Packaging with integrated freshness indicator for liquid or semi-solid foods
The integration of a pH-sensitive indicator in packaging lids addresses the issue of food waste by visibly indicating spoilage, ensuring safe consumption and reducing waste through irreversible color change.
Patent Information
- Application Number
- DE202025002524
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2025-08-29
- Publication Date
- 2026-04-16
- Estimated Expiration
- 2035-08-31
AI Technical Summary
Consumers often discard food after its best-before date, despite it being still edible, due to the lack of a simple, visible indicator to determine spoilage, leading to significant food waste.
Packaging with an indicator element in the lid area that changes color irreversibly when certain spoilage parameters are reached, using a pH-sensitive indicator separated by a diffusion-selective barrier, integrated into existing packaging with minimal cost.
The solution provides easy integration and low-cost implementation, enhancing consumer safety and reducing food waste by visibly indicating spoilage.
Smart Images
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Abstract
Description
Problem:
[0001] Consumers often discard food after its best-before date, even though it is still edible. At the same time, there is no simple, visible indicator to show whether a product is actually spoiled. This leads to significant food waste. Solution:
[0002] The problem is solved by packaging with an indicator element located in the lid area that changes color once certain spoilage parameters are reached. The indicator element is separated from the food by a diffusion-selective barrier, preventing direct migration of dyes or chemicals into the food. Types of embodiment: - The indicator is pH-sensitive and irreversibly changes from a first color to a second color when a threshold value (e.g. pH 5.2-5.5) is undershot. - Synthetic pH indicators (e.g. Bromocresol Purple, Bromothymol Blue) or natural indicators (e.g. Anthocyanins from red cabbage, berries) can be used as dyes. - The indicator element includes: • a substrate (e.g. paper, cellulose fleece, polymer film), • an indicator layer (dye, possibly with buffering), • a diffusion membrane (e.g. cellulose acetate, regenerated cellulose), • an adhesive layer for fastening in the lid area. - The attachment is preferably done as a round insert (Ø 12-20 mm) in the inner area of the lid. - The color change is irreversible, so the display remains even after resealing or temperature fluctuations. - Alternative designs: Time-temperature indicator (TTI) based on polymeric dye systems. Advantages: - Easy integration into existing packaging. - Very low additional costs per unit (less than 3 cents for mass production). - Increased safety for consumers and reduction of food waste. Reference symbol list 1 lid 2 adhesive layer 3 carriers 4 indicator layer 5 Diffusion membrane