Phosphate-Free Dishwashing Detergent with Stabilized Protease
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Solution Overview
Problem
Conventional automatic dishwashing detergents face challenges in maintaining cleaning performance across varying water hardness and conditions, particularly with the use of biodegradable complexing agents that can negatively affect proteases, leading to suboptimal results in soft or hard water and under stressed conditions like hot, long cycles.
Innovation Solution
A phosphate-free automatic dishwashing composition incorporating a complexing agent system and a novel protease variant with specific amino acid substitutions, optimized for improved performance in both soft and hard water, and under stressed conditions such as hot, long cycles, ensuring effective cleaning of protein and starch-based soils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If biodegradable complexing agents are used to replace phosphate, then environmental performance is improved, but cleaning performance deteriorates due to negative effects on proteases
Solution Approach 1:
The patent applies parameter changes by modifying the protease enzyme through site-directed mutagenesis to create variants with altered amino acid sequences (e.g., substituting specific residues like Aspartate at position 127 with Glutamate). These parameter changes in the enzyme structure enable the protease to maintain stability and activity in phosphate-free formulations with biodegradable complexing agents, resolving the contradiction between environmental performance and cleaning effectiveness
Solution Approach 2:
The invention creates a composite enzyme system by combining the novel protease variant with specific complexing agents (gluconate, lactate, or tartrate) in defined ratios. This composite formulation ensures that the protease remains stable and active while the complexing agents provide water softening and metal binding functions, achieving both environmental goals and cleaning performance
2Adaptability or versatility
If complexing agents are used at high levels to handle hard water, then water hardness management is improved, but protease activity deteriorates due to extraction of structural calcium metal ions
Solution Approach 1:
The patent employs parameter changes by modifying the protease's amino acid sequence to alter its metal ion binding characteristics. The novel protease variants (e.g., with substitutions at positions 127, 128, or 242) have modified structural properties that reduce their dependence on calcium ions for stability, allowing them to function effectively even when complexing agents sequester calcium at high concentrations in hard water conditions
Solution Approach 2:
The invention introduces an intermediary mechanism where the novel protease variant acts as a mediator that can maintain its structural integrity and catalytic function through alternative metal ion interactions or enhanced structural rigidity, rather than relying solely on calcium ions. This allows the system to tolerate high levels of complexing agents without losing protease activity
3Reliability
If detergent composition is optimized for soft water performance, then cleaning in soft water is improved, but performance in hard water deteriorates and vice versa
Solution Approach 1:
The patent applies universality by designing a protease variant that performs multiple functions across different water hardness conditions. The novel enzyme structure (with specific amino acid substitutions) provides both hard water and soft water cleaning efficacy, eliminating the need for separate formulations. The protease maintains stable activity whether complexing agents are present at high levels (hard water) or low levels (soft water), achieving universal performance across varying water conditions
4Reliability
If hot, long dishwashing cycles are used to clean toughest items, then cleaning performance is improved, but enzyme stability deteriorates due to increased stress
Solution Approach 1:
The patent employs parameter changes by creating protease variants with modified amino acid sequences that increase thermal stability. The novel enzymes (with substitutions such as Aspartate to Glutamate at position 127) have enhanced structural rigidity and resistance to denaturation, allowing them to maintain activity and stability even under the stressful conditions of hot, long dishwashing cycles while continuing to deliver superior cleaning performance
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
The composition provides enhanced cleaning performance on tough stains like egg and crème brulee, maintaining shine and soil removal efficiency even in challenging conditions, with the protease variant maintaining stability and effectiveness in phosphate-free formulations.
Implementation Method 1
comprises a complexing agent system and a novel protease
Implementation Method 2
The compositions provide improved cleaning under a plurality of conditions versus compositions comprising conventional proteases
Data Source
AI summary
A phosphate-free automatic dishwashing cleaning composition comprising i) a protease wherein the protease is a variant having at least 60% identity with the amino acid sequence of SEQ ID NO:1 and comprising at least one amino acid substitution (using the SEQ ID NO: 1 numbering) selected from the group consisting of X54T; X126A, D, G, V, E, K, I; X127E, S, T, A, P, G, C; and X128E, C, T, D, P, G, L, Y, N; and ii) from 10 to 50% by weight of the composition of a complexing agent system comprising from 0 to less than 30% by weight of the composition of citric acid.