FIBER SUPPLEMENTED ACIDIFIED DAIRY PRODUCTS AND METHODS FOR PROVIDING THE SAME

Abstract

Provided is a method for providing a spoonable acidified dairy product, comprising the steps of: a) providing an alpha-glucan composition comprising essentially linear isomalto/malto-polysaccharides (IMMPs) wherein the content of α(1.fwdarw.6) glycosidic linkages is at least 70%; b) supplementing a milk product with said alpha-glucan composition; and c) acidifying the supplemented milk product to a pH below 5, preferably to a pH of about 4.6. Also provided are products obtainable by such a method. Also provided is the use of IMMPs with a content of α(1.fwdarw.6) glycosidic linkages of at least 70% to improve the stability and/or sensory properties of acidified dairy products.

Claims

1. A method for providing a spoonable acidified dairy product, comprising the steps of: a) providing an alpha-glucan composition comprising essentially linear isomalto/malto-polysaccharides (IMMPs) including a content of α(1.fwdarw.6) glycosidic linkages of at least 70%; b) supplementing a milk product with said alpha-glucan composition; and c) acidifying the supplemented milk product to a pH below 5.

2. The method according to claim 1, wherein said milk product is selected from the group of fresh milk, skim milk, reconstituted milk powder from mammals.

3. The method according to claim 1, wherein said supplemented milk product comprises an IMMP content of at least 1.5 wt %.

4. The method according to claim 1, wherein step c) comprises the steps of (c1) inoculating the supplemented milk product with at least one lactic acid producing micro-organism; and (c2) allowing for fermentation.

5. The method according to claim 1, wherein step c) comprises adding an amount of chemical acidifying agent to the supplemented milk product to obtain a final pH below 5.

6. (canceled)

7. The method according to claim 1, wherein the alpha-glucan composition comprises IMMPs with a content of α(1.fwdarw.6) linkages of at least 70%, wherein the IMMPs are linear gluco-oligosaccharides of the general formula A-B, glucans comprising such a linear moiety, or a mixture comprising different gluco-oligosaccharides/moieties of the general formula A-B, wherein (i) the linkage between the moiety A and the moiety B is an α(1.fwdarw.6) glycosidic linkage; (ii) moiety A comprises at least two consecutive α(1.fwdarw.6) glycosidic linkages; (iii) moiety B comprises at least two consecutive α(1.fwdarw.4) glycosidic linkages.

8. The method or use according to claim 1, wherein said alpha-glucan composition is obtained by subjecting a starch substrate to a treatment with a debranching enzyme and to a treatment with a GTFB-type 4,6-α-glucanotransferase.

9. The method according to claim 8, wherein the debranching enzyme is iso-amylase (EC 3.2.1.68) or pullulanase (EC 3.2.1.41).

10. The method according to claim 8, wherein the GTFB-type 4,6-α-glucanotransferase is GTFB from Lactobacillus reuteri 121.

11. The method according to claim 8, wherein said starch substrate is selected from the group consisting of cereal starches comprising: corn, wheat, rice, barley or rye starches, root or tuber starches comprising: tapioca, sweet potato, arrow root or potato starch, and leguminous starches comprising: pea or bean starches.

12. The method according to claim 1, wherein the Brookfield viscosity of the acidified dairy product is in the range of 5000 mPas to 70000 mPas.

13. The method according to claim 1, wherein said acidified dairy product comprises one of yoghurt, Greek style yoghurt, quark, skyr, curd or cheese.

14. The method according to claim 1, wherein said acidified dairy product comprises an IMMP content of at least 1.5 wt %.

15. A spoonable acidified dairy product obtainable by a method according to claim 1.

16. A spoonable acidified dairy product comprising at least 1.5 wt % of essentially linear isomalto/malto-polysaccharides (IMMPs) having a content of α(1.fwdarw.6) glycosidic linkages of at least 70%.

17. The spoonable acidified dairy product according to claim 16, wherein the IMMPs comprise linear gluco-oligosaccharides of the general formula A-B, glucans comprising such a linear moiety, or a mixture comprising different gluco-oligosaccharides/moieties of the general formula A-B, wherein (i) the linkage between the moiety A and the moiety B is an α(1.fwdarw.6) glycosidic linkage; (ii) moiety A comprises two or more consecutive α(1.fwdarw.6) glycosidic linkages; (iii) B comprises at least two consecutive α(1.fwdarw.4) linked glucose residues.

18. The spoonable acidified dairy product according to claim 16, having a Brookfield viscosity in the range of 5000 mPas to 70000 mPas.

19. The spoonable acidified dairy product according to claim 16 comprising yoghurt, Greek style yoghurt, quark, skyr, curd or cheese.

20. The method according to claim 4 wherein said at least one lactic acid producing micro-organism is selected from the group consisting of Lactobacillus sp., Leuconostoc sp., Lactococcus sp., Streptococcus sp., and Pediococcus sp.

21. The method according to claim 4 wherein said at least one lactic acid producing micro-organism is selected from the group consisting of Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus bifidus, Lactobacillus bulgaricus and Streptococcus thermophiles.

22. The method according to claim 5, wherein the chemical acidifying agent comprises one or more compounds selected from the group consisting of acetic acid, citric acid, lactic acid, malic acid, succinic acid, tartaric acid and glucono delta-lactone.

23. The method according to claim 8, wherein said treatment with a debranching enzyme and said treatment with a GTFB-type 4,6-α-glucanotransferase are performed simultaneously.

Description

DETAILED DESCRIPTION

[0092] The disclosure will now refer to the following Examples.

Example 1: Preparation of IMMP Fibres

[0093] IMMP fibres suitable for use according to the invention may be prepared by enzymatic treatment of a starch with pullulanase (EC 3.2.1.41) and a GTFB-type 4,6-α-glucanotransferase. In this Example, a comparison was made between IMMPs obtained by only GTFB-type 4,6-α-glucanotransferase and IMMPs obtained by both pullulanase and GTFB-type 4,6-α-glucanotransferase. Moreover, IMMPs obtained by either sequential or simultaneous treatment with pullulanase and GTFB-type 4,6-α-glucanotransferase are compared.

[0094] Thus, three distinct synthetic routes were compared. Each route started with the gelatinisation of starch and was followed by one of the three treatments; (i) GTFB-type 4,6-α-glucanotransferase (GTFB) enzyme only, (ii) first debranching followed by GTFB enzyme or (iii) simultaneously debranching and GTFB treatment.

[0095] Promozyme D6 (Novozymes, Batch ATN60003), a commercially available pullulanase, was used as a debranching enzyme. The GTFB enzyme used was a truncated version of the 4,6-α-glucanotransferase GTFB enzyme of Lactobacillus reuteri 121 denoted GTFBdNdC. This was produced by Avebe as described in Bai et al. 2015 and 2017 [4] [5].

[0096] Prior to enzymatic treatment, potato starch (Avebe, batch G3771649) was gelatinized by jet cooking with tap water at a mass ratio between 1:4 and 1:7 and a temperature of 160° C. in a Henan laboratory jet-cooker. The gelatinized starch (5 or 10 L) was poured into a pre-heated RVS steel reaction vessel. CaCl.sub.2 (Merck, Batch A609182) was added to a final concentration of 1 mM, the temperature was set at the indicated temperature and 3 M acetic acid (VWR, Batch 16D254124) was added to set the pH. At this point, the enzymatic treatments were performed by either: [0097] i) setting the temperature to 40° C., adjusting the pH to 4.7, adding GTFB enzyme to a final concentrations of 30 kUnits per kg starch and incubating for 43 hours. After 43 hours, the reaction was stopped by heating to above 90° C. for 30 min. The reaction mixture was cooled to 50 to 60° C.; [0098] ii) setting the temperature to 58.5° C., adjusting the pH to 4.7, adding 0.2 wt % liquid Promozyme D6 per kg of starch, followed by overnight incubation. This reaction was terminated by heating to 80° C. (internal temperature) for 30 min. Upon cooling to 40° C. and, if necessary, re-adjusting the pH to 4.7, 30 kUnits per kg starch GTFB enzyme was added. After 26 hours of incubation, the reaction was stopped by heating to 90° C. The reaction mixture was cooled to 50-55° C.; [0099] iii) setting the temperature to 40° C., adjusting the pH to 4.7, adding 23.7 kUnits per kg starch of GTFB enzyme and after 15 min adding 0.05 wt % liquid Promozyme D6 per kg starch. After overnight incubation, another 0.05 wt % liquid Promozyme D6 per kg starch was added. After a total incubation time of 36 hours (or shorter for products with a lower percentage of α(1.fwdarw.6) linkages), the reaction was terminated by heating to above 90° C. for at least 15 min. After the reaction mixture was cooled to between 50-60° C., it was optionally filtered using a Buchner with Whatmann paper.

[0100] Subsequently, protein and salt were removed by ion exchange involving addition of either (i and ii) approximately 10% v/v Amberlite MB 20 resin (Dow, extensively rinsed with demi-water prior to use) or (iii) approximately 10% v/v Amberlite FPA40-C1 resin (Dow, Batch A075EAG043) and Amberlite 252 resin (Dow, Batch A075DBH033) and incubating for 45-60 min. Resins were prepared according to the manufacturer's instructions. The mixture was passed over a 45 μm sieve and, in case of iii also filtrated using a Buchner with Whatmann paper. A solution of 4% NaOH (Merck, Batch 1.06482.500) was added to adjust the pH to about 6. The product was spay dried using either an Anhydro Denmark spray drier with a nozzle (T.sub.in 250° C., T.sub.out 110° C.) or with a wheel (T.sub.in 270° C., T.sub.out 140° C.).

[0101] Dextrose Equivalent (DE) quantification of the product was carried out using the Luff-Schoorl procedure. The content of α(1.fwdarw.6) linkages is quantified by NMR spectroscopy. 1HNMR spectra were recorded in D20 at 340 K using a 600 MHz Bruker machine. The fraction of α(1.fwdarw.6) glycosidic linkages is calculated by dividing the anomeric α(1.fwdarw.6) by the sum of the anomeric α(1.fwdarw.4) and α(1.fwdarw.6) signals. The molecular weight distribution of the product was analysed via GPC-RI-MALLS. Briefly, the carbohydrate products were dissolved in 50 mM NaNO.sub.3. Samples were filtered (0.5 μm) before injection. The system consisted of a HPLC—Dionex Ultimate 3000 equipped with a GPC column (Shodex-OHpak SB-803 HQ, 8.0×300 mm), a refractive index detector (Wyatt—Optilab T-rEx 658 nm) and a Multi Angle Laser Light Scattering detector (Wyatt—Dawn Heleos II (18 angles). The molecular properties of the products are summarized in Table 1. The NMR analysis showed that product obtained from route i has only 25% of (α1.fwdarw.6)-glycosidic linkages, while the products of route ii and iii have, respectively, 76% and 87% of α(1.fwdarw.6)-glycosidic linkages. Moreover, a product obtained via route i has a much higher molecular weight than the products obtained via routes ii or iii.

TABLE-US-00001 TABLE 1 Effect of preparation method on molecular properties of IMMP product. Content of Molecular Preparation α(1.fwdarw.6) DE weight Short method linkages (g/100 g) (kDa) name i) GTFB only 25% 0.7 6000 & 300.sup.1 IMMP-25 ii) Pullulanase + 76% 5.8 15.sup.2  IMMP-76 GTFB sequential iii) Pullulanase + 87% 9.2 10.3 IMMP-87 GTFB simultaneous .sup.1About 75% of the product has a molecular weight of 6000 kDa and about 25% had a molecular weight of about 300 kDa. .sup.2The bulk of the product has a molecular weight of 15 kDa but there is a small fraction with a significantly higher molecular weight.

[0102] As shown in Table 1, IMMPs obtained from treatment with only GTFB-type enzyme have a significantly lower content of α(1.fwdarw.6) linkages than IMMPs obtained using both pullulanase and GTFB-type enzyme. This indicates that debranching is essential to obtain a high (>70%) content of α(1.fwdarw.6) linkages.

[0103] IMMPs obtained by sequential and simultaneous treatment with both enzymes had very similar properties. Thus, IMMPs suitable for use in a method of the invention may be obtained by either simultaneous or sequential treatment of starch with a debranching enzyme and a GTFB-type 4,6-α-glucanotransferase enzyme.

Example 2: Effect of Content of Alfa(1-6) Glycosidic Linkages of IMMP on Yoghurt Viscosity

[0104] In this Example, the effect of the content of α(1.fwdarw.6) linkages of the IMMP fibres on the viscosity of yoghurt was assessed.

[0105] Yoghurts comprising 3 wt % of the different IMMPs prepared in Example 1 and following the recipes of Table 2 were prepared as follows. First, a 10% starter culture stock solution was made by heating 90 g of the milk to 40-50° C. in a sterile beaker and dissolving 10 g of Delvo culture (DSM, Batch FW-221). For a yoghurt mix of 800 g, 1.6 ml of starter culture must be added before fermentation.

[0106] The milk and the water were weighed and added to a Thermomix beaker, which was set to 40° C. and stirred. Skimmed milk powder (SMP) and IMMP (carbohydrate) were added and hydrated for 10 minutes at 40° C. Subsequently, the mixture was pre-heated to 65° C. for 30 seconds and homogenized at 150/50 bar. It was then pasteurized for 5 minutes at 85° C. and cooled to 40° C. The starter culture stock solution (1.6 ml per 800 g of milk mixture) was added and the mixture was incubated in the beaker in a 32° C. water bath to allow for fermentation. After fermentation, the yoghurts were cooled down to 8-10° C., homogenized with an IKA magic at 3000 rpm, filled in sterile plastic containers and placed in the refrigerator at 4-6° C.

TABLE-US-00002 TABLE 2 Yoghurt recipes. No Fibre IMMP-87 IMMP-25 Ingredient g g g Skimmed milk 500 500 500 40% cream 75 75 75 SMP (Elk, 60 60 60 Campina) IMMP fibre 0 30 30 Drink water 365 335 335 Total 1000 1000 1000

[0107] The viscosity of the yoghurts was measured using an Anton Paar Modular Compact Rheometer, MCR302 SN81328338 and SN81464746, cup spindle CC27 SN23477 and SN32606. The temperature was set to 10° C. After placing the sample in the rheometer, it was left for a 300 s waiting period to allow reformation of networks. Subsequently, a constant shear rate of 10 s.sup.−1 was applied for two minutes. The viscosity at the start and end of the 2-minute measurement are reported in Table 3.

TABLE-US-00003 TABLE 3 Viscosity of yoghurts over time. 3 d at 4° C., 5 d at 4° C., 14 d at 4° C., mPas mPas mPas Sample begin end begin end begin end No 1993 1394 2093 1480 2237 1547 IMMP IMMP- 1882 1577 1981 1631 2124 1830 25 IMMP- 2626 1959 2825 1974 3156 2168 87

[0108] As can be seen in Table 3, the addition of IMMP-25, characterised by a content of α(1.fwdarw.6) linkages of 25%, had only a negligible effect on the yoghurt viscosity despite its high molecular weight. In contrast, the addition of IMMP-87, containing 87% of α(1.fwdarw.6) linkages, produced a yoghurt with a significantly increased viscosity.

[0109] Thus, this example shows that a high content of α(1.fwdarw.6) linkages is essential to obtain the desired increase in viscosity. See also Example 7 herein below, demonstrating that the addition of IMMP with 70% or more of α(1.fwdarw.6) linkages has a desirable effect on yoghurt.

Example 3: Comparison Between IMMP and Other Slow-Digestible and/or Prebiotic Fibres

[0110] In this Example, IMMP fibres containing 87% or 96% α(1.fwdarw.6) linkages are compared to the exemplary prebiotic or slow-digestible fibres Frutafit® TEX! and VitaFiber™ with regard to their effect on yoghurt viscosity. Frutafit® TEX! is an inulin type soluble prebiotic fibre with nutritional and functional properties. It is a powdered food ingredient based on chicory inulin with a very high purity developed to improve texture and mouthfeel in various food applications. Inulin from chicory is a polydisperse mixture of linear fructose polymers with mostly a terminal glucose unit, coupled by means of 6(2-1) bonds. The number of units (degree of polymerization) can vary between 2 and 60. Frutafit® TEX! consists of more than 99.5% oligofructose/inulin. VitaFiber™ is an isomalto-oligosaccharide made from non-GMO, corn-free starch source. VitaFiber™ is a mixture of branched oligosaccharides containing 50/50 α(1.fwdarw.4) and α(1.fwdarw.6) bonds, is well soluble and is applied as a low caloric sweetener and is regarded as not digestible in the small intestine.

TABLE-US-00004 TABLE 4 Yoghurt recipes. Fibre type: Frutafit ® No Fibre IMMP-87 IMMP-96 TEX! VitaFiber ™ Moist cont. fbres 6.5% 8.7% 5.7% 4.4% Ingredients % g % g % g % g % g Full milk 87 870 87 870 87 635 87 870 87 870 Skimmed 3 30 3 30 3 22 3 30 3 30 milk powder Fibre 0 0 3 32.1 3 24.0 3 31.8 3 31.4 Water 10 100 7 67.9 7 45.6 7 68.2 7 68.6 Total 100 1000 100 1000 100 730 100 1000 100 1000

[0111] Yoghurts were prepared according to the recipes in Table 4. All recipes contain about 3 wt % fat and 4 wt % protein. Yoghurts were prepared following the procedure outlined in Example 2. Note that the measured moisture content of the carbohydrates was used to adjust the amounts of carbohydrate such that each yoghurt (except for the negative control) contained 3% dry matter content of the carbohydrate. All recipes were made in duplicate, except for the yoghurt with IMMP-96, comprising a content of α(1.fwdarw.6) linkages of 96% and being prepared according to method (iii) of Example 1.

[0112] The viscosity of the yoghurts was measured after fermentation at day 7 using an Anton Paar Modular Compact Rheometer, MCR302 SN81328338 and SN81464746, cup spindle CC27 SN23477 and SN32606. The temperature was set to 10° C. After placing the sample in the rheometer, measurements started with a 300 second waiting period to allow network reformation. The shear rate was set to linearly increase from 0.01 to 100 s−1 at 1 Hz linear and then to decrease linearly from shear rate 100 to 0.01 s−1 at 1 Hz. The measurement took 1 hour per sample. For the determination of the viscosity, 2 measurement points were used. Point 3 at 6.26 Hz at increasing shear rate from 0.01 to 100 s.sup.−1 (UP) and point 31 at 6.26 Hz at decreasing shear rate 100 to 0.01 s−1 (DOWN). Results are shown in Table 5.

TABLE-US-00005 TABLE 5 Yoghurt viscosity (mPas) after 7 days of fermentation. UP DOWN No fibre 2600 1300 VitaFiber 2800 1400 Frutafit TEX! 2700 1400 IMMP-87 4450 2700 IMMP-96 4200 2500

[0113] The viscosity of yoghurt comprising 3 wt % IMMP fibre was approximately 2-fold higher than that of a yoghurt which did not comprise any fibre. This effect was slightly more pronounced for IMMP-87 than for IMMP-96. In contrast, addition of 3w % VitaFiber or Frutafit TEX! fibres did not have a significant effect on the viscosity of the yoghurt as compared to a yoghurt devoid of soluble fibre.

Example 4: Effect of IMMP Concentration on the Viscosity of Yoghurt

[0114] In this Example, the effect of supplementing with IMMPs with a content of about 87% of α(1.fwdarw.6) linkages on the viscosity of a yoghurt is assessed over a range of IMMP concentrations.

[0115] Yoghurts were prepared as follows. Fresh milk was weighed and added in the Thermomix. Dry ingredients were added gently to prevent lumps and splashing. The mixture was heated up till 40° C. and stirred at speed 3 for 10 minutes to hydrate. After hydration, it was heated up to 85° C. for 5 minutes, followed by cooling down to 40° C. in a stainless-steel beaker. Starter culture stock solution was added similar to Example 2 and the mixture was transferred to containers and allowed to ferment in a stove by 30° C. for 1 night. After fermentation the pH was below 4.6. To prepare stirred yoghurts, the yoghurt was homogenized with IKA Magic at 3000 rpm, filled in containers and stored in the refrigerator. Set yoghurts were stored in the refrigerator after fermentation without homogenisation. Amounts and sources of the ingredients are indicated in Table 6. A Delvo starter culture (DSM, Batch FVV-221) was used.

TABLE-US-00006 TABLE 6 Ingredients used to prepare yoghurt with different levels of IMMP-87. IMMP-87 conc (w/w) (moisture content 6.5%) Ingredients (g) 0 1.5% 3% 6% Milk full (Jumbo 870 870 870 870 supermarket) Skimmed milk powder 30 30 30 30 (Friesland Campina, Batch L112758) GTFB-87% (Avebe, 0 15.8 31.6 63.3 Batch HL190510) Water 100.0 84.2 68.4 36.7 Total 1000 1000 1000 1000

[0116] The Brookfield viscosity was measured after 1, 7 and 14 days at refrigerator temperatures of 4 to 6° C. using a Brookfield DV2 with a helipath spindle at 10 rpm. The results are summarised in Tables 7a and 7b for the set and stirred yoghurts respectively.

TABLE-US-00007 TABLE 7a Dependency of Brookfield viscosity (mPas) of set yoghurts on IMMP-87 concentration. IMMP-87 Time 0% 1.5% 3% 6% 24 h 84300 89200 92200 100600 7 days 83400 91600 96400 100200 14 days 74200 90800 96200 108400

TABLE-US-00008 TABLE 7b Dependency of Brookfield viscosity (mPas) of stirred yoghurts on IMMP-87 concentration. IMMP-87 Time 0% 1.50% 3% 6% 24 h 12300 13800 15900 18800 7 days 17400 — — 25600 14 days 16400 21300 19900 24500

[0117] From Tables 7a and 7b, it can be concluded that supplementation with a range of concentrations of IMMP-87 increased the viscosity of both set and stirred yoghurts. For set yoghurts, this effect was particularly noticeable upon storage for 7 or 14 days. The increase in yoghurt viscosity depended on the IMMP concentration, with higher concentrations showing a higher viscosity.

Example 5: Comparison of IMMP and Other Slow Digestible and/or Prebiotic Fibres

[0118] In this Example, IMMP fibres with a 96% content of α(1.fwdarw.6) linkages were compared to the exemplary fibres Frutafit® TEX!, Frutafit® HD, Orafti® P95 and VitaFiber™ with regards to their effect on the Brookfield viscosity and storage modulus G′ of chemically acidified milk gels.

[0119] Acid milk gels were prepared as follows. Skimmed milk powder stock was prepared by dissolving 290 g skimmed milk powder (Elk, Friesland Campina) in 710 ml demineralized water. A simulated milk ultra-filtrate solutions SMUF and SMUF* were prepared according to the recipes in Table 8a. A 30 wt % fibre stock in SMUF* solution was prepared comprising either IMMP-96, Frutafit® TEX!, Frutafit® HD, Orafti® P95 or VitaFiber™ taking the moisture content of the fibres into account. 100 ml acid milk gel solutions were prepared by mixing the three stock solutions at a temperature of 30° C. and adding glucono delta lacton, following the recipe in Table 8b. After 17 hours of incubation, the acid milk gels are poured into plastic 50 g pots and stored at 4° C. for 7 days.

TABLE-US-00009 TABLE 8a Simulated milk ultra-filtrate (SMUF and SMUF*) solution recipes. SMUF SMUF* Monopotassium phosphate 3.16 g 3.16 g Potassium citrate tribasic 2.40 g 2.40 g Sodium citrate dehydrate 3.58 g 3.58 g Potassium sulphate 0.36 g 0.36 g Potassium carbonate 0.60 g 0.60 g Potassium chloride 1.2 g 1.2 g Calcium chloride dihydrate 2.64 g Magnesium chloride 1.30 g hexahydrate Demineralised water 2 L 1.96 L

TABLE-US-00010 TABLE 8b Recipe of 6 wt % fibre acid milk gels. Skimmed milk powder stock (g) 25.57 Fibre stock solution (g) 20 SMUF (g) 53.33 Glucono delta lacton (g) 1.1

[0120] After 7 days, the Brookfield viscosity and the storage modulus of the acid milk gels was measured.

[0121] The Brookfield viscosity measurements are performed with the viscosity meter LVDVI+ and LVDV II+ from Brookfield. The measurements are performed with LV spindles 2 and 3 (S62/S63) at 6 rpm for 30 seconds. The average within these 30 seconds is considered the viscosity in mPas.

[0122] The storage modulus G′ was measured using Modular Compact rheometers MCR 302 SN81328338 and SN81464746 with cup spindle CC27 SN23477 and SN32606 from Anton Paar. Prior to the measurement, the solution was mixed during 60 s at a rate of 300 s−1. Then, stress controlled measurements in time (one measurement every minute) were performed at 1 Hz Hz using a strain of 1% during 17 hours. The temperature was set at 30° C. for all the experiment. Before the measurements where started, the samples were covered with paraffin oil to prevent evaporation. The results of these measurements are shown in Table 9.

TABLE-US-00011 TABLE 9 Brookfield viscosity (mPas) and storage modulus G′ of acid milk gels comprising 6 wt % fibre. Brookfield viscosity (mPas) Storage modulus G′ No fibre 2300 110 Frutafit ® HD 3800 170 Vitafiber ™ 2450 135 Orafti ® P95 2950 135 Frutafit ® TEX! 3850 175 IMMP-96 5500 320

[0123] Both the Brookfield viscosity and the storage modulus of an acid milk gel supplemented with 6% IMMP-96 was significantly increased (respectively with a factor of 2.4 and 2.9). Supplementing with 6 wt % of any of the other fibres did not significantly increase either the Brookfield viscosity or the storage modulus.

Example 6: Effect of IMMP Concentration on the Viscosity of Acid Milk Gels

[0124] In this Example, the effect of the concentration of IMMP fibres with an approximately 96% content of α(1.fwdarw.6) linkages on the viscosity of chemically acidified acid milk gels was assessed.

[0125] Acid milk gels were prepared as described in Example 5, following the recipes of Table 10.

TABLE-US-00012 TABLE 10 Acid milk gel recipes with different concentrations of IMMP-96. IMMP-96 0% 1.5% 3% 6% 12% Skimmed milk powder stock (g) 25.57 25.57 25.57 25.57 25.57 IMMP-96 stock (g) 0 5 10 20 40 SMUF (g) 73.33 68.33 63.33 53.33 33.33 Glucono delta lacton 1.1 1.1 1.1 1.1 1.1

[0126] After storing for 7 days at 4° C., the Brookfield viscosity and storage modulus G′ of the acid milk gels were measured as described in Example 5. The results are shown in table 11.

TABLE-US-00013 TABLE 11 Dependency of Brookfield viscosity (mPas) and storage modulus G′ of acid milk gels on IMMP-96 concentration. IMMP-96 0% 1.5% 3% 6% 12% Brookfield viscosity (mPas) 2300 3100 3800 5500 9150 Storage modulus 110 130 220 320 430

[0127] These results indicate that supplementing acid milk gels with IMMP-96 results in a higher storage modulus and a higher viscosity across a range of concentrations. Both properties appear to have a roughly linear dependence on IMMP-96 concentration within the measured range.

Example 7: Influence of the Content of Alfa (1→6) Glycosidic Linkages in IMMP on Yoghurt Viscosity

[0128] IMMP's with different contents of alfa (1.fwdarw.6) glycosidic linkages were prepared according to the procedure described in Example 1(iii). After termination the reaction at 36 hours, IMMP with 87% alfa (1.fwdarw.6) glycosidic linkages was obtained (IMMP-87). By taking samples earlier in time, IMMP's with either 70% or 77% alfa (1.fwdarw.6) glycosidic linkages were obtained (IMMP-70 and IMMP-77, respectively).

[0129] To assess the effect of the IMMP's on the viscosity of yoghurt, stirred yoghurts were prepared as was done in Example 4. The amount of IMMP fibre was corrected for its moisture content (m.c.). The Brookfield viscosity was measured after 7 and 14 days storage at refrigerator temperatures of 4 to 6° C. using a Brookfield DV2 with a helipath spindle at 10 rpm.

[0130] The results in Table 12 show that supplementation with IMMP's having at least 70% of alfa (1.fwdarw.6) glycosidic linkages increases the viscosity of stirred yoghurt. The increase in viscosity is positively related to the alfa (1.fwdarw.6) content and the concentration of the IMMP.

TABLE-US-00014 TABLE 12 Yoghurt recipes (A) and Brookfield viscosities (B) obtained using IMMP having a alfa (1 -> 6) glycosidic linkages of 87, 77 or 69%. A IMMP-87 IMMP-77 IMMP-70 conc w/w conc w/w conc w/w Ingredients (g) 0% 3% 6% 3% 6% 3% 6% Milk full (Jumbo 870 870 870 870 870 870 870 supermarket) Skimmed milk 30 30 30 30 30 30 30 powder (Friesland Campina) IMMP-87 0 32.2 35.7 (Avebe,; 6.7% m.c.) IMMP-77 0 32.6 65.3 (Avebe, 8.1% m.c.) IMMP-70 0 31.3 62.3 (Avebe, 3.7% m.c.) Water 100 67.8 35.7 67.4 34.7 68.7 37.7 Total 1000 1000 1000 1000 1000 1000 1000 B IMMP-87 IMMP-77 IMMP-70 Storage time 0% 3% 6% 3% 6% 3% 6%  7 days 17000 21300 24100 18100 20100 17400 18600 14 days 17400 21900 27500 20100 23600 19400 20900

REFERENCES

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