WO2015133973A1

WO2015133973A1 - Low sugar fruit juice from 100% fruit juice and its process steps

Info

Publication number: WO2015133973A1
Application number: PCT/TH2015/000003
Authority: WO
Inventors: Cheunjit PRAKITCHAIWATTANA; Kiattisak HANSAWAT
Original assignee: Chulalongkorn University
Priority date: 2014-03-06
Filing date: 2015-01-22
Publication date: 2015-09-11

Abstract

This invention is related to the development of low sugar fruit juice from 100% fruit juice which comprises of 100% fruit juice as the main fruit juice mixed with 100% fruit juice of which sugar is reduced by biological process in the proportion that decreases the sugar content in 100% fruit juice served as the main fruit juice from 5- 50%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively. Low sugar fruit juice from 100% fruit juice can be kept as fresh, frozen, pasteurized in hermetically sealed package, commercially sterilized, and/or by using other means of reduction or inactivation of microorganisms to prolong its shelf life.

Description

TITLE OF THE INVENTION

LOW SUGAR FRUIT JUICE FROM 100% FRUIT JUICE

AND ITS PROCESS STEPS

TECHNICAL FIELD OF THE INVENTION Food technology, in particular, low sugar fruit juice from 100% fruit juice

This invention is related to low sugar fruit juice from 100% fruit juice which comprises of 100% fruit juice as the main fruit juice mixed with 100% fruit juice of which sugar is reduced by biological process in the proportion that decreases the sugar content in 100% fruit juice served as the main fruit juice from 5-50%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively. Low sugar fruit juice from 100% fruit juice can be kept as fresh, frozen, pasteurized in hermetically sealed package, commercially sterilized, and/or by using other means of reduction or inactivation of microorganisms to prolong its shelf life.

BACKGROUND OF THE INVENTION Fruit juice is nutritious. Generally, its main component is water while carbohydrate, sum of sucrose, glucose, fructose, and sorbitol, is at the amount of 1 1 -16 g/100 ml. There are small amount of protein and mineral. Certain types of juice contain high level of potassium, vitamin A, folate, and vitamins. Furthermore, fruit juice is a source of biologically active ingredients, particularly, antioxidants. Now, natural antioxidants especially from fruits are popular among consumers and researchers. A large number of epidemiological studies show that consuming natural antioxidants results in decreasing the risk of certain type of cancer and cardiovascular disease. Fruit antioxidants come from different compounds, for example, vitamin, phenolic compounds, nitrogen compounds, carotenoids, etc. Thus, product from 100% fruit juice is of the highest value among all products from fruit.

The requirements under Notification of the Ministry of Public Health (Number 214) B.E. 2543 (2000) has specified that "juice" packaged in hermetically sealed container shall have or be derived from fruits, plants, or vegetables whether or not carbonated or oxygenated. Juice is also classified as special controlled food. It shall be absent of pathogenic microorganisms and its contaminants do not exceed the maximum level. The use of sugar or other sweeteners shall be in accordance with the Codex Alimentarius Commission. Furthermore, labeling of the drinks shall be as follows:

1) "100% fruit juice" shall be used for fruit juice which has or is derived from fruit only

2) "100% fruit juice from concentrated juice" shall be used for fruit juice which is made by diluting of concentrated juice in order to obtain the juice which has similar quality and specification as required in 1) Absorption of carbohydrates from juice is explained as follows. Sucrose, glucose, and sorbitol are carbohydrates usually found in fruit juice. Sucrose is disaccharides which are hydrolyzed to glucose and fructose by sucrase at epithelium of small intestine. Glucose is then fast absorbed while fructose has slower absorption rate. The efficiency of fructose absorption will be faster and reach its maximum when fructose concentration is equal to that of glucose. Type of carbohydrates affects the absorption rate in the intestine. Indigested carbohydrates will cause osmotic load and diarrhea. Thus, quality of carbohydrates in juice directly affects the health of consumers.

Juice and overnutrition is explained as follows. Health related studies show positive relationship between sweetened drinks and increased body weight in children and adults as a result of excessive energy from several types of drinks. One of the drinks is fruit juice. A study shows prevalence of the overnutrition in children aged 2-5 years is increased in those who drink fruit juice. The research also reported that drinking sweetened drinks for a long period of time not only affects the body weight but also causes high level of triglycerides in blood. Recently, people is thus in doubt whether fruit juice is a healthy drinks even though the juice is a source of important nutrients and biologically active ingredients.

From the above concern, juice with low sugar content is produced by conventional method such as diluting with water. However, the drawback of this method is that the flavor and other nutrients are also diluted. The other method used to lower sugar content is ion-exchange membrane but it is complex and costly. Recently, there is a release of low sugar juice which is claimed that its ingredients are 100% natural. This type of product is mostly processed by extracting juice from plants other than low sugar fruits and adjusting sweetness by using Stevia. This juice lacks nutrients compared to 100% juice and also the consumer acceptance on its flavor.

U.S. Food and Drug Administration's Definitions of Nutrient Content Claim (sugar) are as follows:

- Low sugar: this term is not defined and may not be used.

- Reduced or less: At least 25% less sugars per Reference Amounts Customarily Consumed than an appropriate reference food (or for meals and main dishes, at least

25% less sugar per lOOg)

Biotechnology can be used to reduce sugar content in juice i.e. fermentation with beneficial bacteria which use acid and sugar as substrate and produce metabolites inhibiting growth of microorganisms and ingredients beneficial for health. Research shows possible use of lactic acid bacteria to develop fermented fruits and vegetables as healthy products and to extend shelf life as well as to reduce the risk of contamination from pathogenic microorganisms, for example, fermenting orange juice and pineapple juice using various strains of lactic acid bacteria. It is found that every strain of lactic acid bacteria tolerates low pH of 3.5 and survives low temperature of 4 °C during storage. During the fermentation of food and drinks with lactic acid bacteria, organic acids, hydrogen peroxide, diacetyl, carbon dioxide, and bacteriocin, an antimicrobial agent used for inhibiting contaminated foodborne pathogens, are produced. The use of lactic acid bacteria to reduce sugar and acid is only found in the study of malolactic fermentation in wine. There is no record of any other publication on the use of lactic acid bacteria in vegetable and fruit juice.

Sugar content can be reduced by lactic acid bacteria due to the fact that lactic acid bacteria can utilize monosaccharide and disaccharides. Lactic acid bacteria can be categorized to two main groups which are homo fermentative and hetero fermentative. Homo fermentative lactic acid bacteria metabolize hexose through glycolysis and yield two molecules of ATP. Hetero fermentative lactic acid bacteria and facultative lactic acid bacteria metabolize hexose and pentose through phosphoketolase and yield lactate, ethanol, carbon dioxides, and a molecule of ATP from each sugar. Furthermore, organic acids in grapes and wines such as malic acid, citric acid and tartaric acid can also be reduced by lactic acid bacteria. Citric acid will be well metabolized when hexose is present.

The report showed the use of starter, developed from strains naturally living in the same source where the raw material grows, called "authochthonous isolate" to ferment the same raw material resulted in better quality of products compared to those fermented by strains from different sources called "allochthonous isolate". The authochthonous isolate can easily adapt to the raw material hence its growth is rapid. It can also compete or inhibit the growth of contaminated spoilage microorganisms. Consequently, quality of fermentation can be better controlled.

Process step to inactivate microorganisms and extend shelf life of juice is thermal process such as pasteurization, ultra pasteurization, commercial sterilization, and ultra high temperature (UHT). Pasteurization is the most appropriate method to preserve the juice which is acidic (pH < 4.6) by using temperature less than 100 °C in order to inhibit the pathogenic and non-spore forming bacteria, as well as reducing number of non-heat resistant bacteria. To maintain the quality of juice, the pasteurized juice shall be kept under the condition unlikely allowed the growth of microorganisms such as refrigeration. There are two processes of pasteurization. One process called 'Low Temperature Long Time (LTLT)' is done by heating with lower temperature at 60 °C for 30 minutes and cooling immediately. The other process called 'High Temperature Short Time (HTST) is done by heating with higher temperature at 72 °C for 15 seconds and cooling rapidly. Pasteurized acidic juice in hermetically sealed container can be kept for more than 6 months. Additionally, there are other methods to reduce and inactivate microorganisms and extend shelf life of juice such as filtration, high pressure process, ozone treatment, etc.

Thus, this invention is based on applying and integrating the knowledge related to microorganisms which efficiently metabolize sugar in 100% fruit juice with the concept of various requirements on juice in order to obtain the health beneficial product and practical method for food processing.

DETAILED DESCRIPTION OF THE INVENTION

This invention is related to the low sugar fruit juice from 100% fruit juice which comprises of 100% fruit juice served as the main fruit juice mixed with 100% fruit juice of which sugar is reduced by biological process at the volume calculated from the actual concentration in any unit but it is best expressed as total soluble solid. The process is done by mixing the 100% fruit juice of which sugar is reduced by any percentage, preferably by 50% with the main juice from 100% fruit juice in order to obtain reduced sugar content compared to its initial sugar content. The sugar content in the main juice shall be reduced by 5-50%, preferably by 15%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively.

The 100% fruit juice used as the main juice can be obtained from any fruit. It can be the same or different from the fruit used to make desugared juice by biological process. However, the same type of fruit makes the best pairing. The same or different methods on keeping quality of the two types of juice can be used such as to be kept as fresh, pasteurization, or the other methods to reduce or inactivate microorganisms to extend its shelf life. Nevertheless, the juice kept as fresh gives the best result.

The 100% fruit juice of which sugar is reduced by biological process can be obtained from any fruit. The juice can be kept as fresh, pasteurized, sterilized, UHT, or derived from other processing methods to obtain aseptic juice. The best process is to use 100% juice frozen at -20 °C for at least 24 hours. The frozen juice shall be thawed in the refrigerator, and added sodium metabisulfite to obtain the final concentration at 200 mg/liter (w/v). The juice shall be kept for 18 hours at room temperature in order to inhibit the contaminated microorganisms. In case of fresh fruit juice, it shall be decontaminated with permitted food additives at the allowable quantity before fermentation. The best method is done by adding sodium metabisulfite to obtain the final concentration at 200 mg/liter (w/v) and keeping for 18 hours at room temperature. After that, the sugar in 100%» fruit juice shall be reduced by biological process which is fermentation with pure and mixed commercial starter culture and/or autochthonous isolate to ensure sugar molecules are mainly metabolized. The best method is to ferment with autochthonous isolate with the initial viable count at about 8 log₁₀ CFU/ml. It is also possible to have the initial viable count at 6-9 logio CFU/ml. The temperature and length of time for fermentation shall be 15-40 °C and 24-120 hours, respectively. The best method is at 25 °C for 72 hours. The growth of microorganisms shall be at 8-12 logio CFU/ml and/or sugar shall be reduced by 10-70% of total soluble solid. Preferably, the growth shall be at 9 logio CFU/ml and the sugar shall be reduced by 50% of its total soluble solid. Cells of microorganisms can be separated by filtration, cold precipitation, or centrifugation, preferably, with cold precipitation.

Furthermore, this invention is related to processing steps of the low sugar fruit juice from 100% fruit juice as follows:

(1) 100% Fruit juice as the main fruit juice mixed with 100% fruit juice of which sugar is reduced by biological process at the volume calculated from the actual concentration in any unit but it is best expressed as total soluble solid. The process is done by mixing the 100% fruit juice of which sugar is reduced by any percentage, preferably by 50%, with the main juice from 100% fruit juice in order to obtain reduced sugar content compared to its initial sugar content. The sugar content in the main juice shall be reduced by 5-50%, preferably by 15%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively.

Additionally, process steps of the low sugar fruit juice from 100% fruit juice can be obtained from desugaring of 100% fruit juice by microorganisms. The sugar content shall be reduced by 5-50%, preferably by 15% without mixing with the main juice. However, the best method is to mix with the main juice from 100% fruit juice as abovementioned.

(2) Low sugar fruit juice from 100% fruit juice can be preserved by methods such as freezing, pasteurization, commercial sterilization, UHT, or other methods to reduce or inactivate microorganisms to extend its shelf life.

The following examples additionally showcase the invention without limiting its scope.

Example of the invention Example 1 Processing steps of low sugar pineapple juice from 100% pineapple juice

1. Juice is prepared by peeling, cutting, and extracting ripe pineapple by juice extractor. The juice is then frozen at -20 °C for at least 24 hours before thawing and decontamination with sodium metabisulfite (KMS). The final concentration of KMS in the juice shall be at 200 ppm and the juice shall be kept for 18 hours. The total soluble solid of pineapple juice is 14 °Brix

2. Lactobacilus plantarum 621 starter culture at the concentration of 10 logio CFU/ml is prepared in 100% pineapple juice thermally treated by UHT. The starter culture is then added to the juice prepared for fermentation at the amount of 10% of the total volume of the prepared juice and fermented at 25 °C for 72 hours. Sugar content in the fermented juice is now reduced by 50%. The desugared juice shall be kept in the refrigerator for 24 hours. Later, the sediment is removed from the fermented juice. The fermented juice with total soluble solid of 7.2 °Brix is used in the next step. 3. The frozen pineapple juice prepared in Step 1 shall be thawed and used as the main ingredient for low sugar pineapple juice. Pearson square is used to calculate the ratio between main juice and fermented juice. In order to produce low sugar pineapple juice (in which sugar is reduced by 15%), the ratio between main juice and fermented juice is 2.1 :4.7. In order to produce less sugar pineapple juice (in which sugar is reduced by 25%), the ratio between main juice and fermented juice is 3.3:3.5

Example 2 Processing steps of low sugar orange juice from 100% orange juice

1. Orange juice for fermentation is prepared by using 100% orange juice thermally treated with pasteurization. It is then filled in an aseptic container. The total soluble solid of orange juice is 11 °Brix. 2. Lactobacilus plantarum 621 starter culture at the concentration of 10 logio

CFU/ml is prepared in 100% orange juice thermally treated with pasteurization. The starter culture is then added to the juice prepared for fermentation at the amount of 10% of the total volume of the prepared juice and fermented at 25 °C for 36 hours. Sugar content in the fermented juice is now reduced by 30%. The desugared juice shall be kept in the refrigerator for 24 hours. Later, the sediment is removed from the fermented juice. The fermented juice with total soluble solid of 7.7 °Brix is used in the next step.

3. The pasteurized orange juice prepared in Step 1 is also used as the main ingredient for low sugar orange juice. Pearson square is used to calculate the ratio between main juice and fermented juice. In order to produce low sugar orange juice (in which sugar is reduced by 15%), the ratio between main juice and fermented juice is 1:1. In order to produce less sugar orange juice (in which sugar is reduced by 25%), the ratio between main juice and fermented juice is 0.85:2.75

Best Mode for Carrying out the Invention

As specified in the detailed description

Claims

1. Low sugar fruit juice from 100% fruit juice comprises of 100% fruit juice as the main fruit juice mixed with 100%» fruit juice of which sugar is reduced by biological process in the proportion that decrease the sugar content in 100% fruit juice served as the main fruit juice from 5-50%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively.

2. Low sugar fruit juice from 100% fruit juice according to claim 1, wherein the 100% fruit juice as the main fruit juice can be obtained from juice of any kind of fruit. It can be the same or different from the juice used to make desugared juice by biological process. The main juice may be fresh, frozen, pasteurized, commercial sterilized, and/or treated with other methods to reduce or inactivate microorganisms to extend its shelf life.

3. Low sugar fruit juice from 100%) fruit juice according to claim 2, wherein the preferred process step is by to use the same kind of fruit for both main juice and fermented juice. The juice shall be frozen at -20 °C for at least 24 hours.

4. Low sugar fruit juice from 100% fruit juice according to claim 1, wherein the 100% fruit juice of which sugar is reduced by biological process is obtained from fermentation of 100%) fruit juice with initial viable count of 6-9 logio CFU/ml in pure and mixed commercial starter culture and/or autochthonous isolate at 15-40 °C for 24-120 hours. The growth of microorganisms shall be at 8-12 logjo CFU/ml and/or sugar shall be reduced by 10-70% of total soluble solid. Cells of microorganisms shall be separated by filtration, cold precipitation, or centrifugation.

5. Low sugar fruit juice from 100% fruit juice according to claim 4, wherein the 100% fruit juice of which sugar is reduced by biological process is preferably obtained from fermentation of 100% fruit juice with pure and mixed autochthonous isolate with the initial viable count at about 8 logi₀ CFU/ml at 25 °C for 72 hours. The growth shall be at 9 logio CFU/ml and/or the sugar shall be reduced by 50% of its total soluble solid. Cells of microorganisms shall be separated by cold precipitation.

6. Low sugar f uit juice from 100% fruit juice according to claims 4 or 5, wherein the 100% juice used during fermentation can be obtained from any kind of fruit. The juice may be fresh, frozen, pasteurized, commercial sterilized, and/or treated with other methods to reduce or inactivate microorganisms to extend its shelf life.

7. Low sugar fruit juice from 100% fruit juice according to claim 6, wherein the best process step is to use the juice frozen at -20 °C for at least 24 hours.

8. Low sugar fruit juice from 100% fruit juice according to claim 1, wherein the best ratio between the main fruit juice and biologically desugared juice is at which sugar content of the main fruit juice is reduced by 15%.

9. Process steps of low sugar fruit juice from 100% fruit juice wherein the process is done by mixing the 100% fruit juice as the main fruit juice with 100% fruit juice of which sugar is reduced by biological process at the ratio that decreases the sugar content of the main juice by 5-50%. Total soluble solid, titratable acidity and pH are 7.0-14.0 °Brix, 0.50-1.80%, and 3.0-4.6, respectively. Low sugar fruit juice from 100% fruit juice can be preserved by methods such as freezing, pasteurization, commercial sterilization, and/or other methods to reduce or inactivate microorganisms to extend its shelf life.

10. Process steps of low sugar fruit juice from 100% fruit juice according to claim 9, wherein 100% fruit juice of which sugar is reduced by biological process is processed under aseptic condition. In case of fresh fruit juice, it shall be decontaminated with permitted food additives at the allowable quantity before fermentation.

11. Process steps of low sugar fruit juice from 100% fruit juice according to claim 10, wherein the preferred method of chemical decontamination is by adding sodium metabisulfite to obtain the final concentration at 200 mg/liter (w/v) and keeping for 18 hours.

12. Processing steps of low sugar fruit juice from 100% fruit juice according to claim 9, wherein the best ratio between the main fruit juice and biologically desugared juice is at which sugar content of the main fruit juice is reduced by 15%.

13. Processing steps of low sugar fruit juice from 100% fruit juice according to claim 9, wherein low sugar fruit juice from 100% fruit juice can be made by fermentation of 100% fruit juice with microorganisms to decrease the sugar content by 5-50% without mixing with the main fruit juice. The preferred method is done by mixing with the main fruit from 100% fruit juice.

14. Processing steps of low sugar fruit juice from 100% fruit juice according to claim 9, wherein low sugar fruit juice from 100% fruit juice can be kept as fresh or using methods such as freezing, pasteurization, commercial sterilization, and/or the others to reduce or inactivate microorganisms to extend its shelf life.