Phytase Treatment in Fermented Soy Products
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Solution Overview
Problem
Phytase treatment of soy-derived products reduces oxidative stability, leading to increased off-flavor formation due to the degradation of phytic acid's sequestering effect on iron and copper, which catalyze lipid oxidation.
Innovation Solution
Concurrent phytase treatment and lactic acid fermentation in soy-based products, followed by pasteurization, cooling, or pH adjustment, minimize off-flavor formation and maintain bioavailability of minerals by controlling the extent of phytic acid degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phytase treatment is applied to soy-derived products, then the bioavailability of multivalent metal cations is enhanced, but the oxidative stability is strongly reduced
Solution Approach 1:
The patent combines phytase treatment with lactic acid fermentation in a single integrated process. The fermentation occurs concurrently with phytase action, allowing the beneficial mineral release from phytic acid degradation to occur while the fermentation process simultaneously manages oxidative stability through the production of organic acids and changes in product composition.
Solution Approach 2:
The patent utilizes changes in pH, temperature, and microbial activity parameters during fermentation to control the oxidative stability. The lactic acid fermentation process alters the chemical environment (pH reduction, production of antimicrobial substances) which prevents lipid oxidation even in the presence of released metal cations, thus maintaining stability while achieving bioavailability enhancement.
2Reliability
If phytic acid is degraded by phytase treatment, then mineral bioavailability increases, but off-flavor formation increases due to lipid oxidation
Solution Approach 1:
The patent merges phytase treatment with lactic acid fermentation to achieve simultaneous mineral release and off-flavor prevention. The fermentation process creates an environment (acidic pH, presence of lactic acid bacteria metabolites) that inhibits lipid oxidation and off-flavor development while allowing phytase to effectively degrade phytic acid and release bound minerals.
Solution Approach 2:
The patent converts the potentially harmful effect of released metal cations (which could catalyze lipid oxidation and cause off-flavors) into a benefit by utilizing the fermentation process. The lactic acid fermentation creates conditions where these metal cations remain in a state that does not promote oxidation, thus the same mineral release that could cause harm is transformed into a beneficial process that improves nutrition without compromising sensory quality.
3Productivity
If phytase is added early in the process, then phytic acid degradation is maximized, but oxidative stability is further compromised
Solution Approach 1:
The patent integrates phytase addition with the fermentation process timeline, adding phytase at a stage where fermentation is already underway or about to begin. This timing allows the phytase to act on phytic acid throughout the fermentation period, maximizing degradation efficiency, while the concurrent fermentation process continuously maintains oxidative stability through its biochemical actions.
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 method enhances the bioavailability of minerals like iron while maintaining high oxidative stability and reducing off-flavor formation in fermented soy-based products, ensuring they remain flavorful and stable during storage and processing.
Implementation Method 1
Phytase can be used to break down phytic acid into digestible components
Implementation Method 2
fermenting the inoculated aqueous liquid by incubation at a temperature in the range of 15-48 °C for 0.5-24 hours
Implementation Method 3
fermentation step d is terminated by one or more of the following actions: pasteurization of the fermented product; cooling of the fermented product
Data Source
AI summary
The present invention relates to a method of preparing a fermented soy-based product, said method comprising: a. providing an aqueous liquid containing 0.5-10 wt. % of soy protein; b. pasteurizing or sterilizing the aqueous liquid; c. inoculating the pasteurised or sterilised liquid with a lactic acid bacterium containing starter culture; d. fermenting the inoculated aqueous liquid by incubation at a temperature in the range of 15-48 °C for 0.5-24 hours to obtain a fermented product; wherein phytase is incorporated in the aqueous liquid followed by pasteurization of said aqueous liquid in step b. or wherein phytase is added to the pasteurized or sterilized liquid no later than 10 minutes before termination of fermentation step d, said phytase being incorporated in the pasteurized or sterilized liquid in an amount of not more than 11 FTU per gram of soy protein; and wherein fermentation step d. is terminated by pasteurization, cooling or pH-adjustment. It was found that by conducting phytase treatment and fermentation in a concurrent fashion, a substantial increase in bioavailabilty of minerals such as iron and magnesium can be achieved whilst at the same time minimizing the negative effect of phytic acid degradation on lipid oxidation. The invention also provides a fermented soy-based product containing soy protein, polyunsaturated fatty acids, iron and/or magnesium and inositol phosphates, wherein the average number of phosphate residues of the inositol phosphates contained in the fermented product is within the range of 1.5-4.0.