Weight Loss Of Samples Research Articles

Shelf-life extension of grape (Pinot noir) by xanthan gum enriched with ascorbic and citric acid during cold temperature storage.

The detrimental health implications of chemical preservatives in fruits have necessitated exploitation of safe and natural alternatives such as edible gums. This work studied shelf-life extension in grape (Pinot noir) under cold storage by xanthan gum (XAN) coatings enriched with ascorbic acid (XANAS) and citric acid (XANCI). Standard scientific methods were used to examine some sensory (color, texture-resilience and hardness), enzyme, anthocyanine and antioxidant activities. Also, the reaction rate mechanism was examined through modeling of selected shelf-life indicators; color change, weight loss, and antioxidants. The results revealed that, Xanthan gum and its acid modified coatings significantly (p < 0.05) suppressed polyphenol oxidase, ascorbic acid oxidase, polymethyl etherase acitivies and maintained the structural integrity of the grape during the 21days storage period. Weight loss (%) in the grape samples was 13.66 < 13.98 < 14.16 < 15.64 in the order XANAS < XANCI < XAN < CONTROL whilst ferric reducing antioxidant power (FRAP) activity was 150.23 > 143.18 > 136.49 > 104.5mg/100g AEAC corresponding to XAN > XANAS > XANCI > CONTROL. Significantly (p < 0.05) higher phytochemical contents were observed in the gum coatings compared to the control. Through statistical parameters such as the coefficient of determination (R 2), root mean square error (RMSE) and reduced Chi square (χ2), the second-order polynomial model predicted precisely the decomposition of color, weight loss and FRAP of grape. Color deterioration was attributed to changes in b* parameter as a result of phenolics and phytochemical decompositions resulting from enzymatic activities. Conclusively, acid modified xanthan gum coatings could preserve phytochemicals, color, antioxidant and textural properties of grape in cold temperature storage.

Effects on the Physiochemical Properties of Stored Pomegranate Seeds by the Application of Aloe Vera Gel as Coating Agent

Pomegranate has drawn the attention of dieticians and medicinal chemists due to its bioactive components. Natural coatings increase the shelf life of such agriculture products and reduce the risks associated with the use of chemical preservatives. Hence, we examined the effects of aloe vera coating on the pomegranate fruit. Aloe vera gel coating was utilized in three proportions of 25%, 33%, and 50%, and its effects on the pomegranate seeds were compared with a control sample. Experiments including moisture reduction, weight loss, sugar content, sensory properties, antioxidant capacity, and microbial analysis were performed over a period of 4 weeks. Results revealed that the percentage of moisture reduction in 50% aloe vera coated sample was lower than in other groups, and the mildew and yeast in these samples were less than in the other groups. However, the 50% aloe vera gel showed the highest level of contamination, over time. Furthermore, the 50% aloe vera gel showed higher sugar content, and over time the amount of sugar reduction in the 50% aloe vera was lower. Additionally, the percentage of weight loss in samples coated with aloe vera was lower than the control group, and in the 50% aloe vera group it was less than in the other groups.

Comparison between reactive MgO- and Na2SO4-activated low-calcium fly ash-solidified soils dredged from East Lake, China

A novel approach to mitigate the environmental concerns associated with cement industry is to replace Portland cement with low carbon alternative materials such as fly ash-based geopolymer cement. Hence, reactive MgO-activated low-calcium Class F fly ash was employed in comparison to Na2SO4-activated fly ash to stabilize a lacustrine soil reused potentially in soft coastal reclamation projects and as reinforced aggregates for anti-corrosion in marine engineering. The microstructural and strength properties were investigated with series of tests including X-ray diffraction (XRD), thermogravimetry/differential thermogravimetry (TG/DTG), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and unconfined compressive strength (UCS). The results demonstrate that the main hydration products in reactive MgO- and Na2SO4-fly ash-solidified soils are, respectively, magnesium silicate hydrate (M-S-H) gel and sodium aluminosilicate hydrate (N-A-S-H) gel. This finding is reconfirmed by the weight loss of solidified samples at 40–200 °C, which is correspondingly attributed to the dehydration of magnesium silicate hydrate (M-S-H) gel and sodium aluminosilicate hydrate (N-A-S-H) gel. The morphology and bonding ability of hydration products affects the microstructure and long-term strength of solidified soils. The microstructural change identified from SEM images coincides well with the quantitative evolution of pore structure. The pores with radius of 0.01–1 µm, i.e., micropore and mesopore, are supposed to be the dominant pores in reactive MgO- and Na2SO4-activated fly ash-solidified soils. The comparison of UCS indicates reactive MgO-activated low-Ca fly ash behaves much superior to Na2SO4-activated fly ash in enhancing the long-term compressive strength of soils. This study provides insight into the promising potential of low-Ca fly ash activated by immerging material – reactive MgO to replace cement in soil improvement.

Biodegradation study of PDLA/cellulose microfibres biocomposites by Pseudomonas aeruginosa

ABSTRACT Aerobic biodegradation of biocomposites has been studied in both solid and liquid media. The research was concentrated on the biodegradation under aerobic and mesophilic conditions using poly-d-lactic acid (PDLA) and PDLA/cellulose microfibres (CMFs) samples as the sole carbon source. To determine the efficiency of the biodegradation, quantitative (mass variations, optical density (OD)) and qualitative (FTIR, NMR and SEM) analyses have been used to follow the polymer changes after degradation. The weight loss and OD of the biocomposites samples PDLA/CMFs were slower than that of pristine PDLA. The PDLA displayed the most important loss of weight (7.09%, 8.95%) compared to its initial weight and the lowest weight loss was detected in PDLA/CMF300 (1.04%, 2.19%) in solid and liquid mediums respectively. Also, the OD value of PDLA was increased from the seven days (0.381) to the last day (0.969). It appears that the major rate-determining factor affecting material degradation was its crystallinity without or with minimal assistance from abiotic factor because crystalline phases inhibit the diffusion of small water molecules. Otherwise, the Pseudomonas aeruginosa was isolated from Mediterranean soil has been found to be a novel candidate to biodegrade PDLA under mesophilic conditions.

Investigations on surface morphologies, microstructure and thermal properties of tungsten-based composites

The purpose of this research is to determine the surface morphologies, microstructural and thermal properties of tungsten-based composites that consist of 93 wt.% tungsten (W), 6 wt.% vanadium carbide (VC) and 1 wt.% graphite (C) powders. W-6 wt.% VC-1 wt.% C powders were mechanically alloyed (MA’d) for 6 hrs using a [Formula: see text] with a rate rpm using tungsten carbide vial and balls and sintered at [Formula: see text] for under [Formula: see text], [Formula: see text] gas flow conditions. The phase composition and microstructural characterization of the tungsten composites were carried out using X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM) and Raman Spectroscopy. SEM images showed the distribution of the tungsten (W), vanadium carbide (VC) and graphite (C) powders and porosity in the tungsten matrix. The Raman spectra exhibited two major peaks, which are recorded at 1331 (vs) [Formula: see text] and 1583 (vs) [Formula: see text] in the Raman spectra. These bands represented carbon phases such as disordered graphite (D) and graphite (G). Thermogravimetric analysis (TGA) measurements were performed to obtain the weight loss and thermal stability of samples in the temperature range [Formula: see text]–[Formula: see text] under argon gas atmosphere. The TG curve revealed a total loss of 3.3% of weight at this temperature range. It is considered that the cause of mass loss is due to the oxidation and gas desorption of materials.

Corrosion Effect of 65% Nitrate Acid on X4CrNi1812 at 333 K

Abstract Austenitic stainless steels are often used for a materials in the construction of machines and equipment for agricultural and for industrial construction. One of the most important factors constructional material is corrosion resistance. Equipment with austenitic stainless steel can be easy join by quickly welding at a not to high construction price, but one with the serious problem in aggressive environment is their corrosion resistance. A few corrosion processes in crevices and awkward corners can be avoided at the design stage (low roughness parameters, round-section and other). But still the construction material is exposed to corrosion. These steels often come into contact with an aggressive environment based on nitric acid. The main aim of this research is to investigate corrosion resistance in different time (48, 96, 144, 192, 240, 288, 336 hours). For this used weight loss of test samples and its profile roughness. The research was conducted on austenitic stainless steel in grade in Nitrate acid at 333 K. Corrosion tests confirmed that the research this steel in 65% nitrate acid as a corrosive environments is characterized through proportionate to time corrosion process whose measure may be surface roughness. In industrial practice roughness parameters for all the research times can be used for determine the stage and size of steel corrosion.

Comparative Study on the Behavior of Virgin and Recycled Polyolefins–Cellulose Composites in Natural Environmental Conditions

Polypropylene–cellulose composites have great potential in many important commercial applications, and it is important to understand and properly evaluate their biodegradative behavior to achieve improved composite formulations in accordance with their future applications. In the present study, an outdoor soil burial test was performed in order to evaluate the susceptibility to degradation of polyolefins–cellulose composites. The structural and morphological changes were analyzed by Fourier transform infra-red spectroscopy with attenuated total reflectance (FTIR-ATR) and scanning electron microscopy (SEM). The weight loss of composite samples after burying in soil was recorded. The presence of new bands, as an indicator of degradation, was confirmed by FTIR-ATR spectra. The thermal stability of the composites after soil burial analyzed by TGA was slightly improved, with relatively higher temperatures being required to decompose the samples after exposure to environmental factors. SEM micrographs presented some modifications of the polymer surface, such as holes, cracks, exfoliations, and fractures. Increasing the cellulose percentage of the composite samples led to increased weight loss. From the obtained results, it can be concluded that composites based on polyolefins and renewable resources undergo a slow process of biodegradation after contact with environmental microorganisms and, with appropriate composition, could be applied to various environmental fields.

SOME PROPERTIES OF BIOMEDICAL Ti6Al4V ALLOY IN DIFFERENT SOLUTIONS

The aim of the present investigation is to study the effect of different simulated solutions onwear behavior, chemical properties and ion release of Ti-6Al-4V alloy which used in humanbody. For this purpose three solutions have been used (Hank's solution, 0.9NaCl andartificial saliva). The corrosion properties of Ti-6Al-4V implant alloy were examined at37ºC by using electrochemical techniques, such as the potentiodynamic method and opencircuit potential (OCP). The electrochemical corrosion characteristics of Ti-6Al-4V implantalloys in three biological solutions were measured in terms of the corrosion potential (Ecorr)and the corrosion current density (icorr ).Wear behavior was investigated by using pin-ondisctribometers at human temperature under different loads (10,15,20)N. The wear testconsisted of measuring the weight loss of samples. The metal ion release of base andalloying element by immersed specimens into various solutions for 7 days (168 hours) at37ºC. The result found that the Ti6Al4V implant alloy in three biological solutions exhibiteda characteristic of a good behavior. The superior corrosion resistance these alloy whichcurrent density measured in (nA/cm2). The weight loss of samples by wear test increase withincrease load and time. After applied heat treatment, about 40% enhancement in the wearbehavior of alloy. The quantity of Al element metal release of implant alloy with variationfluids which increase with decrease the value of pH and little amount of vanadium elementin hank's solution.

Solid-phase photodegradation of polystyrene by nano TiO2 under ultraviolet radiation

Solid phase photodegradation of polystyrene (PS) and Polystyrene – titanium dioxide nano composite (PS-TiO2) was studied under ultraviolet radiation of wavelength of 253 nm. Titanium dioxide (TiO2) photocatalyst was synthesized via sol-gel method and characterized using SEM, EDX and XRD. Photodegradation of PS and PS-TiO2 was monitered using GPC, FTIR spectroscopy, UV-DRS, SEM and weight loss measurements. An appreciable decrease in the values of average molecular weights were observed from the GPC data with the increase in the UV exposure time for PS as well as PS-TiO2 composites. FTIR and UV–vis spectra revealed that the photodegradation of PS and PS-TiO2 composite was accelerated by the increase in UV irradiation time and also with the increase in the percentage of TiO2. It was also evident from the FTIR spectra that photooxidative degradation was the possible mechanism of degradation. Band gap energies of PS and PS-TiO2 determined using Tauc plot decreased upon increase in UV irradiation. The change in surface morphology of the irradiated samples compared to the pristine ones were clearly observed in their SEM images. Weight loss of the polymer samples increased upon increase in UV irradiation time. Mechanical properties (tensile and flexural) of raw as well as irradiated samples of PS and PS-TiO2 composites showed an appreciable decrease in their values with increase in irradiation time. The values of dielectric constant of the UV irradiated polymer specimens showed higher values compared to that of non irradiated specimens at varying frequencies. Dielectric strength of the polymer specimens decreased with the increase in UV irradiation time.

Termiticidal Activities of The Bark Crude Extract of Derris Elliptica Benth Against Coptotermes sp

Tuba (Derris elliptica) is one of the insecticide-producing plant which can reduce the pest population due to its active compound, rotenone (C23H2206). The rotenone is deposit in all parts of tuba plant, as such as roots, stems, and leaves. The aim of this research aims was to evaluate the effectiveness of tuba bark extract against subterranean termite Coptotermes sp. The powder of tuba bark extract with 40-60 mesh size macerated with the ethanol by solvent obtains the extract. The extract was made into varions concentration namely 0,5%, 1%, and 1,5%, and applied to the paper disc. There are two types of termite test in this study, namely toxicity test and respiratory test. The mortality of termite and the weight loss of the paper disc were used as indicators of extract activity. The result showed that the concentration of 1,5% indicated the highest mortality from both of two types of test. This study was similar for the lowest weight loss of sample which was also given by concentration 1,5%.

Environmental usefulness of PLA/PEG blends for controlled‐release systems of soil‐applied herbicides

ABSTRACTBlends consisting of biodegradable polylactide (PLA) and poly(ethylene glycol) (PEG) were investigated for their usefulness as an environmentally friendly herbicide formulation with prolonged activity. The aim of this study was to evaluate the release rate of selected soil‐applied herbicides from the PLA/PEG blend containing PEG of various molecular weights and to assess the phytotoxicity of the PEGs according to OECD 208 guidelines. The release rate of immobilized herbicides was correlated with degradation of the blends used. The progress of PLA/PEG blend degradation in water, soil, and activated sludge was estimated by sample weight loss, changes in blend composition, and microscopic observations of the blend surfaces during the experiment. The proposed formulation of the immobilized herbicide in a blend consisting of slowly biodegradable PLA and water‐soluble PEG provides the possibility to release the herbicides for a relatively long time, for approximately six months, which is a demand of weed management. The effect of PEGs on plant growth and development was dependent on both their concentration and molecular weight. With a higher concentration in soil and a higher molecular weight of PEG, a more harmful effect on plants was noticed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47856.

The Resistance of Blast Furnace Slag- and Ferrochrome Slag-Based Geopolymer Concrete Against Acid Attack

In this study, blast furnace slag- (BFS) and Elazig ferrochrome slag (EFS)-based geopolymer concretes were produced. Samples were immersed in 5% phosphoric acid (H3PO4), hydrochloric acid (HCl), hydrofluoric acid (HF) and sulfuric acid (H2SO4) solutions for 12 weeks. The compressive strengths, ultrasonic pulse velocities, weight and length changes of the samples were determined in this process. At the same time, visual inspections of the samples were investigated. Scanning electron microscopy (SEM) analysis was performed for the microstructure analysis of the samples removed from the solutions. 5% H2SO4 solution had the most negative effect on the samples. As the EFS ratio in the geopolymer concrete mixture increased, the loss rate in the strength of the samples exposed to acid solutions decreased. H3PO4 solution caused less weight loss in samples than other acid solutions. It was seen that the samples immersed in H3PO4 and HCl solutions shrank and that the samples immersed in HF and H2SO4 solutions expanded. Softening, cracking and corruption occurred on the surfaces of the samples exposed to the acid solutions for 12 weeks. With increasing EFS ratio in the mixture, the deterioration of the samples’ surfaces exposed to acid solutions decreased. Ettringite formations were seen in the SEM images of geopolymer concretes immersed in 5% H2SO4 solution.

Effects of rain and heat-cool cycles on the weathering behavior of basalt from Wudalianchi, Heilongjiang Province, NE China

This paper evaluates the weathering behavior and weathering degree of basalt from the Wudalianchi UNESCO Global Geopark in the north-east of China. The geopark possesses the most typical and perfect geoheritage examples of a modern volcanic eruption activities in China. Laboratory experiments were conducted on basalt samples to simulate basalt’s weathering process under different environmental conditions. The basalt samples were subjected to either 10 rain cycles or 375 heat-cool cycles. After different numbers of cycles, the weight loss, ultrasonic velocity, and 3D surface morphology were quantitatively evaluated. All the treatments led to sample weight loss. However, the different factors (i.e., water and temperature) result in different degrees and patterns of basalt weathering. In the rain cycles, the sample surfaces became smoother, but new pores were detected. The coupled effects of the mechanical erosion by rain and the tensile stress generated by water invasion and air escape are considered the primary mechanism of grain detachment from the sample surface. In the heat-cool cycles, the sample surfaces became rougher, and the sample’s mechanical properties display a decreasing trend with an increase in heat-cool cycles. Thermally-induced stress led to grain detachment in the sample surface and internal particle dislocation, which initiates internal cracks. The experimental results have direct significance for the protection of basalt in the Wudalianchi UNESCO Global Geopark.

Thermogravimetric and kinetic studies of metal (Ru/Fe) impregnated banana pseudo-stem (Musa acuminate)

Pyrolysis/gasification have proved to be promising conversion techniques to convert biomass into fuels. The current research work focuses on impregnation of Ru and Fe into banana pseudo-stem to study kinetics, pyrolytic behaviour and their impact during pyrolysis through thermogravimetric analyser (TGA). Samples weight loss were analyzed by TGA at four different heating rates (5–20 °C min−1) over the temperature range of 30–900 °C. Isoconversional models such as Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sinose (KAS), and Kissinger’s methods were employed to calculate the activation energy and pre-exponential factor for Ru-impregnated (FWO: Eα = 73.32 kJ mol−1, KAS: Eα = 68.23 kJ mol−1 and Kissinger’s: Eα = 165.94 kJ mol−1) Fe-impregnated biomass (FWO: Eα = 86.78 kJ mol−1, KAS: Eα = 82.34 kJ mol−1 and Kissinger’s: Eα = 192.37 kJ mol−1) and compared with raw biomass (FWO: Eα = 116.22 kJ mol−1, KAS: Eα = 113.39 kJ mol−1 and Kissinger’s: Eα = 194.86 kJ mol−1). Lower activation energy and reduced weight loss were observed for metal impregnated biomass over the raw biomass.

A new technique to prepare a hydrophobic and thermal insulating polyester woven fabric using electro-spraying of nano-porous silica powder

This paper studies the potential electro-spraying of a polyester woven fabric by silica aerogel particles using a fluorocarbon finishing method. For the first time, the samples of different mixtures of silica aerogel and fluorocarbon were prepared and successfully coated on the polyester fabrics using an electro-spraying process. The prepared fabrics were characterized by FTIR, SEM, and EDS and compared with the un-treated sample in term of some physical properties including heat transfer, 3 M water repellency, water contact angle, air permeability and abrasion fastness. According to the results, a decreasing trend in the heat transfer was observed from 71.65 (0.5)% for the un-sprayed fabric to 38.35 (1.06) and 30.99 (0.4)% for the electro-sprayed fabrics for 16 and 24 h, respectively. As for the air permeability, a similar trend was observed in which the sample containing a higher amount of aerogel has less air permeability. Also, the results indicated that the presence of aerogel particles improves the hydrophobic properties of the electro-sprayed samples. Thus, the sample electro-sprayed with the aerogel/fluorocarbon mixture for 24 h, showed the most hydrophobicity with the contact angle of 152.2 (0.8)°. Also, the weight losses of the sprayed samples after the abrasion test were insignificantly less than 5% leading to a low dust-releasing behavior of the aerogel particles from the fibers surface.

An environmentally friendly soil improvement technology for sand and dust storms control

Background: Dust storms occur when unchecked, strong, or turbulent winds combine with exposed loose and dried soil surfaces. Sand and dust storms have a significant impact on society, economy, and environment at local, regional, and global levels. The environmental and health hazards of such storms cannot be permanently reduced, however, by taking appropriate measures, its impact can be reduced. The present study aimed to investigate the effects of microbial precipitation of calcium carbonate (CaCO3) as a biocompatible agent on soil stabilization and control of dust storms using ureaseproducing bacteria (UPB) as a biological improvement technique, which were isolated, identified, sprayed on the soil surface. Methods: For this purpose, the erosion of bio-cemented soil samples was investigated experimentally in a wind tunnel under the condition of wind velocity of 0 to 98 km.h-1 in two soil types with sandy and silty texture in a completely randomized design with three replicates. Results: The investigation of the threshold wind velocity of soil particles showed that soil particles began to move at velocity of 8 and 10 km.h-1 in silty and sandy soils, respectively, but in all biological samples (MICP), particles did not move until the wind speed reached 97 km.h-1. It was also revealed that the weight loss of all MICP-treated samples at different wind velocities was significantly reduced compared to the control group. Differences in the amount of soil loss among bio-cemented samples and control treatments were even superior at higher velocities, so that at velocities more than 57 km.h-1, soil losses increased significantly in the control group, while in soils treated with bacteria, soil loss was very low (about 2.5 kg.m-2.h-1). Comparison of the bacteria used in this study also showed that Bacillus infantis and Paenibacillus sp3 had high efficiency in controlling dust storms. Conclusion: The formation of abrasion-resistant surface layers on soil samples treated by biocementation showed that cementation by biological methods could be an effective way to stabilize surface particles and control sand and dust storms.

Efficacy of Combinations of Methoprene and Deltamethrin as Long-Term Commodity Protectants.

Wheat, corn, and brown rice were treated with different combinations of a deltamethrin suspension concentrate (SC) formulation and a new emulsifiable concentrate (EC) formulation, at rates of either 0.5 or 1.0 ppm alone or in combination with 1.25 and 2.5 ppm methoprene (10 treatments in all, including an untreated control). Treated commodities were stored at ambient conditions on the floor of an empty grain bin in Manhattan, KS, USA, in 5-kg lots for individual replicates. The commodities were sampled and bio-assayed every three months for 15 months by exposing 10 mixed-sex parental adults of selected adult stored product insects on 70–80 g of the commodity. For all treatments, there was no regression of declining efficacy with respect to the month. Therefore, the data were combined for analysis. On wheat and brown rice, there was no reproduction of Rhyzopertha dominica (Fabricius) in any of the treatments, and there was no weight loss in either commodity that was caused by feeding of the parental adults or developing progeny. There was reproduction of Sitophilus oryzae (L.) on wheat but, for several combinations, the EC formulation gave better suppression of progeny compared to the standard SC. However, on brown rice, only the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene was different than other treatments with respect to progeny development, sample weight loss caused by feeding, and weight of the feeding damage itself. Progeny production was correlated with grain damage. No progeny of Tribolium castaneum (Herbst) developed on the treated corn, but there was some variation in insect damage, with less damage in those treatments involving the EC formulation. Progeny production of Sitophilus zeamais (Motschulsky) was at the lowest in the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene. The resulting insect damage was the lowest in this combination as well. Results of this study were used by the registrant (Central Life Sciences) in the United States (US) to modify the commercial formulation to replace the deltamethrin SC with the EC, at label rates of either 0.5 ppm EC + 1.25 ppm methoprene, or 1.0 ppm EC + 2.5 ppm methoprene, on wheat, corn, and rice.

PERBANDINGAN TINGKAT KEAWETAN KAYU SENGON (Falcataria moluccana L. Nielsen) DAN KAYU SUGI (Cryptomeria japonica D. Don) DENGAN EKSTRAK LIMBAH KULIT KAYU JATI (Tectona grandis L.F.) TERHADAP SERANGAN RAYAP TANAH Coptotermes curvignathus Holmgren

The aim of the study was to obtain a comparison of the durability of sengon (Falcataria moluccana) and sugi wood (Cryptomeria japonica) after preservation with Jati (Tectona grandis) tree bark waste to subterranean termites Coptotermes curvignathus Holmgren attack and to determine the best concentration of wood preservation from Jati extract. Evaluation the durability of wood used the JIS K 1571 2004 standar method. Test parameters in the study were preservative retention, termite mortality and weight loss of the wood test sample. The results showed the highest retention was achieved in Sengon wood of 0.466 kg /m3 and the followed by Sugi wood which was 0.740 kg /m3. The lowest termites mortality value was in non-teated wood of Sengon wood with value 13.091%, and in other sengon wood which treated by extract of Jati bark with concentration of 2%, 4%, 5%, the termites mortality was 100%. Meanwhile in Sugi wood the termites mortality in non-treated wood was 12.576% and other Sugi wood which treated by extract of Jati bark with concentration of 1%, 2%, 3%, 4%, 5% the mortality value reached 100%. The average percentage values of the highest weight loss was 15.483% in non-treated sugi wood, while the lowest weight loss was in sengon wood which was given 5% extract of teak bark with a concentration of only 2.099%. The optimal concentration of Jati tree bark for wood preservation to Sengon wood was on concentration 25, meanwhile in Sugi wood was on concentration 1%.Keywords: Cryptomeria japonica, ekstrak kulit kayu, Falcataria moluccana, preservation, Tectona grandis

ФОРМИРОВАНИЕ ФУНКЦИОНАЛЬНО-ТЕХНОЛОГИЧЕСКИХ СВОЙСТВ МЯСНОГО ФАРША ПОД ВОЗДЕЙСТВИЕМ КОМПЛЕКСА ФЕРМЕНТОВ

The aim of the work was to study the effect of the transglutaminase enzyme (TG) and bacterial concentrates on the formation of functional and technological properties of the first-grade minced beef. The analysis of water binding capacity (WBC) of experimental samples revealed that the combination of microorganisms and transglutaminase enzymes has a synergistic effect on the technological properties of minced meat. The maximum values of WBC in samples containing the TG enzyme were established within 6–12 hours period of aging (59.56–58.49 %), and in samples containing a set of bacterial cultures and the TG enzyme – within 12–18 hours period (61.58–57.04 %). The increase in the water-binding capacity of minced meat correlated with a decrease in weight losses when heated. A significant reduction in weight loss in samples containing the TG enzyme (individually or in combination with bacterial cultures enzymes) was found. The lowest weight loss when heated was observed in the samples of minced O-TG in the period of 6–12 hours (19.03–19.99 %) and in the samples of O-Pro+TG within the12–18 h period (20.27–21.71 %). In the result of rheological studies, the most pronounced elastic properties in the samples of O-TG and O-Pro+TG were established, with an increase in elastic deformation within 24 hours of aging period up to 3.26–3.32 mm values. The maximum strengthening of the meat structure under the influence of a set of microorganisms and TG enzymes occurred after 12 hours of aging, the level of total deformation reduced to 14.00 mm; the level of plastic deformation reduced to 10.96 mm. An increase in water binding capacity, reduction of product weight loss when heated, improvement of both plastic and elastic properties of minced meat were observed with the use of a set of microorganisms and TG enzymes involved in the binding of biopolymers of food systems.

Investigation of the Effect of Oscillating Magnetic Field on Fresh-Cut Pineapple and Agar Gel as a Model Food During Supercooling Preservation

Abstract. In this study, the effect of an oscillating magnetic field (OMF) on the supercooling of fresh-cut pineapple and agar gel was investigated. The pineapple was preserved in a supercooled state at -7°C, and its supercooled state was maintained for 14 days with the presence of the OMF, whereas the untreated sample was spontaneously nucleated within 24 h. Agar gel was prepared as equivalent to the soluble solids content of pineapple and showed a comparable supercooling behavior when exposed to a similar OMF treatment. Examination of the microstructures showed that cellular damage due to ice crystal formation did not occur in the supercooled pineapple and agar gel, implying that the OMF successfully inhibited ice nucleation during supercooling. The weight losses of pineapple samples preserved with refrigeration, freezing, and supercooling for 14 days were determined to be 7.3%, 23.8%, and 0.8%, respectively. Furthermore, the visual appearance showed that supercooling effectively prolonged the shelf-life of pineapple without freezing damage. The results suggest that the developed OMF technology can inhibit ice nucleation during supercooling and can be used to preserve fresh-cut fruits at subzero temperature while ensuring the food quality. In addition, a solid model food could be used as a substitute for predicting the supercooling behavior of food products. Keywords: Food preservation, Fresh-cut fruit, Oscillating magnetic field, Pineapple, Supercooling.