Curcumin as the active compound of turmeric has antioxidative, antiinflammatory, antimicrobial and anticancer properties among others. However, its disadvantageous properties like low solubility, poor bioavailability and rapid degradation under neutral or alkaline pH conditions or when exposed to light limit its clinical application. These problems can be solved by a smart combination of using a natural enhancer like piperine and preparing nanoparticles by a proper method like electrospray. Due to these facts it was aimed in this study to develop curcumin and piperine loaded zein-chitosan nanoparticles step by step. For that purpose various formulation parameters like the concentrations of zein, curcumin, piperine and chitosan and the preparation parameters like the applied voltage and the nozzle diameter were investigated step by step. The nanoparticles were characterised by investigating their shapes, morphologies, particle sizes with help of SEM images and the cytotoxicity on neuroblastoma cells. It was succeeded to prepare curcumin and piperine loaded zein-chitosan nanoparticles having a mean particle size of approximately 500 nm and high encapsulation efficencies for curcumin (89%) and piperine (87%). Using a curcumin concentration of 10-25 µg/ml resulted in reduction of the viability of approximately 50% of the neuroblastoma cells. The here developed nanoparticle formulation consisting of solely natural compounds showed good cytotoxic effects and is a promising approach with appropriate properties for final consumption.

Eggshell membrane (ESM) is a natural proteinaceous by-product of the food industry, especially in the pasteurized egg industry, resulting in the availability of much discarded egg waste. In the literature, eggshell (ES) and ESM usage for their adsorbent properties to remove various organic and inorganic hazardous chemicals, especially from wastewater, has gained interest. In addition, agricultural (olive leaf) and food industry (eggshell and eggshell membrane) waste can together be valorized to produce value-added functional products. This study’s objective was to evaluate the eggshell membrane’s loading capacity for bioactive compounds obtained from olive leaf extract (OLE) in order to prepare functional biomaterial. In this study, waste eggshell membranes were used to adsorb the phenolic compounds from olive leaf extract to design functional biomaterials. Using the foam separation method, both separation of the eggshell membrane and adsorption of bioactive compounds to the eggshell membrane were achieved simultaneously. The characterization studies showed that OLE was successfully adsorbed to the eggshell membrane. Cytotoxicity and antimicrobial studies showed that prepared OLE-loaded membranes were functional materials with bioactive properties. In conclusion, ESM was determined as a promising protein in the production of functional antioxidative and antimicrobial food or dietary supplement after the adsorption of bioactive olive leaf polyphenols.

The present study proposes a method for designing small bioactive nanoparticles using silk fibroin as a carrier to deliver hydrophobic polyphenols. Quercetin and trans-resveratrol, widely distributed in vegetables and plants, are used here as model compounds with hydrophobic properties. Silk fibroin nanoparticles were prepared by desolvation method and using various concentrations of ethanol solutions. The optimization of the nanoparticle formation was achieved by applying Central Composite Design (CCD) and the response surface methodology (RSM). The effects of silk fibroin and ethanol solution concentrations together with the pH on the selective encapsulation of phenolic compounds from a mixture were reported. The obtained results showed that nanoparticles with an average particle size of 40 to 105 nm can be prepared. The optimized system for the selective encapsulation of the polyphenols on the silk fibroin substrate was determined to be 60% ethanol solution and 1 mg/mL silk fibroin concentration at neutral pH. The selective encapsulation of the polyphenols was achieved, with the best results being obtained in the case of resveratrol and quercetin and encapsulation of gallic and vanillic acids being rather poor. Thin-layer chromatography confirmed the selective encapsulation and the loaded silk fibroin nanoparticles exhibited antioxidant activity.

With new consumption trends and mindset of a healthier way of life, there is an increasing demand for functional foods. To provide stable and functional products to consumers, the stability of the active compounds must be preserved during the processing of food. For this purpose, encapsulation techniques have been used in various industries in order to overcome problems such as stability, low solubility, and degradation under process conditions for food applications. Electrospinning and electrospraying are two highly versatile and scalable electrohydrodynamic methods, which have gained increasing attention in the various encapsulation applications. This review will give readers an overview of the latest electroencapsulation (electrospraying and electrospinning) of natural bioactive compounds for functional foods applications.