JPS6245853B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to certain acetals that act as generators in response to conditions of use in food products to produce the desired aldehydes. It is well known that acetaldehyde and propionaldehyde occur in a variety of fresh and cooked foods such as fruits, meats, dairy products, baked goods, and vegetables. Acetaldehyde has been discovered to be particularly important in contributing to the flavor impact and freshness effect of certain foods such as tangerines and red strawberries. When a fresh effect is required, acetaldehyde is indispensable in adulterating artificial flavors. Similarly, propionaldehyde is said to contribute to the flavor of a wide range of fruits and foods. Other aliphatic aldehydes such as butyraldehyde and octylaldehyde having carbon numbers from C-4 to about C-12 also have impact and special flavor effects in a wide range of flavors corresponding to the occurrence of these aldehydes in a wide range of foods. Giving is known. For example, butyraldehyde is an apple,
2-Methylpropanol is present in strawberries, milk, fish, beef, pork, bananas, peaches, grapes, cabbage, onions, potatoes, ginger, bread and blue cheese; milk, cacao, egg,
Present in fish, beef, pork, and cilantro. 2-Methylbutanal is found in cocoa, eggs, fish,
Found in beef, beer, star grapes and olives. 3-Methylbutyraldehyde is present in cocoa, fish, chicken, beef, beer, peanuts, star grapes, olives, peaches, and mushrooms. Valeraldehyde is present in milk, tea, fish, chicken, beef, pork, beer, lingonberries, star grapes, grapes, olives, mushrooms, onions and potatoes. 2-
Ethoxypropanal is present in rum. 3
-Ethoxypropanol is similar. 3-Methylpentanal is present in beer. 2-Methylpentanal is present in onions. 2-
Ethylbutanol is present in mandarin oranges and bread. Hexanal includes bananas, tangerines, fava beans, milk, fish, chicken, beef, lamb, black tea,
Found in lingonberries, grapes, olives, melons, peaches, cucumbers, mushrooms, onions, potatoes, and tobacco. Heptaldehyde is found in tangerines, bilberries, star grapes, grapes, olives, peaches and bread. Octaldehyde is found in bread, carrots, olives and tangerines. Nonylaldehyde is found in bananas, tangerines, bilberry, milk,
Fish, beef, beer, tea, chicken, star grapes, melon, olives, carrots, ginger,
and found in bread. Decanal includes bread, ginger, milk, fish, cacao, beer,
Found in cucumbers, grapes and tangerines. Andecylaldehyde is found in tangerines, milk, fish, beef, and cucumbers. Dodecyl, on the other hand, is found in milk, fish, beef, tangerines, grapes and cucumbers.
Cis-6-nonenal is found in melons and cucumbers. Phenylacetaldehyde is found in peaches, beans, mushrooms, peppers, and blue cheese. Many efforts have been made over the past two decades to provide stable, immobilized acetaldehyde that dissociates only under the desired conditions of use and does not dissociate before use. The main reason for the difficulty in immobilizing acetaldehyde is its physical properties such as being a gas at room temperature (21 °C) under normal conditions, being miscible with water, and having a high degree of chemical reactivity and instability. exist. The chemical instability of acetaldehyde is exemplified by its tendency to polymerize to paraldehyde and metaldehyde, to be oxidized to acetic acid, and to chemically combine with itself and other substances in the presence of acids or bases. To perfect the immobilization of acetaldehyde, workers have attempted to encapsulate acetaldehyde in clathrates that envelop various types of complexes, including crystal defects, ie, types based on oligosaccharides or monosaccharides. The inclusion of the complex dissociates acetaldehyde under the conditions of use, such as when the dry beverage powder is dissolved in water. Generally, the disadvantage of this method is that only a small amount of acetaldehyde is fixed in a stable form using a large amount of matrix per aldehyde unit, which makes the use of aldehyde in this manner quite expensive. . For example, USP 3314803 relates to a method of encapsulating acetaldehyde in a mannitol matrix. 2-10% of the initial acetaldehyde is dissociated when spray drying the mannitol-acetaldehyde mixture. However, when exposed to open, normal conditions, acetaldehyde is lost to the atmosphere and reduces to a maximum of 1-2% fixation over a few days. Such loss of acetaldehyde from its matrix can occur in food bases such as dry beverage powders contained within the package in the presence of small amounts of water or water vapor present in the food or introduced during normal packaging operations. Observed when containing capsules. Other examples of polysaccharides wrapping matrices in patents are carbohydrate complexes in USP3625709,
Including the use of arabinogalactan in USP3264114 and the use of lactose in USP3736149. All of the latter methods have the disadvantage of a low degree of acetaldehyde immobilization. Additionally, they are unstable in the presence of water or water or water vapor that occurs when stored in non-hermetically sealed packaging that is sufficiently permeable to atmospheric moisture or to exposure that occurs during normal packaging operations. shows. USP 3,767,430 discloses a method of immobilizing acetaldehyde in a sucrose crystal matrix, but the amount of acetaldehyde is less than 0.1, and generally about 0.001-0.05%. A second method of immobilizing acetaldehyde is that of chemical derivatization, which overcomes several, often conflicting requirements, such as the requirements of chemical inertness and stability under normal storage conditions. When the food product is mixed or prepared for use, it must satisfy the properties of rapid aldehyde dissociation and not interfering with the aroma or taste of the desired flavor.
To meet that latter requirement, the derivatives and conversion products other than the target aldehyde should be relatively odorless and tasteless. Many attempts have been made in the patents to provide suitable chemical derivatives for generating acetaldehyde. A variety of aldehyde derivatives have been proposed including carbamates, carbonates, ureidos, ethylidene compounds (USP 2305620) and certain acetals (USP 3857964). All of the above-mentioned derivatives have at least some of the disadvantages of being tasteless, toxic, or being too stable as they dissociate at a reasonable rate in the desired food product. The use of known acetals derived from monohydric alcohols such as dimethyl, diethyl and dihexyl acetals and of other aliphatic aldehydes up to acetaldehyde, propionaldehyde and about dodecylaldehyde is pre-precluded by the taste of the acetal itself. The acetal is usually unacceptablely different from the parent aldehyde and, especially in the case of C ₁ to about C ₈ aldehyde acetals, interferes with the desired flavor balance. Furthermore, the use of alcohols to make such acetals is limited to alcohols having 1 to 5 carbon atoms. Because C ₆ or above, approx.
Alcohols up to C ₁₂ impart their own flavor and also distort the intended flavor. Provides aldehyde acetals derived from polyols or high molecular weight monoalcohols that meet the key requirements of stability and immobilization of aldehydes in seasoning and flavored food bases, and of the contemplated use. It is an object of this invention to provide a rapid dissociation effect under conditions.
These acetals do not interfere with the desired flavor, are stable to moisture, heat and oxidation under normal storage conditions, can be incorporated into dry seasonings and retain stability, and are Provides a higher proportion of stable, fixed acetaldehyde in dry seasoning or flavor bases than previously discovered. The acetals of this invention have the general formula (In the formula, R surrounded by a dotted circle is a polyvalent saturated aliphatic hydrocarbon group having 2 to 6 carbon atoms; n is an integer of 1 to 6; R ₁ is lower alkyl; R ₂ is lower alkyl; When n is an integer from 2 to 6,

The groups are bonded to the same or different carbon atoms of R. The acetals of this invention can be synthesized by reaction of a suitable vinyl alkyl ether with the desired polyol in the presence of an acid catalyst, for example by reaction of propylene glycol () with propylene ethyl ether () to form the compound (). do. Polyols or high molecular weight monoalcohols found to be useful include propylene glycol, glycerin, mannitol, sorbitol,
Neopentyl glycol, pentaerythritol, diethylene glycol monomethyl ether,
hexamethylene glycol, diethyl maleate,
or other relatively mild monoalcohols or polyols that can form linear acetals by reaction with vinyl ethers. For higher aldehydes ( _C3 - _C12 ), the hydroxy compound reacts with the corresponding higher alkyl vinyl ether (). (wherein R, R ₁ , R ₂ , R ₄ and R ₅ are explained above) When the polyhydroxy compound has a vicinal OH group, it can form a 1,3-diochlorane structure. , and similarly in the method if
When the OH group is present on every other carbon, 1,3
- A dioxane structure is formed. When attempts are made to form vicinal linear acetals such as 1,2,3-tris-[(1'-ethoxy)ethoxy]propane, there is a tendency to form cyclic linear acetals. It becomes obvious. Cyclic acetals, such as the acetals with dioxolane or meta-dioxane mentioned above, can be used to improve the pH of citrus drinks such as orange juice or grapefruit juice, e.g. a pH of about 1.8-3.5.
is too stable to hydrolyze at a reasonable rate to give acetaldehyde. For example, 1,3-ethylideneglycerol and 1,2-ethylideneglycerol type compounds do not hydrolyze at an adequate rate in citrus drinks at room temperature. A search of the literature on methods for synthesizing 1,2,3-tris[(1'-ethoxy)ethoxy]propane revealed that despite several attempts, this compound had not been synthesized. . Russian researchers have published papers on the reaction between ethyl vinyl ether and glycerol and the reaction between glycerol trivinyl ether and alcohol. (a) MF Shostakovsky
etc., Bull.Acad.Sci., Union of Soviet Socialist Republics, Div.Chem.Sci., etc.
137−140 (1954) (b) MF Sjostakovsky et al., ibid., 583−
587 (1954) (c) MF Sjostakovsky et al., ibid., 313−
316 (1955) (d) MF Sjostakovsky et al., ibid., 317−
320 (1955) Therefore, 1,2,3-tris-[(1'-ethoxy)ethoxy]propane XI as the target compound was not found in the literature. This compound is said to be unstable and decomposes to form dioxolane XII when ethyl vinyl ether and glycerol react in the presence of an acid catalyst or when glycerol trivinyl ether and ethanol react: In both reactions using glycerol trivinyl ether and ethyl vinyl ether, the reaction mixture was allowed to come to natural temperature after all reagents were mixed. In each case an exothermic reaction resulted in an increase in temperature between 75 and 95°C. Unexpectedly, if an equimolar ratio of vinyl ether reactant to moles of alcohol reactant is maintained by keeping the reaction temperature below about 120°C and adding the alcohol and vinyl ether reactants simultaneously dropwise, The formation of cyclic products is suppressed. Therefore, 4 moles of ethyl vinyl ether and 1 mole of glycerin are simultaneously added dropwise into a reaction flask containing a soluble mixture containing dimethyl ether of diethylene glycol and the hitherto unsynthesized trimethylhexadecyl ammonium chloride and a hydrochloric acid catalyst. Similar reactions occur successfully with other polyhydroxyl compounds, such as propylene glycol, mannitol, sorbitol, etc., resulting in the corresponding multilinear
It was found that acetal was produced. Since the materials, such as mannitol and sorbitol, are not soluble in ethyl vinyl ether, the reaction can be carried out with non-reactive cosolvents of the polyhydroxy compound, such as dimethylformamide, hexamethylphosphoric triamide, dimethyl sulfoxide, or N-methyl-2-pyrrolidone. May be promoted. To our knowledge, multilinear acetals derived from polyols are novel compounds not available by known synthetic methods. When the above synthesis method is applied to glycerin, trislinear acetal mixed with acetal (31% yield) is obtained. The yield of acetal is 36.4%. Alternatively, the synthesis method described above can be used with propylene glycol to give dilinear acetals (67% yield) and mannitol in n-methyl-2-pyrrolidone solvent to give acetals (about 70% yield). Example 4 - (1'-ethoxy)ethoxymethyl-2-methyl-1,3-dioxolane and 1,2,3
- Tris[(1'-ethoxy)ethoxy]propane 5 ml of 36% hydrochloric acid and a 50% isopropyl alcohol solution of trimethylhexadecyl ammonium chloride in a 2000 ml flask with a mechanical stirrer, heating mantle, thermometer, condenser and two-legged funnel. 1.6ml was added. Then, 294.4 g of glycerin (3.16 m) and 921.6 g of ethyl vinyl ether (12.8 m) were simultaneously added dropwise at a constant rate over a period of 1 hour at a temperature of 23 to 39°C. At this point the reaction mixture became homogeneous and yellow in color. Then, the mixture was gently heated to reflux at 40° C. with stirring for an additional hour. After standing at room temperature for 14 hours, the reaction mixture was then quenched with 10 g of sodium carbonate while stirring. After distilling the light fraction at 760 mmHg to a pot temperature of 110°C and a head temperature of 56°C, the product was flash distilled under the following parameters to obtain a 51.4%
of 1,2,3-tris-[(1'-ethoxy)ethoxy]-propane (31% yield) and 37.3% of 4-
(1'-ethoxy)ethoxymethyl-2-methyl-
588 g of a yellow oil containing 1,3-dioxolane (36.4% yield) was obtained: Pot temperature Head temperature Vacuum 60-212°C 40-144°C 10-0.1 mmHg )
The flash distillate was rectified on the column at approximately 7 plate speeds:

[Table] The purity of the acetal was determined by gas chromatography. 6′ x 1/4″ for 1,2,3-tris-[(1′-ethoxy)ethoxy]-propane
A stainless steel column was used with 20% SE30 on pickled Chromasorb omega packing at 135° C. to 220° C. at 4°/min, He flow ˜60 ml/min. And 4-
(1'-ethoxy)ethoxymethyl-2-methyl-
For 1,3-dioxolane, a 20% Carbowax 20m column was used, other parameters as above. Spectral and Physical Data (A) 1,2,3-Tris[(1'-ethoxy)ethoxy]propane d25/250.9561 n ²⁰ _D 1.4222 BP 117°C under 1.0mmHg, 102°C under 0.11mmHg NMR Spectrum Methyl proton (18H) - heterogeneous quartet with centroid at ~1.15δ; monoalkoxy proton (11H) - broad multiplet with centroid at about 3.48δ; dialkoxymethine proton (3H) -
A broad multiplet with a center of gravity at approximately 4.67δ. IR spectrum (CCl ₄ solution) 1054 cm ^-1 , 1080 cm ^-1 , 1095 cm ^-1 , 1105 cm ^-1 and 1133 cm ^-1 (highest intensity band in spectrum). (B) 4-(1'-ethoxy)ethoxymethyl-2-
Methyl-1,3-dioxolane d25/251.0073 n ^D ₂₀ 1.4243 BP 51℃ at 0.09 mmHg NMR spectrum Sharp peak with center of gravity at ~1.2δ (~
Multiplet of 6), 3 methyl group; 9 protons; broad multiplet extending from 3.1δ to 4.3δ, alkoxy proton, 7 protons; quartet with center at 4.66δ, linimer acetalmethine, 1 proton; center at 5.01 δ quartet, dioxolane acetalmethine, 1 proton. IR spectrum (CCl ₄ solution) Strong ether C- between 980 cm ^-1 and 1200 cm ^-1
O-C Stretch Band Example 2 1,2-di-[(1'-ethoxy)ethoxy]propane 36.5 mL in a 250 ml flask with condenser, static nitrogen head, mechanical stirrer, and two-legged funnel.
8 drops of % hydrochloric acid, 7 ml of bis-(2-methoxyethyl) ether and 1 drop of a 50% solution of trimethylhexadecyl ammonium chloride in isopropanol. Next, 43.3 g of ethyl vinyl ether and 15.2 g of propylene glycol were added dropwise at a constant rate from a separating funnel at 40° C. over 23 minutes.
Refluxing was continued for a further 2 hours at 40°C, the mixture was cooled and 0.4g of solid sodium hydroxide was added.
After removing the light fraction under vacuum, the product was directly distilled. 14″×~10 under the following parameter conditions
Distillation was carried out using a mm concentrator column:

[Table] Spectral and physical data d25/250.9153 n ²⁰ _D 1.4112 BP at 0.04 mmHg at 47° NMR spectrum Multiplet with centroid at 1.18δ, 15 protons, methyl group; broad multiplet with centroid at 3.57δ 7 protons, hydrogen adjacent to one oxygen; broad multibullet centered at about 4.71δ, 2-proton, acetalmethine proton. IR Spectrum Strong ether C-O-C stretch absorption between 1020 cm ^-1 and 1200 cm ^-1 , 1061 cm ^-1 (maximum), 1087 cm ^-1 , 1104 cm ^-1 and 1140 cm ^-1 . Example 3 1,2-bis[(1'-ethoxy)propoxy]
Propane 15 g propenylethyl ether, 5.1 g propylene glycol in a 50 ml flask with addition funnel, magnetic stirrer, thermometer and static nitrogen head.
g, bis-(2-methoxyethyl) ether 6.2 g
and 1 drop of a 50% isopropanol solution of trimethylhexadecyl ammonium chloride. After adding 3 drops of concentrated hydrochloric acid, the mixture was stirred for 3 hours at 41-43°C and, after cooling, left overnight at room temperature. After heating at 40℃ for a further 3 hours, 4.5g of
The mixture was quenched with KOH. After removal of the light fractions under vacuum, the shoots were removed under the following parameters:
The product was distilled in a pass still:

[Table] Example 4 1,2,3,4,5,6-hexa-[(1'-ethoxy)ethoxy]hexane 250 ml with static nitrogen head and magnetic stirrer
18.6g mannitol, 100ml N in flask
-Methylpyrrolidinone and 64.8g of ethyl vinyl ether were charged. Then 10 drops of concentrated hydrochloric acid were added and the mixture was stirred for 4.5 hours at 22-28°C and left overnight. The next day, the infrared spectrum of the properly prepared sample was virtually free of absorption due to hydroxyl groups and the strong C-O-C band of ether. The reaction mixture was poured into 750 ml of water with excess NaOH with stirring and then extracted with two 150 ml portions of hexane. Each abstract was washed with successive 750 ml portions of water. The combined organic phase portions were dried over solid sodium carbonate-sodium sulfate and then evaporated in vacuo at approximately 10 mm Hg to yield 59 g of crude oil. Distilled using a Short Pass Micro Still under the following conditions.

【table】

[Table] IR spectrum (CCl ₄ solution) The weak and broad band at 3500 cm ^-1 indicates some kind of free hydroxyl; from 990 cm ^-1 to
1200cm ^-1 , 1044cm ^-1 (max), 1082cm ^-1 , and
There is a strong C-O-C stretch band at 1136 cm ^-1 . NMR spectrum (CCl ₄ solution, control TMS) Asymmetric quartet of 1.0δ to 1.4δ at center of mass approximately 1.25, methyl proton - 34.5 proton (theoretical
36); Broad multiplet of 3.2δ to 4.0δ at center of gravity of about 3.6δ, hydrogen of monoalkoxy-substituted carbon, 20 protons; 4.45δ to 5.1 at center of gravity of about 4.75δ
A broad and complex multiplet between δ, acetalmethine protons, 5.5 protons (theoretical
6.0). The ratio of methyl to alkoxy to acetal methine protons in the spectrum in CDCl ₃ is 33.9/20/
It was 5.9. The ratio of _d4 -MeOD exchange spectrum is 32.8/20/5.7
On the other hand, the ratio of the d ₆ -DOAc exchange spectrum is
It was 34.9/20/5.9. Oxidation analysis of the hydrolyzed acetal in the presence of hydroxylamine at pH 3.5 revealed that 96.4% of the theoretical acetaldehyde was formed, which means that 20% of the 6th hydroxyl in the molecule is This shows that it has not become free OH. Test example 1 1% in 95% ethanol with orange flavor
Eight drops of the solution and 14 ml of citric acid syrup were combined in a 4 ounce container at about 23°C and water was added to bring the volume to 4 ounces (approximately 114 g of water was added). Orange flavor is an orange terpene containing 5% by weight acetaldehyde. Citric acid syrup was prepared by adding 1 gallon of 67.5% sucrose water, 14 ml of a 25% by weight aqueous benzoic acid solution, and 44 ml of a 50% aqueous citric acid solution. The pH of this syrup is usually around
It is 3.1. 12% 4 as orange flavor
A third drink was prepared using an orange terpene containing -(1'-ethoxy)ethoxymethyl-2-methyl-1,3-dioxolane. Four of five professional perfumers measured the subtle differences in flavor in each drink, and a fifth blind-selected and judged the source-fortified drinks. When retesting, only 1 out of 5 people was able to identify the fortified drink by blind selection when the newly prepared drinks were mixed for 20 minutes to 1/2 hour. Test Example 2 Test (a) Using the same method as in Test Example 1, drink No. 1 without fortifying the orange flavor of 7.7% 4-(1'-ethoxy)ethoxymethyl-2-methyl-1 with the same orange flavor. , 3-Dioxalane-fortified drink No. 2, and 7.7% 1,2,
Drink No. 3 was prepared using 3-tris[(1'-ethoxy)ethoxy]propane.
Four professional perfumers investigated the 'freshness' effect of drinks and found the following results:

[Table] This test showed the strong effects of source-enriched drinks. Test (b) Prepare two types of orange drinks by the method described in test (a) and prepare 8% 1,2,3-tris-[(1'-
Orange flavors enriched with ethoxy)ethoxy]propane were compared to those without or with sources of acetaldehyde. As in Example 5 and Example 6(a), at room temperature of about 23°C
produced drinks. Two minutes after making the drink, four professional perfumers examined and presented the source-enriched drink to investigate the effect of 'Fresh Youth'. Test (c) Two types of orange-flavored drinks were made in the same manner as in test (b). 8% for one drink
One was fortified with 1,2,3-tris[(1'-ethoxy)ethoxy]propane and the other was left without added source or aldehyde. The water used to make the drink was pre-cooled to 10° C., and after mixing with the citric acid syrup, a 1% alcoholic solution of flavor oil was added. Once again, four professional perfumers investigated which source-enriched beverages within two minutes of mixing had the effect of 'fresh' juice. Two perfumers found noticeable effects within one minute. Test Example 3 Consideration test regarding hydrolysis of various acetals (a)-4-(1'-ethoxy)ethoxymethyl-2
-Methyl-1,3-dioxolane The above acetal was dissolved in 50 ml of dilute sulfuric acid at pH 3.0. When the absorption of the solution was measured using the ultraviolet spectrum at 275 ml, the following data were obtained in comparison to the theoretical aldehyde formation. This test showed that essentially only the linear acetal portion of the molecule exhibits this PH and temperature:

[Table] Test (b) The same method as Test (a) except that 1,2,3-tris[(1'-ethoxy)ethoxy]propane acetal was dissolved in 10% ethanol, under various PH conditions. The above acetal was hydrolyzed. The results are shown below:

[Table] Test (c) In the same manner as test (a), 1,2-di[(1'-
Ethoxy)ethoxy]propane in various forms in sulfuric acid
Hydrolyzed under PH conditions:

【table】

Claims (1)

[Claims] 1. General formula (wherein R surrounded by a dotted circle is a saturated aliphatic hydrocarbon group having 2 to 6 carbon atoms; n is an integer of 1 to 6; R ₁ is lower alkyl; R ₂ is lower alkyl; n is an integer from 2 to 6, the groups are bonded to the same or different carbon atoms of R).