Nanoencapsulation of oregano essential oil using cellulose nanocrystals extracted from hazelnut shell to enhance shelf life of fruits: Case study: Pears

This study aimed to investigate the potential application of cellulose nanocrystals (CNCs) extracted from an agricultural waste for encapsulation of oregano essential oil (OEO) and subsequently their use for coating to improve the shelf life of pears as a model. By hydrolyzing hazelnut shell cellulose under the optimum conditions, high crystalline CNCs with a zeta potential of −67.8 ± 4.4 mV and a diameter of 157 ± 10 nm were produced. Different concentrations of OEO (10–50 % w/w) were incorporated into CNCs and characterized using FTIR, XRD, SEM and TEM. OEO containing 50 % CNC with the highest EE and LC was selected for coating. Pears were coated with gluten containing 0.5, 1.5 and 2 % encapsulated OEO (EOEO) and pure OEO and stored for 28 days. Physicochemical, microbial and sensory properties of the pears were examined. Microbial analysis showed that EOEO2% was more effective in controlling microbial growth than controls and pure OEO, and a 1.09 Log reduction in bacterial count was recorded on day 28 of storage when compared to control. It was concluded that CNCs produced from an agricultural waste and loaded on an essential oil could be used to extend the shelf life of pear and potentially other fruits.