Mohammad Mousavi

All-cellulose nanocomposite film made from bagasse cellulose nanofibers for food packaging application

All-cellulose nanocomposite (ACNC) film was produced from sugarcane bagasse nanofibers using N,N-dimethylacetamide/lithium chloride solvent. The average diameter of bagasse fibers (14 μm) was downsized to 39 nm after disk grinding process. X-ray diffraction showed that apparent crystallinity and crystallite size decreased relatively to an increased duration of dissolution time. Thermogravimetric analysis confirmed that thermal stability of the ACNC was slightly less than that of the pure cellulose nanofiber sheet. Tensile strength of the fiber sheet, nanofiber sheet and ACNC prepared with 10 min dissolution time were 8, 101 and 140 MPa, respectively. Water vapor permeability (WVP) of the ACNC film increased relatively to an increased duration of dissolution time. ACNC can be considered as a multi-performance material with potential for application in cellulose-based food packaging owing to its promising properties (tough, bio-based, biodegradable and acceptable levels of WVP).

Sonodisruption of re-assembled casein micelles at different pH values

Casein solutions with different pH values were sonicated at a frequency of 35kHz and increasing acoustic powers. As the sonication power increased, turbidity of solutions and particle diameter decreased at any given pH value, suggesting particles disruption due to the ultrasonic treatment. The magnitude of decrease in re-assembled micelles diameter was greater at a higher pH, indicating an interaction between pH and sonication power in sonodissociation. This interaction is attributed to a looser structure of micelles at higher pH values which increases the efficiency of ultrasonic disruption and not directly to the increased cavitation efficiency. We argue that increased cavitation efficiency with increasing sonication power, which enhances shear forces is the most likely reason for sonodisruption of re-assembled casein micelles.

Stability of vitamin D3 encapsulated in nanoparticles of whey protein isolate

Vitamin D(3) was entrapped in whey protein isolate (WPI) nanoparticles prepared by different calcium concentration and aggregation pH. Its stability was investigated in presence of air for 7days. Residual of vitamin D(3) in nanoparticles was higher compared to control samples (water, native WPI and denaturized WPI). Presence of calcium in composition of particles resulted in formation of compact structure and inhibition of oxygen diffusion in particle. Lower concentration of vitamin D(3) (280μg/ml versus 560μg/ml) had negative effect on residual amount of vitamin. The loss of vitamin D(3) during storage time was described by a second order reaction. The results illustrate that these nanoparticles can be used in clear or non clear beverages as enriching agent.

Grape Drying: A Review

The drying of grapes is a more complex process compared to the dehydration of other agricultural materials due to the necessity both of a pretreatment operation prior to drying and further processing operations after drying. To date, most researchers have concentrated on pretreatment and drying where the primary effects of pretreatment on drying have been evaluated. It seems appropriate that a review should now be presented to critically examine all the corresponding published data in the literature and to compare the conditions used in these studies in order to highlight the grape drying process by considering the important aspects of both the pretreatment and post-drying operations. The result of this study will be useful in identifying the future research directions needed for grape drying and also to facilitate the development of an analytical framework for the design of novel drying equipment.

Development and characterization of the kefiran-whey protein isolate-TiO2 nanocomposite films.

Biodegradable kefiran-whey protein isolate (WPI)-titanium dioxide (TiO2) blend films were developed and characterized as a function of incorporating amount of TiO2 nanoparticles (1, 3 and 5% wt.). Results showed that the water vapor permeability, moisture content, moisture absorption and water solubility decreased by increasing the nano-TiO2 content. Mechanical tests revealed the plasticizing effect of TiO2 nanoparticles on the kefiran-WPI-TiO2 film. Addition of TiO2 nanoparticles to kefiran-WPI films significantly decreased tensile strength and Youngs modulus, while increased its elongation at break. Differential scanning calorimetry data indicated that the glass transition temperature significantly changed by adding nano-TiO2. X-ray diffraction analysis also demonstrated that crystal type in kefiran-WPI was not affected by incorporation of TiO2 nanoparticles. A uniform distribution at 1 and 3% wt. loading levels of TiO2 nanoparticles was observed using scanning electron microscopy (SEM) micrographs.

Effect of γ-irradiation on the physical and mechanical properties of kefiran biopolymer film.

In this study, the effect of different γ-ray dosages (3, 6, and 9 kGy) on the functional properties of kefiran biopolymer was investigated. The obtained results showed that increasing γ-ray dosage brought about an increase in the tensile strength of film specimens up to three-times. However, elongation at break, and tensile energy to break of γ-irradiated kefiran films decreased in the wake of increasing γ-ray dosage. γ-Irradiation could improve surface hydrophobicity, sensitivity of kefiran film specimens to water, and water vapor permeability, but yellowness of films increased, simultaneously. XRD spectrum confirmed increased crystallinity of γ-irradiated films. Melting point of films was constant but glass transition temperature decreased drastically at high γ-ray dosage (9 kGy). ATR-FTIR analysis confirmed that γ-ray engendered no changes in chemical functional groups. According to the result, a mechanism was proposed to percept the effects of γ-irradiation on kefiran biopolymer and its role on the functional properties of kefiran film. Hence, the functional properties of kefiran films were depend on the ratio of cross-linkages between polymer chains and produced mono and disaccharide by γ-irradiation.

Optimal Development of a New Stable Nutraceutical Nanoemulsion Based on the Inclusion Complex of 2-Hydroxypropyl-β-cyclodextrin with Canthaxanthin Accumulated by Dietzia natronolimnaea HS-1 Using Ultrasound-Assisted Emulsification

Solubilizing the potent anticancer pigments in nanoemulsion (NE) systems containing 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) is a novel and promising strategy to incorporate them into water-based drug formulations. The concentration effects of sunflower oil (SO, 5.61–17.39% w/w), surfactant mixture of Tween 80 (T80) and Span 20 (S20) (1:1 weight ratio, 3.95–14.05% w/w), and the inclusion complex of HP-β-CD with canthaxanthin (CTX) synthesized by Dietzia natronolimnaea HS-1 (2.61–14.39% w/w) were evaluated to formulate a stable NE using ultrasound-assisted emulsification. The NEs were evaluated regarding droplet size and polydispersity index (span), physical stability, turbidity, and loss of antioxidant activity (LAA). Response surface modeling showed that the NEs containing 12% T80/S20, 8.30% SO, and 12% CTX/HP-β-CD had the lowest droplet size (105.5 nm), span (0.394), droplet growth ratio (0.112), turbidity (0.139), and LAA (9.36%). The predicted values obtained were close to the experimental values, indicating the suitability of the constructed models. Transmission electron microscopy and confocal laser-scanning microscopy also demonstrated that the formed droplets of the NEs produced at optimal formulation were spherical in the range of 20–100 nm. A significant correlation was found between droplet size with stability (r = −0.960, p < 0.01) and turbidity (r 2 = 0.876, p < 0.01) values. GRAPHICAL ABSTRACT

Green bionanocomposite based on kefiran and cellulose nanocrystals produced from beer industrial residues

Environmental concern about synthetic polymers and nanoparticles bring about development of the green bionanocomposite. Nanocellulose (NC) as safe nanofiller was prepared from beer industrial residues by acid hydrolysis in this study. ATR-FTIR spectrum showed no change in chemical structure of kefiran and NC after mixing. However, mechanical, visual, and WVP properties of kefiran/NC films improved with NC, but thermal properties and water sensitivity of them declined, simultaneously.

Preparation and characterization of nanocellulose from beer industrial residues using acid hydrolysis/ultrasound

The aim of this work was to prepare nanocellulose (NC) from beer industrial residuals (BIR) by an acid hydrolysis/ultrasound method using three hydrolysis times (2, 4, and 6 hours). The atomic-force micrographs showed that the obtained NCs had whisker, oval, and spherical shapes. The average diameters of the NCs ranged between 73 and 146 nm. The chemical characterization of BIR and purified cellulose confirmed that α-cellulose content increased from 44 % to 92 % and lignin contents decreased from 32 % to 5 %. FT-IR analysis showed a substantial change in chemical structure of NCs (especially over the 2-hour hydrolysis time) compared to that of purified BIR fibers. XRD results revealed that the NCs’ crystallinity and crystallite size were positively affected by acid-hydrolysis time. TGA results showed that the thermal stability of NCs increased as a result of hydrolysis. BIR, a low-value residue, was turned to nanocellulose, a high-performance nanomaterial.

Modelling and optimising of physicochemical features of walnut-oil beverage emulsions by implementation of response surface methodology: Effect of preparation conditions on emulsion stability

The major purpose of this study is to apply response surface methodology to model and optimise processing conditions for the preparation of beverage emulsions with maximum emulsion stability and viscosity, minimum particle size, turbidity loss rate, size index and peroxide value changes. A three-factor, five-level central composite design was conducted to estimate the effects of three independent variables: ultrasonic time (UT, 5-15 min), walnut-oil content (WO, 4-10% (w/w)) and Span 80 content (S80, 0.55-0.8). The results demonstrated the empirical models were satisfactorily (p < 0.0001) fitted to the experimental data. Evaluation of responses by analysis of variance indicated high coefficient determination values. The overall optimisation of preparation conditions was an UT of 14.630 min, WO content of 8.238% (w/w), and S80 content of 0.782% (w/w). Under this optimum region, responses were found to be 219.198, 99.184, 0.008, 0.008, 2.43 and 16.65 for particle size, emulsion stability, turbidity loss rate, size index, viscosity and peroxide value changes, respectively.