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Nanocellulose as an additive in foodstuff

Innventia Report No.: 403


Göran Ström, Camilla Öhgren and Mikael Ankerfors

Innventia Report No.: 403 June 2013


Innventia Report No.: 403

Acknowledgements The authors wish to thank RISE Research Institutes of Sweden for financial support.


Innventia Report No.: 403 1

Table of contents Page

1 Summary ................................................................................................................. 2

Sammanfattning .............................................................................................................. 2

2 Introduction .............................................................................................................. 2

3 Materials and methods ............................................................................................ 3

3.1 Preparation of MFC ...................................................................................................... 3

3.2 Characterization of structure of MFC gels using microscopy ...................................... 5

3.3 MFC in food emulsions ................................................................................................ 5

3.4 MFC in food foams ....................................................................................................... 6

3.5 MFC as an additive in bread ........................................................................................ 6

3.6 MFC as an additive in hamburger ................................................................................ 8

4 Results and discussion ............................................................................................ 9

4.1 Structure of MFC gels as characterized by microscopy .............................................. 9

4.2 Impact of MFC on food emulsions ............................................................................. 13

4.3 Impact of MFC on food foams .................................................................................... 16

4.4 Impact of MFC on properties of baked bread ............................................................ 19

4.5 4.5 Impact of MFC water retention during frying of hamburger ................................. 21

5 Conclusions ........................................................................................................... 23

6 References ............................................................................................................ 24

7 Innventia Database information ............................................................................. 25



1 Summary The impact of microfibrillated (MFC) as an additive in food stuff has been studied in a cooperation between the Swedish Institute for Food and Biotechnology (SIK) and Innventia AB. The work included microscopy studies of MFC, the effect of MFC on stability of oil in water emulsions and foams containing high amounts of dissolved sugar. Also studied was the impact of MFC as an additive in bread and hamburger.

The work showed that MFC has a strong potential to stabilize oil in water emulsions and foams. Very stable foams were obtained at low additions of MFC. An addition of MFC in dough gave the bread better appearance like higher volume and more even form. The bread also became smoother. As an additive in hamburger MFC gave no off-flavour and the same texture and mouthfeel as hamburger without MFC. Moreover, hamburger with MFC could hold more water during frying without negative side effects.

Sammanfattning Mikrofibrillerad cellulose (MFC) har utvärderats som tillsats i livsmedel i ett samarbete mellan Institutet för Livsmedel och Bioteknik (SIK) och Innventia AB. Arbetet omfattade mikroskopistudier av MFC, inverkan av MFC på stabiliteten av olja i vattenemulsioner och skum innehållande höga halter av löst socker. Vidare studerades inverkan av MFC som tillsatsmedel i bröd och hamburgare.

Arbetet visade att MFC har en god förmåga att stabilisera olja i vatten emulsioner och skum. Mycket stabila skum erhölls vid låga tillsatser av MFC. En tillsats av MFC till deg resulterade i att brödet fick högre volym, jämnare form och blev slätare. En tillsats av MFC till hamburgare gav ingen bismak och samma textur och munkänsla erhölls som för hamburgare utan MFC. Vidare kunde hamburgare med MFC behålla vattnet i större utsträckning vid stekning än hamburgare utan MFC.

2 Introduction Microfibrillated cellulose (MFC) also referred to as nanofibrillated cellulose (NFC) or just nanocellulose is microfibrills released from the cell wall of cellulose, see figure 1. The material can be obtained after thorough homogenization using a high pressure homogenizer (Pääkkö et al. 2007; Wågberg et al. 2008; Aulin et al. 2011). The microfibrills have a diameter in the nano size range and a length in the micro size range. It is obtained as a highly viscous gel with a solid content of a few percent. This material was pioneered by Turback and co-workers (Turback et al. 1983) about 30 years ago and the area was recently reviewed (Klemm et al. 2012).

The process to prepare MFC has been developed during the last decade. One of the most important discoveries is the fact the various pre-treatments of the pulp may drastically reduce the energy consumption during the homogenization step (Ankerfors 2012), and also generate a more uniform material. An example of a MFC gel is shown in Figure 2.

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1. First, a 4% cellulose suspension was mechanically refined using a Voith refiner with 90 kWh/tonne at a specific edge load of 1.5 Ws/m to 50 SR.

2. Next, the enzyme was added. The pulp was dispersed in 2.5 L of a phosphate buffer (pH 7, final pulp concentration 4% w/w) with 0.17 µL mono-component endoglucanase per gram fibre (5 ECU/µL) and was incubated at 50 C for 2 h. The samples were mixed manually every 30 min.

3. Then, the samples were washed with deionized water and the monocomponent endoglucanase was denaturated at 80 C for 30 min. At the end, the pulp sample was washed with deionized water.

4. The pre-refined and enzyme-treated pulp was refined once again with the Voith refiner, this time, to 90 SR (average refining energy 152 kWh/tonne, specific edge load 1.5 Ws/m).

5. Finally the pulp was passed through 3 large and 5 small slits one time in a high-pressure homogenizer (Microfludizer M-110EH, Microfluidics, USA).

In Innventia’s terminology, this MFC corresponds to generation 1. The total charge density of this MFC is normally 0.04-0.05 meq/g as determined by conductometric titration (Katz et al. 1984).

Generation 2. In order to prepare the anionic MFC, a carboxymethylation pre-treatment method was used (Walecka 1956a; Walecka 1956b). In this procedure 110 grams of fibres (Dissolving Plus, Domsjö Fabriker AB, Sweden) were pre-treated per batch. The procedure can be divided into five steps (Wågberg 2008):

1. Firstly, the never dried fibres were dispersed in deionised water at 10000 revolutions using an ordinary laboratory pulper. This was conducted in smaller batches of 30 g of fibres in two litres of deionised water.

2. The fibres were then liquid exchanged to ethanol by washing the fibres in one litre of ethanol four times with a filtering step in between.

3. The fibres were then impregnated for 30 minutes with a solution of monochloroacetic acid amounts in 500 mL of iso-propanol. The fibres were then added in portions to a solution of 16.2 g of NaOH in 500 mL methanol and mixed with two litres of iso-propanol that had been heated just below its boiling temperature in a five litre reaction vessel fitted with a condenser. The carboxymethylation reaction was allowed to continue for one hour.

4. Following the carboxymethylation step, the fibres were filtrated and washed in three steps. Firstly, the fibres were washed with 20 L of deionised water. Secondly, they were washed with two litres of acetic acid (0.1 M) and finally with ten litres of deionised water. The fibres were then impregnated with a two litre NaHCO3-solution (4% w/w solution) for 60 minutes in order to convert the carboxyl groups to their sodium form. Then the fibres were washed with 15 litres of deionised water and drained on a Büchner funnel.

5. Finally, the pulp was passed 3 large and 5 small slits one time in a high-pressure homogenizer (Microfludizer M-110EH, Microfluidics, USA) in the same fashion as was described by (Pääkkö et al. 2007) for enzymatically treated pulps.



In Innventia’s terminology, this MFC corresponds to generation 2. The total charge density of this MFC is normally 0.5-0.6 meq/g which corresponds to a degree of substation of roughly 0.1%.

Seven different samples of MFC were used in the studies, see Table 1.

Table 1. MFC samples used in the present work. DS are given for MFC generation 2 and it refers to the degree of substitution of the pulp after the carboxymethylation.

Sample MFC type Dry substance (%)

Comment Used in

1 Gen 2 (lab) 1.8 CLSM, TEM

2 Gen 1 (lab) 1.0 CLSM 3 Gen 1

(pilot) 2.4 CLSM

4 Gen 1 (pilot)

1.0 Sample 3 pressed to 30% dryness and then dispersed to 1%

CLSM, TEM

5 Gen 2 (lab) 2.25 Hamburger, bread

6 Gen 1 (lab) 2.1 Food emulsions

7 Gen 2 (lab) 1.95 Foams

3.2 Characterization of structure of MFC gels using microscopy CLSM. The samples 1-4 were analysed under the confocal laser scanning microscope, CLSM, Leica TCS SP5 II (Heidelberg, Germany). The staining, akriflavine or acridineorange dissolved in water was dried on a cover glass. The samples were places in the cavity of the objects slide, and the stained cover glass was sealed on top. The light source was an Argon laser with an emission maximum at 488nm and the signal emitted in the wave length interval 500-580 nm was recorded. A 10x air objective and a 63x water objective was used. Computer zooming was done at 1x, 5x and 10x and images were recorded with formats of 1024x1024 pixels.

TEM. A small amount of sample 1 and 4 was placed in a gold cup and cryofixed in liquid propane. The frozen samples were fractured in vacuum and etched before coating. After sublimation of the water, replicas were formed by rotary shadowing of platinum/carbon on top. The replicas were cleaned in solvent before examination. Micrographs were taken in a TEM, LEO 906e, (LEO Electron Microscopy Ltd, Germany) at an accelerating voltage of 80 kV.

3.3 MFC in food emulsions Emulsion preparation. Sample 6 of MFC was mixed with a stick mixer, Ultra Turrax T25 (JANKE & KUNKEL IKA® -labortechnik, Germany) together with rapeseed oil (ICA) and water in four different combinations with a an MFC content between 0.5-1% and 10-50% of rapeseed oil for two minutes. The emulsions formed were stored in refrigerator for three days where after the stability was documented before and after centrifugation (3000 rpm for 30 min).

Emulsions containing 0.5-1% MFC (sample 6) and 10-20% rapeseed oil was made in a high pressure homogenizer Panda 2k (Niro Soavi, Italy) at two different pressures, 100



and 1000 bar. Thereafter the stability was checked after storage in refrigerator in three days before and after centrifugation.

CLSM. The high pressure homogenized emulsions were studied in confocal laser scanning microscope, CLSM, Leica TCS SP5 II (Germany). Akriflavine and Nile red, staining the MFC and the fat droplets respectively, was dissolved in water, mixed and dried on a cover glass. The emulsions were places in the cavity of the objects slide, and the stained cover glass was sealed on top. The light source was an Argon laser and a HeNe-laser with an emission maximum at 488 nm and 594 nm, respectively. The signals were emitted in the wave length interval of 500-570 nm and 605-670 nm. A 20x water objective was used. Computer zooming was done at 1x, 2x and 4x and images were recorded with formats of 1024x1024 pixels.

3.4 MFC in food foams Foams were prepared from solutions containing a high amount of sugar, MFC generation 2 (sample 7) emulsifier (Colco 2282-00 alpha-gel, delivered by Aromatic AB) and water. The composition of the liquids used is given in Table 2. The foams were generated from a 200 g solution using an OBH kitchen hand mixer at highest speed for 90 seconds.

Table 2. Composition of the liquids used for foam generation.

Sample Sugar (wt.-%)

Emulsifier(wt.-%)

MFC (wt.-%)

Water (wt.-%)

Volume of 200 g solution (mL)

A 48 1.0 0 51.0 168

B 48 1.0 0.2 50.8 168 C 42 1.0 0 57,0 185 D 42 1.0 0.4 56.6 185 E 48 0.5 0 51.5 168

F 48 0.5 0.1 51.4 168

G 48 0.5 0.2 51.3 168

The foams were poured into measuring cylinders. The initial foam volume was determined and is given in Table 2. The drainage of liquid out from the foam column was read from the bottom of the measuring cylinder at different time intervals.

The density gradient of the foam column formed from sample D was measured 52 hours after foam generation by sucking out 50 mL foam and take the weight of the rest of the foam and the cylinder, and subtract it from the weight before the foam was sucked out from the cylinder.

3.5 MFC as an additive in bread Bread was produced with and without MFC (sample 5) and with and without different enzymes. The recipe is shown in Table 3.



Table 3. Recipe of bread.

Ingredients Relative amount (%) Amount (g)

Flour 100 182,73 g MFC (sample 5) 55.6 (1.35) 101.52 (2.54 ) Extra water 7.11 13 Yeast 4.16 7.62 Sugar 2.78 5.07 Salt 1.67 3.03 Emulsifier 0.5 0.9 Enzymes 0-100 ppm

Mixing of the ingredients was performed in a Kitchen Aid (St. Joseph, Michigan, USA) model KSM90. The mixing was carried out as 2:30 min at medium speed and 2:30 min at the highest speed. Thereafter, the dough was removed, briefly kneaded on a lightly floured table and shaped into a round loaf. Covered with kitchen cloth, the dough was left to rest 10 min on the table. After resting, the dough was divided into pieces of 45 g. Pieces were then kneaded, hand shaped into round balls and let to rest 5 min. Using a special board, pieces of dough were then moulded until forming a perfectly even round ball. After that, pieces of dough were placed on grills covered by baking paper and fairly shared into two batches: one for freezing and the second one immediately baked and analyzed.

Pieces of dough for freezing were transferred in a freezing room to be frozen at -20 °C. Two hours later, frozen dough pieces were transferred in plastic bags and stored in the same freezing room at -20 °C. After 7 days freezing storage pieces of dough were withdrawn from the freezing room, put on trays with baking paper and covered with a plastic sheet. When placed on tray, dough pieces were thawed 2 hours in a thawing chamber calibrated at 25 °C and 65% relative humidity (RH). Thereafter the plastic cover was removed and the samples were transferred in a proofer from the brand Sveba Dahlen, model Fermatic. The proofing lasted 36 minutes at 38 °C and 80% RH.

Then the trays were placed for 10 minutes in an oven from Sveba Dahlen, model S8, previously set at 210 °C and 20% RH. Afterwards trays were put on a table and let cooling one hour at room temperature. Then the buns were transferred into plastic bags.

The experimental design is shown in Figure 3. Totally 12 different types of buns were analyzed; with or without MFC, no enzyme or α-amylase or hemicellulase and freeze stored or not (indicated by the ´prefix).



Figure 3. Experimental design for evaluating MFC as additive in bread.

A macroscopic investigation was performed on the buns by taking photos of the cross section and the surface of the buns using a Nikon Digital Camera D90 (Nikon Corporation, Japan) equipped with a lens Micro-Nikkor 55 mm 1:2.8. The aim was to observe crust aspect, bread shape and crumb aspects. The slices cut for texture analyzes were also photographed with the same camera, to observe the crumb aspect and control its homogeneity.

The texture was anlaysed by measuring the compressive stress using a modified version of the AACC method 74-09 (AACC, 2001) using an Instron Universal Testing Machine 5542 (Instron, USA) two hours after baking. For each sample three breads were used for texture measurements. Two vertical slices of 2 cm thickness were cut out from each bread. A cylindrical metal probe of 20 mm diameter was pushed into the crumb in the middle of the slices with a constant speed of 1.7 mm/s. The compressive stress at 25% compression was used as a measure of the bread firmness. The measurements were performed 2 h after baking.

3.6 MFC as an additive in hamburger Hamburgers were performed with and without different additives; water, MFC (sample 5) and potato starch. All hamburgers contained 100 g of minced meat, and water, MFC and potato starch were added in different amounts. MFC was added to hamburgers in form of a 2.25% gel. The additives were gently kneaded in the minced meat. The hamburgers were formed to a circle with a diameter of 10 cm before frying. The hamburgers were weighted before and after frying and the juiciness and taste was judged after cooling.

Enzyme SampleMFCEmulsifier

E472 (2)

No (0)

No

‐amylase

Hemicellulas

Yes (1)

No

‐amylase

Hemicellulas

2.0.02.0.0´2.0.12.0.1´2.0.22.0.2´

2.1.02.1.0´2.1.12.1.1´2.1.22.1.2´



4 Results and discussion

4.1 Structure of MFC gels as characterized by microscopy CLSM. The microstructure of the four gel types of MFC was studied in CLSM using florescent staining. MFC was shown to be distributed differently in the different samples dependent on generations and manufacturing, see Figure 4. Sample 1, generation 2 made in lab scale is shown in Figure 4a-c; sample 2, generation 1 made in lab scale in Figure 4d-f; sample 3, generation 1 made in pilot scale in Figure 4g-I and sample 4, generation1 made in pilot scale (i.e. sample 3) but pressed and re-dispersed in Figure 4j-l.

Sample 1, which is a generation 2 sample made in lab scale, contain some very large fibres with a thickness of about 50 m and more than 100 m in length, in contrast to the samples containing generation 1 that contain no such large fibre pieces. However, there are few thin fibres with a thickness of about 0.5 m and length around 100 m in sample 1, which there is a lot of in sample 2-4, compare Figure 4c, f, i and j.

In sample 2 there is few large fibres compared to the other samples containing generation 1, sample 3 and 4, see Figure 4d, g and j. Sample 3 and 4 show very similar microstructure at both low and high magnifications in CLSM. However, sample 4 which is the pressed and re-dispersed pilot made generation 1, appears to be somewhat more inhomogeneous at low compared to sample 3, which is the same material but before pressing and re-dispersion.

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Characterization of MFC using microscopy techniques shows that merging of fibrils into large fibres with different thickness varies between the different generations and to some extent between lab-scale and pilot-scale manufactured MFC. Generation 2 contain the largest fibres (50 m in thickness and >100 m in length). Generation 1 contain a lot of thin fibres (0.5 m in thickness and 100 m in length) which not is found to a large extent in generation 2. On a high magnification in TEM both types are characterized by thin fibrils with a thickness of 20-30 m. The fibres are built up of fibrils densely packed targeted in the same direction.

4.2 Impact of MFC on food emulsions A first test of the potential for MFC (sample 6) as an oil-in-water emulsion stabilizer was made with a simple stick mixer with mixtures of 0.5-1% MFC, 10-50% rape seed oil and water. The results from the stability studies of the emulsions are shown in Table 3. The emulsions containing the highest amount of MFC and oil was the most stable ones after three days storage. After centrifugation it was possible to separate both an oil and a water phase from the emulsion, except in emulsion 2 with 50% oil that was very stable.

Homogenizing in Panda was thereafter performed at two different pressures for emulsion 1, 3 and 4. (Emulsion 2 was already stable by simple mixing with Ultra Turrax). This homogenizing showed that it was possible to make emulsion in all the combinations tested. Figure 7 shows the phase separation of the emulsions after three days of storage and following centrifugation. Only some of the water phase was possible to press out of the emulsion after centrifugation. The higher the amount of MFC and oil the less water is possible to press out of the emulsion.

Table 4. MFC as stabilizing agent in emulsions.

Emulsion MFC sample 6 (%)

Oil (%)

Mixing in Ultra Turrax and 3 days storage

Centrifugation after Ultra Turrax and 3 days storage

Pressure in homogenizer, (bar)

Homogenizing and 3 days storage

Centrifugation after homogenizing and 3 days storage

1a 1 20 stable separates in 3 phases

100 stable separates in 2 phases

1b 1 20 stable separates in 3 phases


2 1 50 stable separates in 2 phases

3a 0.5 20 separates separates in 3 phases


3b 0.5 20 separates separates in 3 phases


4a 0.5 10 separates separates in 3 phases


4b 0.5 10 separates separates in 3 phases


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as stabilizinreasing the m emulsionsreased homodroplets (hiplets and thth a more li

ugar and emenerated wittal set up iser foam gen

tuations 23 andsured.

).

me visible bead drained o

The initial fwith increa


ng agent forcontent of

s is characteogenizing pgher MFC

he MFC in quid texture

mulsifier dith a kitchens shown in Fneration.

d 47 hours after

eneath the fout from the

foam volumasing conte


r emulsionsf MFC, oierized by smpressure), a

content), an the bulk pe.

issolved in n hand mixeFigure 10 w

r foam generati

foam colume foam.

me increasedent of suga

odstuff o.: 403

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. It is l and

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ion are

mn

d with r and



Table 5. Composition and foam characteristics of the investigated samples.

Sample Emulsifier (wt.-%)

MFC (wt.-%)

Sugar (wt.-%)

Initial foam volume (mL)

T1 (h)

T2 (h)

A 1 0 48 540 ~3 ~5

B 1 0.2 48 450 24 58 C 1 0 42 620 2 3,5 D 1 0.4 42 370 >52 >52 E 0.5 0 48 440 0,1 0,3 F 0.5 0.1 48 380 0,2 1,2 G 0.5 0.2 48 350 0,3 2,0

Figure 11. Foam stability given as volume of the liquid column beneath the foam column as a function of time after foam generation for samples E, F and G. The right diagram is an enlargement of the time interval up to 7 hours.

Foams generated from sample E, F and G had low stability as can be seen in Figure 11 These samples contained only 0.5% emulsifier and 0, 0.1 and 0.2% MFC, respectively. Even though the foam stability was low, MFC had a significant positive impact on the foam stability

When the content of emulsifier was increased to 1% the initial foam volume increased significantly and very high foam stability was obtained in the presence of MFC. The stability parameters T1 and T2 increased roughly 10 times when 0.2% MFC was present (B) compared to the reference without MFC (A). When the content of MFC was raised to 0.4%, the foam showed no tendency to drain liquid within the 52 hours the experiment lasted. Instead of extending the time for the foam stability characterization, this foam was subjected to a determination of its density gradient (see Figure 13). The foam column was divided into 7 volume units, each with a volume of 50 mL. The bottom volume unit had a slightly higher density than the other units, which were very constant in density.

0

20

40

60

80

100

120

140

160

0 10 20 30 40 50 60

Volume of drained

liquid, m

l

Time, h

E F G

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5 6 7

Volume of drained

liquid, m

l

Time, h

E F G

Figurethe foaand D

MFCwas obserand 1

Figurecollapssamplefoam g

1

1

1

1

Volume of drained

liquid, m

l

e 12. Foam stabam as a functio.

C also appeaobserved afrved within15

e 14. Observatiose on top of thee C, 23, 27 andgeneration.

0

20

40

60

80

00

20

40

60

0 20

A

bility given as von of time after f

ared to redufter two day

n 3 days for

ons of foam e foam column od 71 hours after

0 40

Tim

B C

olume of the liqfoam generation

uce foam brys for foamthe system

of r

Figure 10.2% M

60 80

e, h

D

quid column benn for samples A

rakeage at tms without M

containing

15. Foam collapFC.

100

Nanoce

neath A, B, C

Figurcolumgene

the top of tMFC. No s0.2% MFC

pse did not occ


re 13. Density gmn of sample Ceration.

he foam. Tsign of this

C as can be s

ur with sample


gradient of the fC, 52 hours afte

This phenomphenomena

seen in Figu

B which contai

odstuff o.: 403

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foam er foam

menon a was ure 14

ned

4.4 The on wstore

The in thcompsoftebreadeven(Comwithofreez

Figure(αa=α-

In Fibake18). Teven

To sumakihigh to be

Impact oeffect of ad

wheat bread ed for 7 day

quality of te Instron tepression strer than bread with no a

n more prompare the rout MFC inze storage o

e 16. Compress-amylase, he=h

igures 17 ad from fresThe buns co

n form and a

ummarize; ing the bunvolume and

e further eva

of MFC on ddition of Mwas studieds.

the bread westing machress of breadad without additives, “nonounced inred and gr

n Figure 16.f the dough

sion stress at 25hemicellulase) P

and 18 the sh dough (Fontaining Malso a higher

MFC has ans softer and even formaluated.

propertieMFC (sampld on bread b

was evaluatehine and by d baked froMFC, see

no add” witn presence reen stacks .) However,

h, see the sta

5% stress for brPrefix ´means f

surface andFigure 17) aMFC resulte

r bun, whic

a clear favoud giving th

m. However

es of bakedle 5) in combaked from

ed by measutaking pho

om fresh dofigure 8 an

th bread conof the enshowing b

, the effect acks with pr

reads containinfreeze stored sa

d cross secand buns bad generally

ch is shown

urable effechem a betterr, the effect

Nanoce

d bread mbinations wfresh dough

uring the textos of the a

ough containnd comparentaining MF

nzymes -abreads conof softeningrefix ´in Fig

g different addiamples.

ctions of theaked from fin bread win the imag

ct on bread r appearancof MFC on


with two dih and dough

xture by coappearance ning MFC we the blues FC, “MFC”amylase andntaining enzg the bread gure 16.

itives; no additiv

e buns are freeze storeith a more s

ges in Figure

baked fromce in form on freeze sto


ifferent enzh that was f

ompression of the bunswas signific stacks sho

”. The effecd hemicelluzymes withwas absent

ves, MFC, enzy

shown for ed dough (Fsmooth cruses 17 and 1

m fresh dougof smooth

ored dough n

odstuff o.: 403

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zymes freeze

stress s. The cantly owing ct was ulase. h and t after

ymes

buns Figure st and 8.

gh by crust, needs

Figurehe=he

e 17. Buns bakeemicellulase) Pr

ed from fresh dorefix ´means fre

ough containingeeze stored sam

g different additmples.

Nanoce

tives; no additiv


ves, MFC, enzy


ymes (αa=α-am

odstuff o.: 403

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mylase,

Figure(αa=α-

4.5 MFC(samsubstadderespeweigattenwas MFCadditindeeadditwithothe hshowlarge

e 18. Buns bake-amylase, he=h

4.5 ImC as a mo

mple 5) to mtance of 2.2d. A hambuectively whght loss is ndant water

present in C addition. tions of waed a more jution of watout any addhamburger

wn in Figureer than the o

ed from freeze shemicellulase) P

mpact of Moisture retenminced mea25% the haurger conta

hen 0, 0.24, seen in Fthe hambuthe hambuThe end w

ater, which uice but alsoter (10%)

dition of wacontaining

e 20. The haone without

stored dough coPrefix ´means f

MFC water ntion agent

at before fryamburgers waining 100g

0.47 and 0igure 19. I

urgers lost 3urgers contaweight was

is a substao a more wagave a moter or MFC100% mea

amburger co.

ontaining differefreeze stored sa

retentiont in hambuying. Sincewill be dilu

g meat was 0.63% MFCIrrespective30±1% wateaining MFCincreased bantial increatery taste aore juice h

C, but otherwat. Photos oontaining ad

Nanoce

ent additives; namples.

during fryurgers was

e MFC is inuted with a diluted wit

C was addede of additioer during fr

C the end wby 10, 23 aease. The hand lost tast

hamburger cwise it was of these twddition of M


o additives, MF

ying of has studied bn form of alot of wate

th 0, 10, 16d to the meonal amounrying, but sweight becoand 41% afhighest watete of hambucompared tsimilar in ta

wo types of MFC and wa


FC, enzymes

amburger by adding a gel with er when MF6 and 27% eat. The resnt of MFCsince more ome higher fter the differ addition urger. The loto the refeaste compar

f hamburgerater is some

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MFC a dry FC is water

sult in C and water after

ferent gave

owest erence red to rs are ewhat

Figure

FigureMFC a

PotatrequistarcThis Lowebut n

e 19. Weight of

e 20. A hamburgand 10% water

to starch wired to loweh was requhigh amou

er addition not either an

0

20

40

60

80

100

120

140

160weight(g)

hamburgers be

ger containing 1 before and afte

was used as er the water

uired to receunt of potaof potato st

ny effect on

‐

ref2

startv

slutvik

Start w

End w

100% meat

efore and after f

100% meat befer frying (b and

a referencer lost to theeive the samto starch gtarch (0.75%the water h

‐30%

MF

ikt

kt

weight

weight

MFC 10%

frying containin

fore and after fr d).

e to the MFe same levelme water lo

gave the ha%) gave noholding capa

‐31%

FC 0,3%0.24%water

Nanoce

g different amo

rying (a and c) a

FC. High aml as for MFost as for 0

amburger a o bad taste oacity.

‐29

MFC 0,5%MFC 0.47%16% water


ount of MFC and

and a hamburge

mount of pC. Addition

0.63% MFCbad consis

or texture of

9%

MFC 0MFC 027% w


d water.

er containing 0

potato starchn of 1.4% p

C, see Figurstency and f the hambu

‐29%

0,9%0.63%water

odstuff o.: 403

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.24%

h was potato re 21. taste.

urger,



To summarize; MFC (i) gave no off-flavor, (ii) gave the same texture and mouthfeel as the hamburger without additions, (iii) hold more water without side effects as watery taste, (iv) is easy to mix with the meat, but (v) due to its low dry weight it is difficult to add the right amount of MFC without adding to much water.

Figure 21. The loss of water during frying of hamburgers containing different amounts of additives (water, MFC and potato starch).

5 Conclusions Characterization of MFC using microscopy techniques shows that merging of fibrils into large fibres with different thickness varies between the different generations and to some extent between lab-scale and pilot-scale manufactured MFC. Generation 2 contain the largest fibres (50 m in thickness and >100m in length). Generation 1 contain a lot of thin fibres (0.5 m in thickness and 100m in length) which not is found to a large extent in generation 2. On a high magnification in TEM both types are characterized by thin fibrils with a thickness of 20-30 m. The fibrillar structure is more fine-meched in generation1 compared to generation 2. The fibres are built up of fibrils densely packed targeted in the same direction.

MFC has a very good potential as stabilizing agent for emulsions. It is possible to make very firm emulsions by increasing the content of MFC, oil and increasing the pressure at homogenizing. The firm emulsions is characterized by smaller oil droplets with a smaller size distribution (increased homogenizing pressure), a more well-distributed MFC around the separate oil droplets (higher MFC content), and a more homogeneous distribution of the oil droplets and the MFC in the bulk phase (increased oil content) compared to emulsions with a more liquid texture.

MFC also has a very good potential as stabilizing agent for food foams already at low additions (0.2%). Higher additions gave extremely stable foams.

0

5

10

15

20

25

30

35

40

ref 4 MFC 0,9% Potatis stärkelse 1% Potatis stärkelse 2%

25% water0.63% MFC27% water

0.75% pot. St.24% water

1.4% pot. St.26% water

Loss of water (%)

35% 35%

29% 27%



MFC has a clear favorable effect on bread baked from fresh dough by making the buns softer and giving them a better appearance in form of smooth crust, high volume and even form. However, the effect of MFC on freeze stored dough needs to be further evaluated.

As an additive in hamburgers MFC gave no off-flavor, gave the same texture and mouthfeel as the hamburger without additions, hold more water without side effects as watery taste, is easy to mix with the meat, but due to its low dry weight it is difficult to add the right amount of MFC without adding to much water.

6 References Ankerfors, M. (1012) Microfibrillated cellulose: Energy-efficient preparation techniques and key properties. Licentiate thesis, KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Division of Fibre Technology, TRITA-CHE-Report 2012:38, ISSN 1654-1081, ISBN 978-91-7501-464-7.

Aulin, C., Johansson, E., Wågberg, L. and Lindström, T. (2010) Adsorption behavior and structural properties of microfibrillated cellulose-based multilayers. Biomacromolecules 11: 872-882.

Pääkkö, M., Ankerfors, M., Kosonen, H., Nykänen, A., Ahola, S., Östberg, M., Ruokolainen, J., Laine, J., Larsson, P. T., Ikkala, O. and Lindström, T. (2007) Enzymatic hydrolosis combined with mechanical shearing and high-pressure homogenization for nanoscale cellulose fibrils and strong gels Biomacromolecules 8: 1934-1941.

Siró, I. and Plackett, D. (2010) Microfibrillated cellulose and new nanocellulose materials: a review. Cellulose 17:459-494.

Turbak, A. F., Snyder, F. W. and Sandberg K. R. (1984) Suspensions containing microfibrillated cellulose US Patent 4,487,634 Dec 11, 1984

Wågberg, L., Decher, G., Norgren, M., Lindfors, T., Ankerfors, M. and Axnäs, K. (2008) The build-up of polyelectrolyte multilayers of microfibrillated cellulose and cationic polyelectrolytes. Langmuir 24:784-795



7 Innventia Database information

Title


Author

Göran Ström, Camilla Öhgren and Mikael Ankerfors

Abstract

The impact of microfibrillated (MFC) as an additive in food stuff has been studied in a cooperation between the Swedish Institute for Food and Biotechnology (SIK) and Innventia AB. The work included microscopy studies of MFC, the effect of MFC on stability of oil in water emulsions and foams containing high amounts of dissolved sugar. Also studied was the impact of MFC as an additive in bread and hamburger.

The work showed that MFC has a strong potential to stabilize oil in water emulsions and foams. Very stable foams were obtained at low additions of MFC. An addition of MFC in dough gave the bread better appearance like higher volume and more even form. The bread also became smoother. As an additive in hamburger MFC gave no off-flavour and the same texture and mouthfeel as hamburger without MFC. Moreover, hamburger with MFC could hold more water during frying without negative side effects.

Keywords

Microfibrillated cellulose, food, foam, emulsion, microscopy

Classification

1320, 1153

Type of publication

Innventia report

Report number

403

Publication year

April 2013

Language

English

INNVENTIA AB Tel +46 8 676 7000 Drottning Kristinas väg 61, BOX 5604 Fax +46 8 411 55 18 [email protected] SE-114 86 Stockholm Sweden VATno 556603110901 www.innventia.com

INNVENTIA AB is a world leader in research and development relating to pulp, paper, graphic media, packaging and biorefining. Our unique ability to translate research into innovative products and processes generates enhanced value for our industry partners. We call our approach boosting business with science. Innventia is based in Stockholm, Bäckhammar and in Norway and the U.K. through our subsidiaries PFI and Edge respectively.

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