Although this technique is simple, it has a weak point that is the incorporated pH sensitive dyes could leach from the polymer-matrix and mix with the food inside the package, leading to food taste and color changes. Moreover, common pH sensitive dyes are toxic to human health if consumed continuously and in high quantity, which is a major concern in the development of food spoilage indicators. Although several techniques to prevent the dye leaching have been developed, most of them involve complicated and expensive procedures. Hence, natural pH sensitive dyes are suitable alternatives for detecting food spoilage. In addition to their low toxicity, they are obtained from sustainable and inexpensive resources.