Field of Invention

The present invention relates to a process for producing lycopene extract from tomatoes and tomato products thereof.

Background of the Invention

The carotenoid pigments occur widely in nature in fruits and vegetables, giving them their characteristic colour from yellow to dark red in numerous natural substances such as carrot, peppers, tomatoes, flowers or certain microorganisms. They can be divided into two classes: pure hydrocarbons such as the carotenes that include compounds such as beta-carotene, alpha-carotene or lycopene, and xanthophylls, which contain an oxygenated function, examples of this type being astaxanthin, capsanthin or cantaxanthin. The two groups of compounds exhibit different behaviour with regard to their physico- chemical properties and different solubility in organic solvents.

All these compounds play an important role in the human diet, and there have beer extensive studies of their properties as antioxidants for the prevention of cancer and other human diseases, and as vitamin A precursors. Moreover, on account of their yellow to red coloration, the carotenoids are used as food supplement and colorant in margarine, butter, oils, soups, sauces etc. (Ninet et al. Microbial Technology 2nd Edn. Vol. 1 529-544 (1979) Academic Press NY Eds Peppier HJ and Perlman D.). ^•

Lycopene is an open-chain unsaturated carotenoid that imparts red colour to tomatoes, guava, rosehip, watermelon and pink grapefruit. Its empirical formula is C ₄₀ H _56. Lycopene is a proven antioxidant. Antioxidants neutralize free radicals, which may damage the body's cells. Research also shows that lycopene in tomatoes can be absorbed more efficiently by the body if processed into juice, sauce, paste and ketchup. The chemical form of lycopene found in tomatoes is converted by the temperature changes involved in processing to make it more easily absorbed by the body.

In the body, lycopene is deposited in the liver, lungs, prostate gland, colon and skin. Its concentration in body tissues tends to be higher than all other carotenoids.

The properties of this compound have been studied extensively. Thus, its antioxidant properties have been described, capturing the free radicals that are produced continuously in the human body, and its application in the prevention of cardiovascular diseases and some types of cancers such as prostate cancer (Giovannucci et al., J Nat. Cancer Inst. 87:

1767-1776 (1995); Stahl et al., Arch Biochem. Biophys 336: 1-9 (1996); Clinton et al.,

Nutr. Rev. 56: 35-51 (1998)) which has given rise to an increase in demand on the part of consumers and therefore the industry has tried to satisfy this demand by manufacturing lycopene by chemical synthesis.

Patent WO 97/48287 describes a method of preparation of lycopene-rich oleoresins from tomatoes by crushing the tomato, subjecting them to heat treatment, extraction of lycopene from the pulp with organic solvents and subsequent elimination of the solvent by evaporation, leading to an oleoresin with a lycopene content in the range 2-10%.

Similar methods of obtaining oleoresins rich in carotenoids in general and lycopene in particular from plants and oils are disclosed in various patents US 5245095 and EP 580745 by precipitation with calcium salts, US 5019668 using a process of transesterification with oils followed by distillation, WO 95/16363 describes fractionation of the tomato in various fractions that include an oleoresin rich in carotenoids, and PCT WO 90/08584 describes the extraction of lycopene using fluids in a supercritical state although the extract obtained is a mixture of various carotenoids and the yields in extraction are very low owing to its low solubility.

In all these cases, owing to the low concentration of lycopene in these natural products and the intracellular distribution of this compound in certain organelles such as chloroplasts or chromoplasts, the extraction yields and product purity obtained are low, as there is production of lycopene-rich oleoresins or dehydrated raw products together with variable amounts of other carotenoid or non-carotenoid compounds. In most cases the methods of extraction described require preparation of the fruit by crushing and extrusion, subjecting the crushed tomatoes to heat treatment to facilitate solvent extraction.

On the other hand, patent WO 97/15554 describes the extraction of carotenoids of plant

origin starting from carrots and tomatoes, including lycopene, by the isolation of chloroplasts and chromoplasts, then digestion of the said organelles with hydrolytic enzymes of proteins such as pectins and/or proteases that permit the release of the lycopene joined to various structural proteins. By subsequent alkaline treatment and extraction with alcoholic mixtures of low molecular weight it is possible to obtain lycopene extracts with yield and purity greater than the oleoresins though without obtaining purified crystals of lycopene, but lycopene-rich raw extracts.

Another important source of lycopene is certain microalgae that are rich in carotenoids, of the Dulaniella type. Various methods of extraction of carotenoids from these organisms and in particular of lycopene have been described, e.g. in US 5378369, US 4713398 and

US 4680314, by extraction with organic solvents (chlorocarbonates, hydrocarbons, etc.) or edible oils DE 4342798. A different process is described in PCT WO 98/08584 where a lycopene extract is obtained using CO2 in the supercritical state, but the extract so obtained is of low purity with respect to lycopene.

Besides, lycopene can be obtained from certain Mucorales fungi such as Phycomyces, Blakeslea or Choanephora by fermentation in a liquid medium. Such technique has been disclosed in European Patent 1201762 and Japan Patent 2003304895.

There are a few drawbacks in the assisting technologies of lycopene extraction. The assisting technologies are either very complicated, need expensive apparatus or machines, low formation of lycopene, waste of raw materials or high production cost.

Summary of the Invention

It is therefore an object of the present invention to overcome the afore-mentioned drawbacks by providing a process for producing lycopene extract. The process according to the present invention is a clean process with efficient effects to obtain high quality lycopene extract.

It is another object of the present invention to provide a flexible process for the exploitation of tomatoes, which permits to manufacture a variety of end products

including tomato wine, fiber food, animal feed, pectin and lots more in various embodiments of the process.

It is a further object of the present invention to provide a process for the production of lycopene from tomatoes in the most efficient manner, in particular for obtaining oleoresin having an optimal combination of high lycopene content and lycopene stability.

It is yet a further object of the present invention is to provide a process for extracting lycopene, which without the addition of antioxidant agents will be capable of retaining the organoleptic and rheological properties of the product, such as the colour, flavor, texture, stability, aroma and shelf life.

Other objects of the invention will become apparent as the description proceeds.

The present invention relates to a process for producing lycopene extract comprising (a), subjecting tomatoes to cold crushing; (b). concentrating said crushed tomatoes to obtain tomato paste containing a pre-determined amount of lycopene; (c). extracting lycopene from said concentrated paste by compressing at least one extraction gas into a container containing said concentrated paste; (d). separating spent paste to obtain lycopene mixture; (e). recovering extraction solvent from said lycopene mixture by converting into gaseous form.

Preferably, the pre-determined amount of lycopene is at least 60mg/100g.

In the preferred embodiment of the present invention, said extraction gas is any one or combination of dimethy ester, propane or butane.

The process for producing lycopene extract from tomatoes according to Claim 1 , wherein said process further comprising a step of subjecting said concentrated paste to an enzymatic reaction prior to extracting lycopene from said concentrated paste.

The enzymatic reaction is carried out at a temperature in the range of about 30°C - 50°C by adding an enzyme. The enzyme is preferably any one or combination of cellulase, hemi-cellulase or pectinase in a ratio of about 2:1 :2.

In the preferred embodiment of the present invention, the process for producing lycopene extract from tomatoes according to the present invention further comprising a step of washing lycopene extract.

The step of washing lycopene extract comprising any one or combination of the step: a. washing with an alkali solution; b. washing with phytic acid or tannic acid or mixture thereof; c. washing with treated water; wherein said washing solution is separated and recovered after each washing process.

In the preferred embodiment of the present invention, wherein said alkali solution is any one or combination of NaOH, KOH or NaHCO ₃ ; the phytic acid is in a concentration of about 1 - 10%; and the tannic acid is in a concentration of about 0.5 - 5%.

The treated water used in the present invention is any one or combination of distilled water, deionized water, de-mineralized water or the like.

In the second embodiment of the present invention, the lycopene extracted tomato paste or spent paste can be further fermented to produce fruit wine. The process for producing fruit wine comprising: (a), subjecting said lycopene extracted paste to sterilization; (b). adding yeast into sterilized paste to form a mixture; (c). fermenting said mixture at a temperature in the range of about 50°C-70°C; (d). separating the spent paste from the fermented wine; (d). filtering said fermented wine to obtain pure wine.

In a further embodiment of the present invention, a process for producing tomato products such as fiber food comprising: (a), mixing said lycopene extracted tomato paste with an alkali solution; (b). discolouring the mixture from step (a); and (c). drying of said mixture to form powder.

The process for producing a tomato product according to the present invention, wherein said alkali solution and said lycopene extracted tomato paste is in a ratio of about 0.8 - 1 : 1 - 3. 18. The alkali solution having a pH in the range of about 8.5 - 9.0 and is preferably any one or combination of NaOH, KOH, Ca(OH) ₂ , or NaHCO ₃ .

Still, another further embodiment of the present invention comprises a process for producing a tomato product including lycopene extracted tomato paste obtainable from the present invention comprising: a. sterilizing said lycopene extracted tomato paste; b. adding an acid solution into said extracted tomato paste to form a mixture; c. heating up said mixture; d. filtering said mixture to separate liquid phase from said mixture; e. discolouring said liquid phase; and f. vacuum drying of said discoloured liquid phase wherein said food product is pectin.

In the preferred embodiment of the present invention, wherein said acid and lycopene extracted tomato paste is in a ratio of about 0.5 - 1 : 1 - 2 and said acid having a pH in the range of about 2 - 3, preferably any one or combination of HIC, HNO ₃ , H ₂ SO ₄ .

The mixture is then heated up to a temperature in the range of about 40°C - 7O ⁰ C.

Brief Description of the Drawings

Figure 1 illustrates in block diagram form, a preferred embodiment of the invention. Figure 2 illustrates in block diagram form, a variant embodiment of the present invention. Figure 3 illustrates in block disgram form, another embodiment of the present invention.

Detailed Description of the Preferred Embodiments

The present invention relates to a process for producing lycopene extract comprising: (a), subjecting tomatoes to cold crushing; (b). concentrating said crushed tomatoes to obtain tomato paste containing a pre-determined amount of lycopene; (c). extracting lycopene from said concentrated paste by compressing at least one extraction gas into a container containing said concentrated paste; (d). separating spent paste to obtain lycopene mixture; and (e). recovering extraction solvent from said lycopene mixture by converting into gaseous form.

The process according to the present invention can be carried out with any variety of tomato, but it is preferably employ high lycopene-containing varieties. This is because the higher content of lycopene in the tomato, the greater flexibility of the process and the ability to control the amounts of the various materials which are produced at certain time. Therefore, tomatoes containing about 60mg/100g of lycopene are preferably used as raw materials in the present invention. However, as stated above, the process is not limited to any particular variety of tomato.

The cold crushing of tomatoes according to the present invention includes washing of the selected tomatoes. After washing, the sorting is carried out to eliminate any remaining waste. Then the tomatoes are pressed and crushed according to cold breaking method. The peels and seeds of the pressed tomatoes are then separated from the pressed tomatoes. The product is then screened to eliminate remaining solid wastes, such as stems, foreign bodies and the like.

In the preferred embodiment of the present invention, the fine crushed tomato paste containing at least 60mg/100g of lycopene is then subjected to enzymatic reaction at a temperature in the range of about 3O ⁰ C - 5O ⁰ C by adding an enzyme. Preferably, the enzyme is any one or combination of cellulase, hemi-cellulase or pectinase in a ratio of about 2:1 :2. The purpose of enzymatic reaction is to break down the cell wall, cellulose and protein of tomatoes for ease of lycopene extraction.

The enzyme reacted tomato paste is then subjected to lycopene extraction. The extraction gases are first compressed into solvent form under a pre-determined pressure. Gases employed in the present invention consisting of propane, butane and dimethy ether. The solvent is then mixed thoroughly with the tomato paste to extract the lycopene from said tomato paste. The extracted lycopene is then separated from extracted paste and the extraction solvent is evaporated and recovered into gas form under reduced pressure. By using the method of compressing the gases into solvent form as an extraction medium, the solvent is much more easier to eliminate from the lycopene extract. This is because under reduced pressure, the solvent can be evaporated even in room temperature. Moreover, lesser or none of the residual will be left in the lycopene extract when compared with those extracted using solvent. A trace amount of residual will be left in the lycopene

extract if the solvent is used to extract lycopene. Therefore, the lycopene extract obtained according to the present invention is purer and cleaner compare with any other prior art.

Washing of lycopene extract is then carried out by means of different solvents. Preferably, the washing is carried out using alkali solution, acid and treated water in several stages. Firstly, the alkali solution preferably any one or combinations of NaOH,

KOH or NaHCO ₃ in the concentration of about 5%, 5% and 10% respectively is introduced into the washing container, mixed thoroughly, to eliminate aflatoxin (AF),

Patulin (Pat) and Sterigmatacystin (ST) which available in the tomato paste. The washing solvent is then subjected to further treatment and recovered for further uses. The ratio of concentrated lycopene and washing solvent is about 2:1.

Second stage of washing involving phytic acid or tannic acid or mixture thereof in a concentration of about 1-10% and 0.5-5% respectively. The ratio of lycopene and washing solvent in this stage is about 3-1: 1-0.3. The acid used may eliminate albumin and heavy metals from tomato paste. The washing solvent is then subjected to further treatment and recovered for further uses.

Lastly, the lycopene extract is washed with treated water preferably any one or combination of distilled water, deionized water, de-mineralized water or the like.

Preferably, the process for producing lycopene extract according to the present invention further comprising a step of drying of pure lycopene extract.

According to a further embodiment of the present invention, the spent paste or lycopene extracted tomato paste separated from lycopene extract may further subjected to a step of fermentation for producing of fruit wine. The lycopne extracted tomato paste is first subjecting to sterilization. The yeast for fermentation is then added into the lycopene extracted paste for fermentation. The fruit wine obtained from the fermentation is then filtered and the sediment is discarded to obtain the pure fruit wine. 99% of the pure fruit wine can be obtained by distillation.

In the preferred embodiment of the present invention, the fermentation of lycopene extracted paste comprising: (a), subjecting said lycopene extracted paste to sterilization; (b). adding yeast into sterilized paste to form a mixture; (b). fermenting said mixture at a

temperature in the range of about 50°C-70°C; (c). separating the spent paste from the fermented wine; (d). filtering said fermented wine to obtain pure wine.

The fermented paste separated from wine production process may further dried to produce animal feeds or food additives.

In a particular embodiment of the present invention, the lycopene extracted paste separated from lycopene extraction (without enzymatic reaction) may further processed to produce fiber food. A process for producing fiber food including lycopene extracted tomato paste (without enzymatic reaction) comprising: (a), mixing said lycopene extracted tomato paste with an alkali solution; (b). discolouring the mixture; and (c). drying of said discoloured mixture to form powder.

According to this embodiment, the lycopene extracted paste obtainable from lycopene extraction according to the present invention is further treated with an alkali solution. The alkali solution having a pH in the range of about 8.5 - 9.0 preferably any one or combination of NaOH, KOH, Ca(OH) ₂ , or NaHCO ₃ . The iatio of alkali solution and lycopene extracted paste is in a ratio of about 0.8 - 1 : 1 - 3.

After this, the mixture is discoloured using H ₂ O ₂ The discoloured mixture is then dried and grinded into power form.

Still, in another aspect of the present invention, a process for producing pectin including lycopene extracted paste obtainable according to the present invention comprising: (a). sterilizing said lycopene extracted tomoto paste; (b). adding an acid solution into said lycopene extracted paste to form a mixture; (c). heating up said mixture at a temperature in the range of about 40 ⁰ C - 70 ⁰ C; (d). filtering said mixture to separate liquid phase from said mixture; (e). discolouring said liquid phase; and (f). vacuum drying of said discoloured liquid phase.

The acid is having a pH in the range of about 2 - 3 preferably any one or combination of HIC, HNO ₃ , or H ₂ SO ₄ The amount of acid and lycopene extracted paste is preferably in a ratio of about 0.5 - 1 : 1 - 2.

The present invention presents the following advantages:

1. The percentage of lycopene extract produced according to the present invention is as high as 95%.

2. The content of aflatoxin, patulin and sterigmatacystin is very low or not detectable.

3. The content of heavy metals is < 2ppm.

4. The content of water is < 0.05% and soluble completely in water.

5. The cold crushing of tomatoes retains the fresh tomato flavors and therefore provides tomato products with stronger tomato flavor. 6. Cold crushing of tomatoes also minimized destroy of lycopene and subsequently provides tomato products with higher nutrition value.

7. The process according to the present invention provides a more economic, energy saving method for producing lycopene extract or food products thereof.

8. The process according to the present invention also provides a process for extracting lycopene by enzymatic reaction. The enzyme breaking down the cell wall, cellulose and protein in tomatoes for an easier way to obtain or extract lycopene from said treated tomotoes.

9. Compressing the extraction gas into solvent as an extracting medium according to the present invention produce a purer and cleaner lycopene extract. This is because the gas-compressed solvent can be evaporated _^ easily by reduced pressure.

Therefore, the possibility of residual remains in the lycopene extract is less compared with using extraction medium in solvent form.

10. The process according to the present invention fully utilizes the raw materials to produce various types of tomato products and is environmental friendly.

Another embodiment of the present invention including a machine for extracting lycopene by carrying out the process according to any one of embodiment of the present invention.

The present invention will hereafter be described in detail with reference to the accompanying examples, which intends to further illustrate the invention, without any intent for the invention to be limited to the specific embodiments described therein.

Example 1

The cold crushed tomato paste containing 65mg/100g of lycopene is poured into a container, and at the same time 200L of enzyme solution (prepared from 0.5kg of enzyme powder) is mixed with the tomato paste. The mixture is then stirred rigorously until a homogenous mixture is formed and heated up to 40°C. After 4 hours of enzymatic reaction, the mixture is poured into an extraction container. The gas of dichloromethane is compressed into solvent form and introduced into the extraction container. The pressure in the container is about 1.2mpa and the temperature not excess 35°C. The mixture is then mixed thoroughly until a homogenous mixture is obtained. Reduce the pressure to allow evaporation of the solvent.

The extracted lycopene is subsequently transferred into washing container and washed with alkali, acid, and water respectively at different stages. The washed lycopene is lastly vacuum dried and about 4.71kg of lycopene is formed. The product obtained from this process presents about 13.1% of purity. The dried lycopene extract may keep in a container with the present of N ₂ .

The lycopene extracted paste separated from lycopene extract is transferred into fermentation container for further fermentation. 450kg of fruit wine may be obtained from the process. The wine is then subject to filtering and discard of sediments to obtain pure wine.

Meanwhile, the fermented paste from wine production may further dried to produce animal foods.

It is to be understood that the present invention may be embodied in other specific forms and is not limited to the sole embodiment described above. However modification and equivalents of the disclosed concepts such as those which readily occur to one skilled in the art are intended to be included within the scope of the claims which are appended thereto.