Room-Temperature Yoghurt via Post-Heat-Treatment Bacterial Inoculation
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Solution Overview
Problem
Conventional yoghurt products with living bacteria have limited shelf life and require refrigerated storage, while heat-treated products lose their beneficial bacteria, compromising both shelf life and health benefits.
Innovation Solution
A second bacteria culture is added to the heat-treated yoghurt-based product that is not active below a certain pH, allowing for the inclusion of living lactic acid bacteria in a commercially sterile product that can be stored at room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the yoghurt-based product is heat treated at 75-110°C to extend shelf life, then the shelf life is extended and room temperature storage is enabled, but the living yoghurt bacteria are killed off
Solution Approach 1:
A second bacteria culture is added to the heat-treated yoghurt-based product before aseptic packing. This second culture is specifically selected to be active at the pH level of the heat-treated product, ensuring that living bacteria are reintroduced after the heat treatment process has extended the shelf life. This preliminary action of adding bacteria post-heat-treatment resolves the contradiction by restoring the beneficial living bacteria while maintaining the extended shelf life achieved through heat treatment.
2Reliability
If the yoghurt-based product is not heat treated to preserve living bacteria, then health benefits are maintained, but shelf life is limited and refrigerated storage is required
Solution Approach 1:
The method performs heat treatment first to extend shelf life and enable room temperature storage, then subsequently adds a second bacteria culture that is active at the product's pH level. This sequential approach allows the product to achieve both extended shelf life and the presence of living bacteria, resolving the contradiction between these two requirements.
Solution Approach 2:
The invention changes the pH parameter consideration by selecting a second bacteria culture that is specifically active at the pH level of heat-treated yoghurt products. This parameter-based selection allows the bacteria to thrive in the heat-treated environment, enabling both extended shelf life through heat treatment and presence of living bacteria for health benefits.
3Reliability
If a second bacteria culture is added after heat treatment, then living bacteria are present in the final product, but the process complexity increases
Solution Approach 1:
The second bacteria culture acts as an intermediary element that bridges the gap between heat-treated product (extended shelf life) and living bacteria requirement. By introducing this intermediary culture after heat treatment, the process achieves both goals with minimal additional complexity, as the bacteria are simply added and allowed to colonize the product before aseptic packing.
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 enables the production of yoghurt-based products with extended shelf life and living bacteria, maintaining health benefits while allowing storage at room temperature or refrigeration.
Implementation Method 1
a first bacteria culture is added, and the product undergoes an incubation period
Implementation Method 2
the product is thereafter heat-treated at a temperature of 75-110°C, during a predetermined period of time
Implementation Method 3
a second bacteria culture is added to the heat treated yoghurt-based product, this second culture being of the type which is not active below a certain predetermined pH
Data Source
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AI summary
The invention relates to a method of producing a yoghurt-based product. The milk raw material is pre-treated normally by pasteurization, de-aeration, homogenization and possible dry matter adjustment. A stabilizer and possible flavourings are also added. A first bacteria culture is added to the milk raw material and the milk raw material is held at a temperature of 37-45°C during an incubation period. Thereafter, the product is heat treated at a temperature of 75-110°C during a predetermined period of time. Thereafter, a second bacteria culture is added to the heat treated, yoghurt-based product. The second bacteria culture must be of the type which is not active below a given pH. The finished product is packed aseptically.