Development of an easy-to-use colorimetric pH label with starch and carrot anthocyanins for milk shelf life assessment

The research article “Development of an easy-to-use colorimetric pH label with starch and carrot anthocyanins for milk shelf life assessment”, co-authored by METU visiting researcher Dr. Mehrdad Forough, has been published in International Journal of Biological Macromolecules.

An intelligent freshness indicator was developed by immobilizing anthocyanins of black carrot (ABC) within the starch matrix (total anthocyanins content of 10 mg/100 mL) to monitor freshness/spoilage of milk. The microstructural, spectral, swelling and solubility properties as well as color stability (as a function of time, temperature and light) of the indicator at different pHs were characterized. The incorporation of ABC did not change the swelling index and water solubility. The prepared label showed visible color changes as a function of pH and excellent color stability after one month storage at different conditions. The total color difference (TCD) value of the indicator corresponded to the pH, acidity, and microbial growth of the pasteurized milk. The Pearson correlation coefficient showed a high correlation between TCD and pH (R = −0.979), while a high and positive correlation between TCD and acidity as well as TMC (R = 0.983 and 0.968, respectively) was observed. The developed label can discriminate fresh milk form the milk entered into the initial (TCD: 7.8 after 24 h) and final (TCD: 34.8 after 48 h) steps of spoilage. The fabricated label opens a new perspective to use anthocyanins-incorporated biopolymers in the milk intelligent packaging as a simple and easy-to-use freshness indicator.

Moazami Goodarzi, M., Moradi, M., Tajik, H., Forough, M., Ezati, P., & Kuswandi, B. (2020). Development of an easy-to-use colorimetric pH label with starch and carrot anthocyanins for milk shelf life assessment. International Journal of Biological Macromolecules, 153, 240-247. doi:10.1016/j.ijbiomac.2020.03.014

Article access: https://www.sciencedirect.com/science/article/pii/S014181301940189X

Tags/Keywords:

Cellulose, Color changes, Dairy spoilage, pH indicator, Smart packaging

Other authors:
Moazami Goodarzi, M., Moradi, M., Tajik, H., Ezati, P., & Kuswandi, B.

Acknowledgment:
The authors are grateful for the financial support (Gran No: 49/PD/3 ) provided by the Faculty of Veterinary Medicine, Urmia University , IRAN.