| 摘要 |
A food expiry label includes a layer of material (such as a water-swollen mammalian gelatine) that undergoes a phase transition (such as from solid to liquid) upon exposure to bacteria or fungi that result in food spoilage. The lable may incorporate a tactile surface that the user can feel underneath the layer of gelatine once the gelatine has changed from solid to liquid. Thus a user detect when a foodstuff is likely to have spoiled or been on the shelf for a predetermined period simply by feeling the label. |
