PARTICULATE ACIDULANT COMPOSITION COMPRISING MALIC ACID AND LACTIC ACID

Abstract

The invention relates to a particulate acidulant composition comprising 20-70 wt. % malic acid, 3-40 wt. % lactic acid and 0-40 wt. % of food acid selected from citric acid, fumaric acid, adipic acid, tartaric acid and acetic acid and combinations thereof, wherein the acidulant composition comprises: 40-90 wt. % of M-particles comprising co-crystal of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said M-particles containing at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid; 5-60 wt. % of L-particles comprising co-crystal of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said L-particles containing at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized polycarboxylic acid; and
wherein the combination of M-particles and L-particles constitutes at least 50 wt. % of the acidulant composition.

The invention also relates to a particulate coating composition, to a method of preparing a food ingredient or a food product and to a confectionery product.

Claims

1. A particulate acidulant composition, comprising: (a) 20-70 wt. % malic acid, (b) 3-40 wt. % lactic acid and (c) 0-40 wt. % of food acid selected from citric acid, fumaric acid, adipic acid, tartaric acid, acetic acid and combinations thereof, wherein the composition comprises: (i) 40-90 wt. % of M-particles comprising a co-crystal of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the M-particles comprising at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid, wherein the M-particles are obtainable by spraying an aqueous solution of partially neutralized polycarboxylic acid onto particles of malic acid in a fluid bed dryer, and wherein the M-particles have a core comprising malic acid in a concentration that is at least 10 wt. % higher than the average malic acid concentration of the particles; (ii) 5-60 wt. % of L-particles comprising a co-crystal of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the L-particles comprising at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized carboxylic acid, wherein the L-particles are obtainable by spraying an aqueous solution of lactic acid onto particles of at least partially neutralized carboxylic acid in a fluid bed dryer, and wherein the L-particles have a core comprising the at least partially neutralized carboxylic acid in a concentration that is at least 10 wt. % higher than the average concentration of the at least partially neutralized carboxylic acid in the particles; and wherein the combination of M-particles and L-particles constitutes at least 50 wt. % of the acidulant composition.

2. The acidulant composition according to claim 1, comprising 60-88 wt. % of the M-particles.

3. The acidulant composition according to claim 1, comprising 6-35 wt. % of the L-particles.

4. The acidulant composition according to claim 1, wherein the partially neutralized polycarboxylic acid in the M-particles is selected from mono-sodium or mono-potassium hydrogen malate, mono-sodium or mono-potassium dihydrogen citrate, di-sodium or di-potassium hydrogen citrate, and combinations hereof.

5. The acidulant composition according to claim 1, wherein at least 25 wt. % of the malic acid in the M-particles is present in the co-crystal of malic acid and partially neutralized polycarboxylic acid.

6. The acidulant composition according to claim 1, wherein the at least partially neutralized carboxylic acid in the L-particles is neutralized lactic acid.

7. The acidulant composition according to claim 6, wherein the neutralized lactic acid is calcium lactate.

8. The acidulant composition according to claim 1, wherein at least 30 wt. % of the lactic acid in the L-particles is present in the co-crystal of lactic acid and the at least partially neutralized carboxylic acid.

9. The acidulant composition according to claim 1, wherein the acidulant composition is a powder comprising at least 90 wt. % particles having a diameter in the range of 120-1200 m.

10. A particulate coating composition, comprising: (a) 30-98 wt. % sugar particles; (b) 2-40 wt. % of M-particles comprising a co-crystal of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the M-particles comprising at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid, wherein the M-particles are obtainable by spraying an aqueous solution of partially neutralized polycarboxylic acid onto particles of malic acid in a fluid bed dryer, and wherein the M-particles have a core malic acid in a concentration that is at least 10 wt. % higher than the average malic acid concentration of the particles; and (c) 0.5-10 wt. % of L-particles comprising a co-crystal of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the L-particles comprising at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized carboxylic acid, wherein the L-particles are obtainable by spraying an aqueous solution of lactic acid onto particles of at least partially neutralized carboxylic acid in a fluid bed dryer, and wherein the L-particles have a core comprising the at least partially neutralized carboxylic acid in a concentration that is at least 10 wt. % higher than the average concentration of the at least partially neutralized carboxylic acid in the particles.

11. A method of preparing a food ingredient or a food product, comprising combining the acidulant composition according to claim 1 with one or more non-aqueous ingredients.

12. The method according to claim 11, wherein the food product is a confectionery product.

13. The method according to claim 11, wherein the acidulant composition is combined with the food product at a concentration of 0.01-20 wt. %.

14. A method of preparing a food ingredient or a food product, comprising combining the particulate coating composition of claim 10 with one or more non-aqueous ingredients.

15. The method according to claim 14, wherein the food product is a confectionery product.

16. A confectionery product, comprising: (a) 0.3-90 wt. % of M-particles comprising co-crystals of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the M-particles comprising at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid, wherein the M-particles are obtainable by spraying an aqueous solution of partially neutralized polycarboxylic acid onto particles of malic acid in a fluid bed dryer, and wherein the M-particles have a core comprising malic acid in a concentration at least 10 wt. % higher than the average malic acid concentration of the particles; and (b) 0.1-60 wt. % of L-particles comprising co-crystals of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, the L-particles comprising at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized carboxylic acid, wherein the L-particles are obtainable by spraying an aqueous solution of lactic acid onto particles of at least partially neutralized carboxylic acid in a fluid bed dryer, and wherein the L-particles have a core comprising the at least partially neutralized carboxylic acid in a concentration at least 10 wt. % higher than the average concentration of the at least partially neutralized carboxylic acid in the particles.

17. The confectionery product according to claim 16, wherein the confectionery product is a candy, chocolate or a chewing gum.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 shows the XRPD pattern of the M-particles according to the invention.

[0031] FIG. 2 shows the XRPD pattern of the L-particles according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Accordingly, a first aspect of the invention relates to a particulate acidulant composition comprising 20-70 wt. % malic acid, 3-40 wt. % lactic acid and 0-40 wt. % of food acid selected from citric acid, fumaric acid, adipic acid, tartaric acid and acetic acid and combinations thereof, wherein the acidulant composition comprises: [0033] 40-90 wt. % of M-particles comprising co-crystal of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said M-particles containing at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid; [0034] 5-60 wt. % of L-particles comprising co-crystal of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said L-particles containing at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized polycarboxylic acid; and
wherein the combination of M-particles and L-particles constitutes at least 50 wt. % of the acidulant composition.

[0035] Whenever reference is made herein to a particular food acid (e.g. malic acid, lactic acid, citric acid, fumaric acid, adipic acid, tartaric acid or acetic acid), unless indicated otherwise, what is meant is the free acid, whether in free form or as a component in a co-crystal.

[0036] The term co-crystal of malic acid and partially neutralized polycarboxylic acid as used herein refers to a crystalline structure comprising at least 25 wt. % malic acid and at least 25 wt. % partially neutralized polycarboxylic acid.

[0037] The term co-crystal of lactic acid and at least partially neutralized carboxylic acid as used herein refers to a crystalline structure comprising at least 30 wt. % lactic acid and at least 30 wt. % partially neutralized carboxylic acid.

[0038] The term at least partially neutralized carboxylic acid encompasses fully neutralized monocarboxylic acid, partially neutralized polycarboxylic acid and fully neutralized polycarboxylic acid.

[0039] The partially neutralized polycarboxylic acid and the at least partially neutralized carboxylic acid may be present in the acidulant composition in anhydrous form or in the form of hydrates.

[0040] The particulate acidulant composition of the present invention preferably comprises 25-60 wt. % malic acid, more preferably 30-50 wt. % malic acid and most preferably 32-45 wt. % malic acid.

[0041] The lactic acid content of the particulate acidulant composition is preferably in the range of 4-35 wt. %, more preferably in the range of 5-30 wt. % and most preferably in the range of 6-25 wt .%.

[0042] The particulate acidulant composition preferably contains 0- 30 wt. %, more preferably 0-18 wt. % and most preferably 2-12 wt. % of food acid selected from citric acid, fumaric acid, adipic acid, tartaric acid and acetic acid and combinations thereof. The inclusion of additional food acids besides malic and lactic acid adds to the complexity of the acidulant composition's flavour contribution. However, ambient stability of the composition can be adversely affected by incorporation of these other food acids in concentrations of more than 10 wt. %.

[0043] Besides malic acid, lactic acid and optional other free acids, the particulate acidulant composition typically contains at least 20 wt. %, more preferably at least 25 wt. % and most preferably 30-60 wt. % salts of carboxylic acids.

[0044] The M-particles comprising co-crystal of malic acid and partially neutralized polycarboxylic acid, preferably constitute 60-88 wt. % of the acidulant composition. Most preferably, the M-particles constitute 70-85 wt. % of the acidulant composition.

[0045] The L-particles comprising co-crystal of lactic acid and at least partially neutralized carboxylic acid preferably constitute 6-35 wt. %, most preferably 8-32 wt. % of the acidulant composition.

[0046] The partially neutralized polycarboxylic acid in the M-particles is preferably selected from mono-sodium or mono-potassium hydrogen malate, mono-sodium or mono-potassium dihydrogen citrate, di-sodium or di-potassium hydrogen citrate, and combinations hereof. More preferably, the partially neutralized polycarboxylic acid in the M-particles is selected from mono-sodium hydrogen malate, mono-potassium hydrogen malate and combinations thereof. Most preferably, the partially neutralized polycarboxylic acid in the M-particles is mono-sodium hydrogen malate.

[0047] According to a particularly preferred embodiment, the M-particles comprise co-crystal of malic acid and mono-sodium hydrogen malate and the L-particles comprise co-crystal of lactic acid and calcium lactate.

[0048] The M-particles in the acidulant composition can suitably be prepared in a fluid bed dryer by spraying an aqueous solution of partially neutralized polycarboxylic acid onto particles of malic acid. In M-particles prepared in this manner, the core contains malic acid in a concentration that is at 10 wt. % higher, more preferably at least 20 wt. % higher and most preferably at least 30 wt. % higher than the average malic acid concentration of these particles. The presence of this type of M-particles in the acidulant composition was found to have the advantageous effect that the sourness perception is prolonged.

[0049] The term core as used herein in relation to a particles refers to the centre of such a particle.

[0050] The at least partially neutralized carboxylic acid in the L-particles preferably is neutralized lactic acid, most preferably calcium lactate.

[0051] The L-particles in the acidulant composition can suitably be prepared in a fluid bed dryer by spraying an aqueous solution of lactic acid onto particles of at least partially neutralized carboxylic acid. In L-particles prepared in this manner, the core contains at least partially neutralized carboxylic acid in a concentration that is at 10 wt. % higher, more preferably at least 20 wt. % higher and most preferably at least 30 wt. % higher than the average concentration of partially neutralized carboxylic acid (e.g. calcium lactate) in these particles. The presence of this type of L-particles in the acidulant composition was found to have the advantageous effect that an almost instantaneous sourness perception can be achieved.

[0052] According to a particularly preferred embodiment, the particulate acidulant composition comprises a combination of M-particles having a relatively high malic acid concentration in the core and L-particles having a relatively high neutralized carboxylic acid concentration in the core. The application of this particular combination of M-particles and L-particles was found to produce a sourness impression that is almost instantaneous and that continues for a long time.

[0053] Co-crystals of malic acid and partially neutralized polycarboxylic acid and co-crystals of lactic acid and the at least partially neutralized carboxylic acid can be detected with the help of X-ray powder diffraction (XRPD). This technique distinguishes the co-crystal by comparing its peak positions and intensities observed in the powder pattern to all known free base forms of the material. The amount of the co-crystals in a material may be quantified by means of XRPD, however other methods such as Raman spectroscopy may be preferred for a more accurate quantification.

[0054] According to a particularly preferred embodiment, at least 20 wt. %, more preferably at least 23 wt. % and most preferably at least 25 wt. % of the malic acid in the M-particles is present in the co-crystal of malic acid and partially neutralized polycarboxylic acid.

[0055] According to another preferred embodiment, at least 25 wt. %, more preferably at least 27 wt. % and most preferably at least 30 wt. % of the lactic acid in the L-particles is present in the co-crystal of lactic acid and the at least partially neutralized carboxylic acid.

[0056] Besides malic acid and lactic acid, the acidulant composition may suitably contain one or more food acids selected from citric acid, fumaric acid, adipic acid, tartaric acid and acetic acid. According to a preferred embodiment, these other food acids are present in the acidulant composition in the form of particles that largely consist of free acid (A-particles). Accordingly, in a preferred embodiment the acidulant composition comprises 2-30 wt. %, more preferably 3-20 wt. % of A-particles containing at least 80 wt. % of food acid selected from citric acid, fumaric acid, adipic acid, tartaric acid and acetic acid and combinations thereof.

[0057] The particulate acidulant composition of the present invention preferably comprising at least 90 wt. % particles having a diameter in the range of 120-1200 m, more preferably in the range of 150-1100 m, and most preferably in the range of 200-1000 m. The particle size distribution of the acidulant composition can suitably be determined with the help of laser diffraction.

[0058] A further aspect of the invention relates to a particulate coating composition comprising: [0059] 30-98 wt. % sugar particles; [0060] 2-40 wt. % of M-particles comprising co-crystal of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said M-particles containing at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid; [0061] 0.5-10 wt. % of L-particles comprising co-crystal of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said L-particles containing at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized polycarboxylic acid.

[0062] The M-particles and L-particles that can be employed in the particulate coating composition are the same M-particles and L-particles as defined herein before in relation to the particulate acidulant composition of the present invention.

[0063] Preferably, the particulate coating composition comprises 40-96 wt. %, more preferably 45-92 wt. % and most preferably 50-90 wt. % sugar particles.

[0064] M-particles are preferably contained in the coating composition in a concentration of 3-35 wt. %, more preferably of 4-30 wt. % and most preferably of 5-27 wt. %.

[0065] L-particles are preferably contained in the coating composition in a concentration of 0.8-9 wt. %, more preferably of 1-8.5 wt. % and most preferably of 1.2-8 wt. %.

[0066] The coating composition of the present invention may suitably be applied to prepare acid-sanded confectionery. Acid-sanding, is the coating of confectionery with a blend of sugar and acid powder.

[0067] Another aspect of the invention relates to a method of preparing a food ingredient or a food product, said method comprising combining the particulate acidulant composition as defined herein before or the particulate coating composition as defined herein before with one or more non-aqueous ingredients.

[0068] In the present method, the particulate acidulant composition or the particulate coating composition is preferably not contacted with aqueous liquids so as to ensure that the M-particles and L-particles remain largely intact.

[0069] The present method of preparing a food ingredient or a food product preferably comprises combining the acidulant composition with one or more ingredients selected from sugars; polyols; flavouring; colouring; plant, vegetable, fruit, or flower extracts; spices; herbs; citrus fibres, dietary, fibers; essential oils; chocolate; cacao; nuts; dairy products; fortifying agents.

[0070] In one embodiment of the present the acidulant composition is incorporated in a food ingredient in a concentration of 0.1-30 wt. %, more preferably of 0.15-25 wt. % and most preferably of 0.2-20 wt. %.

[0071] According to a preferred embodiment, acidulant composition is incorporated in a particulate food ingredient together with particulate sugar. Particulate sugar is preferably incorporated in the food ingredient in a concentration of 30-98 wt. %, more preferably of 40-95 wt. % and most preferably of 50-90 wt. %.

[0072] Examples of food ingredients that may suitably be prepared by the present method include coating compositions, such as the particulate coating composition described herein.

[0073] In another embodiment of the invention the particulate acidulant composition or the particulate coating composition is applied in a confectionery product, more preferably a confectionery product selected from candies and chewing gum.

[0074] The acidulant composition is preferably applied in the food product in a concentration of 0.01-20 wt. %, more preferably of 0.1-15 wt. % and most preferably of 1-10 wt. %.

[0075] The particulate coating composition is preferably applied in the food product in a concentration of 1-70 wt. %, more preferably of 2-60 wt. % and most preferably of 5-50 wt. %.

[0076] According to a particularly preferred embodiment, the particulate coating composition is applied as a coating onto the food product.

[0077] Yet another aspect of the invention relates to a confectionery product comprising: [0078] 0.3-90 wt. % of M-particles comprising co-crystals of malic acid and partially neutralized polycarboxylic acid selected from malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said M-particles containing at least 30 wt. % malic acid and at least 30 wt. % of the partially neutralized polycarboxylic acid; and [0079] 0.1-60 wt. % of L-particles comprising co-crystals of lactic acid and at least partially neutralized carboxylic acid selected from lactic acid, malic acid, citric acid, fumaric acid, adipic acid, tartaric acid, and combinations thereof, said L-particles containing at least 30 wt. % lactic acid and at least 30 wt. % of the at least partially neutralized polycarboxylic acid.

[0080] The M-particles and L-particles that can be employed in the confectionery product are the same M-particles and L-particles as defined herein before in relation to the particulate acidulant composition of the present invention.

[0081] The M-particles are preferably contained in the confectionery product in a concentration of 0.5-80 wt. %, more preferably in a concentration of 0.6-70 wt. % and most preferably in a concentration of 0.7-60 wt. %.

[0082] The concentration of L-particles in the confectionery product is preferably in the range of 0.2-50 wt. %, more preferably of 0.25-40 wt. % and most preferably of 0.3-30 wt. %.

[0083] The confectionery product preferably contains 1-70 wt. %, more preferably 3-50 wt. % and most preferably 6-40 wt. % sugar.

[0084] The confectionery product of the present invention preferably is a candy, chocolate or a chewing gum. Examples of candies soft candy (hydrocolloid based and/or soft panned), hard candy (hard boiled and/or hard panned) an aerated candy. According to a particularly preferred embodiment, the confectionery product is a candy, most preferably an acid sanded candy.

[0085] According to a particularly preferred embodiment, the M-particles and L-particles are contained in a coating layer that surrounds the core of the confectionery product. The coating layer preferably has the same composition as the particulate coating composition described herein.

[0086] The invention is further illustrated by the following non-limiting examples.

EXAMPLES

Example 1

[0087] Particulate acidulant compositions according to the present invention were prepared by dry blending food acid components in accordance with the recipes shown in Table 1.

TABLE-US-00001 TABLE 1 Wt. % 1 2 3 4 M particles .sup.1 80 80 80 80 L particles .sup.2 20 15 14 14 Citric acid .sup.3 5 3 Tartaric acid .sup.4 6 3 .sup.1 Purac Powder MA (42-50 wt. % sodium hydrogen malate; 50-58 wt. % malic acid; 95% < 710 m; produced in fluid bed dryer by spraying aqueous solution of sodium hydrogen malate onto a bed of malic acid particles) .sup.2 Purac Powder 55 (53-57 wt. % lactic acid; 40-45 wt. % calcium lactate, 1-3 wt. % silicates; 98% < 710 m; produced in fluid bed dryer by spraying aqueous solution of lactic acid onto a bed of calcium lactate particles) .sup.3 Citric acid anhydrous (99.5 wt % citric acid, D[4, 3] 950 m RFI Food Ingredients) .sup.4 L(+) Tartaric acid powder (99.5 wt % tartaric acid, 295-400 m, Distillerie Bonollo

[0088] FIG. 1 shows the XRPD pattern of the M-particles. From this pattern it can be deduced that a substantial part of the M-particles consisted of co-crystal of malic acid and sodium hydrogen malate.

[0089] FIG. 2 shows the XRPD pattern of the L-particles. From this pattern it can be deduced that a substantial part of the L-particles consisted of co-crystal of lactic acid and calcium lactate.

[0090] The particulate acidulant compositions 1 to 4 were subjected to the following tests: [0091] Hygroscopicity of the acidulant composition at 30 C., 75% RH; [0092] Acid migration into gelatine mass at 30 C., 75% RH; Acid migration is tested, by spreading 0.5 g acidulant formulation on the surface of a gelatine tube. When the acid migrates into the gel a change of pH creates a colored layer that can be measured in thickness (mm), and compared between the samples. Monitoring the migration layer and appearance is performed every 2 days during at least 14 days. [0093] Sensory analyses of acid sanded jelly candies, prepared using a coating blend comprising 30 wt. % acidulant composition and 70 wt. % sugar. The acid sanded jelly candies were prepared by applying the coating onto commercially available gummy candy (Haribo gold bears) using steam. The coated candies were evaluated by an expert panel 4 weeks after preparation. Sensory evaluation was performed on sour intensity (score 1-10) and time lapse to first sour perception (in seconds).

[0094] The results of these tests are shown in Table 2

TABLE-US-00002 TABLE 2 1 2 3 4 Hygroscopicity .sup.1 16.6% 18.6% 18.2% 18.0% Acid migration .sup.2 4.5 mm 4.5 mm 4.0 mm 5.0 mm Sensory 7.2 7.7 7.3 7.7 evaluationsour intensity (score 1 minimum; to 10 maximum) Sensory 2.6 2.2 2.3 1.9 evaluationtime lapse till first sour perception (seconds). .sup.1 Maximum percentage water uptake after 16 days at 30 C., RH = 75% .sup.2 Penetration equal or below 5 mm is satisfactory as long as the acidulant is not liquefied.

[0095] No liquefaction was observed for any of the acidulant compositions in the acid migration test.

Comparative Example A

[0096] Acid sanded jelly candies were prepared in the same way as in Example 1, except that this time the acidulant composition consisted of malic acid powder comprising co-crystal of malic acid and sodium hydrogen malate (Purac Powder MA).

[0097] It was found that the candies prepared with this malic acid powder had a time lapse to first sour perception around 4 seconds, showing a prolonged effect but with a slow release of sourness. Moreover salty notes could be perceived which reduce the freshness of the flavour profile.

Comparative Example B

[0098] An acidulant composition is prepared by blending malic acid powder and lactic acid powder in a weight ratio of 80:20. This acidulant composition is tested in the same way as the acidulant compositions of Example 1.

[0099] It is found that the blend of malic acid powder and lactic acid powder is highly hygroscopic. Furthermore, this acid blend is found to produce a liquefied mass on the gelatine surface in the acid migration test.