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The main goal of this study was to prepare bionanocomposites by combination of gelatin (10% w/v), k-carrageenan (0.5%) and nano-SiO 2 (1, 3 or 5%). Then, mechanical properties (tensile strength, elongation at break, Young's modulus), gas permeability (water vapor, oxygen), water solubility, color, UV-vis transmission/absorbance, water vapor adsorption isotherms and Fourier transform infrared (FTIR) analysis of nanocomposites were evaluated. As the results indicated, inclusion of nano-SiO 2 (at each level) could increase tensile strength and Young's modulus significantly, with the latter becoming nearly 110% higher at 5% nanoparticle level compared with gelatin-carrageenan biocompostes. Furthermore, incorporation of 5% nano-SiO 2 could decrease water vapor permeability of biocomposites from 8.9 to 1.6 × 10 -11  g m -1  s -1  Pa -1 and their oxygen permeability from 226 to 97 cm 3  μm m -2  day -1  atm -1 . Water vapor adsorption isotherms revealed that the water activity of 0.5 was the critical point beyond which the difference in equilibrium moisture content between nanoparticle-incorporated films and biocomposites increased considerably. Besides, this research demonstrated that including 5% of nano-SiO 2 is a good solution to delay UV light driven reactions as it elevated absorbance of UV light (220 nm) by biocomposites up to 4 times., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The barberry (Berberis vulgaris) extract which is a rich source of anthocyanins was used for spray drying encapsulation with three different wall materials, i.e., combination of maltodextrin and gum Arabic (MD+GA), maltodextrin and gelatin (MD+GE), and maltodextrin (MD). Response Surface Methodology (RSM) was applied for optimization of microencapsulation efficiency and physical properties of encapsulated powders considering wall material type as well as different ratios of core to wall materials as independent variables. Physical characteristics of spray-dried powders were investigated by further analyses of moisture content, hygroscopicity, degree of caking, solubility, bulk and absolute density, porosity, flowability and microstructural evaluation of encapsulated powders. Our results indicated that samples produced with MD+GA as wall materials represented the highest process efficiency and best powder quality; the optimum conditions of microencapsulation process for barberry anthocyanins were found to be the wall material content and anthocyanin load of 24.54% and 13.82%, respectively. Under such conditions, the microencapsulation efficiency (ME) of anthocyanins could be as high as 92.83%., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Abstract Encapsulation of fatty acids/fish oils within complexes could overcome low water solubility and oxidation susceptibility of these essential oils when considering their incorporation into food products; besides, it can mask their undesirable flavour and odour. So, in this research, nanoencapsulation of omega-3 (ω 3) fatty acids by gelatin-gum Arabic complexes was optimized through response surface methodology (RSM). The effects of three independent variables including gelatin concentration (33–66%), ω 3 concentration (10–30%), and homogenization speed (10,000–20,000 rpm), on different responses i.e. particle size, moisture content, colour values, free oil, encapsulated oil, and encapsulation efficiency were determined. It was revealed that homogenization speed had the highest impact on particle size; at 10,000 rpm, the smallest nanocapsules with (26–114 nm) were produced. Moisture content of dried nanocapsules was between 4.2 and 7.3%, and gelatin concentration was the most important factor. Similarly, colour values were mostly affected by gelatin concentration and increasing gelatin ratio lowered L values and raised b values of powders. Encapsulation efficiency of powder particles was between 69.74 and 98.41%, and homogenization speed had the highest effect on this response (P < 0.01). SEM graphs revealed that the nanocapsules had rather smooth and fragile surfaces, with some porous structures. Graphical abstract Image 10890 Highlights • The soluble complexation, caused suitable nanoscale carriers for fish oil. • The optimum gelatin-GA complexation led to the highest encapsulation efficiency. • Nanocapsules having ω 3 fatty acids could be produced successfully to enrich food products. [ABSTRACT FROM AUTHOR]