Complex Spectroscopic Study for Fusarium Genus Fungi Infection Diagnostics of “Zalp” Cultivar Oat

At present, one of the critical problems in agriculture is the identification of cereals, including oats, infected by Fusarium spp. genus fungi. Timely diagnostics can prevent the further disease spread and help to identify the already stored infected grains. In this regard, the aim of this work is to develop the spectroscopic approaches that determine the infected grains. As an object of the investigation the “Zalp” cultivar oat, both healthy and infected grains of the 2020 harvest were chosen. The spectroscopic diagnostics included FTIR in the mid-IR region, Raman, and luminescence methods. Combination of chemometric tools with FTIR and Raman spectroscopy allowed obtaining approaches based on identified characteristic spectral features which may be used as infection markers. These approaches make it possible to detect the infection on the grain husk. The carotenoid type fungi pigment was identified within the resonance conditions of Raman scattering excitation. The luminescence study of infected oat husk revealed the presence of characteristic chlorophyll α peak which is absent in healthy grain husk.

Micronized Oat Husk: Particle Size Distribution, Phenolic Acid Profile and Antioxidant Properties

Oat husk (OH; hull) is a by-product generated from oat processing and is rich in insoluble fibre and phenolic compounds. The aim of this work was to study the particle size distribution, antioxidant activity, and phenolic profile of micronized OH. For this purpose, the hull was first sterilized using superheated steam and was then ground using an impact classifier mill. The particle size distribution (PSD) of the ground husk was determined using the laser diffraction method and the parameters characterizing the PSD of the ground husk, and its antioxidant activity were calculated. In addition, UPLC-MS/MS analysis of phenolic acids was also performed. Micronization of the sterilized husk effectively decreased the size of the particles, and with the increasing speed of the rotor and classifier, the median size of the particles (d50) decreased from 63.8 to 16.7 µm. The following phenolic acids were identified in OH: ferulic, caffeic, p-hydroxybenzoic, vanillic, syringic, and synapic acid. Ferulic acid constituted about 95% of total phenolic acids. The antioxidant activity of the obtained extracts increased as the particle size of the micronized husk decreased. The highest half maximal inhibitory concentration (EC50 index) was found for chelating power, and the lowest was found in the case of radical scavenging activity against DPPH.

Physic-Mechanical Properties of Composites Based on Secondary Polypropylene and Dispersed of Plant Waste

The physic-mechanical properties of filled composites based on secondary polypropylene are investigated. As fillers the dispersed wastes of processing of agricultural plants - buckwheat and oat husk, as well as needles flour and wood flour were used. Water absorption, abrasion, impact strength and bending strength of composites were investigated. It has been proven that oat and buckwheat husks can be effectively used in composites based on secondary polypropylene and replace traditional wood fillers. It has been shown that the physic-chemical properties of the filled composites depend on the structure and physicochemical interactions on the phase separation surface, as well as on the surface properties of the filler particles. It is established that for the production of filled composites with improved physic-mechanical characteristics it is necessary to use fillers with small specific surface and concentration of surface functional groups, and the acid-base characteristic of the surface should be closer to neutral. It is shown that these conditions provide for the formation of a uniform structure of the filled composite with less internal stresses.

Preparation of Nutrient Media from Lignocellulose: Compositional Optimization of Multienxyme Cocktail

Lignocellulose is a global inexhaustible resource for obtaining various products of biotechnological synthesis. The enhanced efficiency of glucose extraction from lignocellulose will increase the yield of such products, thus decreasing their cost. The goal of the study was to optimize the composition of multienzyme cocktail (MEC) of commercial enzymatic preparations (EP) Cellolux-A, Ultraflo Core and Bruzyme BGX for efficient enzymatic hydrolysis of the substrate – oat husk treated with 4 wt.% nitric acid under the pilot-plant conditions. Mathematical processing of experimental data obtained by implementation of the simplex-centroid design of experiments revealed the optimal EP ratio equal to 1/4 : 3/4 : 0 (Cellolux-A – 18 mg/g substrate, Ultraflo Core – 55 mg/g substrate). The optimized composition of MEC allows increasing the reducing substances yield by a factor of 1.95. The equation of experimental statistical model was used to investigate the hydrolysis kinetics at different concentrations of MEC. It was shown that a threefold increase in the MEC concentration increases the reducing substances yield versus the substrate weight and the glucose yield versus the cellulose weight in the substrate by 13 %. The hydrolysate obtained using the optimized MEC served as a nutrient medium for biosynthesis of a valuable bioengineering product – bacterial nanocellulose, the yield of which constituted 6.1 % of the hydrolysate glucose.