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.

Biochar research has been gaining recent interest in agricultural applications because of its use as a soil amendment. Biochar is a porous carbonaceous solid produced from heat in the absence of any introduced oxygen (pyrolysis). It has relatively high surface area and slow-release properties that makes it suitable for fertilizer formulation. In this study, rice straw is used for biochar production using modified carbonizer at 600-650°C temperature range. After synthesis in the nanoscale level, the biochar produced was infused with nutrients such as nitrogen, phosphorus, potassium and zinc. The morphological characteristics were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive Xray spectrometry (EDS). Nutrients were incorporated in the biochar and analysis revealed concentrations of 4.96% N, 3.46% P, 2.25% K, and 10.90% OM. The nanoscale biochar-based fertilizer was then applied into rice production. Rice grown in soil amended with nanoscale biochar-based fertilizer showed higher yield than control treatments but with comparable result from the inorganic fertilizer treatments. This implies that biochar can be used as an alternative to chemical based fertilizer when infused with the essential nutrients needed by plants. Furthermore, the soil amended with the nanoscale biochar-based fertilizer was also found to have a higher nutrient and organic matter content after harvest. Therefore, it could preserve the soil fertility which is beneficial in the long term.