Please have a look at enclosed PDF entitled Smart packaging systems for food applications: a review (J Food Sci Technol (October 2015) 52(10):6125–6135,DOI 10.1007/s13197-015-1766-7)

Abstract Changes in consumer preference for safe food have led to innovations in packaging technologies. This article reviews about different smart packaging systems and their applications in food packaging, packaging research with latest innovations. Active and intelligent packing are such packaging technologies which offer to deliver safer and quality products. Active packaging refers to the incorporation of additives into the package with the aim of maintaining or extending the product quality and shelf life. The intelligent systems are those that monitor the condition of packaged food to give information regarding the quality of the packaged food during transportation and storage. These technologies are designed to the increasing demand for safer foods with better shelf life. The market for active and intelligent packaging systems is expected to have a promising future by their integration into packaging materials or systems.

Patent US5609096 - Vegetable freshness keeping device ... - Google

www.google.co.in/patents/US5609096

Mar 11, 1997 - A vegetable freshness sensor production method and a freshness keeping ... ispackaged, thereby forming the desired gas sensor. In the above .

Abstract

Recently, the demand for safe and high quality foods, as well as changes in consumer preferences have led to the development of innovative and novel approaches in food packaging technology. One such development is the smart or intelligent food packaging technology. Intelligent packaging has enabled to monitor and communicate information about food quality. This technology also helps to trace a product’s history through the critical points in the food supply chain. In general, occurrence of elevated CO2 gas level is the prime indicator of food spoilage in packed foods and also its maintenance at optimal levels is essential to avoid spoilage in foods packed under modified-atmosphere packaging (MAP) conditions. Hence, a CO2 sensor incorporated into food package can efficiently monitor product quality until it reaches the consumer. Although much progress has been made so far in the development of sensors monitoring CO2, most of them are not versatile for food packaging applications and suffers from limitations such as high equipment cost, bulkiness, and energy input requirement, including safety concerns. Therefore, the development of efficient CO2 sensors that can intelligently monitors the gas concentration changes inside a food package and specific to food packaging applications is essential. In the present review, progress on the development of different types of CO2 sensors such as optical sensors, polymer opal films, polymer hydrogels, etc., which can be readily applicable to food packaging applications, is discussed.

http://www.tandfonline.com/doi/abs/10.1080/02652030701426987#aHR0cDovL3d3dy50YW5kZm9ubGluZS5jb20vZG9pL3BkZi8xMC4xMDgwLzAyNjUyMDMwNzAxNDI2OTg3P25lZWRBY2Nlc3M9dHJ1ZUBAQDA=

https://ac.els-cdn.com/S0956713511004610/1-s2.0-S0956713511004610-main.pdf?_tid=df98e696-b3a4-11e7-b6cf-00000aab0f6c&acdnat=1508290816_0bbf1eb3c0e7774760931d81aa73c215

Thank you all for your valuable information. I'm going to review these advances for my future study.