FERMENTATION AND ROASTUNG Dr. Tobias Lohmüller 2017 Innovations for a better world.
Targets Flavor (Cocoa): - Cocoa - Chocolaty - Bouquet of cocoa (Volatile) - Important Factors: - Genotype - 93 Different genotypes identifies (Y. Morillo et al. 2014) - Growth/Fermentation/Drying - Origin (Fermentation/Genotype) Development of the taste pre-coursers for the roasting process 2
Fermentation & Genotype Impact of genotype & fermentation on roasting Reducing sugar Amino acids Volatile acids (ph) Fruity flavor Vitamins Bioactive molecules 3
Fermentation & Genotype Fermentation Fermentation Microorganism activity produces heat Microorganism activity, heat, and metabolites are responsible for flavor precursors Schwan and Wheals, 2004; Camue et al., 2008; Elwers et al., 2009; Afoakwa 2014 Generation of flavor precursors More than 600 aroma are formed 2% of dry matter are volatile acids 4
Fermentation & Genotype Subcellular changes & enzymatic activity Elwers et al., 2009 P P P P Fermentation: Metabolites microorganisms are responsible for bean inactivation and flavor creation. Subcellular changes of fat and water vacuoles Intrinsic reaction by Aspartylendopeptidase + Carboylpeptidase activated by ph change 50 µm P Flavor precursors are generated used later for final flavor development. Those biochemical peptide fragmentation are critical for cocoa flavor development! 5
Roasting Technology & Flavor Development Nib Roasting Bean Roasting 1. Diameter 2. Surface Elwers et al., 2009 What is the status of new roaster generation? 6
Roasting Technology & Flavor Development Maillard Reactions Maillard Reaction Products (MRPs) Amides: Amino acids, Petides/proteines Compounds with free amino groups Carbonyl compounds: Reducing sugar (e.g. glucose, fructose maltose ect.) 0,6-0,85 < 0,6 0,6-0,85 Amadori colorless compounds 7
Roasting Technology & Flavor Development Ideal Roaster: - Enables homogeneous/reproducible roasting - Control of biochemical processes & morphological changes - Recipe development & differentiation 110 C Standard Roasting Parameters - Time - Temperature - Airflow 110 C Gradient Inherent: - Moisture content - Heterogeneity (temperature/moisture content) The main roasters are working like dryers! 8
Roasting Technology & Flavor Development What is influenced roasting? Cocoa note development Water Temperature Time ph Reducing Sugar Amino Acids Acetic Acid J Proteome Res. 2009 9
Roasting Technology & Flavor Development What is influenced roasting? Cocoa note development Water Temperature Time ph Reducing Sugar Amino Acids Acetic Acid J Proteome Res. 2009 10
Moisture Measurement Three ways to use the moisture information HydroKen Debacterisation Morphological Changes Biochemical Reactions Elwers et al., 2009 11
Moisture Measurement Reactions and morphological processes Root Cause: - The pull (partial pressure) of moisture out of the glassy region will cause cellular disruptions. - Temperature gradient passing to the glass transition point can cause fissures (change of specific volume (Perdon et al. 2000) Glassy region Rubbery region Gradient Formation (Hypothetical) T: temperature MC: moisture content C: central M: midpoint S: surface Siebenmorgen et al., 2004 Cnosson & Siebenmorgen, 2000 Fissures and cellular disruption causes e.g. losses of volatile/aroma compleity and reduced shelf life 12
Moisture Measurement Three ways to use the moisture information HydroKen Debacterisation Morphological Changes Biochemical Reactions Elwers et al., 2009 13
Moisture Measurement Biochemical Reactions 1 2 3 4 Biochemist Reaction o Mailliard o Caramelisation o Oidation All biochemical reactions are linked to moisture content. Roasting file: 1. Drying phase 2. Roasting phase (early stage) 3. Roasting phase (advanced stage) 4. Roasting phase (finale stage) 14
Moisture Measurement Biochemical Reactions reducing sugar Early stage Amadori-Products Carboymethyllysine Advanced stage Interim Products 1, 3 & 4-Deoyosone and Fragments Final stage Maillard Products like Pyrallin, Pentosidin, Furan, Pyrimidin, Imidazolon, Melanoidine 15
Moisture Measurement Biochemical Reactions reducing sugar Early stage Amadori-Products Carboymethyllysine Advanced stage Interim Products o Optimal Mailliard reaction are taking place at 10-3% moisture continent Final stage 1, 3 & 4-Deoyosone and Fragments Maillard Products like Pyrallin, Pentosidin, Furan, Pyrimidin, Imidazolon, Melanoidine o Product unspecific roasting notes are developed at < 3%. Mailliard reaction are going to stop. o Optimal temperature for Early stage 80-100 C Temperature/Moisture/pH & Time drives the flavor development 16
Moisture Measurement Three ways to use the moisture information HydroKen Debacterisation Morphological Changes Biochemical Reactions Elwers et al., 2009 17
Moisture Measurement Debacterisation CCP Protocol: - Debacterisation o Moisture content (> 3 %) o Temperature (> 110 C) o Time (> 10 min) - Date and Lot ID - Operator Moisture content can be measured online! HydroKen Start Debacterisation (water injection) End 18
Moisture Measurement Biochemical Reactions Practical Eamples of Moisture Measurement: - Debacterisation Monitoring: o Issue: Auditors request! Monitor moisture content directly during debacterisation. Solution: Implementation of a quantitative online moisture meter - Reproducibility of Recipes: All roasters should taste the same. o Issue: Temperature slope and time was similar between different roadsters; but flavour not Solution: Drying slope can be used to normalize recipe; flavour will be within specification 19
Moisture Measurement Biochemical Reactions - Taste optimisation: Increase cocoa notes o Issue: Week cocoa notes Increased incubation time at specific temperature and spesific moisture level before drying Control of Biochemical Reactions - Keep required moisture value for specific reaction at specific temperature constant (e.g. Amadori-Products) - Link temperature to your moisture content to accelerate the time for precourser formation. reduce drying slope Process can be controlled by moisture measurement! Moisture (%) Time (min) 20
Moisture Measurement Biochemical Reactions - Increase throughput: o Issue: Some recipe contain holding time to guaranty taste and moisture content during roasting Solution: Reduce cycle time by reducing holding time because of knowing the moisture content 21
Thank you! 22