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The problems caused by the pollution of the environment by petroleum polymers in recent years have caused researchers to think of replacing petroleum polymers with biodegradable and natural polymers. The aim of this research was to produce composite film of chitosan (Chit)/zero-valent iron (Fe) nanoparticles/oregano essence (Ess) (Chit/Fe/Ess). Central composite design was used to study physical, morphological, antioxidant and antimicrobial properties of films. The results showed that with the increase of iron nanoparticles and oregano essence, the thickness of the film increased. The moisture, solubility and water vapor permeability of the film decreased with the increase of iron nanoparticles and oregano essence. The results of the mechanical test showed that with the increase of iron nanoparticles and oregano essence, the tensile strength and elongation at break point decreased. Iron nanoparticles and oregano essence increased significantly the antioxidant activity of the film. The results of the antimicrobial activity of the prepared films show that the addition of iron nanoparticles and oregano essence enhanced the antimicrobial activity of the film against Escherichia coli and Staphylococcus aureus. X-ray diffraction analysis showed that iron nanoparticles were physically combined with chitosan polymer. Fourier transform infrared (FTIR) results confirmed the physical presence of iron nanoparticles and oregano essence in the polymer matrix. The results of scanning electron microscopy (SEM) showed that the surface of nanocomposite films is more heterogeneous than chitosan. Iron nanoparticles and oregano essence could delay the thermal decomposition of chitosan and increase the thermal stability of chitosan film.
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This paper investigates the addition of lecithin-emulsified black seed oil (BSO) nanoemulsions (LNEO) and whey protein isolate-stabilized Pickering emulsions (WPEO) to soy protein isolate (SPI)-based films and their effect on improving the shelf life of bread slices. The half-life of antioxidant activity, water vapor permeability, biodegradability, density, color difference, and film thickness significantly increased (p < .05) when BSO was added. However, the incorporation of BSO significantly reduced the solubility, tensile strength, strain to break (except for WPEO), and transparency (p < .05) of the samples. The interaction between SPI film and BSO-loaded nanocarriers, as well as the morphological properties of films, was evaluated using FT-IR and FE-SEM. SPI-based films containing LNEO-5% and WPEO-5% were selected based on their mechanical and barrier properties. The effect of films on the shelf life of bread slices was investigated for 17 days of storage. LNEO samples obtained the most acceptable results in the bread in terms of sensory evaluation and color properties. According to the results, bread slices packed in SPI film containing LNEO-5% showed no signs of mold growth until the 17th day of storage, whereas the sample packed in a low-density polyethylene bag began to corrupt on the 6th day. This study highlights the potential of BSO-loaded SPI films as a novel active packaging for the bakery industry.
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In this study, barley sprout powder/pectin (BS/Pec) composite film was prepared. Quercetin (Qu) and vanadium oxide (V2O5) nanoparticles were used to improve the physicochemical and structural characteristics of the film. The structural, physicochemical and thermal properties of the films were investigated by various techniques such as TGA, SEM, XRD, FTIR, texture analysis, etc. The thickness and tensile strength of the films increased from 120 µm to 2.4 MPa to 220 µm and 6 MPa respectively with the increase of V2O5 nanoparticles and quercetin pigment. Nanoparticles of V2O5 and quercetin decreased the moisture content of the film from 50% to 20%. Quercetin had little effect in reducing water vapor permeability (WVP), but V2O5 nanoparticles had a significant effect in reducing WVP. The pure BS/Pec film had almost 30% antioxidant properties, which increased to 81% with the increase of quercetin. Adding quercetin and V2O5 nanoparticles to the film increased the antimicrobial properties of the film against both Escherichia coli and Staphylococcus aureus bacteria. The SEM images showed the inhomogeneous surface of the BS/Pec film caused by BS powder fibers. The interactions between the components of the films (electrostatic type) was confirmed by FTIR results. The degradation temperature of the overall structure of the film in the presence of nanoparticles indicated the positive effect of nanoparticles in increasing the thermal resistance of the film. Investigating the crystal structure of the film showed that the BS/Pec film has an amorphous/crystalline or semi-crystalline structure. Considering that the prepared film has good mechanical properties and as well as antioxidant/antimicrobial properties, this film as an active composite can be used in food products packaging.
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This study aimed to investigate in situ exopolysaccharides (EPSs) production by Bacillus coagulans IBRC-M 10807 under different fermentation conditions to improve the technical-functional properties of whole wheat flour sourdough and obtain high-quality products. For this purpose, the effectiveness of four efficient factors including B. coagulans (8 Log CFU/g), FOS (0%, 2.5%, and 5% based on flour weight), fermentation temperature (30, 35, and 40°C), and fermentation time (12, 18, and 24 h) was investigated on the production of functional sourdough. Our work focused on optimizing probiotic sourdough by investigating probiotic viability, pH, total titratable acidity, antioxidant properties, and EPS measurement. The first optimal formulation for maximized production of the in situ EPSs by the numerical optimization included FOS 0%, B. coagulans IBRC-M 10807 8 Log CFU/g, fermentation temperature of 30°C, and fermentation time of 12 h. In this case, EPSs was 59.28 mg/g and probiotic was 10.99 Log CFU/g. The second optimal formula by considering the highest viability of probiotic together with EPS production was determined as FOS 4.71%, B. coagulans IBRC-M 10807, 8 Log CFU/g, fermentation temperature of 30°C, and fermentation time of 20 h. The predicted amount of the EPSs and probiotic viability via the second formulation were 54.4 mg/g and 11.18 Log CFU/g, respectively. Analyses of optimal sourdough using FTIR, SEM, and DSC revealed that FOS and probiotics significantly reduced the enthalpy of amylopectin retrogradation and delayed it compared to other samples. Therefore, improving the final product's technological capabilities and shelf life can be credited with potential benefits.
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This research aimed to extract flaxseed mucilage (FM) and investigate its rheological properties (static and dynamic tests) compared with animal oil. In the next stage, the D-optimal design was applied to investigate the effect of FM (0-60%) and FF (0-30%) replacements with animal oil and cake flour, respectively on the sponge cake's physicochemical, textural, and sensory properties. According to the flow behavior test, FM showed Newtonian behavior while animal oil had pseudoplastic behavior. The results of the dynamic test showed with an increase in frequency, the loss modulus (G×´) and storage modulus (G') of samples increased. However, G' was higher than G×´ in all samples. By replacement of FM and FF, the moisture content, water activity, antioxidant capacity, crumb hardness, and cohesiveness of the samples increased while springiness, crust hardness, and specific volume decreased (P < 0.05). Lightness of samples with replacement of FF decreased (P < 0.05). The overall acceptance score was enhanced with an increase in FM substitution while it was decreased with the replacement of FF (P < 0.05). The amounts of fat, calories, and peroxide values were decreased in sponge cake with the incorporation of FF and FM (P < 0.05). In general, the substitution of FM (60%) and FF (28%) in the cake formulation as an optimized sample to make new products with low-calorie content is possible without significant decreases in product quality.
Assuntos
Linho , Farinha , Farinha/análise , Manipulação de Alimentos/métodos , PolissacarídeosRESUMO
Amaranth selective hydrolyzed protein (ASPH) may improve sourdough properties and bread quality. In this regard, this study focused on investigating the influence of protein hydrolysates on sourdough fermentation and bread properties. Based on the findings, ASPH further increased Lactobacillus plantarum and Saccharomyces cerevisiae growth in sourdough compared with amaranth protein isolates and amaranth flour. ASPH at 5 g/kg resulted in sourdough with higher pH and total titratable acidity (TTA) after 20 h of fermentation at 30°C. The prepared sourdough using APH (S-ASPH) at 3 g/kg increased the specific volume (4.57 ml/g) and TTA (4.76 ml) while decreasing water activity, hardness, cohesiveness, and chewiness of the bread (S-ASPH-B) compared with the control. Moreover, transition temperature and enthalpy reduced whereas sensory properties and shelf life represented an increase with S-ASPH addition. Overall, the obtained data indicated the improvement of bread quality by S-ASPH sourdough.
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In this study, biodegradable and edible films based on eggplant flour (EF) and corn starch (CS) were prepared using casting method at proportion of 0-100, 25-75, 50-50, 75-25 and 100-0%, w/w. The mechanical, barrier, physical, and biodegradability properties were evaluated. Tensile strength, elongation at break, Young's modulus, thickness, density and Lâ parameter of pure starch films were higher than those of other films. Solubility, water vapor permeability (WVP), moisture content and swelling index of films were augmented with the substitution of CS by EF. Color measurement of the edible films indicated that increasing the proportion of EF increased aâ, bâ and opacity values. The highest amount of water sorption was obtained for pure EF films. Moreover, the incorporation of EF accelerated films biodegradability compared to ones with only starch. In general, EF is a promising material for the formulation of edible and biodegradable films with adequate physical properties for food applications by direct contact.