Steam Heat Treatment Research Articles

Thermal modification of Lantana camara stalks and its characterization

Abstract This paper deals with value addition and utilization of Lantana camara, an invasive species with unprecedented rate of growth, by thermal modification. Lantana camara stalks were thermally modified using vacuum heat treatment (VHT), oil heat treatment (OHT), and steam heat treatment (SHT) at 180 °C and 200 °C and subsequently changes in physical, chemical and mechanical properties were studied. Weight loss was observed in vacuum and steam heat treated samples due to thermal degradation while oil heat treated samples showed weight gain due to oil uptake. SHT exhibited the highest (19 %) weight loss at 200 °C. The color of the modified lantana attained uniform dark colour, OHT exhibited the most intense effect on colour changes. Fourier transform infrared (FTIR) and Fourier transform near infrared (FTNIR) spectroscopic analyses indicated degradation of hemicellulose and change in cellulose crystallinity due to heat treatment. Dimensional stability of thermally modified Lantana stalks improved across treatments, with SHT achieving the highest anti-swelling efficiency of 67.3 % at 200 °C and lowest water absorption (43 %) after 72 h of water soaking. The dynamic modulus of elasticity of thermally modified Lantana remained constant in all the treatment processes. Overall, the results indicate that thermal modification can increase utilization potential of L. camara.

The Optimization of the Steam-Heat-Treated Process of Rattan (Calamus simplicifolius) Based on the Response Surface Analysis and Its Chemical Changes

The objective of this study is to investigate the impacts of steam heat treatment parameters (e.g., temperature, time, and pressure) on the impact toughness of rattan (Calamus simplicifolius). The Box–Behnken design response surface analysis was employed to optimize the steam heat treatment parameters. Impact toughness was selected as the evaluation index, with single-factor tests conducted as a baseline for comparison. Changes in chemical composition, cellulose crystallinity, and pyrolysis properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, Thermogravimetry–Fourier transform infrared (TG-FTIR) spectra, and wet-chemistry methods for both untreated control samples and the heat-treated samples. The results show that a 1 h steam heat treatment at 160 °C under 0.1 MPa pressure has the optimal process parameters for the rattan. The achieved impact toughness value closely matches the predicted value at 71.29 kJ/m2. After the steam heat treatment, hemicellulose and cellulose contents decrease, whereas relative lignin content increases significantly, leading to improved toughness characteristics in Calamus simplicifolius samples. The TG results indicate that maximum weight loss occurs at temperatures of 352 °C, 354 °C, and 361 °C, respectively, for three different samples. This suggests that the thermal stability is enhanced as a result of the heat treatment. These findings will help optimize the heat treatments of the rattan material.

Evaluating the Performance of Early-Age Fly Ash Concrete Subjected to Steam and Autoclave Heat Treatments

Evaluating the Performance of Early-Age Fly Ash Concrete Subjected to Steam and Autoclave Heat Treatments

Effects of Steam Treatment Time and Drying Temperature on Properties of Sweet Basil's Antioxidants, Aroma Compounds, Color, and Tissue Structure.

This study has developed a production method for high-quality Genova tea with excellent antioxidant properties. The antioxidant properties of each part of the Genova basil plant (i.e., leaves, flowers, and stems) were determined; the leaves and flowers showed higher antioxidant values. We also investigated the effects of steaming time and drying temperature on the antioxidant composition and properties, color, and aroma using leaves with good yield potential and high antioxidant properties. The color showed excellent green color retention with freeze- and machine-drying at 40 °C without steam-heat treatment. Steaming for 2 min was effective in maintaining high values of total polyphenol content, antioxidant properties (1,1-diphenyl-2-picrylhydrazine and hydrophilic oxygen radical adsorption capacity), rosmarinic acid, and chicoric acid, and a drying temperature of ≤40 °C was recommended. Freeze-drying without steaming was the best method to retain all three of Genova's main aroma components, Linalool, trans-alpha-bergamotene, and 2-methoxy-3-(2-propenyl)-phenol. The method developed in this study can improve the quality of dried Genova products and be applied in the food industry, cosmetics, and pharmaceutical industries.

Thickness determination of multiphase layer via combined Rietveld and Grazing Incidence X-ray diffraction approach

Plates of Maraging-300 steel with a chemically grown layer on the surface were prepared by heat treatment in superheated steam at different times. The grown coating on the martensitic substrate was characterized in terms of thickness, compositional and structural information by means of optical and scanning electron microscopies and by Grazing Incidence X-ray Diffraction (GIXRD). The results showed the presence of the hematite, magnetite, and austenite crystalline phases in two different sublayers composing the entire reacted layer: an austenite sublayer over the maraging substrate, and an oxide sublayer at the top, right above the austenite layer, composed of interspersed hematite and magnetite. Quantitative Phase Analysis by the Rietveld method under GIXRD was used to obtain the thicknesses of multiphase chemically reacted layers. The methodology and mathematical formalism are described. The comparison with estimated values from optical and scanning electron microscopy have shown a good agreement between the imaging and diffraction techniques, suggesting that the reacted layer increases progressively with the heat treatment time.

A Primary Study on Mechanical Properties of Heat-Treated Wood via in-situ Synthesis of Calcium Carbonate

This study aims to improve the value of fast-growing wood and extend the heat-treated wood utilization using inorganic calcium carbonate (CaCO3) crystals via an in-situ synthesis method. CaCl2 and Na2CO3 solutions with a concentration ratio of 1:1 were successively introduced into the thermally modified poplar wood obtained by steam heat treatment (HT) at 200°C for 1.5 and 3 h, resulting in the in-situ synthesis of CaCO3 crystals inside the heat-treated wood. The filling effect was best at the concentration of 1.2 mol/L. CaCO3 was uniformly distributed in the cell cavities of the heat-treated wood, and some of the crystals were embedded in the fissures of the wood cell walls. The morphology of CaCO3 crystals was mainly spherical and rhombic polyhedral. Three main types of CaCO3 crystals were calcite, vaterite, and aragonite. The HT of poplar wood at 200°C resulted in degrading the chemical components of the wood cell wall. This degradation led to reduced wood mechanical properties, including the surface hardness (HD), modulus of rupture (MOR), and modulus of elasticity (MOE). After CaCO3 was in-situ synthesized in the heat-treated wood, the HD increased by 18.36% and 16.35%, and MOR increased by 14.64% and 8.89%, respectively. Because of the CaCO3 synthesization, the char residue of the 200°C heat-treated wood samples increased by 9.31% and the maximum weight loss rate decreased by 19.80%, indicating that the filling with CaCO3 cannot only improve the mechanical properties of the heat-treated wood but also effectively enhance its thermal stability.

Multi-Scale Evaluation of the Effect of Thermal Modification on Chemical Components, Dimensional Stability, and Anti-Mildew Properties of Moso Bamboo.

By promoting greenhouse gas sequestration, bamboo and bamboo-based products can improve carbon storage, and thus help decrease greenhouses gas emission through replacing traditional products like concrete, steel, and alloy. Thermal modification is a useful way to effectively enhance the dimensional stability and mold-resistance property of bamboo and bamboo-based products compared with chemical treatment. This work investigates the change in anti-mildew properties, micro-structure, and chemical composition of bamboo after heat treatment. Saturated steam heat treatment was applied for this project. SEM results showed that the structural damage of parenchyma cells resulted in the separation of thin-walled cells and vascular bundles. Thus, the original regular structure of bamboo, characterized by plump and intact cells, changed markedly. After thermal modification, bamboo samples exhibited improved dimensional stability and anti-fungal properties due to the decrement of hemicellulose and cellulose. The hardness and MOE of the modified bamboo were 0.75 and 20.6 GPa, respectively.

Combined Heat Treatment Method for Producing of Ultra-High Performance Concrete

Decreasing an overall time of curing for UHPC products is a perspective task that can be solved by combining different heat treatment technologies. The paper presents the results of studying the UHPC microstructure after combined steam and non-steam heat treatment. Concrete specimens after demolding were steam cured for 16 hours, than – in oven camber. Heat treatment in oven chamber for 8 hours under temperature 250 ̊С leads to micro-defects self-healing, due to the new crystalline phase formation. The combined heat treatment allows unleashing of additional potential of UHPC mixes, which could take years in normal conditions The considered curing method with further treatment in oven can not only accelerate the process, but also unleash the additional part of UHPC pozzolanic potential for different mix compositions.

Textural Properties of Chinese Water Chestnut (Eleocharis dulcis) during Steam Heating Treatment.

Chinese water chestnut (CWC) has become one of the most popular foods in China. The textural properties of food contribute considerably to consumer preferences. Fresh fruits and vegetables are normally softened after thermal treatment. However, CWC retains most of its crispness and hardness after steaming. To explore the relationship between thermal processes and sensory changes, a method for measuring the texture of CWC is warranted. This study aimed to examine the textural properties of CWC subjected to varying degrees of thermal treatments using instrumental and sensory methods. Instrumental tests included the shear force test and puncture test, while trained panelists assessed the sensory attributes. Two sensory attributes were selected for evaluation: crispness and hardness. The results indicated that with the extension of thermal treatment time, the crispness and hardness of CWC decreased slightly, while cells and starch grains were damaged. Sensory results showed a significant correlation with shear force index (slope of rising curve) (p < 0.05) and puncture index (slope of rising curve, slope of descending curve and compression work) (p < 0.05). Thereafter, the instrumental tests parameters could be used to establish regression models for predicting crispness and hardness and controlling the quality of CWC products.

A validated qualitative method using oleuropein as a robust biomarker to confirm ground black pepper (Piper nigrum L.) adulteration with olive (Olea europaea L.) by-products

Olive stone and olive pomace were first identified as black pepper adulterants at the end of the 19th century. Nowadays, there is a worldwide boom in olive oil consumption. The olive oil and table olive industry generate tremendous volumes of olive wastes and this is presenting fraudsters with significant opportunities to use olive oil by-products as bulking agents in other foods such as black pepper. Despite the development of analytical methods for black pepper (Piper nigrum L.) authentication, it has been difficult to both detect and identify the specific fraudulent addition of Olea europaea L. waste by-products to this well-known spice. As such, there is a need for the development of a targeted method to address this issue. In this study, a secoiridoid phenolic biomarker of olive oil by-products, oleuropein, was identified as a target for the development of a novel analytical method, coupling ASE®) extraction and LC-MS/MS analysis for the identification of phenolic compounds as biomarkers of black pepper adulteration with olive wastes. The described operating conditions were used for the quantitation of oleuropein in olive oil by-products as well as the qualitative detection and identification of oleuropein in black pepper as a proof of the presence of olive waste addition as a bulking agent. Oleuropein was detected and quantified in all the olive oil by-product samples, even those subjected to processes such as olive-pomace extraction with hexane and sterilisation with steam heat-treatment. The method was validated for the qualitative detection of oleuropein in black pepper with selectivity and specificity values equal to 1 for 1.5% of olive pomace addition. The proposed method is simple and automated, requiring no purification step and can be applied as a rapid routine analysis to arm the industry against this potential fraud.

Change in Micro-Morphology and Micro-Mechanical Properties of Thermally Modified Moso Bamboo.

In recent years, saturated steam heat treatment has been considered as an environmentally friendly and cost-effective modification method compared with traditional heat treatment media. In this study, bamboo was treated by saturated steam, and the change in chemical composition, cellulose crystallinity index, micro-morphology, and micromechanical properties were analyzed by a wet chemistry method, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), nanoindentation, and so on. Results illustrated that the parenchyma cell walls were distorted due to the decomposition of hemicellulose and cellulose in bamboo samples. As expected, the hemicellulose and cellulose content decreased, whereas the lignin content increased significantly. In addition, the cellulose crystallinity index and thus the micromechanical properties of bamboo cell walls increased. For example, the hardness increased from 0.69 GPa to 0.84 GPa owing to the enhanced crystallinity index and lignin content.

Study on the Effect of Two-Step Saturated Steam Heat Treatment Process on the Properties of Reconstituted Bamboo

With the aim of utilizing reconstituted bamboo as a carbon cycle-oriented material, the improvement of physical and mechanical properties has been actively studied to solve using problems. The saturated steam heat treatment process has been widely used in worldwide. With the development and exploration of this technology, two-step saturated steam heat treatment process appears in some practical production, that is, after a period of saturated steam heat treatment at a lower temperature, the bamboo bundles are taken out and seasoned for a period of time, and then put back into the heat tank again, and heated at a higher temperature for another period of time. During the two-step saturated steam heat treatment, the physical and mechanical properties of bamboo changed. However, the mechanism of two-step saturated steam heat treatment has not been thoroughly discussed. For purpose that this paper all discuss and find out the mechanism of two-step saturated steam heat treatment on the change of physical and mechanical properties of reconstituted bamboo. In this work, the one and two-step saturated steam heat treatments were carried out according to the actual production parameters, and the physical and mechanical properties of the reconstituted bamboo board made of treated bamboo bundles were analyzed, including the color change, the thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR) and shear strength. The results indicate that two-step saturated steam heat treatment is better than one-step. Based on the detailed study of the chemical composition, crystallinity and micro-morphological characteristics of the heated bamboo bundles, it is further revealed that during two-step saturated steam heat treatment, oxygen air is added to the reaction system between the two heat treatment processes to further catalyze the oxidation of hemicellulose and enhance the crystallinity of cellulose, so as to improve the properties of the final products. Our work has optimized the saturated steam heat treatment process which is widely used in industry, pointing out a new idea in the experimental and theoretical basis for the development of recombinant bamboo manufacturing industry.

Efficient removal of phosphate from aqueous solution by mesoporous Zr/La hydroxide fibers prepared with high-pressure steam heat treatment

One-dimensional mesoporous Zr/La bimetallic hydroxide fibers (ZLFs) were prepared for the first time, by one-step electrospinning and high-pressure steam heat-treatment method, and they were used for effective removal of phosphate. The as-obtained fibers had a homogeneous composition and a large surface area, and they benefited from the high-pressure steam heat-treatment. Optimum heat-treatment conditions were confirmed, and the special hydrolysis mechanism in fibers and the Zr/La hydroxides formation process were analyzed. ZLFs with maximum surface area of 233.31 m2/g were obtained at a Zr/La mole ratio of 0.4:0.6. Influence of the Zr/La mole ratio of fibers on the adsorption property was examined; an impressive phosphate adsorption performance was observed with saturated adsorption capacity reaching 453.63 mg/g at a Zr/La mole ratio of 0.5:0.5. Notably, the ZLFs exhibited great anti-interference abilities against co-existing ions and pH values, along with good recycling performance. In summary, the ZLFs, produced via an easy method, with outstanding adsorption performance and high reusability, have great potential as adsorbents in the phosphate adsorption field.

Effect of soaking and heating stimulation on the formation of isothiocyanates in Eruca sativa Mill. seeds and sprouts

The present work investigated the effects of soaking followed by heating on the metabolism of glucosinolates (GLs) in rocket seeds and sprouts. Soaking for 1 h increased myrosinases (MYR) activity of seeds. Heating at 70°C for 10 min after soaking resulted in the highest isothiocyanates (ITCs) formation in seeds. Both immerse-heating and steam-heating decreased the total GLs content in seeds and 2-day old sprouts. However, steam-heating showed minor effect on total GLs content when compared with immerse-heating. Both methods showed a decreased MYR activity in seeds and sprouts. Nevertheless, heating had a positive impact on ITCs formation. Under immerse-heating, ITCs formation was the highest in seeds and sprouts at 70°C heating. However, under steam-heating, ITCs formation in seeds and sprouts was higher at 70 and 60°C, respectively. The results indicated that steam-heating treatment was effective for improving ITCs formation in rocket seeds and 2-day old sprouts.

Multi-scale evaluation of the effect of saturated steam on the micromechanical properties of Moso bamboo

Abstract The changes in chemical composition and micro-mechanical properties of Moso Bamboo fiber cells were evaluated by applying saturated steam heat treatment at 160, 170, and 180 °C for periods of 4, 6, and 8 min, and subsequent analysis by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopic, and nanoindentation methods. The hemicellulose and cellulose content decreased as expected, while the relative lignin content showed an upward trend. Significant changes in the bamboo micro-structure were detected by scanning electron microscope under the action of high-temperature and saturated steam. Both temperature and time were shown to affect micromechanical properties of the bamboo cell wall. In addition, higher cell wall elastic modulus and hardness were observed (a rise from 16.1 to 19.2 GPa and from 0.6 to 0.8 GPa, respectively), as compared with those of the untreated sample. Meanwhile, the creep ratio decreased after saturated steam heat treatment.

Modification of the Physicochemical Properties of High-Crystallinity Granular Y Zeolite by Steam Heating and Acid Treatment

Modification of the Physicochemical Properties of High-Crystallinity Granular Y Zeolite by Steam Heating and Acid Treatment

Nutrient Composition of Steam Cooked Pangasius Meat and Their Analysis of Proximate, Fatty Acid and Mineral Composition

The aim of this research has to be removal of saturated and mono-unsaturated fatty acid it was done by steaming method. After deafatted meat were analyse the nutritional compositions. Catfish essential fatty acid is low because of a small amount of n-3 family PUFA and high amount of MUFA and SFA. The SFA and trans C18: 1 MUFA can increase risk of chronic cardiovascular diseases that affects the heart, blood vessels, and brain. Effective processing of heat treatment method can get reduced of the fat content in Pangasius catfish fillet in this meat was contain essential proteins and provide a good protein food for consumers. The present project is therefore proposed to develop a suitable preprocessing method for removal of fat from catfish fillets. normal steam pressure cooking method as used heat treatment such as steam cooked method were used to reduce in the SFA and MUFA content of fish fillets. The present research is proposed to study the proximate composition, fatty acid composition and minerals composition of steam defatted fillets. This chemical composition such as mainly had studied about mineral such as sodium, iron, phosphorus, calcium, magnesium and zinc. Fatty acid composition has been studied about saturated and mono-unsaturated fatty acid it is rendered to produced free fatty acid oxidized odour it can be produced off-flavour of the products it were removed by different heat treatment were conducted by microwave energy treatment and grilled and steam heat treatment it was reduced to saturated and monounsaturated fatty acid and is this was increased about poly-unsaturated fatty acid and provide to nutritional stuff for human begins.

Fabrication of Crack-Free Flattened Bamboo and Its Macro-/MicroMorphological and Mechanical Properties

This work aimed to help the bamboo industry develop methodology for producing imperfection-free bamboo boards that can serve either decorative or structural benefit to consumers seeking to engage with the bioeconomy. Specifi- cally, softened and slotted bamboo tubes were handled by a roller device with nails to render crack-free flattened bamboo board. Softening temperature and time were optimized herein according to findings regarding chemical composition and board mechanical properties. The optimal softening parameters for saturated steam heat treatment is proved to be 160°C for 8 minutes. The flattened bamboo board possesses an increased bending strength of 101.5 MPa and a decreased bending modulus of 7.7 GPa, being compared with only-softened bamboo. The corresponding changing mechanism is determined in-depth by the micro- morphological and mechanical results based on in-situ SEM and AFM technologies. Under the action of nails and rolling processes, the bamboo texture becomes compact with crushed and fragmented conduit walls. The resulting cell cavity then becomes stretched and compressed, taking on a morphology which allows for the mechanical penalties associated with flattening to be avoided. According to the micro-mechanical results obtained by AFM, compared with unflatten bamboo, the Young’s modulus of the cell membrane in transverse direction (YT) decreases to 1.00 GPa while the corresponding Young’s modulus in radial direction (YR) increases to 7.29 GPa.

Effects of bamboo species, steam-heating treatment, and adhesives on mechanical properties and dimensional stability of oriented bamboo scrimber boards

Effects of bamboo species, adhesives, and steam-heating treatment (SHT) were examined relative to mechanical properties and dimensional stability of oriented bamboo scrimber board (OBSB) made from makino bamboo (Phyllostachys makinoi Hayata) and moso bamboo (P. pubescens (Mazel)) strips. Results indicated that OBSB produced using makino bamboo culms bonded with water-soluble phenol formaldehyde resin (PF) had significantly higher ultrasonic wave velocity (Vu (//)), tap tone sound velocity (Vt (//)), dynamic modulus of elasticity (DMOEu (//)), and DMOEt (//) than that produced using moso bamboo bonded with water-soluble urea formaldehyde resin (UF) (p &lt; 0.05). The two types of OBSB showed the same trend of DMOEu &gt; DMOEt &gt; modulus of elasticity (MOE). In addition, OBSB made using steam-heated makino bamboo and PF had the largest modulus of rupture (MOR) (210.5 MPa), exceeding that of OBSB made using laminated bamboo timber and wood-plastic composite (WPC). However, OBSB made using steam-heated moso bamboo and UF exhibited the highest screw holding strength (SHS). Improvement in dimensional stability was observed in OBSB manufactured using steam-heated culms. Finally, OBSB glued with UF had lower water absorption, thickness swelling, and volumetric swelling than that glued with PF.

Effect of Saturated Steam Heat Treatment on Physical and Chemical Properties of Bamboo.

The aim of this study was to investigate the effects of the heat treatment time and initial moisture content of bamboo on the corresponding chemical composition, crystallinity, and mechanical properties after saturated steam heat treatment at 180 °C. The mechanism of saturated steam heat treatment of bamboo was revealed on the micro-level, providing a theoretical basis for the regulation of bamboo properties and the optimization of heat treatment process parameters. XRD patterns of the treated bamboo slices were basically the same. With the increase in the initial moisture content of bamboo, the crystallinity of bamboo increased first and then decreased after treatment. Due to the saturated steam heat treatment, the content of cellulose and lignin in bamboo slices increased while the content of hemicellulose decreased, but the content of cellulose in bamboo with a 40% initial moisture content increased first and then decreased. The shear strength of treated bamboo changed little within 10 min after saturated steam heat treatment, and then decreased rapidly. During the first 20 min with saturated steam heat treatment, the compressive strength, flexural strength, and flexural modulus of elasticity of the treated bamboo increased, and then decreased.