Migration

0 downloads 0 Views 749KB Size Report
Jan 29, 2018 - Speakers Corner. Filling oil migration in chocolate -. Impact of chocolate composition, conching and crystallization. Dipl.-Ing. Isabell Rothkopf ...
ProSweets 2018 Speakers Corner 29. January 2018

Filling oil migration in chocolate Impact of chocolate composition, conching and crystallization

Dipl.-Ing. Isabell Rothkopf

© Fraunhofer IVV

Background - Migration

Hazelnut oil gradient

chocolate

Milk powder sugar

Solid fat

cocoa

Liquid fat

Particle with bound fat

Nut oil filling

Diffusion path

According to: Galdámez JR, Szlachetka K, Duda JL, Ziegler GR (2009) Oil migration in chocolate: A case of non-Fickian diffusion. Journal of Food Engineering 92(3):261–268. doi: 10.1016/j.jfoodeng.2008.11.003

© Fraunhofer IVV

Migration in cylindrical model systems

The model cylinders are placed on nougat. At the end of storage, the cylinders are cut in slices and the nut oil content in each slice is analyzed.

3 2 1 Master Thesis Bettina Sonnleitner (2016)

© Fraunhofer IVV

3 2 1

1

Impact of composition

dark chocolate

dark chocolate + cocoa butter 50:50

cocoa butter

Cocoa butter + cocoa powder

Cocoa butter + sugar + cocoa powder

Cocoa butter + sugar

© Fraunhofer IVV

Results of basic migration measurements

25

chocolate 1:1 mixture cocoa butter

hazelnut oil [%]

20

Bottom slice of cylinders stored at 23 °C and HNO detection via fatty acids with GC-FID

15 10

Faster migration with particles?

5

Chocolate after 8 weeks storage?

0

0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Results of basic migration measurements

85 80

SFC [%]

75

Bottom slice of cylinders stored at 23 °C and SFC via NMR with 3 weeks storage

Cocoa butter 1% SFC per 1% oil Chocolate 2% SFC per 1% oil

70 65

chocolate 1:1 mixture cocoa butter

60

Problem with sampling of chocolate after 8 weeks!

55 0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Results of particle variation migration measurements

hazelnut oil [%]

20

cocoa butter 30% sugar 10% sugar 20% cocoa powder 30 % cocoa powder

15

Higher migration with sugar and cocoa particles, but lower than in pure cocoa butter

10

5

0 0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Results of particle variation migration measurements

hazelnut oil [%]

20

cocoa butter 50% sugar 25% sugar 25% cocoa powder 50 % cocoa powder

15

Higher migration with sugar and cocoa or only cocoa particles, but lower than in pure cocoa butter

10

5

0 0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Impact of composition II

dark chocolate w/o lecithin

Basic dark chocolate II

dark chocolate reduced fat

39.0 % cocoa liquor 13.5 % cocoa butter 47.5 % sugar

39.0 % cocoa liquor 13.0 % cocoa butter 47.5 % sugar 0.5 % lecithin

42.0 % cocoa liquor 7.0 % cocoa butter 50.5 % sugar 0.5 % lecithin



Basic chocolate is different from other experiments, but same receipt



Chocolate with reduced fat and without lecithin should have same flow properties (5% fat equals 0.5 % lecithin with regards to flow properties)

© Fraunhofer IVV

Results of basic migration measurements

25

chocolate w/o lecithin reduced fat

hazelnut oil [%]

20

Bottom slice of cylinders stored at 23 °C and SFC via NMR with 3 weeks storage

15 10

No impact of fat reduction or lecithin removal

5 0

0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Impact of conching

dark chocolate w/o lecithin

Basic dark chocolate II

dark chocolate reduced fat

39.0 % cocoa liquor 13.5 % cocoa butter 47.5 % sugar

39.0 % cocoa liquor 13.0 % cocoa butter 47.5 % sugar 0.5 % lecithin

42.0 % cocoa liquor 7.0 % cocoa butter 50.5 % sugar 0.5 % lecithin



Short (0.5h) conching: 30 min @ 1500 1/min @ 50 °C



Long (6.5h) conching: 160 min @ 800 1/min @ 80 °C 200 min @ 1000 1/min @ 80 °C (-> lecithin and remaining cocoa butter) 25 min @ 2400 1/min @ 45 °C

© Fraunhofer IVV

Results of basic dark chocolate II Bottom slice of cylinders stored at 23 °C and SFC via NMR with 3 weeks storage

25

normal short

hazelnut oil [%]

20 15

Less migration in beginning and higher migration at the end of storage time in normal conched chocolate

10 5 0

0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Results of chocolate without lecithin Bottom slice of cylinders stored at 23 °C and SFC via NMR with 3 weeks storage

25

normal short

hazelnut oil [%]

20 15

Less migration in beginning and higher migration at the end of storage time in normal conched chocolate

10 5 0

0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Results of fat reduced chocolate Bottom slice of cylinders stored at 23 °C and SFC via NMR with 3 weeks storage

25

normal short

hazelnut oil [%]

20 15

Less migration in beginning and higher migration at the end of storage time in normal conched chocolate

10 5 0

0

2

4

6

8

storage time [weeks] © Fraunhofer IVV

10

12

Impact of crystallization

βVI dark chocolate

dark chocolate

© Fraunhofer IVV

βVI dark chocolate + cocoa butter 50:50

βVI cocoa butter

dark chocolate + cocoa butter 50:50

cocoa butter

Results of polymorphic change migration measurements

chocolate 1:1 mixture cocoa butter

30

hazelnut oil [%]

25

Difficulties with sampling due to swelling of the cylinders

20 15 10

 Use of middle slice

5 0 0

2

4

6

storage time [weeks] © Fraunhofer IVV

8

Results of polymorphic change migration measurements

25

hazelnut oil [%]

20

chocolate 1:1 mixture cocoa butter

30 25

hazelnut oil [%]

chocolate 1:1 mixture cocoa butter

Difficulties with sampling due to swelling  Use of middle slice for GC-FID analysis

20 15 10 5 0 0

2

4

6

8

storage time [weeks]

15 10

β(VI): Faster migration with particles

5

Results are confirmed by SFC via NMR

0 0

2

4

6

storage time [weeks] © Fraunhofer IVV

8

Results of migration measurements

Inconsistent results: Basic experiment (chocolate with different amounts of cocoa butter) indicates slightly faster migration with more particles Crystal transformation to β(VI) results in enormous migration which might be caused by capillary flow Mixtures of cocoa butter with sugar and cocoa particles show lower migration with more particles, while particle mixtures of sugar and cocoa powder show fastest migration among particle containing samples Impact of conching seems to depend on storage time ?

Minimum particle amount

© Fraunhofer IVV

Acknowledgement

Colleagues and Students: Wolfgang Danzl

AiF 18978N

Gottfried Ziegleder Bettina Sonnleitner

Laura Waldschütz Anna Graf © Fraunhofer IVV

We look forward to working together with you!

www.ivv.fraunhofer.de © Fraunhofer IVV

Suggest Documents