JP2023158690A - Vitamin b2-containing beverage - Google Patents

Abstract

To provide: a beverage containing a vitamin B2 type, maltodextrin, and isomaltulose in which vitamin B2 content is suppressed from being reduced; and a beverage containing a vitamin B2 type, maltodextrin, and isomaltulose in which an unpleasant odor derived from a vitamin B2 type is alleviated.SOLUTION: A beverage contains a) 0.0011 to 0.01 w/w% of a vitamin B2 type in terms of riboflavin, b) 15 w/w% or more of maltodextrin, and c) isomaltulose. The beverage can further contain d) 0.00025 to 0.0025 w/w% of a vitamin B1 type.SELECTED DRAWING: None

Description

The present invention relates to a beverage containing vitamin B2.

Maltodextrin is generally a carbohydrate with a dextrose equivalent (DE) of 10 to 20, which indicates the degree of hydrolysis of starch decomposition products, and is absorbed relatively quickly in the small intestine, so it can quickly become an energy source after ingestion. Isomaltulose, also known as Palatinose (registered trademark), is a disaccharide composed of glucose linked with α-1,6 glucosyl to fructose, and is easily digested and absorbed. Therefore, it is known that it can be used as a sustainable energy source.

Furthermore, among vitamins, vitamin B1 and its derivatives or their salts (hereinafter referred to as "vitamin B1") are involved in glucose metabolism and branched amino acid metabolism, and are known to have various medicinal effects such as relieving fatigue. Vitamin B2 and its derivatives or their salts (hereinafter referred to as "vitamin B2") are water-soluble vitamins that are involved in energy metabolism such as the TCA cycle, electron transport system, and β-oxidation of fatty acids, and are involved in energy production. It is a water-soluble vitamin.
In recent years, products containing maltodextrin and isomaltulose, which are carbohydrates that serve as energy sources, and vitamin B, which contributes to energy production, have been distributed as soft drinks (including jelly drinks) for the purpose of replenishing energy during exercise.・It is on sale.

Until now, a technique has been known that can improve the decrease in the content of vitamin B2 in an oral solution containing vitamin B2, herbal medicine-derived ingredients, and polyvinylpyrrolidone by incorporating propyl gallate (Patent Document 1) ).

WO2014/087818

In the process of developing a beverage containing vitamin B2, maltodextrin, and isomaltulose, the present inventors encountered the problem of stability of vitamin B2. Furthermore, the generation of unpleasant odors derived from vitamin B2s became a problem.

That is, an object of the present invention is to provide a beverage containing vitamin B2, maltodextrin, and isomaltulose in which a decrease in the content of vitamin B2 is suppressed. Furthermore, it is an object of the present invention to provide a vitamin B2, maltodextrin, and isomaltulose beverage in which the unpleasant odor derived from vitamin B2 is alleviated.

Therefore, as a result of extensive studies to solve the above problems, the present inventor unexpectedly found that vitamin B2 and maltodextrin were added to a specific concentration in a beverage containing vitamin B2, maltodextrin, and isomaltulose. The present invention was completed based on the discovery that the above blending can provide a beverage in which the content of vitamin B2 is suppressed from decreasing.
Furthermore, we have discovered that if a specific concentration of vitamin B1 is added to a beverage containing vitamin B2 and maltodextrin at a specific concentration or higher, and isomaltulose, it is possible to provide a beverage that alleviates the unpleasant odor derived from vitamin B2. , completed the invention.
Aspects of the present invention obtained from this knowledge are as follows.
(1) a) at least one type of vitamin B2 selected from the group consisting of vitamin B2, derivatives thereof, and salts thereof in an amount of 0.0011 to 0.01 w/w% calculated as riboflavin, and b) 15 w/w% A beverage characterized by containing w% or more of maltodextrin, and c) isomaltulose,
(2) c) The beverage according to (1), wherein the concentration of isomaltulose is 0.1 to 10 w/w%,
(3) a) The beverage according to (1) to (2), wherein the vitamin B2 is at least one selected from the group consisting of riboflavin, riboflavin butyrate, and sodium riboflavin phosphate;
(4) The beverage according to any one of (1) to (3), which is in liquid or gel form. (5) The beverage according to any one of (1) to (4), which has a pH of 2.0 to 5.0. Beverages mentioned;
(6) d) containing 0.00025 to 0.0025 w/w% of at least one type of vitamin B1 selected from the group consisting of vitamin B1, derivatives thereof, and salts thereof; The beverage according to any one of 1) to (5),
(7) d) The beverage according to (6), wherein the vitamin B1 is at least one selected from the group consisting of thiamine, fursulthiamine, thiamine disulfide, benfotiamine, thiamine lauryl sulfate, and salts thereof. ,
It is.

According to the present invention, it has become possible to provide a beverage containing vitamin B2, maltodextrin, and isomaltulose in which a decrease in the content of vitamin B2 is suppressed.
Furthermore, it has become possible to provide a beverage in which the unpleasant odor derived from vitamin B2 is alleviated.

The vitamin B2s in the present invention are vitamin B2, derivatives thereof, or salts thereof, and are not particularly limited as long as they are commonly used in foods, quasi-drugs, pharmaceuticals, and the like. Examples of vitamin B2 in the present invention include riboflavin, riboflavin phosphate, riboflavin butyrate, flavin adenine dinucleotide, and salts thereof. Vitamin B2 in the present invention can be produced by a known method, and commercially available products such as riboflavin and sodium riboflavin 5'-phosphate produced by DSM Co., Ltd., and riboflavin 5'- produced by Iwaki Pharmaceutical Co., Ltd. Sodium phosphate ester and the like can be used. Preferred among vitamin B2 are riboflavin, riboflavin butyrate, and sodium riboflavin 5'-phosphate. The content of vitamin B2 in the present invention is 0.0011 w/w% or more as riboflavin in the beverage, preferably 0.0011 w/w% to 0.01 w/w%, more preferably 0.0011 w/w % to 0.005 w/w%.

Maltodextrin in the present invention is not particularly limited as long as it has a dextrose equivalent (DE) of about 10 to 20 and is commonly used in foods, quasi-drugs, pharmaceuticals, etc. Maltodextrin in the present invention can be produced by a known method, and commercially available products such as TK-16 (DE16-19) and Paindex #2 (DE10-12) manufactured by Matsutani Chemical Industry Co., Ltd. are used. be able to. The content of maltodextrin in the present invention is 15 w/w% or more in the beverage, preferably 15 w/w% to 30 w/w%, more preferably 15 w/w% to 25 w/w%.

Isomaltulose in the present invention is also referred to as Palatinose (registered trademark), and is a disaccharide composed of glucose linked to fructose with an α-1,6 glucosyl bond, and is used as a sweetener. If so, there are no particular restrictions. Isomaltulose in the present invention can be produced by a known method, and commercial products such as crystalline Palatinose PST-N and powdered Palatinose PST-NP manufactured by Mitsui Sugar Co., Ltd. can be used. The content of isomaltulose in the present invention is not particularly limited, but from the viewpoint of the effects of the present invention, it is preferably blended in the beverage at 0.01 w/w% or more, preferably 0.01 w/w% or more. The content is from w/w% to 10w/w%, more preferably from 0.5w/w% to 10w/w%, even more preferably from 0.5w/w% to 5w/w%.

The vitamin B1 class in the present invention is vitamin B1, a derivative thereof, or a salt thereof, and is not particularly limited as long as it is commonly used in foods, quasi-drugs, pharmaceuticals, and the like. In the present invention, vitamin B1 includes, for example, thiamine and its salts, thiamine derivatives such as dicethiamine, fursulthiamine, thiamine disulfide, bisbenthiamine, bisbuthiamine, benfotiamine, cicothiamine, octothiamine, and prosulthiamine; Examples include salts thereof. Examples of the salts thereof include nitrates, hydrochlorides, lauryl sulfates, and the like. Further, the vitamin B1 type in the present invention can be produced by a known method, and commercially available thiamine nitrate manufactured by DSM Co., Ltd., thiamine lauryl sulfate manufactured by Taisho Technos Co., Ltd., and Watanabe Chemical Co., Ltd. Fursultiamine, etc., manufactured by Co., Ltd., can be used. Among vitamin B1, preferred are thiamine, fursulthiamine, thiamine disulfide, benfotiamine, thiamine lauryl sulfate, and salts thereof, and more preferred are thiamine, fursulthiamine, thiamine lauryl sulfate, and their salts. It's salt. The content of vitamin B1 in the present invention is preferably 0.00025 to 0.0025 w/w%, more preferably 0.00028 w/w% to 0.002 w/w% in the beverage from the viewpoint of the effects of the present invention. It is.

The pH of the beverage of the present invention is preferably 2 to 7 at room temperature, and more preferably 3 to 4 from the viewpoint of flavor and suppressing the growth of microorganisms. As a pH adjuster for adjusting the above pH, a pH adjuster commonly used for foods, quasi-drugs, pharmaceuticals, etc. can be used. Examples include organic acids and salts thereof such as citric acid, malic acid, tartaric acid, and acetic acid, inorganic acids and salts thereof such as phosphoric acid and hydrochloric acid, and inorganic bases such as sodium hydroxide. From the viewpoint of flavor, citric acid, malic acid, phosphoric acid, gluconic acid and salts thereof are preferred.

The beverage of the present invention may contain other ingredients such as vitamins (excluding vitamin B1 and vitamin B2), minerals, amino acids or their salts, plant extracts, lactic acid bacteria, fruit juice, etc., to the extent that they do not impair the effects of the present invention. Components may be included as appropriate. Furthermore, the beverage of the present invention may contain antioxidants, colorants, flavors, corrigents, surfactants, thickeners, stabilizers, preservatives, sweeteners, and acidulants to the extent that the effects of the present invention are not impaired. It is also possible to appropriately mix additives such as the following.

The beverage of the present invention is not particularly limited, and may be, for example, a liquid beverage, a jelly beverage, a smoothie beverage, a beverage containing fruit juice or pulp, or a frozen beverage such as an ice slurry, and is not limited to general foods. There may also be foods with functional claims, foods with nutritional function claims, and foods for specified health uses. Liquid drinks include health drinks, soft drinks, carbonated drinks, sports/functional drinks, alcoholic drinks, non-alcoholic drinks, milk drinks, tea drinks, coffee drinks, fruit and vegetable drinks, etc. Useful in beverages and jelly drinks. Moreover, it is preferable that the beverage be packaged in a container because it can be drunk as is.

When the beverage of the present invention is packaged in a container, the container is not particularly limited, and specific examples include bottles, cans, PET bottles, pouch containers, paper packs, etc., and preferably bottles, cans, and PET bottles. , a pouch container. The capacity is also not particularly limited, but in the case of liquid beverages, specifically, it is preferably 30 ml to 500 ml, more preferably 50 ml to 300 ml, and still more preferably 100 ml to 200 ml. In the case of a jelly drink, specifically, the amount is preferably 10 g to 300 g, more preferably 15 g to 200 g, even more preferably 30 g to 200 g.

Thickeners or gelling agents to be added to jelly drinks include gellan gum, xanthan gum, guar gum, locust bean gum, carrageenan, agar, glucomannan, pectin, gelatin, methylcellulose, alginic acid or its salts, and the like.

The beverage of the present invention can be produced by a conventional method, and the method is not particularly limited. When the beverage of the present invention is made into a liquid beverage, for example, each component is weighed, dissolved in an appropriate amount of purified water, stirred, and then the pH is adjusted as necessary, and purified water is added to adjust the volume. It can be manufactured by performing filtration treatment or sterilization treatment as necessary, filling a container, heat sterilization, and cooling as necessary. Preferably, all or part of the raw materials are sterilized at 90 to 130°C for 1 second to 5 minutes, and then further cooled to about 10 to 40°C. For sterilization, a normal sterilizer may be used, such as a plate type sterilizer, a tubular type sterilizer, a jacketed tank, etc. Further, a normal cooler may be used for cooling, and for example, a heat exchange plate, a tubular type cooler, a jacketed tank, etc. can be used.

In addition, when the beverage of the present invention is made into a jelly beverage, for example, each component is weighed, dispersed and/or dissolved in an appropriate amount of purified water, heated as necessary, the pH is adjusted, and the remaining purified water is It can be manufactured by adding the following steps to adjust the volume, subjecting it to filtration treatment or heat sterilization as necessary, filling it into a container, heat sterilization, and cooling as necessary.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. In the following examples and comparative examples, maltodextrin is TK-16 (DE18) manufactured by Matsutani Chemical Co., Ltd., vitamin B2 is riboflavin manufactured by DSM Co., Ltd., and isomaltulose is manufactured by Mitsui Sugar Co., Ltd. Crystalline Palatinose PST-N manufactured by Manufacturer Co., Ltd., native type gellan gum was used, and citric acid monohydrate and trisodium citrate dihydrate were food additives.

<Beverage preparation>
(Comparative example 1)
First, a riboflavin solution in which riboflavin was dissolved in purified water (warm water) at a concentration of 10 mg/100 g, and citric acid monohydrate, trisodium citrate dihydrate, and isomaltulose were added to the purified water. Citric acid/isomaltulose solutions were prepared so that the respective concentrations were 1.0 g/27 g, 0.5 g/27 g, and 5.0 g/27 g.
Next, the riboflavin solution and the citric acid/isomaltulose solution were weighed out to the final prescribed amount, maltodextrin was added, and after thorough stirring, the total amount was adjusted to prepare a sample solution. The prepared sample solution was filled in screw tubes (manufactured by Maruem Co., Ltd., No. 6) in an amount of 30 mL each, and sterilized at 85° C. for 20 minutes to prepare a drink (liquid drink).

(Examples 1 to 3, Comparative Examples 2, 4, 5)
First, a riboflavin solution prepared by dissolving riboflavin in purified water (warm water) at a concentration of 10 mg/100 g, citric acid monohydrate, trisodium citrate dihydrate, and isomaltulose are added to the purified water. Citric acid/isomaltulose solutions were prepared with respective concentrations of 1.0 g/54 g, 0.5 g/54 g, and 5 g/54 g.
Next, measure the riboflavin solution and citric acid/isomaltulose solution to the final prescribed amount, add maltodextrin as necessary, stir well, dissolve, adjust the total volume, and sample. A solution was prepared. The prepared sample solution was filled in screw tubes (manufactured by Maruem Co., Ltd., No. 6) in an amount of 30 mL each, and sterilized at 85° C. for 20 minutes to prepare a drink (liquid drink).

(Examples 4 and 5, Comparative Example 3)
First, a riboflavin solution prepared by dissolving riboflavin in purified water (warm water) at a concentration of 10 mg/100 g, and citric acid monohydrate and trisodium citrate dihydrate were added to the purified water, and the respective concentrations were adjusted. Citric acid solutions of 1.0g/54g and 0.5g/54g were prepared.
Next, measure the riboflavin solution and citric acid solution to the final prescribed amount, add maltodextrin, add isomaltulose if necessary, stir well, dissolve, and adjust the total amount. and prepared a sample solution. The prepared sample solution was filled in screw tubes (manufactured by Maruem Co., Ltd., No. 6) in an amount of 30 mL each, and sterilized at 85° C. for 20 minutes to prepare a drink (liquid drink).

(Comparative Examples 4 and 5)
First, a riboflavin solution prepared by dissolving riboflavin in purified water (warm water) at a concentration of 10 mg/100 g, citric acid monohydrate, trisodium citrate dihydrate, and isomaltulose are added to the purified water. Citric acid/isomaltulose solutions were prepared so that the respective concentrations were 1.0 g/27 g, 0.5 g/27 g, and 5.0 g/27 g.
Next, measure the riboflavin solution and citric acid/palatinose solution to the final prescribed amount, add maltodextrin as necessary, stir well, dissolve, adjust the total volume, and add the sample solution. Prepared. The prepared sample solution was filled in screw tubes (manufactured by Maruem Co., Ltd., No. 6) in an amount of 30 mL each, and sterilized at 85° C. for 20 minutes to prepare a drink (liquid drink).

(Example 6, Comparative Example 6)
First, a riboflavin solution in which riboflavin was dissolved in purified water (warm water) at a concentration of 10 mg/100 g, and citric acid monohydrate, trisodium citrate dihydrate, and isomaltulose were added to the purified water. Citric acid/isomaltulose solutions were prepared so that the respective concentrations were 1.0 g/27 g, 0.5 g/27 g, and 5.0 g/27 g.
Next, native gellan gum was added to purified water at a ratio of 0.36g/90g, dispersed, heated to 100°C while stirring, and maintained at 100°C for 3 minutes to prepare a gellan gum solution. did. The prepared gellan gum solution was stirred while maintaining the temperature at 70° C. or higher.
Then, weigh out the gellan gum solution, riboflavin solution, and citric acid/isomaltulose solution to the final prescribed amount, add maltodextrin as necessary, stir well, dissolve, and adjust the total amount. , a sample solution was prepared. The prepared sample solution was filled in transparent standing pouches (Ibis 100-SP, manufactured by Yamato Materials Co., Ltd.) in an amount of 100 g each, sterilized at 85° C. for 20 minutes, and then cooled with water to prepare a drink (jelly drink).

(Examples 7 to 10, Comparative Example 7)
First, a riboflavin solution in which riboflavin was dissolved in purified water (warm water) to give a concentration of 10 mg/100 g, a thiamine solution in which thiamine nitrate was dissolved in purified water to a concentration of 100 mg/100 g, and a thiamine solution in which thiamine nitrate was dissolved in purified water to a concentration of 100 mg/100 g. hydrate, trisodium citrate dihydrate, isomaltulose and maltodextrin are added and dissolved to give respective concentrations of 1.0g/108g, 0.5g/108g, 5.0g/108g, 28. A citric acid/isomaltulose/maltodextrin solution with a ratio of 0g/108g was prepared.
Next, the riboflavin solution, thiamin solution, and citric acid/isomaltulose/maltodextrin solution were weighed out to the final prescribed amounts, stirred thoroughly, and the total amount was adjusted to prepare a sample solution. The prepared sample solution was filled in screw tubes (manufactured by Maruem Co., Ltd., No. 6) in an amount of 30 mL each, and sterilized at 85° C. for 20 minutes to prepare a drink (liquid drink).

(Example 11, 12)
First, a riboflavin solution was prepared by dissolving riboflavin in purified water (warm water) to a concentration of 10 mg/100 g.
Next, native gellan gum and isomaltulose were mixed in powder form, added to purified water so that the respective concentrations were approximately 0.36 g/90 g and approximately 5.0 g/90 g, dispersed, and heated to 100 g while stirring. The mixture was heated to 100°C and maintained at 100°C for 3 minutes. Then, while maintaining the temperature at 70°C or above, maltodextrin, citric acid monohydrate, trisodium citrate dihydrate, and riboflavin solution were added, and the respective concentrations were 28.0g/162g and 1.0g. /162g, 0.5g/162g, and 2.0mg/162g common solutions were prepared. Note that the prepared common solution was stirred while maintaining the temperature at 70° C. or higher.
Thereafter, the common solution was weighed out to the final prescribed amount, thiamine nitrate was added as needed, stirred well to dissolve, and the total amount was adjusted to prepare a sample solution. The prepared sample solution was filled in transparent standing pouches (Ibis 100-SP, manufactured by Yamato Materials Co., Ltd.) in an amount of 100 g each, sterilized at 85° C. for 20 minutes, and then cooled with water to prepare a drink (jelly drink).

<Test Example 1: Calculation of residual rate of riboflavin>
Regarding the drinks of Examples 1 to 6 and Comparative Examples 1 to 6 shown in Tables 1 to 4, the amount of riboflavin in the drinks stored in the dark at 5°C and the amount of riboflavin in the drinks stored in a constant temperature bath at 65°C in the dark for 5 days. After that, the temperature was returned to room temperature, the light shielding was removed, and the amount of riboflavin in the drink was irradiated with light for 15 minutes at 3000 Lux using a CIE standard light source D65 using an optical tester, using the HPLC (liquid chromatography) method. =3. The average amount of riboflavin in beverages stored in the dark at 5°C was stored in a constant temperature bath at 65°C with protection from light for 5 days, then returned to room temperature, removed from light, and tested with a light tester to meet the CIE standard. The average value of the amount of riboflavin in the beverage that was irradiated with light at 3000 Lux for 15 minutes using light source D65 was calculated as the residual rate (%) of riboflavin. The calculation results for Examples 1 to 6 and Comparative Examples 1 to 6 are shown in Tables 1 to 4.

As shown in Table 1, although Example 1 and Comparative Example 1 differed only in the concentration of riboflavin, the residual rate of riboflavin in Example 1 was significantly higher than in Comparative Example 1. Further, from Comparative Examples 2 and 3 and Example 1, the residual rate of riboflavin was significantly higher in Example 1 in which both maltodextrin and isomaltulose were blended.

As shown in Table 2, the residual rate of riboflavin was found to increase depending on the amount of maltodextrin. From Comparative Example 4, it was found that when the concentration of maltodextrin was low, the residual rate of riboflavin was rather low. As shown in Examples 1 to 3, when the concentration of maltodextrin was 15 w/w% or more, the residual rate of riboflavin was high.

As shown in Table 3, it was found that the residual rate of riboflavin increased depending on the concentration of isomaltulose.

As shown in Table 4, even in the jelly dosage form, the residual rate of riboflavin was significantly higher in Example 6, which contained maltodextrin, than in Comparative Example 6, which did not contain maltodextrin. In addition, the decrease in the residual rate of riboflavin was more significantly suppressed when the dosage form was a jelly rather than a liquid. Therefore, it was considered that the decrease in the residual rate of riboflavin could be suppressed regardless of the dosage form.

<Test Example 2: Evaluation of unpleasant odor>
The unpleasant odor of the drinks of Examples 7 to 12 and Comparative Example 7 in Tables 5 and 6 at room temperature was evaluated.
After storing it in a constant humidity and temperature chamber at 40°C and 75% RH for 5 days with light shielding, it was returned to room temperature, the light shield was removed, and light was irradiated for 24 hours at 3000 Lux with CIE standard light source D65 using a light tester. The drinks were absolutely evaluated by three testers using the evaluation criteria shown in Table 7.
In addition, each tester used a different beverage, and the beverage (liquid beverage) was evaluated by smelling it directly from the screw tube, and the beverage (jelly beverage) was evaluated using a Promax Cup (Asahi Kasei Pax). Approximately 25g of the sample was poured into a container (EI-90D, manufactured by EI-90D) and evaluated by smelling it, and the average value of each tester's evaluation score was calculated. The evaluation results are shown in Tables 5 and 6.

As shown in Example 7 and Examples 8 to 10 in Table 5, Examples 8 to 10 in which thiamine nitrate was blended had lower evaluation scores than Example 7 in which thiamine nitrate was not blended, and the unpleasant odor was noticeably lower. It was relaxing. However, as shown in Example 7 and Comparative Example 7, when the amount of thiamine nitrate blended was too large, the evaluation score was the same as when thiamine nitrate was not blended. Therefore, it was considered that unpleasant odors could be significantly alleviated by incorporating thiamine nitrate at a specific concentration or less.

As shown in Table 6, even in the jelly dosage form, Example 12, which contains thiamine nitrate, had a lower evaluation score than Example 11, which did not contain thiamine nitrate, and the unpleasant odor was significantly alleviated. In addition, the jelly dosage form was more effective at alleviating unpleasant odors than the liquid dosage form. Therefore, it was considered that unpleasant odors could be alleviated by incorporating thiamine nitrate at a specific concentration or less, regardless of the dosage form.

According to the present invention, it has become possible to provide a beverage containing vitamin B2, maltodextrin, and isomaltulose, and suppressing a decrease in the content of vitamin B2.
Furthermore, it has become possible to provide a beverage that contains vitamin B2, maltodextrin, and isomaltulose and has alleviated the unpleasant odor derived from vitamin B2.

Claims (7)

a) At least one type of vitamin B2 selected from the group consisting of vitamin B2, derivatives thereof, and salts thereof, containing 0.0011 to 0.01 w/w% in terms of riboflavin, b) Malt containing 15 w/w% or more A beverage characterized by containing dextrin and c) isomaltulose. c) The beverage according to claim 1, wherein the concentration of isomaltulose is 0.1 to 10% w/w. The beverage according to claim 1 or 2, wherein a) the vitamin B2 is at least one selected from the group consisting of riboflavin, riboflavin butyrate, and sodium riboflavin phosphate. The beverage according to claim 1 or 2, which is in liquid or gel form. The beverage according to claim 1 or 2, which has a pH of 2 to 7. d) containing 0.00025 to 0.0025 w/w% of at least one vitamin B1 selected from the group consisting of vitamin B1, derivatives thereof, and salts thereof; 2. The drink described in 2. d) The beverage according to claim 6, wherein the vitamin B1 is at least one selected from the group consisting of thiamine, fursulthiamine, thiamine disulfide, benfotiamine, thiamine lauryl sulfate, and salts thereof.