Mini review: fruit residues as plant biostimulants for bio-based product recovery

The request of natural products has augmented in the last years due to the increase in intolerance and allergy reactions showed by humans versus pesticides and certain chemical compounds used in agriculture. In response to this demand, innovative methods and new natural matrices have been exploited to obtain products able to increase plant nutrients use efficiency. In this context, agro-industrial residues contain bioactive molecules, including antioxidants and phenols, which may be used by farmers to improve crop productivity. Phenols are ubiquitous in plants and are essential components of the human diet by virtue of their antioxidant properties. They may also act as positive growth regulators by modifying the root architecture and, consequently, the uptake of macronutrients, potassium especially. In order to understand their effects on the plant metabolic pathways, agro-industrial residues were supplied to maize plants and the activity of specific enzymes was evaluated. In this review, developments and improved understanding on fruit residues on primary and secondary plants metabolism are discussed.