Two-Step Fermentation for Ambient-Stable Probiotic Milk
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing fermented milk products with live bacteria struggle to prevent post-acidification when stored at ambient temperatures, which can affect product quality and viability of bacteria.
Innovation Solution
A two-step fermentation method involving a first culture that generates monosaccharides and is subsequently inactivated, followed by a second lactose-deficient culture that metabolizes these monosaccharides to achieve a stable pH, reducing post-acidification and maintaining live bacteria viability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a single-step fermentation with lactose-deficient strains is used, then post-acidification is reduced, but the product cannot achieve the desired pH level and texture
Solution Approach 1:
The fermentation process is divided into two distinct sequential steps: first fermentation with lactose-fermenting strains to generate monosaccharides and achieve initial pH reduction, followed by second fermentation with lactose-deficient strains to utilize the generated monosaccharides and achieve final pH without excessive post-acidification. This segmentation allows each strain type to perform its optimal function at the appropriate stage.
Solution Approach 2:
The first fermentation step performs a preliminary action by generating monosaccharides from lactose before the second fermentation begins. This preliminary generation of substrate ensures that when lactose-deficient strains are introduced, they have immediate access to metabolizable carbohydrates, enabling controlled pH reduction without relying on lactose metabolism that would cause post-acidification.
2Object-affected harmful factors
If heat treatment is applied to inactivate starter culture strains, then post-acidification is controlled, but product attributes such as appearance, texture, and flavour are impacted
Solution Approach 1:
The invention changes the biological parameter of the fermentation system by introducing a two-strain sequential fermentation approach instead of relying on heat treatment. The first strain (lactose-fermenting) is heat-sensitive and performs its function during controlled fermentation, then naturally dies off or is removed, avoiding the need for aggressive heat treatment that would damage product quality. The second strain (lactose-deficient) is heat-resistant and performs the final pH adjustment.
3Reliability
If live bacteria are maintained in the product, then health benefits and probiotic claims are enabled, but post-acidification increases during ambient storage
Solution Approach 1:
The invention applies local quality by using two different bacterial strains with complementary metabolic characteristics. The first strain (lactose-fermenting) is optimized for initial fermentation and pH reduction, while the second strain (lactose-deficient) is optimized for utilizing generated monosaccharides without causing excessive post-acidification. Each strain has a specialized local function that together achieves the overall goal of maintaining live bacteria while controlling post-acidification.
4Manufacturing precision
If two-step fermentation with sequential cultures is used, then pH control and post-acidification reduction are achieved, but process complexity increases
Solution Approach 1:
The invention merges two fermentation processes into a unified sequential workflow that can be integrated into existing production systems. The first fermentation and second fermentation are combined in sequence, with the effluent of the first becoming the input of the second. This merging approach achieves sophisticated pH control without requiring completely separate production lines or complex multi-parameter control systems.
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 effectively reduces post-acidification and maintains high cell counts of live bacteria during ambient storage, ensuring product stability and health benefits.
Implementation Method 1
a first culture comprising one or more lactic acid bacteria strains capable of metabolizing said carbohydrate and generating at least one monosaccharide
Implementation Method 2
a second culture comprising one or more lactic acid bacteria strains which are lactose-deficient and capable of metabolizing the at least one monosaccharide generated during said first fermentation
Data Source
AI summary
The present invention is in the field of dairy technology. It relates to methods for producing fermented milk products comprising live bacteria which products have no or low/reduced post-acidification when stored at ambient temperature. The invention furthermore relates to fermented milk products produced by the method.