development of biodegradable nanoparticles derived from plant mucilage and its application as an edible coating

plants gums, hydrophilic colloids, hydrocolloids, mucilages and hydrophilic polymers are compounds that can produce gel. coating materials which applied on food products increased shelf life of food by affecting water loss, gas exchange, oxidation process and decreasing the food spoilage and affect shelf life of food products. coating material could carry antioxidant, antibacterial and/or other compounds responsible of food color and flavors. some advantages of edible coating are antibacterial activity, improvement of nutritional values, flavors and also decreasing the environment pollutions. in order to develop biodegradable nanoparticles from plant polymers and study of the effect of nanoparticle application as edible coating on shelf life of cucumber fruits, the experiment was conducted at the research laboratories of ferdowsi university of mashhad (fum) and industrial laboratory of school of pharmacy, mashhad university of medical science. at the first, some plant mucilage including tragacanth (astragalus gummifera), marshmallow flower (malva silvestris) and seeds of plantain (plantago lanceolata), basil (ocimum basilicum), psylium (plantago psylium) and lallemantia (lallemantia royleana) were extracted by water as natural polymers at room temperature. ethyl-cellulose™ also used as semi-artificial polymer. then acetone fraction of the extracts prepared and dispersed in water solution which had different hydrophile–lipophile balance (hlb) values (5-15) during different stirring level (500, 750 and 1000 rpm) by phase dispersion method for production of nanoparticles. nanoparticle properties and morphological characteristic determined by particle size analyzer and electronic scanning microscopy (sem) respectively. the solution contained nanoparticles sprayed on fresh cucumber fruits (as a model) as edible coating and the shelf life evaluated. results showed that mucilage of tragacanth (astragalus gummifera), marshmallow flower (malva silvestris), lallemantia (lallemantia royleana) and ethyl-cellulose™( as a control) produced particles at nanometer scale (100-200 nm) but plantain (plantago lanceolata), basil (ocimum basilicum) and psylium (plantago psyllium) had no significant acetone fraction. the best solution’s hlb for production of suitable nanoparticles (app. 100 nm in size) in the mentioned natural polymers were 7 at 1000 rpm. the results of the second set of experiment showed that application of the solutions containing nanoparticle as edible coating decreased cucumber spoilage caused by mold and improved shelf life of the commodity in the package. the results of the present study showed that medicinal plants mucilage are valuable source of natural polymeric compounds and could be used as edible coating using nanotechnology.