Development of superabsorbent soy protein-based bioplastic matrices with incorporated micronutrient for use in horticulture

The increase in the consumption of organic products from sustainable horticulture coupled with the concern for the effects of drought, increasingly pronuncied, has increased the need to seek new techniques to help minimize the environmental impact. In this way, the elaboration of superabsorbent protein-based matrices with micronutrients has been investigated, thus being able to retain water from the medium to supply it to the plant together with the micronutrients in a controlled manner. However, the incorporation into the matrices of the generally used salts (sulfates) cause them to lose their superabsorbent capacity, so we must look for another way to incorporate these micronutrients. The main objective of this work was the evaluation of the incorporation of different salts (sulfate and hydroxycarbonate), which create different ionic forces in the medium. In this way, the effect of the ionic strength on the superabsorbent capacity of the matrices is compared. Thus, soy protein-based matrices with different concentrations of salt have been obtained, verifying that the incorporation of these to the matrices leads to worse mechanical properties. In addition, it has been proven that the incorporation of a salt that creates a weak ionic strength (hydroxycarbonate) makes the matrices have a better absorption capacity, while the incorporation of a salt with a high potential to generate ionic forces (sulfate) makes that these materials lose their superabsorbent capacity.