Synthesis of Nano-Scale Biopolymer Particles from Legume Protein Isolates and Carrageenan

Abstract

Pozadina istraživanja. Proteini i polisaharidi iz namirnica mogu se upotrijebiti za sintezu biopolimernih nanočestica koje se koriste u proizvodnji hrane i farmaceutskih proizvoda. U fokusu je ovoga rada bila proizvodnja biopolimernih nanočestica iz proteina mahunarki, pri čemu je regulirana njihova elektrostatska interakcija s karagenanom. Eksperimentalni pristup. Određeni su profili izolata proteina dobivenih iz zlatnog graha (Vigna radiata), mletačkog graha (Vigna unguiculata) i crnog grama (Vigna mungo). Zatim je izolatima dodan karagenan te se tijekom njihove interakcije podešavala pH-vrijednost od 5,0 do 7,0 radi određivanja optimalnih uvjeta za dobivanje biopolimernih nanočestica. Nakon toga su odabrane smjese polimera zagrijavane 20 min na 85 °C kako bi se potakla interakcija između biopolimera. Rezultati i zaključci. Kompleksi biopolimernih nanočestica dobiveni su pri pH-vrijednosti od 6,5. Čestice su uglavnom bile sferičnog oblika, promjera otprilike 100-150 nm. Zagrijavanjem im se povećao promjer za otprilike 2,5 puta. Osim toga, negativni površinski naboj se povećao, čime se smanjila agregacija čestica u širem rasponu pH-vrijednosti (4,0-7,0) te povećala mogućnost njihove primjene u hrani. Novina i znanstveni doprinos. U radu je prikazana mogućnost primjene proteina zlatnog graha, mletačkog graha i crnog grama u sintezi stabilnih biopolimernih nanočestica, koje se mogu upotrijebiti za inkapsulaciju i prijenos bioaktivnih spojeva.Research background. Food proteins and polysaccharides can be used for the synthesis of nano-scale biopolymer particles with potential applications in the fields of food and pharmaceuticals. This study focuses on utilizing legume proteins for the production of biopolymer particles via regulation of their electrostatic interactions with carrageenan. Experimental approach. Protein isolates were obtained from mung bean (Vigna radiata), cowpea (Vigna unguiculata) and black gram (Vigna mungo) and their protein profiles were determined. Next, these isolates were allowed to interact with carrageenan at pH=5.0-7.0 to determine optimum conditions for obtaining nano-scale biopolymer particles. Selected biopolymer mixtures were then subjected to a heat treatment (85 °C for 20 min) to enhance the interactions among biopolymers. Results and conclusion. Nano-scale biopolymer complexes were obtained at pH=6.5. They were roughly spherical in shape with a majority having a diameter in the range of approx. 100-150 nm. Heating of the biopolymer mixtures increased the diameter of the biopolymer particles by approx. 2.5-fold. In addition, their negative surface charge was increased, stabilizing them against aggregation over a broader pH range (4.0-7.0), enhancing their potential to be utilized in food matrices. Novelty and scientific contribution. This study reports the applicability of mung bean, cowpea and black gram proteins for the synthesis of stable biopolymer particles. These biopolymer particles can be potentially used for the encapsulation and delivery of bioactive components