Nanoencapsulation of Chavir (Ferulago angulata) essential oil in chitosan carrier: Investigating physicochemical, morphological, thermal, antimicrobial and release profile of obtained nanoparticles.

The essential oil obtained by steam-distillation from Ferulago angulata (FA) was stabilized by ionic-gelation technique within chitosan nanoparticles (CSNPs). The aim of this study was to investigate different properties of CSNPs loaded with FA essential oil (FAEO). GC-MS analysis detected the major components of FAEO as α-pinene (21.85 %), ß-ocimene (19.37 %), bornyl acetate (10.50 %) and thymol (6.80 %). Due to presence of these components, FAEO showed stronger antibacterial activity against S. aureus and E. coli with MIC values of 0.45 and 2.12 mg/mL, respectively. Chitosan to FAEO ratio of 1: 1.25 exhibited a maximum encapsulation efficiency (60.20 %) and loading capacity (24.5 %) values. By increasing loading ratio from 1:0 to 1:1.25, mean particle size and polydispersity index were significantly (P < 0.05) increased from 175 to 350 nm and 0.184 to 0.32, respectively, while zeta potential was decreased from +43.5 to +19.2 mV, indicating the physical instability of CSNPs at higher FAEO loading concentrations. SEM observation proved successful formation of spherical CSNPs during the nanoencapsulation of EO. FTIR spectroscopy indicated successful physical entrapment of EO within CSNPs. Differential scanning calorimetry also proved the physical entrapment of FAEO into polymeric matrix of chitosan. XRD exhibited a broad peak at 2θ = 19° - 25° in loaded-CSNPs as indication of successful entrapment of FAEO within CSNPs. Thermogravimetric analysis showed that encapsulated essential oil was decomposed at higher temperature than its free from, indicating the success of encapsulation technique in stabilizing FAEO within CSNPs.

Efficiency of nanoemulsion of essential oils to control Botrytis cinerea on strawberry surface and prolong fruit shelf life.

Strawberry fruit is highly susceptible to decay by fungi. The objective of this study was to determine if essential oils (EOs) or nano-emulsions (Nano-EM) of EOs from Thymus vulgaris (Th), Matricaria chamomilla (Mc), Pistacia atlantica (Pa), or Mentha longifolia (Me) could inhibit growth of strawberry spoilage fungi Botrytis cinerea and their effect, if any, on strawberry quality parameters. An In vitro study showed that Th and Me EOs had the same minimal inhibitory concentrations (MIC) of 0.021 % while the MICs for Mc and Pa EOs were 0.9 % and 1.5 %, respectively. Th and Me EOs were used for subsequent experiments. In the second experiment, the application of Th and Me EOs and their nano-EM at 0.021, 0.1, 0.5 and 1 % were studied to control B. cinerea growth on the fruit surface. Nano-EM of EOs had higher antifungal activity in the control of B. cinerea than EOs on fruit surface. Generally, antifungal activity was increased at higher concentrations of Nano-EM, but in the case of EOs, their antifungal activity was not increased by increasing concentration. Nano-EM of EOs with 0.5 % was selected for further study. Finally, the quality changes and postharvest losses of fruit treated with Nano-EM of EOs of Th and Me at 4 °C were studied. The results of third experiment showed that Nano-EM of both EOs reduced microbial load, decay index, weight loss and induced greater firmness, vitamin C, total flavonoid and antioxidant activity in strawberry during storage. NanoEM-ThEO 0.5 % was more effective than NanoEM-MeEO 0.5 % to retain strawberry firmness, vitamin C and total flavonoid.

Improving quality and quantity attributes of grape juice concentrate (molasses) using ohmic heating.

The effect of ohmic heating method (OHM) on quality and quantity attributes of black grape molasses was investigated and compared with the conventional heating method (CHM). Results showed that the samples prepared by OHM had the highest antioxidant activity than CHM. Increasing of voltage gradient had a positive effect on the saving of antioxidant activity. Changes in pH for OHM were lower than CHM. Heating methods had no significant effect on phenol content. Antioxidant capacity and phenol content of treated samples were lower than the fresh sample at the same water content. The titratable acidity of treated samples using CHM was higher than the OHM. The OHM saved about 2.4-7.2-fold of processing time and 6.3-fold of energy consumption than the CHM. Heat generation and electrical conductivity depended on sample moisture content. OHM provides minimal damage to the sensory characteristics. As a final result, the OHM significantly improved the quality and saved the quantity parameters of the grape molasses processing than the CHM.

One-pot nanoparticulation of potentially bioactive peptides and gallic acid encapsulation.

Whey protein isolate was hydrolyzed to an in vitro antioxidative hydrolysate, followed by transglutaminase-induced cross-linking and microemulsification in an oil phase. The obtained microemulsion was then dispersed in a gallic acid-rich model wastewater which caused gallic acid transportation into internal nanodroplets. Whey peptides were consequently gelled, yielding nanoparticles. Electrophoresis showed that ß-lactoglobulin and low molecular weight peptides were cross-linked by transglutaminase. Protein hydrolysis and subsequent enzymatic cross-linking increased the ζ-potential value. Microscopic investigation indicated that most particles were non-spherical. Non-cross-linked and cross-linked peptides underwent a form of heat-triggered self-assembly in the dry state, while nanoparticles did not show such behavior. Peptide crystallites size was increased by cross-linking and acid-induced particle formation. The latter also caused a reduction in intensity of C-H stretching and C-N bending peaks in infra-red spectrum. Gallic acid release from particles to simulated gastrointestinal fluids was through diffusion from swollen particles, and reached almost 70% release.

One-Pot Procedure for Recovery of Gallic Acid from Wastewater and Encapsulation within Protein Particles.

A whey protein isolate solution was heat-denatured and treated with the enzyme transglutaminase, which cross-linked ≈26% of the amino groups and increased the magnitude of the ζ-potential value. The protein solution was microemulsified, and then the resulting water-in-oil microemulsion was dispersed within a gallic acid-rich model wastewater. Gallic acid extraction by the outlined microemulsion liquid membrane (MLM) from the exterior aqueous phase (wastewater) and accumulation within the internal aqueous nanodroplets induced protein cold-set gelation and resulted in the formation of gallic acid-enveloping nanoparticles. Measurements with a strain-controlled rheometer indicated a progressive increase in the MLM viscosity during gallic acid recovery corresponding to particle formation. The mean hydrodynamic size of the nanoparticles made from the heat-denatured and preheated enzymatically cross-linked proteins was 137 and 122 nm, respectively. The enzymatic cross-linking of whey proteins led to a higher gallic acid recovery yield and increased the glass transition enthalpy and temperature. A similar impact on glass transition indices was observed by the gallic acid-induced nanoparticulation of proteins. Scanning electron microscopy showed the existence of numerous jammed/fused nanoparticles. It was suggested on the basis of the results of Fourier transform infrared spectroscopy that the in situ nanoparticulation of proteins shifted the C-N stretching and C-H bending peaks to higher wavenumbers. X-ray diffraction results proposed a decreased ß-sheet content for proteins because of the acid-induced particulation. The nanoparticles made from the enzymatically cross-linked protein were more stable against the in vitro gastrointestinal digestion and retained almost 19% of the entrapped gallic acid after 300 min sequential gastric and intestinal digestions.

Effect of processing parameters on fouling resistances during microfiltration of red plum and watermelon juices: a comparative study.

This study evaluated the total (R t ), reversible (R rev ), irreversible (R irr ), and cake (R c ) resistances during microfiltration of watermelon juice (as a juice with colloid particles) and red plum juice (as a juice without colloid particles). Results showed that the total resistance decreased by about 45% when the feed velocity was increased during clarification of red plum juice due to change in cake resistance. Also, increasing the feed temperature from 20 to 30°C decreased the total fouling resistance by about 9% due to decreases in the irreversible and reversible fouling resistances. Also, mixed cellulose ester (MCE) membrane (which is hydrophilic) had a lower cake resistance compared to polyvinylidene fluoride (PVDF) membrane (which is hydrophobic). Examination of the microfiltration of watermelon juice showed that R t decreased by about 54% when the feed temperature was increased from 20 to 50°C, partially due to the reduction of reversible fouling resistance by 78%. Also, increasing transmembrane pressures from 0.5 to 2.5 bars greatly increased total fouling resistance. The feed velocity had a different effect on fouling resistances during microfiltration of watermelon juice compared to red plum juice: in contrast with red plum juice, increasing the feed velocity for watermelon juice increased cake resistance.