USE OF SOLUBLE TOMATO SOLIDS FOR REDUCING THE SALT CONTENT OF FOOD PRODUCTS

Abstract

The present invention is primarily directed to a method for reducing the amount of sodium chloride in a food product without adversely affecting the salty taste thereof, comprising adding soluble tomato solids (STS) to said food product and reducing the amount of salt normally added thereto. In a preferred embodiment of this method, the STS used is characterized in having an acidity level, formol number and color intensity within certain defined ranges or with defined minimal/maximal values.

Claims

1-9. (canceled)

10. A method for partially replacing salt in potato crisps comprising the steps of: a) preparing a seasoning pre-blend comprising defined amounts of salt and powdered STS; b) adding a defined amount of said seasoning pre-blend to a batch of potato crisps or said foods and mixing said pre-blend with said crisps.

11. The method according to claim 10, wherein the STS used is characterized in having an acidity level within the range of about 3% to about 4%.

12. The method according to claim 10, wherein the STS used is characterized in having: a) an acidity level within the range of about 3% to about 4%; b) a formol number greater than about 400, preferably greater than 500; and c) a color intensity of up to 20, preferably up to 15 wherein said color intensity value is determined as the a.sup.2+b.sup.2 value derived from a colorimetric measurement; wherein said acidity level, formol number and color intensity number are measured in a STS sample having a concentration of 60 Brix.

13. The method according to claim 10, wherein the addition of the pre-blend to the potato crisps and the mixing together thereof is performed in a tumbler.

14. The method according to claim 10, wherein the pre-blend mixture of powdered STS and salt comprises up to about 50% w/w powdered STS, wherein the total amount of said mixture added to the potato crisps is substantially equal to the amount of salt added to regular salted crisps.

15. The method according to claim 10, wherein the pre-blend mixture of powdered STS and salt comprises up to 50% w/w powdered STS and more than 50% salt, wherein the total amount of said mixture added to the potato crisps is substantially equal to the amount of salt added to regular salted crisps.

16. A reduced salt food product comprising STS and a reduced amount of salt when compared to the regular fully-salted product, wherein said food product has a saltiness substantially similar to that of the regular fully-salted product, and is substantially devoid of any additional tomato-derived flavors.

17. The reduced salt food product according to claim 16, when prepared by a method for reducing the amount of sodium chloride in a food product without adversely affecting the salty taste thereof comprising adding soluble tomato solids (STS) to said food product and reducing the amount of salt normally added thereto.

18. The reduced salt food product according to claim 16, wherein said food product is selected from the group consisting of fried snack foods, baked snack foods, breads, seeds and nuts, powdered seasonings and flavors, powdered spices, powdered soups, soups in liquid form, instant powder gravies and sauces, gravies and sauces in liquid form, table and/or cooking salt, dried herbs and breakfast cereals.

19. The reduced salt food product according to claim 18, wherein said product is a fried snack food product.

20. The reduced salt food product according to claim 19, wherein said product comprises potato crisps.

21. The reduced-salt food product according to claim 16, wherein said product is selected from the group consisting of fried snack foods, baked snack foods, breads, seeds and nuts, powdered seasonings and flavors, powdered spices, powdered soups, soups in liquid form, instant powder gravies and sauces, gravies and sauces in liquid form, table and/or cooking salt, dried herbs and breakfast cereals.

22. The reduced-salt product according to claim 21, wherein said product is a fried snack food product.

23. The reduced-salt product according to claim 22, wherein said product comprises potato crisps.

24. A salty taste enhancing composition comprising STS, wherein the STS is characterized in having an acidity level within the range of about 3% to about 4%.

25. A salty taste enhancing composition comprising STS, wherein the STS is characterized in having: a) an acidity level within the range of about 3% to about 4%; b) a formol number greater than about 400, preferably greater than 500; and c) a color intensity of up to 20, preferably up to 15 wherein said color intensity value is determined as the a.sup.2+b.sup.2 value derived from a colorimetric measurement; wherein said acidity level, formol number and color intensity number are measured in a STS sample having a concentration of 60 Brix.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] As mentioned hereinabove, the present inventors have previously reported the flavor enhancement properties of an STS preparation (at a 60 Bx concentration).This natural, additive-free product contains significant amounts of sugars (fructose and glucose together account for about 37-39% of the total weight of the STS) and free amino acids (approximately 8.5%, of which 2.5% is Glutamic acid).

[0059] The process for producing STS (at a concentration of 60Bx) is described in U.S. Pat. No. 6,890,574, which is incorporated in its entirety into the present disclosure. Briefly, tomatoes are processed (as described in U.S. Pat. No. 5,837,311, in order to obtain two fractionsan STS-rich tomato serum and a pulp. Following heat treatment, the serum is then concentrated to a Brix level higher than 4.5, for example 60 Bx (or any other desired Bx strength). This concentration step is commonly performed using a continuous evaporator, by means of feeding said evaporator with a continuous stream of serum at an elevated temperature, usually for a period of greater than 20 minutes, under vacuum.

[0060] It is to be noted that the clear (i.e. non-opaque) property of the STS (which relates to the absence of insoluble tomato solids) is apparent only when it is diluted to Brix value of about 4.5 Bx. At higher Bx levels (including the 60 Bx level as used in the STS of the examples of the present invention), the product is opaque.

[0061] The process of preparing STS described hereinabove yields at all Bx values, a liquid product that is suitable for addition (at, for example, 60 Bx) to liquid based foods and beverages. However, in order to incorporate the STS into solid food products (in particular, into snack foods such as potato crisps) a powdered form has been developed by the present inventors. This powdered form is produced by drying the STS (by means of either spray drying on a suitable carrier such as maltodextrins (as described in co-owned U.S. Pat. No. 6,890,574), or by using any other suitable dehydration step that is well known to the skilled artisan in this field). In this powdered preparation (as used in the present invention), the water in the STS 60 Bx (approximately 50%) is substituted with maltodextrins.

[0062] It has unexpectedly been found by the present inventors that the powdered form of STS may be used to partially reduce the level of salt normally used to flavor potato crisps and other food products, thereby reducing the total salt concentration in said products. Furthermore, by carefully selecting the relative amounts of STS and salt, products having flavor properties very similar to those containing the regular salt level products (i.e. equivalent levels of saltiness without the significant addition of tomato-derived flavors) may be obtained. The use of the powdered form of the STS to partially replace the salt in potato crisps is described in Example 1, below.

[0063] As mentioned hereinabove, the present inventors have now found that it is necessary to control certain properties of the STS within defined ranges in order to achieve optimal salty-taste enhancing characteristics. These properties include titratable acidity, formol number and color intensity. It is to be noted that the STS compositions having properties that fall within these ranges also possess other flavor-enhancing properties. However, it has been further found by the inventors that when said properties of the STS compositions fall within other defined ranges, said compositions possess flavor enhancing properties only (i.e. they lack the specific ability to replace or partially replace salt). The extensive investigations carried out by the inventors have led them to define the following ranges for the aforementioned properties:

TABLE-US-00001 Values for STS as Values for STS as salty-taste and flavor enhancer Properties flavour enhancer: only: Formol Number 40, preferably 43 40, preferably 43 in 5 Bx STS Formol Number 40, preferably 43 40, preferably 43 in 5 Bx Tomato Serum* Formol Number 400, preferably 500 400, preferably 500 in 60 Bx STS % acidity 3%-4% 3.0% (expressed as % Citric Acid) in STS % acidity 0.25%-0.33% 0.25% (expressed as % Citric Acid) in Tomato Serum* Color intensity 20, preferably 15 20, preferably 10 a.sup.2 + b.sup.2 In STS

[0064] These defined numerical ranges now permit, for the first time, the manipulation of the indicated properties of STS in order to pre-determine the type of flavor enhancement that is to be obtained using STS-containing compositions.

[0065] Titratable acidity is a measure of the content of acids determined by titration with sodium hydroxide solution to a pH-value of 8.1, The measurement of titratable acidity is well known in the art, and the details of one commonly used method may be found in the protocol (reference number IFUMA03) published by the International Federation of Fruit Juice Produce (Paris, France; obtainable on-line at http://www.ifu-fruitjuice.com/indexcommande.php). The titratable acidity determined by this method (expressed in units of mmoles of H.sup.+ per liter) may be converted to the equivalent of citric acid by means of multiplying the titratable acidity value mentioned above by the specific conversion factor for citric acid, 0.064, thereby yielding a result expressed in grams per liter.

[0066] The determination of formol number (a measure of the number of amino acid groups) is also well known to all skilled artisans in the field. The method is based on titration of amino acids with formaldehyde in the presence of potassium hydroxide, in accordance with the following reaction:

RCH(NH.sub.2)COOH+HCHO+KOH.fwdarw.RCH (NHCH.sub.2OH) COOK+H.sub.2O

[0067] The determination of formol number takes place in three steps:

[0068] 1) Neutralisation of titratable acidity by means of an end point titration at pH 8.2 with NaOH 0.1 eq/l

[0069] 2) Addition of an excess of formol (HCHO) to the solution. This operation locks the NH.sub.2 groups of amino acids due to the decrease in pH and allows titration of the COOH groups of amino acids with an end point titration at pH 8.2

[0070] 3) Second endpoint titration at pH 8.2 to determine total amino acid content. The details of one commonly used standard method for determining the formol number may be found in the protocol (reference number IFUMA30) published by the International Federation of Fruit Juice Produce (details given above).

[0071] A color intensity value (a.sup.2+b.sup.2) which may be used as a browning evaluation index may be calculated directly using the software associated with most modern tristimulus calorimetric devices (e.g. the HunterLab type ColorQuest XE calorimeter).

[0072] The titratable acidity and the formal number of the STS may be influenced by means of selecting tomato strains having fruit that yield sera having these factors within the desired range. Thus, in one preferred embodiment, the STS may be prepared from a tomato serum having an acidity level within the range of about 0.25% to about 0.33%, and a formol number of at least 40 (at a concentration of 5 Brix).

[0073] Tomato strains suitable for preparing such sera include (but are not limited to): [0074] H-9780 (Heinz, USA) [0075] AB-2 (A.B. Zeraim Ltd., Israel)

[0076] Additional factors which may influence the titratable acidity and the formol number of the STS include the growth conditions use to cultivate the tomato plants (including climate, soil type etc.). These factors are well known to the skilled artisan in this field and may be advantageously selected or altered in order to obtain tomatoes that yield serum having the desired acidity. Further refinement of the acidity and formal number of the STS may also be achieved by blending sera obtained from two or more different strains.

[0077] In addition to the selection of tomato strains yielding serum having the desired formol number, it is important to carefully control the exposure of the serum and of the STS prepared therefrom to heat during processing and storage, in order to prevent an undesirable reduction in said formol number.

[0078] The browning evaluation index (color value) of the STS may similarly be controlled, such that said index has a value of 20 or less, by means of avoiding excessive exposure of the tomato serum to high temperatures with a combination of long time during STS preparation. This reduction in exposure to high temperature with a combination of time may be achieved by means of selecting tomato strains yielding serum having higher Brix levels. In this way the evaporation ratio (i.e. the ratio between the final concentration of the STSusually 60 Bxand the concentration of the serum prior to evaporation) is reduced. In such a situation, less harsh conditions of temperature and time may be used in order to obtain the final desired concentration. In one preferred embodiment, the evaporation ratio is not greater than 15. In a still more preferred embodiment, the evaporation ratio is not greater than 10.

[0079] As already mentioned, STS (in either its powdered or liquid forms) may be used to replace the salt in many different products. The following non-exhaustive, non-limiting lists provide examples of such products:

[0080] Food products in which the salt may be partially replaced by powdered STS:

[0081] 1 Potato chips and/or crisps (salted or seasoned, with or without added oil)

[0082] 2. Baked snacks (salted and seasoned, with or without added oil)

[0083] 3. Fried snacks (salted and seasoned, with or without added oil)

[0084] 4. Extruded baked and fried snacks (salted and seasoned, with or without added oil)

[0085] 5. Powdered seasonings and flavors

[0086] 7. Powdered spices

[0087] 8. Powdered soups

[0088] 9. Instant powder gravies and sauces

[0089] 10. Table and/or cooking salt

[0090] 11. Dried herbs

[0091] Food products in which the salt may be partially replaced by liquid STS:

[0092] 1. Baked snacks (salted and seasoned, with or without added oil)

[0093] 2. Fried snacks (salted and seasoned, with or without added oil)

[0094] 3. Extruded baked and fried snacks (salted and seasoned, with or without added oil)

[0095] 4. Breakfast cereals

[0096] 5. Gravies and sauces in liquid form

[0097] 6. Soups in liquid form

[0098] 7. Breads and other savory baked products

[0099] 8. Seeds and nuts.

[0100] 9. Meat products

[0101] The following examples are provided for illustrative purposes and in order to more particularly explain and describe the present invention. The present invention, however, is not limited to the particular embodiments disclosed in the examples.

EXAMPLE 1

Partial Replacement of Salt in Potato Crisps by Powdered STS

[0102] Materials and Methods: [0103] 1. Unsalted potato crisps (WalkersSmith UK) were purchased in a local supermarket. [0104] 2. Salt and powdered STS were blended as follows: [0105] a. 0.75 g salt (1.5% in finished product)=Reference. [0106] b. 0.625 g Salt+0.125 g STS. (1.25% salt in finished product) [0107] c. 0.5 g salt+0.25 g STS. (1% salt in finished product) [0108] d. 0.325 g salt+0.325 g STS (0.75% salt in finished product [0109] 3. A series of 50 g batches of crisps were put in a laboratory-scale conical tumbler and heated with an electric heat gun for 30 seconds. [0110] 4. The appropriate salt and powdered STS blends were sprinkled onto each batch of the heated crisps while tumbling for 2.5 minutes. [0111] 5. An internal taste panel was conducted in order to compare crisps flavored with the various salts and STS blends. The results are presented in the following table:

TABLE-US-00002 % Salt (w/w) in finished % of salt product Blend reduction results 1.5 0.75 g salt + 0 g STS 0 Typical salty crisps taste 1.25 0.625 g Salt + 0.125 g STS 16.6% Very good taste. Salty taste was not infected. 1 0.5 g salt + 0.25 g STS 33.3% Salty taste was not infected. Minor tomato taste 0.75 0.325 g salt + 0.325 STS .sup.50% Minor reduction in salty taste. Minor tomato taste.

[0112] The results of this study indicate that a salt reduction in potato crisps of up to about 50% may be achieved with minimal taste change, by the addition of powdered STS to the seasoning. Furthermore, salt reduction in said crisps of up to about 33.3% may be achieved with no loss whatsoever of saltiness in the product.

EXAMPLE 2

Partial Replacement of Salt in Barbecue (BBQ) Flavored Potato Crisps by Powdered STS

[0113] Materials and Methods: [0114] 1. Unsalted potatoes crisps (Extra) were obtained from EliteFrito-Lay Israel. [0115] 2. The following basic BBQ seasoning composition was used in this study:

TABLE-US-00003 Ingredient (%) Chili powder 30 (salt free) Sugar 25 Citric acid 3 Paprika (sweet) 25 Onion powder 10 Garlic powder 8 [0116] 3. The BBQ seasoning was blended with powdered STS as follows:

TABLE-US-00004 No. 1 (control) No. 2 No. 3 No. 4 Ingredient (% w/w) (% w/w) (% w/w) (% w/w) BBQ seasoning 85 85 85 85 Salt 15 12.5 10 7.5 Powdered STS 0 2.5 5 7.5 [0117] 4. 50 g batches of crisps were heated in a microwave oven for 30 seconds. [0118] 5. The batches of warm crisps were placed in plastic bags. [0119] 6. 10% (w/w) of the blends 1-4 were sprinkled on the potato crisps with the seasoning blends as follows:

TABLE-US-00005 In finished product 1 (control) 2 3 4 % (w/w) Salt 1.5 1.25 1.0 0.75 % ((w/w) STS 0 0.25 0.5 0.75 [0120] 7. The bags were shaken for 1-2 minutes. [0121] 8. An internal taste panel was conducted in order to compare crisps flavored with the various salt and STS blends. The results are presented in the following table:

[0122] Results:

TABLE-US-00006 % powdered % salt in STS in Reduction finished finished of salt No. product product (%) results 1 (control) 1.5 0 0 Typical BBQ taste with salt 2 1.25 0.25 16.6% Less salty taste than 1. 3 1 0.5 33.3% Salty taste similar to 1 Minor tomato taste. 4 0.75 0.75 .sup.50% Reduction in salty taste. Minor tomato taste.

[0123] The results of this study indicate that a salt reduction in potato crisps of up to about 50% may be achieved with minimal taste change, by the addition of powdered STS to the seasoning. Furthermore, salt reduction in said crisps of up to about 33.3% may be achieved with no loss whatsoever of saltiness in the product.

EXAMPLE 3

Partial Replacement of Salt in Bread by Liquid STS

[0124] Breads generally contain about 1.5-2% salt. The purpose of this study was to reduce the salt level in bread by substituting part of the salt with liquid STS.

[0125] Materials and Methods:

TABLE-US-00007 Sample Sample Sample Sample Materials 1 (g) 2 (g) 3 (g) 4 (g) Instructions Hard winter 450 450 450 450 Place in a white wheat flour dough mixer Hydrogenated 9 9 9 9 Place in the vegetable fat dough mixer and mix Baking 25 25 25 25 Place in the improver dough mixer and continue mixing Fresh yeasts 25 25 25 25 Mix together Sugar 4.5 4.5 4.5 4.5 with the sugar and part of the water. Add to the mixer and keep mixing Salt 7.5 5 5 5 Mix with part of the water. Add in the end Liquid STS 0 2.5 0 0 Mix together with salt and water Tap water 250 250 250 250 Temperature 28-30 C. Mix the ingredients until a uniform mix is formed. Remove portions of the dough and allow them to rest for 5 minutes. Knead the dough by hand and flatten it with a rolling pin. Roll the dough and put in baking dish and in warm chamber (40 C.) for 35 minutes until it doubles its volume. Pre-warm a baking oven to 220 C. and place the baking dish, lower the temperature to 180 C. and bake for 35 minutes. Remove the bread from the baking dish and place it on a steel net to cool.

[0126] Results and Conclusions:

TABLE-US-00008 Sample No. % Salt* % STS* Results 1- reference 1.66 0 Regular bread taste 2 - 33% less salt 1.11 0.55 Taste like the reference 3 - 33% less salt 1.11 0 Less salty *% of the flour

EXAMPLE 4

Partial Replacement of Salt in Roasted Sunflower and Pumpkin Seeds by Liquid STS

[0127] Roasted sunflower and pumpkin seeds, which are consumed as a snack food product in many countries, generally contain about 1.5-2% salt. The purpose of this study was to partially replace the salt in these seeds by liquid STS.

[0128] Materials and Methods: [0129] 1. Fresh de-hulled sunflower and pumpkin seeds were purchased in a local supermarket. [0130] 2. Salt and water or/and liquid STS were blended and sprayed on the seeds using a conical laboratory tumbler as follows: [0131] a. 1.6% salt in finished product6.2% of saturated (26%) salt solution=Reference. [0132] b. 33% less salt with liquid STS6.2% of a salt (17.5%) and liquid STS (8.5%) solution. [0133] c. 50% less salt with liquid STS6.2% of a salt (13%) and liquid STS (13%) solution. [0134] 3. The seeds were heated and roasted with an electric heat gun for 2.5 minutes. [0135] 4. The seeds were cooled in a dish. [0136] 5. The samples were tested by a taste panel

[0137] Results:

TABLE-US-00009 % Salt in finished Liquid % of salt product STS % w/w reduction results 1.6 - reference 0 0 Salty typically taste 1.07 0.53 33% More salty than the reference, An attractive tan color 1.07 0 33% Similar salty taste as the reference. An attractive tan color 0.8 0.8 50% Similar salty taste as the reference. Attractive tan color 0.8 0 50% Less salty than the reference. Attractive tan color

EXAMPLE 5

Effect of STS Acidity on Salty-Taste and Flavor Enhancement of Tomato Juice

[0138] In this study, tomato juice was used as a model for the evaluation of salt and taste enhancement. The basic formulation used had the following composition:

TABLE-US-00010 Ingredients Content Tomato concentrate 28 bx 15% Cold water (15 C.) 85% Salt 0.125%*.sup. STS 1%* *Added

[0139] Two separate batches of STS were selected for use in this study: one having an acidity (measured as citric acid equivalent) of 3.5%, while the acidity of the other batch was 2.5%.

[0140] These two batches, together with a third sample from which the STS (but not the salt) was omitted were sampled by a professional taste panel, using a semi-quantitative 1-10 scale (0=none; 10=extensive). The results are presented in the following table:

TABLE-US-00011 Overall Tomato Products taste flavour Acidity Saltiness Reference 5 5 5 5 Reference + STS 8 8 6 8 3.5% acidity Reference + STS 8 8 5 5 2.5% acidity

[0141] It may be seen from the above results that the STS batch with 3.5% acidity resulted in a significantly greater enhancement of the saltiness of the tomato juice than the batch having an acidity of 2.5%. Both batches caused a similar, significant enhancement of other flavours (overall taste and tomato flavour).

EXAMPLE 6

Effect of STS Acidity on Salty-Taste and Flavor Enhancement of Potato Chips

[0142] Four separate batches of potato chips were prepared with different amounts of salt and STS powder, as indicated in the following table. Two different STS samples were selected for use in this study: one having an acidity of 3.5% and the other having an acidity of 2.5%.

[0143] A comparison of these batches with respect to various taste and flavor properties was performed by a panel of professional tasters. Scores are given on a 0-10 scale which 0=none, 10=extensive.

TABLE-US-00012 Overall Potato Product taste flavour Acidity Saltiness Potato chips 1.5% salt 10 6 0 10 less salt Potato 5 5 0 5 chips (1.0% salt) less salt Potato 10 8 2 10 chips + 0.5% STS powder** 3.5% acidity less salt Potato 8 8 0 5 chips + 0.5% STS powder** 2.5% acidity **prepared by spray drying STS on Maltodextrin

[0144] As will be seen from these results, the batch that included STS with an acidity of 3.5% performed much better as a salt replacer than the batch having an acidity of 2.5%. Both batches caused a similar, significant enhancement of other flavours (overall taste and potato flavour).

EXAMPLE 7

Effect of Browning and Formol Number on STS Efficacy in Salty-Taste Enhancement and Flavor Enhancement in Tomato Juice

[0145] It has been found that a high degree of browning influences the ability of STS to enhance both salty taste and flavor.

[0146] This effect is illustrated in the following study that was performed using tomato juice with and without STS. In one of the batches the tomato juice included 1% browned STS, while another batch included 1% non-browned STS. The browned STS batch was prepared by exposing the tomato serum used to prepare said batch to an excessively high temperature during the evaporation stage.

[0147] Flavor evaluation was performed by a panel of professional tasters. Scores are given on a 0-10 scale in which 0=none and 10=extensive. The panelists were also asked to indicate their preferred product. Preference was scored as percentage against a reference product without STS. In addition, the formol number of each of the STS batches was measured. The results of these tests are shown in the following table:

TABLE-US-00013 Color intensity Formal a.sup.2 + b.sup.2 number Overall Tomato Products In STS.sup.1 in STS taste flavor Acidity Saltiness Bitterness Preferences.sup.2 Reference 5 5 5 5 3 without STS Reference 13 45 8 8 6 8 2 100% +1% non browned STS Reference 25 35 4 4 5 4 4 20% +1% browned STS .sup.1Color intensitybrowning evaluation index. .sup.2preferences% preferred on reference product.

[0148] The results indicate that the non-browned STS sample (i.e. the sample having a color intensity value of 15 or less and a formol number of 45) was greatly superior to the browned STS sample with regard to the ability of said samples to cause enhancement of saltiness and of other flavors.

[0149] While specific embodiments of the invention have been described for the purpose of illustration, it will be understood that the invention may be carried out in practice by skilled persons with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.