TECHNOLOGY AND EQUIPMENT FOR PROCESSING ACTIVATED AGRICULTURAL PLANT WASTE INTO BIOETHANOL

The article is devoted to the development of technology and equipment for the production of bioethanol from agricultural plant waste, activated by the steam explosion method. The value and novelty of research lies in obtaining new data on the effective acidic and enzymatic hydrolysis of activated raw materials, and developing a technology for the conversion of plant raw materials into bioethanol. The studies were carried out on the basis of the Department of Wood Materials Processing of Kazan National Research Technological University (Republic of Tatarstan, Kazan). A pilot plant for the production of bioethanol and the principle of its operation are presented. Pine wood waste and wheat straw (collected in Kukmor region of the Republic of Tatarstan in the period August-September 2021) were used as raw materials. Steam-explosive activation of raw materials was carried out at temperatures of 165 ⁰C and 210 ⁰C for 5 minutes. Acid hydrolysis parameters: H2SO4 concentration - 0.5% and 1.5%, hydromodule 1:15, hydrolysis temperature - 187⁰C, hydrolysis duration - 5 hours. Enzymatic hydrolysis parameters: preparation - Cellulox-A (OOO PO Sibbiopharm, Russia) - 6 and 12 g/kg of raw material, hydrolysis temperature - 45 ⁰C, substrate pH 4.7 (acetate buffer), raw material concentration in the substrate 33 g/l, the duration of hydrolysis is 72 h. Alcoholic fermentation of hydrolysates was carried out at 32-34⁰C using Saccharomyces cerevisiae yeast, fermentation duration 7 h, yeast concentration 25 g/l. The bioethanol yield in % of reducing substances was recalculated after determining the mass yield. It is concluded that the vapor-explosive activation of pine wood at a temperature of 210 ºC makes it possible to obtain by acid hydrolysis and anaerobic fermentation of reducing substances up to 0.26 kg (0.33 l) of ethanol from 1 kg of activated raw materials, and activation of wheat straw at the same temperature allows obtaining up to 0.172 kg (0.218 l) ethanol with 1 kg of activated straw

Hydrolysis of S. platensis Using Sulfuric Acid for Ethanol Production

S. platensis is a microalga that contains carbohydrate composition of 30.21% which makes it potential to be used as raw material for ethanol production. Hydrolysis of S. platensis is the first step for converting its carbohydrates into monosaccharides. The second step is fermentation of monosaccharides into ethanol. This research aims to study the effect of temperature and microalgae concentration on the hydrolysis of S. platensis using sulfuric acid as catalyst. This research was conducted using 300 mL sulfuric acid of 2 mol/L, hydrolysis temperatures of 70, 80 and 90 °C, and microalgae concentrations of 20, 26.7, and 33.3 g/L. The effect of temperature is significant in the hydrolysis of S. platensis using sulfuric acid. At microalgae concentration of 20 g/L and hydrolysis time of 35 minutes, the higher the temperatures (70, 80, and 90 °C), the more the glucose yields would be (8.9, 13.5, and 22.9%). This temperature effect got stronger when the hydrolysis was running for 15 minutes. Every time the hydrolysis temperature increased by 10 °C, the glucose yield increased by 13.0% at microalgae concentration of 33.3 g/L. At temperature of 90 °C and time of 35 minutes, the higher the microalgae concentrations (20, 26.7, and 33.3 g/L), the higher the glucose yields would be (25.5, 27.7, and 28.2%). The highest glucose concentration obtained was 2.82 g/L at microalgae concentration of 33.3 g/L, temperature of 90 °C, and time of 35 minutes.

Production Process of a Carbonated Drink from Red Flesh Dragon Fruit (Hylocereus polyrhizus)

The purpose of this study is to present a suitable production process of a carbonated drink from ingredients originated from red flesh dragon fruits. Additionally, optimal parameters in the hydrolysis and pasteurization stages of the juice were determined so that the product could retain the highest bioactive ingredients while still maintaining favorable color. The investigated parameters of pectinase hydrolysis process included hydrolysis temperature (35, 40, 45 and 50oC), hydrolysis time (1 hour, 2 hours, 3 hours and 4 hours), concentration pectinase enzyme level (0.4; 0.6, 0.8 and 1%) and enzyme pectinase content (0.2, 0.4, 0.6 and 0.8%). Outcomes which were considered in optimization processes included polyphenol content, vitamin C content and DPPH scavenging activity. The results are expected to aid in diversification of products from dragon fruit raw materials to meet the increasing demand of consumers.

A Novel Gelatinase from Marine Flocculibacter collagenilyticus SM1988: Characterization and Potential Application in Collagen Oligopeptide-Rich Hydrolysate Preparation

Although the S8 family in the MEROPS database contains many peptidases, only a few S8 peptidases have been applied in the preparation of bioactive oligopeptides. Bovine bone collagen is a good source for preparing collagen oligopeptides, but has been so far rarely applied in collagen peptide preparation. Here, we characterized a novel S8 gelatinase, Aa2_1884, from marine bacterium Flocculibacter collagenilyticus SM1988T, and evaluated its potential application in the preparation of collagen oligopeptides from bovine bone collagen. Aa2_1884 is a multimodular S8 peptidase with a distinct domain architecture from other reported peptidases. The recombinant Aa2_1884 over-expressed in Escherichia coli showed high activity toward gelatin and denatured collagens, but no activity toward natural collagens, indicating that Aa2_1884 is a gelatinase. To evaluate the potential of Aa2_1884 in the preparation of collagen oligopeptides from bovine bone collagen, three enzymatic hydrolysis parameters, hydrolysis temperature, hydrolysis time and enzyme-substrate ratio (E/S), were optimized by single factor experiments, and the optimal hydrolysis conditions were determined to be reaction at 60 ℃ for 3 h with an E/S of 400 U/g. Under these conditions, the hydrolysis efficiency of bovine bone collagen by Aa2_1884 reached 95.3%. The resultant hydrolysate contained 97.8% peptides, in which peptides with a molecular weight lower than 1000 Da and 500 Da accounted for 55.1% and 39.5%, respectively, indicating that the hydrolysate was rich in oligopeptides. These results indicate that Aa2_1884 likely has a promising potential application in the preparation of collagen oligopeptide-rich hydrolysate from bovine bone collagen, which may provide a feasible way for the high-value utilization of bovine bone collagen.

Preparation of High-purity Alumina via Hydrolysis of Aluminum Isopropoxide after Desilication with Lanthanum Oxide

High-purity alumina refers to ultra-fine alumina powder with a purity exceeding 99.99% and a uniform particle size. This material exhibits excellent corrosion resistance, high-temperature resistance, wear resistance, and oxidation resistance. Owing to the high silicon content of alumina prepared by means of the alcohol-aluminum hydrolysis method, the purity of the alumina is often unsatisfactory. Therefore, in this work, a new method for adding lanthanum oxide to isopropanol in the early aluminum isopropoxide synthesis stage is proposed. When lanthanum oxide was added, the silicon content of the precursor aluminum isopropoxide decreased to 0.0051%.Remove calcium, sodium, magnesium and other impurities by cleaning with hydrochloric acid under an ultrasonic field. The optimal hydrolysis conditions were determined as follows: hydrolysis temperature: 55, hydrolysate concentration: 80%, water to alkoxide ratio: 6:1. The alumina precursor calcined at 1200 yielded a high-purity alumina with a purity level of more than 99.99%, and the particle size reaches 2.037 μm.

Modelling Based Analysis and Optimization of Simultaneous Saccharification and Fermentation for the Production of Lignocellulosic-Based Xylitol

Simultaneous saccharification and fermentation (SSF) configuration offers efficient use of the reactor. In this configuration, both hydrolysis and fermentation processes are conducted simultaneously in a single bioreactor, and the overall processes may be accelerated. However, problems may arise if both processes have different optimum conditions, and therefore process optimization is required. This paper presents a mathematical model over SSF strategy implementation for producing xylitol from the hemicellulose component of lignocellulosic materials. The model comprises the hydrolysis of hemicellulose and the fermentation of hydrolysate into xylitol. The model was simulated for various process temperatures, prior hydrolysis time, and inoculum concentration. Simulation of the developed kinetics model shows that the optimum SSF temperature is 36 °C, whereas conducting prior hydrolysis at its optimum hydrolysis temperature will further shorten the processing time and increase the xylitol productivity. On the other hand, increasing the inoculum size will shorten the processing time further. For an initial xylan concentration of 100 g/L, the best condition is obtained by performing 21-hour prior hydrolysis at 60 °C, followed by SSF at 36 °C by adding 2.0 g/L inoculum, giving 46.27 g/L xylitol within 77 hours of total processing time. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Production of Omega-3 Fatty Acids by Enzymatic Hydrolysis from Lemuru Fish By-Products

Production of omega-3 fatty acids from lemuru fish by-products was studied by enzymatic hydrolysis using a lipase enzyme in one liter of the batch reactor. The hydrolysis temperature of fish oil was set at 45 to 55 ℃ for 0 to 24 h, whereas agitation from 50 to 150 rpm. RSM-Box Bhenken was used to study the effect of these parameters on omega-3 (EPA, docosahexaenoic acid (DHA), and α-linolenic acid (ALA)) content. The % free fatty acid (FFA), acid index, peroxide index, iodine index, and saponification index of lemuru fish oil was 0.925, 2.52, 42.5, 97.28, and 160.11%, respectively. GC-MS analysis results showed that unsaturated fatty acids content (62.34%), which are consisted of omega-3 (EPA, DHA, and ALA), omega-6 and omega-9, was much higher than saturated acids (12.97%). The experiment data showed that the highest EPA (1.221%) and DHA (0.312%) content were reached at 50 ℃ and 24 h with 150 rpm of agitation. However, through the RSM-Box Bhenken analysis and 3D surface plot, it was suggested that the optimum condition was obtained at 45 ℃ and 24 h with 150 rpm of agitation with the content of EPA, DHA, and ALA were 1.709, 0.49, and 1.237%, respectively.

Hydrolysate from Mussel Mytilus galloprovincialis Meat: Enzymatic Hydrolysis, Optimization and Bioactive Properties

Mussel production generates losses and waste since their commercialisation must be aligned with target market criteria. Since mussels are rich in proteins, their meat can be explored as a source of bioactive hydrolysates. Thus, the main objective of this study was to establish the optimal production conditions through two Box–Behnken designs to produce, by enzymatic hydrolysis (using subtilisin and corolase), hydrolysates rich in proteins and with bioactive properties. The factorial design allowed for the evaluation of the effects of three factors (hydrolysis temperature, enzyme ratio, and hydrolysis time) on protein/peptides release as well as antioxidant and anti-hypertensive properties of the hydrolysates. The hydrolysates produced using the optimised conditions using the subtilisin protease showed 45.0 ± 0.38% of protein, antioxidant activity via ORAC method of 485.63 ± 60.65 µmol TE/g of hydrolysate, and an IC50 for the inhibition of ACE of 1.0 ± 0.56 mg of protein/mL. The hydrolysates produced using corolase showed 46.35 ± 1.12% of protein, antioxidant activity of 389.48 ± 0.21 µmol TE/g of hydrolysate, and an IC50 for the inhibition of ACE of 3.7 ± 0.33 mg of protein/mL. Mussel meat losses and waste can be used as a source of hydrolysates rich in peptides with relevant bioactive properties, and showing potential for use as ingredients in different industries, such as food and cosmetics, contributing to a circular economy and reducing world waste.

Optimization of Enzymatic Extraction of ACE Inhibitory Peptide from Rohu (Labeo rohita) Fish Waste using RSM

Background: Hypertension is one of the cardiovascular disease that kills people silently across the globe. It can be controlled, in one of the way, by ACE inhibitory peptide extracted from aquatic resources. Methods: Rohu (Labeo rohita) fish wastes were quantified for their anatomical yield; analyzed for their proximate composition and optimized the enzymatic extraction parameters for ACE inhibitory peptides. Response surface methodology with Box-Benhken Design (RSM-BBD) was used to optimize alcalase concentration (0.5-2% v/w), hydrolysis temperature (45-60°C), hydrolysis time (60-240 min.) and solid: liquid (S/L) ratio (0.2-1) to obtain rohu fish waste peptides. Results: More waste generated in smaller (49.4%) than medium and bigger (34.5%) fish. Quantum of edible flesh (59.06%) was followed by head (23.9%), trimmings (5.18%), scales (4.19%) and swim bladder (0.65%). However, protein content was highest in swim bladder (34.1%) followed by scales (22.9%), trimmings (18.7%) and head (17.1%). Alcalase concentration (1.08%, v/w), temperature (52.10°C), hydrolysis time (129.18 min) and S/L ratio (0.8:1) were found optimum for extraction ACE inhibitory peptide with DH, ACE inhibition and PY of 19.27%, 54.98% and 51.37% respectively. Results showed the potential of extracted ACE inhibitory peptide as ingredients in functional food.

Sustainable Hydrogen Production from Starch Aqueous Suspensions over a Cd0.7Zn0.3S-Based Photocatalyst

We explored the photoreforming of rice and corn starch with simultaneous hydrogen production over a Cd0.7Zn0.3S-based photocatalyst under visible light irradiation. The photocatalyst was characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The influence of starch pretreatment conditions, such as hydrolysis temperature and alkaline concentration, on the reaction rate was studied. The maximum rate of H2 evolution was 730 μmol·h−1·g−1, with AQE = 1.8% at 450 nm, in the solution obtained after starch hydrolysis in 5 M NaOH at 70 °C. The composition of the aqueous phase of the suspension before and after the photocatalytic reaction was studied via high-performance liquid chromatography, and such products as glucose and sodium gluconate, acetate, formate, glycolate, and lactate were found after the photocatalytic reaction.