Enzymatic Hydrolysis of Spent Coffee Grounds for High Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing instant coffee face challenges in achieving high yield while minimizing the consumption of green coffee beans and reducing the production of off-flavors and toxic substances, particularly due to high temperature hydrolysis methods that lead to decomposition products like 5-HMF, which inhibit enzyme activity and affect aroma retention.
Innovation Solution
A process involving low-temperature extraction of roasted and ground coffee beans with water at 80°C or less, followed by steam explosion and enzymatic hydrolysis using carbohydrate and carboxylic ester hydrolysing enzymes, with optional pre-treatment and post-treatment steps to enhance enzyme accessibility and activity, and the use of coffee-derived surfactants to improve yield and aroma preservation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wet thermal hydrolysis is performed at elevated temperatures (180°C or above) to increase yield, then the amount of hydrolysis products increases, but off-flavours, toxic substances, and degradation of solubilised components are produced
Solution Approach 1:
The patent changes the temperature parameter from high (180°C or above) to low (below 100°C) to resolve the contradiction. This parameter change allows the hydrolysis process to proceed at temperatures that prevent the formation of off-flavours and toxic substances while still achieving effective breakdown of polymeric carbohydrates through enzymatic action
Solution Approach 2:
The patent replaces the thermal mechanism (high-temperature hydrolysis) with an enzymatic mechanism. Instead of using heat to break down carbohydrates, the invention uses enzymes such as mannanases, cellulases, and hemicellulases to catalyze the hydrolysis reaction at low temperatures, thereby avoiding the harmful effects of high temperature while maintaining high productivity
2Productivity
If high temperature hydrolysis is used to increase yield, then more solubilised components are recovered, but enzyme activity is inhibited by decomposition products like 5-HMF
Solution Approach 1:
The patent changes the temperature parameter to below 100°C, which prevents the formation of decomposition products like 5-HMF that would otherwise inhibit enzyme activity. This parameter change ensures that enzyme activity is maintained throughout the hydrolysis process while still achieving high yield of solubilised components
Solution Approach 2:
The patent applies preliminary action by pre-treating the coffee grounds with steam or other methods before enzymatic hydrolysis to make the polymeric carbohydrates more accessible to enzymes. This preliminary treatment enhances enzyme efficiency and yield without requiring high temperatures that would produce inhibitory decomposition products
3Productivity
If traditional extraction methods are used, then the process is simple, but the yield of total solids is limited to 50-60%
Solution Approach 1:
The patent segments the extraction process into multiple sequential steps: initial water extraction, steam explosion pre-treatment, and enzymatic hydrolysis. Each step targets different components of the coffee grounds, progressively increasing the overall yield of total solids from the initial 50-60% to 65% or more by recovering additional solids that would otherwise remain trapped in the grounds
4Quantity of substance
If green bean consumption is reduced to lower production cost, then the amount of coffee beans used decreases, but maintaining high yield becomes more challenging
Solution Approach 1:
The patent changes the extraction parameters (temperature, use of steam explosion, enzymatic treatment) to maximize the recovery of solids from each kilogram of green beans. These parameter changes enable the process to achieve 65% or more yield, meaning less than 1.54 kg of green beans are needed per kg of final product, thereby reducing green bean consumption while maintaining high productivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process achieves a high yield of instant coffee with reduced production of decomposition products, higher retention of aroma compounds, and improved enzyme activity, resulting in a higher yield of total solids (up to 75% or more) with better flavor preservation.
Implementation Method 1
Extracting roast and ground coffee beans with water having a temperature of 80°C or less, to produce a first extract
Implementation Method 2
steam exploding the spent coffee grounds, wherein the steam explosion is performed in the temperature range of 50-170°C, at a pressure of 0.1 to 10 bar for 0.1 to 5 hours
Implementation Method 3
Hydrolysing the aqueous suspension using a hydrolysing enzyme to produce a second extract
Implementation Method 4
carbohydrate and carboxylic ester hydrolysing enzymes
Implementation Method 5
coffee-derived surfactants which are provided by alkaline catalysed transesterification reactions of sugars and coffee oil
Data Source
AI summary
Disclosed herein is a process for production of an instant coffee product in a high yield, comprising the steps of extracting roast and ground coffee beans with water having a temperature of 80°C or less, to produce a first extract and spent coffee grounds, adding water to the spent coffee grounds to produce an aqueous suspension, hydrolysing the aqueous suspension using a hydrolysing enzyme to produce a second extract and spent remains, adding the first extract to the second extract, optionally after concentration and/or drying of the second extract, to obtain a combined extract, and drying the combined extract to obtain an instant coffee product. The high yield is obtained due to the reduction of enzyme inhibiting substances.