Elicitation: A Tool for Enriching the Bioactive Composition of Foods

Abstract

Elicitation is a good strategy to induce physiological changes and stimulate defense or stress-induced responses in plants. The elicitor treatments trigger the synthesis of phytochemical compounds in fruits, vegetables and herbs. These metabolites have been widely investigated as bioactive compounds responsible of plant cell adaptation to the environment, specific organoleptic properties of foods, and protective effects in human cells against oxidative processes in the development of neurodegenerative and cardiovascular diseases and certain types of cancer. Biotic (biological origin), abiotic (chemical or physical origin) elicitors and phytohormones have been applied alone or in combinations, in hydroponic solutions or sprays, and in different selected time points of the plant growth or during post-harvest. Understanding how plant tissues and their specific secondary metabolic pathways respond to specific treatments with elicitors would be the basis for designing protocols to enhance the production of secondary metabolites, in order to produce quality and healthy fresh foods.

The effect of stinging nettle and field horsetail extracts on the synthesis of biologically active compounds in germinated leguminous and quinoa seed

“…Plants respond to these stressors by activating an array of mechanisms, similar to the defence responses to pathogen infections or environmental stimuli, affecting the plant metabolism and enhancing the synthesis of different classes of phytochemicals (Baenas et al, 2014;Dueñas et al, 2015). Some plant extracts may function as a source of biological substances that stimulate the synthesis of compounds which have biologically active and health-promoting properties.…”

Elicitation and treatment with precursors of phenolics synthesis improve low-molecular antioxidants and antioxidant capacity of buckwheat sprouts

“…Phenolics are mainly produced in the phenylpropanoid pathway, thus the induction of this metabolic pathway with elicitors seems to be an eff ective and simple tool for improving their level. So far, polyphenol synthesis was eff ectively increased by elicitation in both cell cultures (Matkowski, 2008;Zhao et al, 2014), as well as in low-processed food (Baenas et al, 2014). The eff ect of UV radiation (wavelengths 260-320 nm, 280-320 nm, and 300-320 nm) on the production of fl avonoid compounds in buckwheat sprouts was studied by Tsurunaga et al (2013).…”

“…Additionally the eff ectiveness of synthesis may be enhanced by enrichment of culture with precursors e.g. shikimic acid, phenylalanine and tyrosine (phenolics synthesis) (Baenas et al, 2014;Świeca et al, 2014c) or galactose, mannose (ascorbic acid synthesis) (Gallie, 2013). Most importantly, there are only a few studies concerning the mechanisms of obtaining the desirable features.…”

“…It may include abiotic elicitors such as metal ions, inorganic compounds, chilling etc., and biotic elicitors from fungi, bacteria, viruses, plant cell wall components, as well as chemicals that are released at the attack site by plants under a pathogen or herbivore attack (e.g., signaling compounds such as salicylic acid, jasmonic acid) (Baenas et al, 2014;Matkowski, 2008). Willow bark is an excellent source of salicylic acid and its derivatives (Durak and Gawlik-Dziki, 2014) and its infusion have already been used for induction of plants metabolism (Gawlik--Dziki et al 2013;Świeca and Dziki, 2015).…”

“…The fi rst one comprises genetic manipulation and is based on metabolic engineering (Liu et al, 2007). The second involves modifi cation of the sprouting process, including elicitation and supported elicitation (Baenas, et al, 2014).…”