Fermented fruit juice

Abstract

To provide a fruit juice fermentation product of a high acidity which is obtained by fermenting a fruit juice containing citric acid and / or malic acid using yeast; and a production method thereof.SOLUTION: It has been found that a fruit juice fermentation product of a high acidity can be produced with yeast belonging to the genus Metschnikowia.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to fermented fruit juice products and the like. [Background technology]

[0002] Fruit juice from tart sweet oranges such as lemons and limes, and plums, is not often consumed as is because it contains a lot of organic acids such as citric acid and malic acid and has a strong sour taste. It is often used as a secondary ingredient to enhance the palatability of food and drink.

[0003] Furthermore, in order to respond to the diversification of preferences, various studies have been conducted regarding the fermentation of fragrant and sour citrus juices. With regard to fermentation using lactic acid bacteria, a method for producing lemon juice fermented liquid has been disclosed (Patent Document 1), which includes a fermentation step of fermenting lemon juice with lactic acid bacteria, and in which the lactic acid concentration of the lemon juice fermented liquid is 1000 mass ppm or more based on the total amount. With regard to fermentation using yeast, a method has been disclosed in which invert sugar syrup is added to lime juice, and Saccharomyces cerevisiae is inoculated at pH 8.1 to cause fermentation (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-171341 [Patent Document 2] Special Publication No. 2015-535425 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a highly acidic fermented fruit juice obtained by fermenting fruit juice containing citric acid and / or malic acid using yeast, and a method for producing the same. [Means for solving the problem]

[0006] The inventors have discovered that a highly acidic fermented fruit juice product can be produced using yeast belonging to the genus Metschnikowia, and have completed the present invention.

[0007] That is, the present invention relates to the following aspects [1] to [9]. [1] A fermented fruit juice product having an acidity of 3.0% by weight or more, obtained by fermenting fruit juice containing citric acid and / or malic acid with a yeast belonging to the genus Metschnikowia that is capable of fermenting the fruit juice. [2] The fermented fruit juice according to [1], wherein the fruit juice containing citric acid and / or malic acid is tart sweet orange juice or fruit juice of a fruit belonging to the Prunus subgenus. [3] The fermented fruit juice according to [1] or [2], wherein the ethanol concentration is 1.0% by volume or less. [4] A fermented fruit juice product according to any one of [1] to [3], in which the content of isoamyl alcohol and / or phenethyl alcohol is increased compared to before fermentation. [5] A method for producing a fermented fruit juice having an acidity of 3.0% by weight or more, which is obtained by inoculating a fruit juice containing citric acid and / or malic acid with a yeast belonging to the genus Metschnikowia that is capable of fermenting the fruit juice, and fermenting the fruit juice. [6] The method of producing according to [5], wherein the pH at the time of yeast inoculation is 4.0 or less. [7] The method of manufacturing according to [5] or [6], wherein the fruit juice containing citric acid and / or malic acid is tart sweet orange juice or fruit juice of a fruit belonging to the Prunus subgenus. [8] The method for production according to any one of [5] to [7], characterized in that activated yeast is inoculated. [9] A food or drink containing the fermented fruit juice described in any one of [1] to [4]. [Effects of the Invention]

[0008] The present invention makes it possible to produce a fermented fruit juice with high acidity by inoculating a yeast belonging to the genus Metschnikowia. It also makes it possible to provide a fermented fruit juice with improved flavor through fermentation. It also provides a production method that allows for the simple production of a fermented fruit juice with high acidity. DETAILED DESCRIPTION OF THE INVENTION

[0009] The fermented fruit juice of the present invention is a fruit juice fermented product having an acidity of 3.0% by weight or more, obtained by inoculating a fruit juice containing citric acid and / or malic acid with a yeast belonging to the genus Metschnikowia that is capable of fermenting the fruit juice, and fermenting the fruit juice. The yeast to be inoculated is not particularly limited as long as it is a yeast belonging to the genus Metschnikowia that is capable of fermenting a fruit juice containing citric acid and / or malic acid. However, yeast that can grow at an acidity of 3% by weight is preferred, yeast that can grow at an acidity of 4% by weight is more preferred, yeast that can grow at an acidity of 5% by weight is even more preferred, yeast that can grow at an acidity of 6% by weight is even more preferred, and yeast that can grow within a pH range of 2.0 to 3.0 is preferred. Examples of such yeast include Metschnikowia pulcherrima and Metschnikowia agaves, and one or more types may be used.

[0010] The yeast belonging to the genus Metschnikowia to be inoculated is not particularly limited as long as it is capable of fermenting fruit juice containing citric acid and / or malic acid, but it is preferable that it has been activated by pre-culture or the like. For example, a dried, refrigerated, or frozen stock yeast may be shaken in liquid, preferably at 20 to 40°C, more preferably at 25 to 35°C, for preferably 1 to 72 hours, more preferably 5 to 24 hours. It is preferable to use a general liquid medium for microorganisms that contains a carbon source, a nitrogen source, inorganic substances, and other trace nutrients required by the yeast. Activation means bringing the yeast into a state that facilitates proliferation.

[0011] In the present invention, the inoculation of the yeast belonging to the genus Metschnikowia can be carried out by inoculating the yeast into fruit juice containing citric acid and / or malic acid, and the amount of inoculation is not particularly limited, but is preferably 0.2 to 10% by volume, more preferably 0.5 to 5% by volume, of the fruit juice. Fermentation conditions are preferably aerobic fermentation by aeration, shaking, stirring, etc. The fermentation temperature can be, for example, 10 to 40°C, and preferably 20 to 35°C. The culture time can be, for example, 2 to 72 hours, and is preferably 4 to 48 hours, and more preferably 6 to 36 hours.

[0012] The fruit juice to be fermented in the present invention is not particularly limited as long as it contains citric acid and / or malic acid and has a strong sour taste, and preferably has an acidity of 1.0% by weight or more at the start of fermentation, preferably 2.0% by weight or more, preferably 3.0% by weight or more, more preferably 4.0% by weight or more, even more preferably 5.0% by weight or more, particularly preferably 5.5% by weight or more, and preferably 11% by weight or less. Acidity refers to the content of organic acids in a liquid measured by neutralization titration with sodium hydroxide and converted into citric acid.

[0013] The pH at the time of yeast inoculation is not particularly limited, but is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less. The pH of fruit juice containing citric acid and / or malic acid is usually 4.0 or less, approximately in the range of 2.0 to 3.5. pH adjustment may be performed, but since yeast belonging to the genus Metschnikowia can grow even at this pH, pH adjustment to 5.0 or more is not particularly necessary. It is preferable not to adjust the pH, as pH adjustment reduces the amount of undissociated citric acid and / or malic acid and lowers the acidity.

[0014] The fruit juice containing citric acid and / or malic acid used in the present invention is not particularly limited to any particular raw material as long as it is a fruit juice with a high acidity, and examples thereof include fruit juices with a high content of citric acid and / or malic acid, such as the juice of sour citrus fruits such as lemon, lime, tangerine, yuzu, sudachi, kabosu, and bitter orange, and the juice of fruits belonging to the Plum subgenus such as plum, apricot, and plum. One or more types may be used, and for example, concentrated fruit juice may be diluted to the above-mentioned acidity level and used.

[0015] Furthermore, fruit juice containing citric acid and / or malic acid preferably has a low sugar content, preferably 8% by weight or less, more preferably 6% by weight or less, even more preferably 5% by weight or less, and particularly preferably 4% by weight or less. It is most preferable that the sugar content is derived from the fruit juice alone, with no added sugars. For example, the sugar content / acidity ratio is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and particularly preferably 0.8 or less. Using low-sugar juice not only reduces calories but also reduces the concentration of ethanol produced. In the case of high-acidity fruit juice, the sum of acidity and sugar content is measured approximately as Brix sugar content (refractive sugar content), so the sugar content is calculated by subtracting acidity from Brix sugar content to obtain the sugar content / acidity ratio.

[0016] In the present invention, nitrogen compounds, minerals, etc. may be used as fermentation aids. Examples of nitrogen compounds that can be used include inorganic nitrogen compounds such as ammonium chloride, ammonium nitrate, ammonium sulfate, and ammonium phosphate; amino acids such as DL-alanine and L-glutamic acid; and organic nitrogen compounds such as peptone, meat extract, yeast extract, malt extract, and corn steep liquor. Examples of minerals that can be used include sodium phosphate, potassium phosphate, manganese sulfate, zinc sulfate, copper sulfate, magnesium sulfate, iron chloride, calcium chloride, ferric chloride, and sodium molybdate. Furthermore, to further increase the acidity of the resulting fruit juice fermentation product, fruit juice may be added during fermentation, preferably in one or more divided additions after the logarithmic growth phase.

[0017] The fermented fruit juice of the present invention, obtained by fermenting a highly acidic fruit juice, is not particularly limited as long as it has a high acidity, but preferably has an acidity of 3.0% by weight or more, more preferably 5.0% by weight or more, even more preferably 7.0% by weight or more, and particularly preferably 9.0% by weight or more. Furthermore, the flavor is improved compared to the fruit juice before fermentation due to the proliferation of yeast.

[0018] The ethanol concentration in the fruit juice fermentation product of the present invention is not particularly limited as long as it is low, but is preferably 1% by volume or less, more preferably 0.8% by volume or less, even more preferably 0.6% by volume or less, particularly preferably 0.4% by volume or less, and most preferably 0.2% by volume or less.Because it is a low-concentration ethanol fermentation product, it can be used in products other than alcoholic beverages and can be used in a wide range of foods.

[0019] Furthermore, the fermented fruit juice product of the present invention preferably contains isoamyl alcohol and / or phenethyl alcohol, and it is preferable that the amount of isoamyl alcohol and / or phenethyl alcohol is increased compared to before fermentation, with either one being at least 1.2 times the amount before fermentation, more preferably at least 1.3 times the amount, particularly preferably at least 1.5 times the amount, and most preferably at least 2 times the amount.The inclusion of isoamyl alcohol and / or phenethyl alcohol provides a floral flavor, and is thought to result in an improved flavor compared to the fruit juice before fermentation.

[0020] The fermented fruit juice product of the present invention can be added to various foods and beverages, etc., to impart the flavor of high-acidity fruit juice, and because it contains a high content of naturally occurring organic acids such as citric acid and malic acid, it is also expected to be used as a health food. The amount added to various foods and beverages is not particularly limited, but is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, and even more preferably 0.1 to 5% by weight. The foods and beverages to which it can be added are not particularly limited, but it can be used in beverages such as non-alcoholic beverages and alcoholic beverages, frozen desserts such as ice cream, fresh sweets such as jellies and yogurt, seasonings such as dressings and sauces, health foods, etc. [Example]

[0021] The present invention will be specifically explained below by showing examples, but the present invention is not limited to the following examples.

[0022] [Preparation 1] Concentrated lemon juice (Preparation 1) was obtained by mixing 143 g of concentrated lemon juice (citric acidity: 31.8 wt %, Brix: 35°) and 357 g of tap water. [Example]

[0023] Fifty grams of lemon juice from Preparation 1 was placed in a 200 mL baffled Erlenmeyer flask, and pre-cultured Metschnikowia agaves (NBRC10860 strain) was inoculated at 1% by volume. The mixture was then shaken and fermented at 30°C for 24 hours to obtain a lemon juice fermentation product (Product 1). The preculture medium used was a sterilized liquid medium containing reduced starch syrup at a final concentration of 10% by weight and yeast extract at a final concentration of 2% by weight, in which the yeast was cultured with shaking at 30°C for 20 hours.

[0024] [Comparative Example 1] Comparative products 1-1 to 1-3 were obtained in the same manner as in Example 1, except that the yeast used was Torulaspora delbrueckii (BIODIVA; manufactured by LALLEMAND) (Comparative Example 1-1), Saccharomyces cerevisiae (NBRC2346 strain) (Comparative Example 1-2), or Kluyveromyces lactis (NBRC1267 strain) (Comparative Example 1-3).

[0025] [Evaluation Test 1] For Example Product 1, Preparation 1, and Comparative Products 1-1 to 1-3, the pH, Brix (using a sugar refractometer), acidity (measured by neutralization titration and converted to citric acid), glucose concentration (F-kit D-glucose, manufactured by Roche), and ethanol concentration (F-kit Ethanol, manufactured by Roche) were measured and are shown in Table 1. Furthermore, for yeast growth, samples in which growth was observed were marked with an O, and samples in which growth was not observed were marked with an X. For Preparation 1, which is a high-acidity juice, the sum of acidity and sugar content is roughly measured as Brix, so the sugar content was calculated from Brix and acidity, and the sugar content / acidity ratio was calculated. The results are shown in Table 1. Furthermore, for Example Product 1, Preparation 1, and Comparative Products 1 to 3, diluted 10-fold with tap water, were subjected to sensory evaluation. Those with a refreshing acidity or floral flavor were marked with an O, and those lacking this flavor were marked with an X.

[0026] [Table 1]

[0027] In Example 1, yeast growth was observed, and a high-acidity lemon juice fermented product was obtained, but no yeast growth was observed in Comparative Examples 1-1 to 1-3. There were no differences in acidity or ethanol concentration between Example Product 1, Preparation 1, and Comparative Products 1-1 to 1-3, and no changes were observed due to the presence or absence of fermentation. However, the glucose concentration of Example Product 1 was lower than that of Preparation 1, presumably due to a decrease due to fermentation. Furthermore, Example Product 1 possessed a refreshing acidity as well as a floral flavor. The addition of the floral flavor resulted in a more pleasant, improved flavor in addition to the acidity, despite the high acidity. Therefore, it was found that a high-acidity fruit juice fermented product with improved flavor can be obtained by inoculating Metschnikowia agaves, which belongs to the genus Metschnikowia. [Example]

[0028] A lemon juice fermented product (Example 2) was obtained in the same manner as in Example 1, except that Metschnikowia pulcherrima FLAVIA (manufactured by LALLEMAND) was used as the yeast.

[0029] [Evaluation Test 2] For Product 2 and Prepared Product 1, evaluation was carried out in the same manner as in Evaluation Test 1, and the aroma component concentration was measured under the following measurement conditions using gas chromatography (hereinafter referred to as GC). The results are shown in Table 2.

[0030] <GC Measurement Conditions> · Detector: FID (250 °C) · Column: InertCap Pure-WAX (ID: 0.25 mm × 30 m, df: 0.25 μm, manufactured by GL Sciences Inc.) · Column temperature: 40 °C (held for 5 minutes) → heated at 10 °C / min → 250 °C (held for 3 minutes) · Carrier gas: Helium (100 kPa), 1.3 ml / min · Injection temperature: 250 °C · Internal standard substance: Cyclohexanol · Specimen: The sample was extracted with diethyl ether according to a conventional method.

[0031]

Table 2

[0032] Yeast growth was observed in Example 2, and a high-acidity lemon juice fermented product was obtained. There was no difference in acidity and ethanol concentration between Product 2 and Prepared Product 1, and no change was observed depending on the presence or absence of fermentation. However, the glucose concentration of Product 2 was lower than that of Prepared Product 1 and was considered to have decreased due to fermentation. In addition, Product 2 contained isoamyl alcohol and phenethyl alcohol, which were considered to be produced by fermentation, and had a floral flavor in addition to a refreshing acidity. Due to the imparted floral flavor, even at high acidity, it had a more preferable and improved flavor rather than just acidity. Therefore, it was found that by inoculating Methynikkowia pulcherrima belonging to the genus Methynikkowia, a high-acidity fruit juice fermented product with improved flavor can be obtained.

[0033] [Preparation 2] Concentrated reconstituted plum juice (Preparation 2) was obtained by mixing 33 g of concentrated plum juice (citric acid acidity: 18.5 wt %, Brix: 30°) with 67 g of tap water. [Example]

[0034] A fermented plum juice product (Product 3) was obtained in the same manner as in Example 1, except that Preparation 2, which is plum juice, was used instead of Preparation 1 and that Metschnikowia pulcherrima was used as the yeast.

[0035] [Evaluation Test 3] The working product 3 and the preparation 2 were evaluated in the same manner as in evaluation test 2. The results are shown in Table 3.

[0036] [Table 3]

[0037] In Example 3, yeast growth was observed, and a highly acidic fermented plum juice product was obtained. There was no difference in acidity between Example 3 and Preparation 2, and no change was observed with or without fermentation. However, the glucose concentration in Example 2 was lower than that of Preparation 2, while the ethanol concentration was higher than that of Preparation 2. This suggests that fermentation reduced glucose and increased ethanol. Furthermore, Example 3 contained isoamyl alcohol and phenethyl alcohol, which are thought to be produced by fermentation, and had a refreshing acidity as well as a floral flavor. The addition of the floral flavor resulted in a more pleasant, improved flavor, in addition to the acidity, despite the high acidity of the plum juice. Therefore, it was found that even with high acidity, a highly acidic fermented juice product with improved flavor can be obtained by inoculating Metchnikowia pulcherrima, a species of the Metchnikowia genus.

[0038] [Test example] Concentrated lemon juice (citric acidity: 31.8% by weight, Brix: 35°) was diluted with tap water to prepare lemon juices of Test Example 1-1 (acidity 4.5% by weight, Brix 5°), Test Example 1-2 (acidity 9.1% by weight, Brix 10°), Test Example 1-3 (acidity 10.9% by weight, Brix 12°), and Test Example 1-4 (acidity 13.6% by weight, Brix 15). Concentrated plum juice (citric acidity: 18.5 wt %, Brix: 30°) was diluted with tap water to prepare the plum juices of Test Example 2-1 (acidity: 3.1 wt %, Brix: 5°), Test Example 2-2 (acidity: 6.2 wt %, Brix: 10°), Test Example 2-3 (acidity: 9.3 wt %, Brix: 15°), and Test Example 2-4 (acidity: 12.4 wt %, Brix: 15°). The same procedure as in Example 2 was used except for using the prepared juices, and attempts were made to obtain each fermented juice by inoculating with Metschnikowia pulcherrima (a species of the Metschnikowia genus). Furthermore, lemon juice of Test Example 1-5 (acidity: 4.5 wt %, Brix: 5°) and plum juice of Test Example 2-5 (acidity: 3.1 wt %, Brix: 5°) were prepared, and Torulaspora delbreckii was inoculated to obtain each fermented juice.

[0039] [Evaluation Test 3] After yeast inoculation, those in which yeast grew well were marked with a circle, those in which yeast grew slightly were marked with a triangle, and those in which yeast did not grow at all were marked with an x. These results are shown in Table 4. In addition, the pH and ethanol concentration were measured and are shown in Table 4. The Brix and acidity of each fruit juice at the time of yeast inoculation are also summarized in Table 4.

[0040] [Table 4]

[0041] Yeast growth was observed in Test Examples 1-1 to 1-3 and 2-1 to 2-3, but no yeast growth was observed in Test Examples 1-4, 1-5, 2-4, and 2-5. Test Examples 1-1 to 1-3 and 2-1 to 2-3 had acidities of 4.5 to 10.9% by weight, and Test Examples 1-4 and 2-4 had acidities of 12.4% by weight or more. Test Examples 1-5 and 2-5 used Torulaspora delbrueckii. From the above, it is thought that there is a relationship between acidity and yeast growth, and it was found that by lowering the acidity at the start of fermentation to less than 12% by weight, highly acidic juice can be fermented using yeast belonging to the genus Metschnikowia.

Claims

1. A fermented fruit juice product having an acidity of 3.0% by weight or more and an ethanol concentration of 1.0% by volume or less, obtained by fermenting fruit juice containing citric acid and / or malic acid and having a sugar content of 5% by weight or less with a yeast belonging to the genus Metschnikowia that is capable of fermenting said fruit juice.

2. 2. The fermented fruit juice according to claim 1, wherein the fruit juice containing citric acid and / or malic acid is a sour sweet orange juice or a fruit juice belonging to the subgenus Prunus.

3. 3. The fermented fruit juice product according to claim 1, wherein the content of isoamyl alcohol and / or phenethyl alcohol is increased compared to before fermentation.

4. A method for producing a fermented fruit juice product having an acidity of 3.0% by weight or more and an ethanol concentration of 1.0% by volume or less, obtained by inoculating a fruit juice containing citric acid and / or malic acid and having a sugar content of 5% by weight or less with a yeast belonging to the genus Metschnikowia that is capable of fermenting said fruit juice, and fermenting the fruit juice.

5. The method according to claim 4, wherein the pH at the time of yeast inoculation is 4.0 or less.

6. 6. The method according to claim 4 or 5, wherein the fruit juice containing citric acid and / or malic acid is a sour sweet orange juice or a fruit juice belonging to the subgenus Prunus.

7. The method according to any one of claims 4 to 6, wherein activated yeast is inoculated.

8. A food or drink comprising the fermented fruit juice according to any one of claims 1 to 3.

Images