Probiotic encapsulation by spray drying Production of particles with new functionality by controlling the milk clotting reaction

Transcription

1 Probiotic encapsulation by spray drying Production of particles with new functionality by controlling the milk clotting reaction Justine GUERIN Jérémy PETIT, Jennifer BURGAIN, Frédéric BORGES, Joël SCHER, Claire GAIANI Université de Lorraine LIBio Laboratoire d Ingénierie des Biomolécules 2 avenue de la Forêt de Haye - TSA Vandoeuvre-lès-Nancy - FRANCE

2 Introduction 1 Product shelf-life Survival problems during storage 0 Survival problems In stomach Digestive enzyme action Acid ph In intestine Viability and functionality of bacteria? Probiotic bacteria Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host FAO/WHO, 2002 Incorporated into many food products One solution Microencapsulation A technology to entrap and protect sensitive compounds or living cells during storage and digestion

3 Microencapsulation SPRAY-DRYING Classical technique used in food industry 1 Low cost Reproducibility Rapidity Useful way to incorporate probiotics into dairy products Gardiner et al., major steps Feed solution 2 3 Atomization Transforming the feed solution into droplets Drying Moisture evaporation from the particle surface Water diffusion to the particle surface Separation of powder from moist gas

4 Our process 3 Feed solution Spray-drying Powder production L. rhamnosus GG Chymosin T inlet 200 C T outlet 85 C Milk proteins 90 % caseins, 10 % denatured whey proteins Under stirring, 30 min 8 C Powder with LGG

5 First objective 4 Powder production containing LGG by spray-drying Optimized drying condition for Good powder properties Good bacterial survival after drying Ideal properties : Small particle size Low moisture content

6 Powder properties 5 Mean particle size 14.7 ± 2.8 µm < 100 µm Advantageous to avoid negative sensorial impact when added to food Hansen et al., 2002 Moisture content 3 µm 5.8 ± 0.2 % Powder morphology Smooth and non spherical particles No bacteria visible at surface Good storage stability < Moisture content < 4 % 7 % Ananta et al., 2005 Bacteria totally embedded inside the microparticles? Khem et al., 2016 ; Liu et al., 2015

7 Bacterial survival after drying 6 Shear stress during spraying? Bacterial count (CFU/g) In the feed solution Before spraying More bacteria after drying WHY? In powder After drying

8 Bacterial survival after drying 7 Small linear chain Bacterial count (CFU/g) In the feed solution Before spraying In powder After drying Before spraying Before spraying

9 Bacterial survival after drying Small linear chain Individual cells 7 Bacterial count 2.7 Bacterial count (CFU/g) In the feed solution Before spraying In powder After drying Before spraying After spraying Before spraying After spraying Chain fragmentation

10 Bacterial survival after drying 8 Bacterial count (CFU/g) In the feed solution Before spraying After spraying In powder After drying Shear stress factor 2.7

11 Bacterial survival after drying 8 Good bacterial survival after drying Loss of 0.3 log after drying Bacterial count (CFU/g) In the feed solution Before spraying After spraying In powder After drying Good bacterial concentration A daily intake of 10 8 CFU/g is recommended FAO/WHO, 2002 Shear stress factor 2.7

12 9 Second objective Production of water insoluble microparticles Enzymatic reactionreaction Enzymatic Chymosin Chymosin action action Control of the clotting Non enzymatic No enzymatic reaction reaction reaction Temperature Temperature increase increase k-casein k-casein hydrolyzes hydrolyzes CMP release CMP release Close approach of micellarofcaseins Close approach micellar caseins Gel formation Gel formation Reconstitution in hot water

13 Microparticles solubility in water 10 powder 35.7 ± 0.4 % 26.8 ± 0.9 % 14.6 ± 0.1 % 8 C 20 C 40 C

14 Microparticles solubility in water 10 powder Chymosin incubation Enzymatic reaction 35.7 ± 0.4 % 26.8 ± 0.9 % 14.6 ± 0.1 % Non enzymatic reaction Protein clotting Water-insoluble microparticles 8 C 20 C 40 C

15 Microparticles solubility in water 10 Non enzymatic reaction powder Chymosin incubation Enzymatic reaction 35.7 ± 0.4 % 26.8 ± 0.9 % 14.6 ± 0.1 % Protein clotting Water-insoluble microparticles 8 C 20 C 40 C Chymosin incubation Enzymatic reaction 79.6 ± 1.2 % 87.5 ± 0.3 % 93.8 ± 0.3 % Non enzymatic reaction Protein rehydration Water-soluble microparticles

16 Microparticles solubility in water 10 powder Chymosin incubation Enzymatic reaction 35.7 ± 0.4 % 26.8 ± 0.9 % 14.6 ± 0.1 % Non enzymatic reaction Protein clotting Water-insoluble microparticles 8 C 20 C 40 C How can we explain these differences?

17 11 Microparticles rehydration at 8 C 10 µm 8 C 3 nm 2 µm Microparticles rehydration Bacteria release Solution of proteins and bacteria Isolated caseins Caseins unable to form a gel

18 Microparticles dispersion at 40 C µm 2 µm 3 nm 40 C Microparticles dispersion Bacteria inside microparticles 3D casein network formation Clotting non-enzymatic step Suspension of microparticles encapsulating bacteria

19 Conclusion 13 Good survival of probiotic bacteria after drying Good powder properties Milk proteins clotting control to produce innovative matrices Clotting non-enzymatic step Feed solution Clotting enzymatic step Powder reconstitution in water 40 C 8 C Water insoluble microparticles Partially rehydrated powder

20 Interest for food industry 16 Water-insoluble microparticles in hot water Powder form Many advantages for storage and transportation of alive microorganisms (1) Vectorization of probiotic bacteria in high moisture content food products (2) Protection during gastric digestion (3) Intestinal release Rehydrated powder in cold water green = alive red = dead Ferment production Probiotic release achieved by a choice of reconstitution temperature

21 Acknowledgment Project Marie Curie (MILK PEPPER-FP ) Centre of Microbial and Plant Genetics Probiotic bacteria strains Dr Sarah Lebeer

22 Thank you for your attention