The study was conducted to reinforce starch‐based biocomposite films using cellulose nanocrystals (CNCs) from garlic stalks. An average yield of 4.6% by mass based from air‐dried garlic stalks was obtained through alkali delignification, acid hydrolysis and sonication. The isolated CNCs are spherical and have an average diameter of 35 nm and crystallinity of 62%. Fourier transform infrared spectra correspond to the structure of cellulose, but some absorption bands corresponding to hemicelluloses were also noticed. Starch‐based biocomposite films with varying amount of the isolated CNCs as reinforcing filler were prepared by solution casting and evaporation method. Scanning electron micrographs of the films showed homogeneous dispersion of CNC in the starch matrix. Improvement in tensile strength and modulus was at maximum when the starch to CNC ratio is 100:5. The thermal stability of the films, on the other hand, decreased with the addition of CNC. Finally, CNC‐reinforced films had lower moisture uptake than nonreinforced films. POLYM. COMPOS. 34:1325–1332, 2013. © 2013 Society of Plastics Engineers

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This study was conducted to extract and encapsulate anthocyanins from black rice bran using chitosan-alginate nanoparticles. Ten black rice varieties were screened for the anthocyanin content and the variety with the highest anthocyanins was used for the encapsulation. The anthocyanins were extracted by defatting the bran with n-hexane and soaking it with 85% acidified ethanol. The crude anthocyanin extract (CAE) was freeze-dried at -110°C for 48 h and then encapsulated in chitosan-alginate nanoparticles using two processes: ionic pre-gelation and polyelectrolyte complex formation. The mass ratio of chitosan and alginate polymers used in this study was 100:10. The treatments applied were as follows: T 0 -0 mg CAE, T 1 -10 mg CAE, T 2 -20 mg CAE, and T 3 -30 mg CAE. The resulting capsules were characterized in terms of chemical properties, surface morphology, particle size, polydispersive index, encapsulation efficiency, and 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity. Screening of rice samples indicated that Ominio bran had the highest anthocyanin content (36.11 mg/g). Anthocyanins were successfully encapsulated in the matrix as shown by the Scanning Electron Microscopy images and Fourier Transform Infrared spectra of the anthocyanin-loaded chitosan-alginate nanoparticles. Among the different concentrations of CAE, T 3 had the highest encapsulation efficiency (68.9%) and antioxidant scavenging activity (38.3%) while T 1 and T 2 had the lowest. Ascending particle size was observed for T 0 (358.5 nm), T 3 (467.9 nm), T 1 (572.3 nm), and T 2 (635.9 nm). All anthocyanin-loaded capsules were found to be of nano-size (<1000 nm). The study concluded that chitosan-alginate nanoparticles can be a good encapsulating material for anthocyanin.

Garlic contains various polyphenolic compounds such as anthocyanin, a bioactive, water-soluble compound generally known for its remarkable health-enhancing properties. However, it is chemically unstable and easily degrades due to various environmental conditions (temperature, pH, presence of oxygen and light, etc.) in addition to its low bioavailability due to fast metabolization and low absorption in the body. Therefore, a nanoencapsulation strategy is essential to address these limitations. In this work, anthocyanin extraction from FBG (Ilocos variety) with 85% acidified ethanol and its encapsulation using the chitosan-alginate nanoparticle system via pre-gelation and polyelectrolyte complex formation were demonstrated. Anthocyanin-loaded chitosan-alginate nanocapsules were characterized in terms of structural features, particle size, morphology, encapsulation efficiency, total phenolic content (TPC), and radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The obtained anthocyanin-loaded nanocapsules have small particle sizes ranging from 50.7 nm to 92.0 nm with high encapsulation efficiency (T3: 78.82%, T2: 68.18%, T1: 65.77%). Results showed that a higher initial concentration of anthocyanin extract promotes higher encapsulation efficiency. Antioxidant activity of the nanocapsules showed low phenolic content (0.11 mg GAE/g) but high DPPH scavenging activity (14.02 mg AAE/g). The chitosan-alginate complex has successfully encapsulated the anthocyanin from fermented black garlic.

Corn cobs can be processed chemically to generate new products for electricity employing a simple, low-cost, and environment friendly method. In this article, silicon carbide (SiC) and activated carbon can be synthesized from corn cobs via sol-gel and a chemical activation method, respectively. SiC was synthesized by reacting the synthesized silica and activated carbon with magnesium powder, which served as catalyst at 600 o C. The SiC was doped with varying amount of Al 2 O 3 (0.01, 0.015, 0.02 and 0.1 g), a p-type dopant, via solvothermal synthesis. The undoped SiC was characterized using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform Infrared (FTIR). Then, the band-gap energy and conductivity of undoped SiC and p-doped SiC were determined. SEM-EDX and FTIR analysis confirmed the presence of Si-C bond in the synthesized SiC from corn cob. It was observed that p-doped SiC absorbs higher energy in the visible region than undoped SiC. FTIR analysis confirmed the incorporation of the aluminum in the SiC. UV-vis spectroscopy confirmed that the synthesized p-doped SiC exhibits higher absorbance compared with undoped SiC. Aluminum doping also increased absorption bands on the visible region making it more efficient for potential application in photovoltaic (solar) cells because of the decreased band-gap energy and increase in conductivity of p-doped SiC. The ratio of 1:1-2 (SiC:Al) showed the lowest band-gap and highest conductivity with a value of 1.57-1.58 eV and 0.080-0.082 mS/cm compared with the amount of other p-dopants. Statistically, it was found that the 1:1-2 ratio of SiC:Al can be an effective p-junction for the application in photovoltaic (solar) cells.

Four new organically templated layered vanadyl(IV) phosphates, (Hcha)VOPO(4) x 0.5 H(2)O (cha = cyclohexylamine) (1), (Hchpa)VOPO(4) x 0.5 H(2)O (chpa = cycloheptylamine) (2), (Hcha)(0.5)(Hchpa)(0.5)VOPO(4) x 0.5 H(2)O (3), and (H(2)aepip)[(VOPO(4))(2)(H(2)O)] x H(2)O (aepip = N-(2-aminoethyl)piperazine) (4), have been synthesized under mild hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, magnetic susceptibility, and electron paramagnetic resonance (EPR) spectroscopy. They displayed a large interlayer gap propped up by an unprecedented double-tiered monoamine in vertical angles generating the lightest layered VPO material ever prepared and characterized. The anionic [VOPO(4)](-) sheets for all four compounds are constructed by a common secondary building unit consisting of one copper-acetate-type {(V(IV)O)(2)(mu(2)-PO(4))(4)} cluster and two vanadium polyhedra. The d(1) state was confirmed by both magnetic susceptibility studies and EPR spectra. Moreover, compounds 1 and 4 showed antiferromagnetism with T(N) at 30 K, the highest ever observed in layered vanadyl phosphates. The structural relationship, template arrangement, magnetic property, thermal stability, and correlation between interlayer gaps and densities are discussed. Compounds 1-3 crystallized in the monoclinic space group P2(1)/c (no. 14) with Z = 8, whereas compound 4 crystallized in the orthorhombic space group Pbca (no. 61) with Z = 4. Crystal data of 1, a = 16.3461(9) A, b = 14.2641(8) A, c = 9.4037(5) A, beta = 94.519(1) degrees, V = 2185.8(2) A(3); 2, a = 17.0773(5) A, b = 14.3449(4) A, c = 9.4251(3) A, beta = 93.976(1) degrees, V = 2303.3(1) A(3); 3, a = 16.6765(4) A, b = 14.2927(3) A, c = 9.4120(3) A, beta = 95.389(1) degrees, V = 2233.5(1) A(3); 4, a = 14.2517(9) A, b = 9.4012(6) A, c = 24.442(2) A, V = 3274.8(4) A(3).