Development of superabsorbent soy protein-based bioplastic matrices with incorporated zinc for horticulture.

Background: The use of superabsorbent materials in horticulture has spread recently. These materials, which can retain water and release it as crops need it, have strong advantages such as the efficient use of water in periods of drought. However, these materials are made of synthetic polymers, which present problems of degradability and, sometimes, toxicity. For this reason, the main objective of this work is the development of biodegradable superabsorbent bioplastic (SAB) matrices using a soy protein isolate (SPI) as raw material. Zinc is also incorporated into these bioplastic matrices as an essential micronutrient for plants, to increase their added value.

Results: The incorporation of zinc chelated with 2,2',2″,2‴-(Ethene-1,2-diyldinitrilo)tetraacetic acid (Zn EDTA) (a salt with which the micronutrient is incorporated) into soy protein-based bioplastic matrices improved their superabsorbent capacity and provided a controlled release of water and nutrients to the crops.

Conclusions: The results show the strong potential for the use of these bioplastic matrices in horticulture as superabsorbent materials that can release nutrients in a controlled manner. © 2019 Society of Chemical Industry.