 180 mm., preferably higher than 200 mm.

6. Process according to anyone of the preceding claims, wherein the process further comprises a sieving step carried out after step (b) or (c), wherein an extractor comprising rotating blades or a vibrating sieve is used.

7. Process according to anyone of the preceding claims, wherein the optional concentration step (d) is carried out using a vacuum of 5066.25 to 81060 Pa (0.05 to 0.8 atm.) below the ambient pressure.

8. Process according to anyone of the preceding claims, wherein steam is used for any heating step.

9. Process according to anyone of the preceding claims, wherein the structure that protects the tomato plants from rain comprises a covering of polyethylene material.

10. Process according to anyone of the preceding claims, wherein the tomato variety is one of the following: Design; Hypeel 108; AP865; according to the register of the SERVIQO NACIONAL DE PROTEQAO DE CULTIVARES of the Ministry of Agriculture of Brazil, Tiziano (supplier: DeRueters); Dracula (supplier: DeRueters); PX755 (supplier: Seminis).

11. Process according to anyone of the preceding claims, wherein the additional ingredients added in optional step (e) comprise vegetables, like onions, extracts of vegetables, herbs, like e.g. basil or parsley, extracts of herbs, salt, monosodium glutamate or meat or a combination thereof.