This study aimed to investigate the effect of essential oil nanoemulsions on the storage quality of loquats, oil-in-water nanoemulsions loaded with Zanthoxylum schinifolium essential oil (ZSEO) and cinnamaldehyde (CA) were prepared using a mixed emulsifier of whey isolate protein and bacterial cellulose nanofibers. The effect of ZSEO/CA ratio (m/m) on the performance and stability of nanoemulsions was investigated by macroscopic and microscopic observation and physicochemical characterization. The results showed that the nanoemulsion with a ZSEO/CA ratio of 7:1 had a uniform particle size distribution without obvious aggregation, and exhibited high shear viscosity and viscoelasticity. Coating with this nanoemulsion could significantly inhibit the increase in mass loss rate and decay incidence of loquats during storage, slow down the decrease in titratable acid content, soluble solid content and hardness, effectively delay postharvest quality deterioration, and extend the shelf life.

To address the problem that Shatangju mandarins are susceptible to pathogenic microbial infection and quality deterioration after harvest, this study prepared cinnamaldehyde (CA)-modified Zanthoxylum schinifolium essential oil (ZSEO) microcapsules (ZSEO/CA-MCs) by the spray drying method using a mixture of bacterial cellulose nanofiber and whey protein isolate (BCNFs/WPI) as Pickering emulsion stabilizer. Meanwhile, ZSEO microcapsules without CA modification (ZSEO-MCs) were prepared as a control. The non-contact inhibitory effects of these microcapsules on pathogenic microorganisms inoculated into Shatangju mandarins were investigated along with their effects on the storage quality of the fruit under ambient conditions. The results showed that ZSEO-MCs and ZSEO/CA-MCs inhibited the lesion diameter of Shatangju mandarins inoculated with Penicillium italicum by 28.93% and 44.66% on the 3rd day of storage, respectively. Moreover, ZSEO/CA-MCs exhibited a more compact core-shell structure, slower release of ZSEO, and a more prolonged antibacterial effect. After 30 days of storage, the decay incidence of the control group not treated with any microcapsules reached 19.40%, while those in the ZSEO-MCs and ZSEO/CA-MCs groups decreased to 15.70% and 10.20%, respectively; both microcapsules extended the storage period by at least 5 days. In addition, microcapsule treatment significantly improved the storage quality of the fruit. Compared with the control group, the ZSEO/CA-MCs group exhibited a lower mass loss rate (by approximately 20% on the 30th day of storage), better firmness maintenance (consistently 15%–20% higher than the control group), and a slower increase in color index (CI). Moreover, ZSEO/CA-MCs delayed the degradation of nutrients: the peak value of total soluble solids (TSS) did not appear until the 20th day of storage, and the contents of titratable acid (TA), ascorbic acid (AA), and total phenols were higher than those of the control group, while the total plate count was significantly lower than that of the control group (P < 0.05). In conclusion, CA-modified ZSEO microcapsules can effectively inhibit the growth of pathogenic microorganisms and reduce nutrient loss through non-contact release of active components, providing a new technical solution for the post-harvest green preservation of Shatangju mandarins and showing good application prospects in the field of fruit and vegetable storage.

Microencapsulation via spray drying can effectively enhance the processing performance and stability of vitamin E (VE), but it is still challenging to produce high VE-loaded microcapsules with low level of surface oil. Herein, we presented a facile method to prepare emulsions synergistically stabilized by gelatin and bacterial cellulose nanofibers (BCNFs), and fabricating highly loaded and stable VE microcapsules through spray drying. The emulsifying performance was significantly improved by increasing the gelatin content from 3% to 7% (m/m). In addition, as the content of BCNFs increased, the droplet sizes of these emulsions became smaller, and their physical stability also improved. After spray drying, the high VE-loaded microcapsules with an integrated spherical structure and uniform size of 10–50 μm had been successfully prepared. With the addition of 0.2% (m/m) BCNFs, the microencapsulation yield of VE microcapsules significantly increased to 81.8%, the VE oil loading rate of microcapsules was the highest at 46.51%, and the surface oil content of microencapsulation reduced from 43.2% to 37.1%. The spray-dried VE microcapsules with 0.2%–0.3% (m/m) BCNFs possessed a denser formation and improved the flowability of the powder as well as the encapsulation performance of the microcapsules. This work provided a new strategy for preparing microcapsules with low surface oil content and high VE-loaded content using BCNFs.