Amylase Variant PS4 Bread Softness Thermal Stability
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Solution Overview
Problem
Current anti-staling amylases used in the bread industry are inadequate in maintaining bread softness and resilience for extended storage periods, as they either lack sufficient temperature resistance or have imbalanced exo- and endo-activity, leading to undesirable textural changes such as stickiness or gumminess.
Innovation Solution
A Pseudomonas saccharophila amylase variant (PS4) with specific amino acid substitutions at positions 31, 58, 172, 230, 362, 118, 209, 249, 301, 369, 377, 404, 407, and 421, which maintains high sequence identity to existing amylase sequences, offering enhanced thermal stability and balanced exo- and endo-activity for improved bread quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional anti-staling amylases are used to maintain bread softness, then bread softness is improved during short-term storage, but bread quality deteriorates after extended storage (21 days) due to insufficient thermal stability and imbalanced enzymatic activity
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the amylase protein structure (e.g., substitutions at positions 31, 58, 172, 230, 362, 118, 209, 249, 301, 369, 377, 404, 407, and 421). These molecular-level parameter changes enhance the enzyme's thermal stability, allowing it to maintain catalytic activity throughout the extended baking and storage process, thereby reliably maintaining bread softness for 21 days or longer.
2Duration of action of stationary object
If amylases with high endo-activity are used to shorten amylopectin sidechains, then bread softness is improved, but undesirable textural changes (stickiness and gumminess) occur
Solution Approach 1:
The patent applies local quality by creating an amylase variant with spatially differentiated catalytic properties. The enzyme possesses specific amino acid substitutions that locally modify its active site characteristics, enabling it to preferentially perform exo-hydrolysis (shortening side chains from the ends) while minimizing endo-hydrolysis (internal bond cleavage). This local modification of enzymatic function at the molecular level achieves bread softness without generating the harmful sticky and gummy textures associated with excessive endo-activity.
3Duration of action of stationary object
If amylases with high exo-activity are used to shorten amylopectin sidechains, then amylopectin retrogradation is retarded, but the enzyme lacks sufficient endo-activity to achieve optimal bread softness
Solution Approach 1:
The patent applies dynamics by engineering an amylase variant with dynamic and balanced dual activity. Through specific amino acid substitutions, the enzyme achieves a optimized balance between exo-activity (for retarding retrogradation and maintaining resilience) and controlled endo-activity (for achieving adequate softness). This dynamic balance of enzymatic functions allows the single enzyme to adaptively perform multiple roles during bread processing and storage, simultaneously improving both resilience and softness without the limitations of conventional single-function amylases.
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 PS4 variant effectively prolongs bread softness and resilience, maintaining high quality even after 21 days of storage, by optimizing starch hydrolysis and minimizing undesirable textural changes, thus addressing the limitations of existing anti-staling amylases.
Implementation Method 1
The PS4 variant or an amylase active fragment thereof has exoamylase activity and/or maltogenic amylase activity
Implementation Method 2
contacting starch with a PS4 variant or an amylase active fragment thereof to generate from the starch one or more linear products
Data Source
AI summary
This invention relates to polypeptides, more specifically amylase polypeptides and nucleic acids encoding these, and their uses e.g. as non-maltogenic exoamy lases in producing food or feed products.