Faridabad: Indian researchers have developed a biodegradable film using lotus stem starch, whey protein concentrate, and psyllium husk that has high structural integrity and low solubility.
Starch can form continuous matrix and has been considered an important polymer due to low cost and renewability. But films made from starch alone have low mechanical strength and high water vapour content. In this study, researchers used starch along with whey protein and psyllium husk (isabgol) to make a biodegradable film.
The stem of lotus plant was used as a source of starch. It contains 10 to 20 percent starch component of total fresh weight of stem. Studies also show that different chemical modifications to starch can improve its physical, barrier, mechanical, and form properties. In this study, the researchers performed two modifications to lotus rhizome starch: oxidation and cross-linking.
Whey protein is a by-product of cheese manufacturing. The polymer interaction between protein and starch can create a continuous film that has improved properties. Psyllium or Isabgol has a highly gelatinous or viscous consistency and has been used as an ingredient to develop films.
“To minimize the use of petroleum-based plastics, there has been an increase in the research to develop biodegradable packaging materials using natural agro-based polymers”, said Charanjit S Riar, scientist at Sant Longowal Institute of Engineering & Technology (Punjab) and a member of the research team.
The biodegradable film was made in two steps. The psyllium husk was first kept in water for 30 minutes, then heated in boiling water for 20 minutes, cooled and blended with whey protein, rhizome starch, and glycerol. The whole mixture was heated at 90 degrees and then poured in Teflon coated moulds. The moulds were then heated, peeled off and stored in special containers to prevent exposure to moisture.
Dr Charanjit S Riar and Dr Sakshi Sukhija