Zinc oxide nanoparticles (ZnO NPs) have been explored for controlling food spoilage microorganism. ZnO NPs were prepared by wet chemical synthesis using zinc nitrate as a precursor and sodium ...hydroxide as reducing agent. Nanorods and hexagonal plate shape ZnO NPs were obtained for different reaction time of 2 h and 24 h, respectively. Effect of hydroxypropyl methylcellulose (HPMC) as capping material on the morphology, size distribution, and optical properties of ZnO nanoparticles was studied by FESEM, TEM, DLS, UV-visible spectroscopy, and XRD analyses. Results showed that HPMC as capping material prevent the agglomeration of nanoparticles during synthesis and maintained uniformity in ZnO NPs size. Strong antimicrobial activity of prepared ZnO NPs was observed and minimum inhibitory concentration (MIC) for food application was determined. MIC for
Staphylococcus aureus
was 0.5 mg/ml. For
Penicillium expansum
1 mg/ml showed approximately 80% inhibition and 2 mg/ml concentration showed 95% inhibition at the twelfth day for all ZnO NPs. HPMC-ZnO bio-nanocomposite films, prepared by incorporating capped ZnO NPs in HPMC biopolymer, showed improved mechanical and barrier properties and decreased transparency of film. Results showed that capped ZnO NPs obtained from 24 h reaction time were more effective in improving the barrier properties of HPMC film.
This research aimed to evaluate and optimize the electrospraying process of microencapsulating the probiotic strain,
Leuconostoc lactis
(NCDC 200), in a soy protein isolate (SPI) and sunflower oil ...(SO) combination matrix. In the present study, experimentation was conducted to establish the concentrations of SPI (12–15% w/v), SO (0–5% w/v), and the voltage range (10–15 kV) for the electrospraying operations. Probiotic characteristics, namely, the loss of viability of probiotic cells and encapsulation efficiency, were studied using Box-Behnken design, and specific runs were compared with the freeze-drying process. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used for microcapsule characterization. The optimized electrospraying process conditions were found to be 13.13% (w/v) SPI, 10.24 kV voltage, and 4.77% (w/v) of SO, for which a viability loss of 0.663 log CFU/g (< 1 log
10
CFU/g) and encapsulation efficiency of 92.93% were achieved. Increasing SPI and SO concentration and decreasing the process voltage significantly reduced the viability loss and improved encapsulation efficiency. The study found no significant difference between freeze-drying and electrospraying techniques for encapsulating probiotics in terms of encapsulation efficiency and viability loss for the optimized formulation. The SEM micrographs confirmed the spherical morphology of electrosprayed microcapsules, and FTIR was useful for characterizing and analyzing the protein-lipid interactions in different microcapsules. The present study could establish the protective effect rendered to probiotic cells by combining SPI and SO at specific concentrations during electrospraying.
Graphical abstract
Knowing the geographical origins of chili papers produced in specific areas is crucial because the geographical origins of various varieties of chili powder have a significant impact on their quality ...and price. In this research, for the first time, NIR (near-infrared) spectroscopy was used for the identification and classification of the geographical origin of chili powder of 6 different varieties, combining the method of PCA (principal component analysis) to extract relevant spectral features from the spectral data and segregate visible cluster trends, SIMCA (soft independent modeling of class analogy) statistically based classification model, and the four machine learning (ML) classifiers, including K-Nearest Neighbors (KNN), Decision Tree (DT), Random Forest (RF), and Support Vector Machine (SVM), were applied for supervised classification. It was found that the SVM classifier, with a
C
value of 4013.0 and γ of 0.04125, delivered the highest cross-validation accuracy of 98.41% and prediction accuracy of 97.22%. The optimization process, guided by a detailed 3D contour plot, led to a model that not only generalized well but also offered remarkable precision, as confirmed by confusion matrices. The classification accuracy of the SIMCA model was 94.04% for the calibration set and 84.74% for the prediction set. The nonlinear SVM technique of classification outperformed the linear SIMCA model and other ML models. In general, the results indicated that chili powder from various geographic origins could be discriminated by the use of NIR spectroscopy combined with the SVM model quickly, nondestructively, and reliably.
Electrospraying for Vitamin C (VC) encapsulation in Chitosan (Cs) nanoparticles was investigated and particle size, zeta potential, loading capacity (LC%) and encapsulation efficiency (EE%) were ...examined. Cs concentration (1–2% w/v) and voltage (21-25 kV) were varied with VC (0.25–0.75 w/w Cs). Twenty experiments in a face-centered CCD-RSM design were evaluated. ANOVA suggested voltage and Cs concentration as significant factors for particle size and VC content affected zeta, LC and EE%. RSM proposed optimum processing parameter at 2% Cs, 0.746 VC: Cs mass ratio and 21 kV voltage with 251.1 ± 59.03 nm particle size, 36.6% LC and an EE of 85.42%. Encapsulated particles were subjected to release behaviour, antioxidant property and analyzed through FTIR, DSC and XRD. Encapsulated VC had better antibacterial properties than Cs nanoparticles, and comparable VC retention in apple juice showed its effectiveness. Overall, nanoencapsulation of VC using electrospraying was successfully developed to be used in numerous food processing applications.
•Vitamin C (VC) successfully nano-encapsulated in Chitosan following electrospraying method.•Electrospraying at higher Chitosan (Cs) concentration increased the VC encapsulation.•VC incorporation in Cs nanoparticle enhanced crystallinity of encapsulated particle.•Inclusion of VC in electrosprayed Cs nanoparticle presented increased antibacterial activity of nanoparticle.•Encapsulated VC added to apple juice retained the colour and VC content.
This study investigated the influence of peanut protein isolate (PPI) incorporation in rice starch blends (RS-PPI) in terms of their rheological, textural, and microstructural properties. Among all ...fitted models in steady-state rheology, the Power-law model had the best fit. Incorporation of PPI improved storage modulus (G′) and loss modulus (G″) but decreased the limiting strain of the linear visco-elastic region. In the frequency sweep study, G′ and G″ increased with PPI addition for the samples containing high starch ratios, whereas the opposite trend was observed for the samples containing low starch ratios. The stress relaxation curves fitted reasonably well with the Peleg model (R2 > 0.995), and the initial and equilibrium force obtained followed the same trend as hardness values obtained from the TPA study. Initially, PPI addition to RS formed an interactive gel network showing honeycomb-like features, but further addition of PPI led to a formation of a non-homogeneous network.
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•Pasting, rheological and textural properties of RS-PPI blends were studied.•RS-PPI blends exhibited shear thinning behavior and Power-law model showed the best fit.•Addition of PPI decreased the pasting properties of RS-PPI blends.•The Peleg model fitted the stress relaxation data reasonably well.•RS-PPI composite gels exhibited honeycomb-like features and segregation of protein and starch occurred at higher PPI ratio.
This research evaluated the microencapsulation of the probiotic, Streptococcus thermophilus, in soy protein isolate (SPI) and sunflower oil (SO) emulsions using electrospraying and freeze-drying. ...Emulsions were formed with SPI (3–15% w/v), Tween 80® (2% w/v), and SO (5% w/v) after homogenization and ultrasonication. The Emulsion Stability Index (ESI), Emulsifying Ability Index (EAI), ζ-potential, particle size, Polydispersity Index (PDI), conductivity, and viscosity were evaluated to compare the emulsion properties at varying SPI:SO concentrations. After probiotic inclusion, the emulsions were electrosprayed and freeze-dried, and the microcapsules’ properties were evaluated (encapsulation efficiency, loss of viability, drying yield, surface hydrophobicity) and characterized (Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Laser Scanning Confocal Microscopy, and Differential Scanning Calorimetry). The ζ-potential (−51.51 mV) and other emulsion parameters obtained after ultrasonication indicated that the emulsion stability had improved. The secondary protein structure modifications were revealed by the emulsions' FTIR spectra, with significant increments in the α-helix and β-turn of the ultrasonicated samples compared to SPI. The electrosprayed microcapsules (13% SPI, 5% SO) demonstrated the highest encapsulation efficiency (90.51%) and the lowest loss of viability (1.05 log·CFUmL−1). The probiotics in the microcapsules were validated by the LSCM images and FTIR spectra. The differences in the morphological properties of freeze-dried and electrosprayed particles were observed through SEM. The electrosprayed microcapsules demonstrated the highest intestinal phase survival (77.03%) of probiotics under simulated gastrointestinal conditions, suggesting targeted probiotic delivery with potential for inclusion in nutraceuticals and functional foods.
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•Ultrasonication improved the Soy protein isolate-Sunflower oil emulsion properties.•Probiotics dispersed in ultrasonicated emulsions were electrosprayed/freeze-dried.•ES microcapsules had highest encapsulation efficiency (90.51%) and lowest viability loss.•ES microcapsules improved probiotic survival under in-vitro digestion conditions.
Effect of polyethylene glycol (PEG) and ZnO nanoparticles concentration on rheological properties of the hydroxypropyl methylcellulose (HPMC) based film forming suspensions (FFS) and, on the ...structural properties of the resulting films were characterized. Rheological properties of FFS were not significantly affected by PEG concentration and ZnO NPs incorporation. Intrinsic viscosity η of aqueous HPMC solution obtained from extrapolation of Huggins and Kraemer plot was 0.115–0.118 (L/g). Coating thickness calculated as a function of coating solution viscosity, concentration and draining time for strawberry coating was 1.26–1.49 μm. Tensile strength (TS) of HPMC film decreased while water vapor permeability (WVP) increased with increasing PEG concentration. Elongation at break (%E) increased up to 25% PEG concentration and decreased afterward. Incorporation of ZnO NPs improved the tensile strength and barrier properties of HPMC film. Relaxation percentage and stress decay rate increased with increasing plasticizer concentration while decreased with incorporation of ZnO NPs.
•Rheological behaviour of aqueous HPMC solution (4% w/v) was Newtonian.•Calculated Intrinsic viscosity η of aqueous HPMC solution was 0.115–0.118 (L/g).•Relaxation % and stress decay rate showed positive correlation with PEG concentration.•Added ZnO nanoparticles improves the HPMC film properties.
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•Cellulose nanocrystals (CNCs) were extracted from cucumber peels successfully.•Prepared CNCs of cucumber peels showed rod-shaped morphology.•These CNCs showed high crystallinity, ...excellent colloidal, and thermal stability.•Developed CNCs can be used to enhance the functionality of biodegradable films.
Cucumber (Cucumis sativus) peels waste being a potential cellulosic sources, were used for extracting cellulose nanocrystals (CNCs), and characterized in the present study. Firstly, the cucumber peels were purified chemically through acid, alkali, and bleaching treatments for cellulose isolation. Later obtained cellulose was acid (60 wt% H2SO₄) hydrolyzed at 45 ℃ for 45 min to obtain CNC45 suspension, and again 10 min sonicated for CNC45-S10 suspension. The effect of sonication on the particle size of CNC45, and CNC45-S10 were investigated with Dynamic light Scattering and Atomic force microscopy. The microstructural changes, thermal, and crystalline properties of resulting fibers and CNC45 were analysed after each treatments through scanning electron microscopy, thermo-gravimetric analyser, and X-ray diffraction respectively. The acid-hydrolysed CNC45 from cucumber peels showed rod-like shape with high crystallinity (74.1 %), excellent thermal stability (>200 °C), and negative zeta potential values (<−30 mV), and CNC45 can be used as potential nanofillers.
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