Steam Treatment Research Articles

Delayed Effect of Superheated Steam Treatment on Starch Retrogradation of Rice Cake After Storage by Modifying Starch Chain-Length Distribution in Rice Flour

This study investigated the effects of superheated steam (SS) treatment on the physicochemical properties of rice flour and the subsequent impact on rice cake quality. The SS-180 resulted in higher final viscosity and significantly increased pasting time and the temperature of rice flour (p < 0.05). A significant enhancement in the water holding capacity of rice flour (p < 0.05) was due to the rice starch aggregated in this SS process. SS treatment also led to an increase in the proportion of short chains of amylopectin in rice flour from 30.40% to 37.59%, while a decrease in long chains retarded retrogradation and improved rice cake texture. The hardness of the SS-treated rice cake was lower than that of the untreated one, but the specific volume was increased significantly (p < 0.05). After 7 days of storage, rice cake with SS-180 treatment showed the lowest hardness, namely, the lowest retrograded process. These findings underscore the potential of SS treatment to enhance the physicochemical properties of rice flour and improve rice cake quality.

Steam Treatment Controls Cyclamen Mite (Phytonemus pallidus) Without Compromising Strawberry Plant Survival, Growth and Yield

ABSTRACT Cyclamen mite is a pest of strawberry that is difficult to control due to its small size and preference for inhabiting concealed spaces in new plant growth. Steam treatment of transplants effectively reduces some strawberry pathogens and may be a valuable tool against cyclamen mite. Strawberry transplants (“Jewel” and “Annapolis”) that were artificially infested with cyclamen mite were steam-treated at 44°C for 1 h or at 48°C for 0.5 h. Both treatments reduced cyclamen mite numbers by > 99% compared to the control, and 44°C for 1 h had no negative effects on plant survival, growth or yield. In a second, similar, field experiment, transplants (“Jewel”) were categorized by crown size as small (6–8 mm) and large (10–13 mm) and steam-treated at 44°C for 1 or 4 h. Steam treatments reduced cyclamen mite numbers by 92–93% compared to the control, but in the 4 h treatment, survival of small crowns was 40%. Steam treatment of strawberry transplants at 44°C for 1 h is an effective tool and may reduce reliance on miticides for cyclamen mite control. Additional research is needed to determine the optimal steam treatment protocols for cyclamen mite control and to understand the effect of the steam treatment on strawberry transplants with different crown sizes.

Selective catalytic conversion of model olefin and diolefin compounds of waste plastic pyrolysis oil: Insights for light olefin production and coke minimization

The primary challenges in ex-situ catalytic pyrolysis of plastic waste to produce light olefins lie in the selective conversion of larger olefins and diolefins downstream of the pyrolyzer. Hence, the catalytic cracking mechanism of plastic pyrolysis oil was explored using an α-olefin (1-decene) and a diolefin (1,9-decadiene) model compounds over an HZSM-5 zeolite-based catalyst in a fixed-bed reactor. Key objectives were to elucidate the reaction pathways for light olefin production, aromatization, and coke formation in catalytic cracking of larger olefins and diolefins. The investigation explored the impact of HZSM-5 steam treatment severity, contact time (∼58–226 ms), and reaction temperature (250–450 °C) on product yields. The severity of steam treatment was found to increase the 1-decene isomerization rate while decreasing the cracking rate and conversion of 1-decene to C3-4 light olefins. In the catalytic cracking of 1-decene, major product types included olefins (linear and nonlinear) and a few naphthenes, while in the case of 1,9-decadiene catalytic cracking, non-linear olefins were absent, with abundant naphthenes followed by lighter diolefins and C3-5 linear olefins. Temperature and contact time variations revealed that the catalytic cracking of 1-decene initiated with double bond rearrangement isomerization, progressing to skeletal isomerization, and intensified cracking reactions producing light C3-4 olefins. Conversely, in the catalytic cracking of 1,9-decadiene, cyclization was the primary reaction pathway, followed by β-scission, resulting in lighter conjugated dienes and light linear olefins. Thermal gravimetric analysis (TGA) of spent catalysts confirmed a higher coke amount generated during 1,9-decadiene cracking compared to 1-decene cracking, indicating that diene compounds serve as precursors for significant coke formation in plastic pyrolysis oil. These insights provide valuable understanding for catalytic upgrading of pyrolysis oil from polyolefin pyrolysis.

Dual purpose of superheated steam treatment: Inactivating surface pathogens of pork belly and replacing blanching

Superheated steam (SHS) treatment is increasingly recognised as an emerging thermal sterilisation technology in food processing because of its high energy efficiency, time-saving benefits and minimal quality loss in raw materials. The aim of this study was to examine the efficacy of SHS treatment as a high-temperature pre-treatment approach for eliminating foodborne pathogens on the surface of pork belly and to determine its impact on nutritional quality. The SHS treatment at 180 °C and 25 kg h−1 for 50 s achieved sterilisation rates of 98.15% ± 1.70%, 96.59% ± 1.40% and 91.30% ± 2.14% for Salmonella typhimurium, Listeria monocytogenes and Staphylococcus aureus, respectively, which were three times higher than those achieved by microwave (MIC) sterilisation (700 W, 20 s). Furthermore, SHS-treated pork belly exhibited the highest moisture content and lowest cooking loss, with no significant changes in pressing loss and pH values. Compared with samples treated with MIC and blanching (99 °C ± 1 °C, 2 min), those treated with SHS showed significantly lower TBARS value and protein carbonyl content, with an increasing trend in L∗ values. Meanwhile, SHS treatment not only preserved the tenderness of the pork belly to the greatest extent but also yielded the highest sensory score of 7.81 out of 9. These findings indicate the potential of SHS treatment in producing premium-quality pasteurised pork belly.

The repeatability of reusing peat as horticultural substrate and the role of fertigation for optimal reuse

Direct reuse of horticultural substrates may facilitate the transition from linear to circular greenhouse cultivation. Characteristics of spent growing media from strawberry cultivation were compared to substrates from ornamentals, mushrooms, microgreens, and greenhouse vegetables. Direct reuse of spent peat as a stand-alone material was tested in three trials under commercial conditions. In the first trial strawberry cultivation on reused growing media with included crop residues resulted in similar yield as for virgin blends in a spring cultivation. In the second trial repeated reuse of spent growing media was tested in an autumn cultivation, either with direct reuse or with reuse after shredding and steam treatment for sanitation. Nutrient retention did not increase further during repeated reuse. Yield was similar to virgin peat for the direct reuse and steam sanitation treatments. Under reuse deterioration in terms of physical properties was not observed. Biological stability remained high for all media during reuse. Reusing peat for strawberry 3 times did not lead to any problems for yield or substrate. In the third trial the effects of fertigation regimes with reduced P and K input on nutrient retention during direct reuse in a spring cultivation were limited. In contrast, significantly lower N, P, K, Mg and Ca contents in the substrate were measured when fertigation was replaced by water in the last two weeks of the cultivation. Cation exchange capacity in the spent peat in all trials remained high during reuse. Ca was the dominant cation on the exchange complex.

Impact of thermal processing methods on physicochemical properties and flavor-related compounds of Pearl gentian grouper with waterless preservation

This study investigated the impact of various treatments (boiling, steaming, microwave heating, and baking) on the physicochemical properties and flavor profile of pearl gentian grouper after undergoing waterless preservation. The grouper meat treated with Csteaming (non-preservation steaming treatment) and WLsteaming (waterless preservation steaming treatment) exhibited the highest levels of springiness (P < 0.05). Additionally, Csteaming and WLsteaming significantly reduced the hardness and cooking loss (P < 0.05) and demonstrated the highest umami values. The TBARS value of the baking groups exhibited a significantly lower level compared to that of the other heat treatment groups (P < 0.05). The primary volatile compounds in the heated grouper samples were nitrogen oxide, sulfides, and long-chain alkanes. The volatile flavor compounds of heated grouper samples were determined by headspace solid-phase microextraction gas chromatography-mass spectrometry, and a total of 35 volatile compounds were identified, including 8 aldehydes, 8 alcohols, 1 acid, 5 nitrogen-containing compounds, 6 hydrocarbons, and 7 ketones. The boiling treatments exhibited the highest levels of 5′-IMP and lactic acid. Meanwhile, steaming treatment emerged as a preferred method for maintaining the umami taste. Additionally, the waterless preservation technique effectively enhanced the content of succinic acid in pearl gentian grouper.

Synchrotron Infrared Microspectroscopy of Zeolite Catalysts

This article reviews recent work undertaken at the beamline B22 of the Diamond Light Source using infrared (IR) microspectroscopy to characterise zeolite catalysts and to study their reactivity in real time. The advantage of vibrational microspectroscopic analysis when linked to the brightness and spectral bandwidth of synchrotron IR light are illustrated. The high spatial resolution means that the uniformity of acid site concentrations within individual large crystals of zeolites and between different crystals can be readily checked and changes to acid site concentrations within crystals resulting from steam treatment mapped. When an in situ reaction cell is coupled with mass spectrometric analysis of evolved gases the rapid time response of the method has provided new insight into the initial stages of the conversion of methanol to hydrocarbons over ZSM-5 and SAPO-34 single crystals. Future prospects for applying the method to other types of zeolite catalysed reactions with improved reaction cell design are also discussed.

Facile Creating a Hierarchical and Hydrophobic Fe-Co/LZSM-5 Catalyst for the Oxidative Desulfurization Process

This research involved top-down dealumination and steam treatment methods to design the hierarchical pores of ZSM-5, which is then wet-impregnated with a Fe-Co. This method overcomes the steric barrier that hinders the oxidative desulfurization (ODS) process and makes the catalyst hydrophobic, thereby allowing it to overcome the biphasic hindrance caused by the difference in polarity between the fuel oil and the oxidant. Characterization of the catalyst's properties based on BET and BJH, XRF, and contact angle, as well as testing its performance on DBT model oil in n-hexadecane and Indonesian commercial diesel were conducted. Simulation of the reaction energy profile using density functional theory calculations was also carried out to deepen insight into the mechanism of the reaction. Results of this study show that the catalyst has excellent catalytic reactivity in the long-chain hydrocarbon ODS process, with a TOF number of 183 h−1.

Robust palladium oxide nano-cluster catalysts using atomic ions and strong interactions for high-performance methane oxidation

Optimizing metal catalyst structures to achieve desired states is vital for efficient surface reactions, yet remains challenging due to the lack of well-defined precursor materials and weak metal-support interaction. Palladium-based catalysts, when not properly tailored for complete methane oxidation exhibit insufficient performance. Herein, we fabricate Pd oxide nano-clusters supported on SSZ-13 using atomic ions with strong metal-support interaction (SMSI). Steam treatment of Pd/SSZ-13 transforms Pd particles into ions and induces SMSI. Subsequently, CO reduction and O2 oxidation yield mildly sintered Pd oxide nano-clusters firmly anchored on extra-framework Alpenta sites of SSZ-13, facilitating superior activity. The robustness from SMSI prevents irreversible deactivation, and water-resistance by complete dehydration suppresses reversible degradation in wet conditions. This catalyst exhibits high performance in bench-scale reactions using monolith catalysts, ensuring applicability for industrial methane abatement. The results demonstrate that sequential treatment to Pd/SSZ-13 offers a promising approach for tailoring metal structures to enable high-performance methane oxidation.

Color Change of Pear Wood (Pyrus communis L.) during Water Steam Treatment

Hydrothermal treatment of wood, particularly steaming with saturated water steam, is often used to achieve a more intensive and homogenous wood color or to vary its hue. However, information on pear wood (Pyrus communis L.) steaming is limited in the available literature. This paper investigates the influence of steaming on the color of pear wood. Green, water-saturated samples of pear wood heartwood and sapwood were steamed with saturated water steam for 24 h at 98 °C. The color of the heartwood and sapwood was assessed both visually and with a standard three-stimulus colorimeter using the CIEL*a*b* system, and compared to the natural color of pear-wood. Additionally, FT-IR spectrometry was employed to analyze chemical changes in the wood samples. The results showed that both heartwood and sapwood experienced a decrease in lightening (L*), an increase in redness (a*), and a decrease in yellowness (b*) during steaming. Furthermore, a trend toward the equalization of L*, a*, and b* parameters between heartwood and sapwood over time was observed. FT-IR spectroscopy revealed that the chemical changes during steaming were primarily related to extractives and hemicelluloses, with no significant changes in cellulose and lignin. The obtained results suggest that pear wood color can be equalized to some extent by steaming and that the extent of the color change to darker tones is dependent on steaming time.

A novel method in radish processing: Augmented flavor and health benefits revealed through Caenorhabditis elegans model

This study investigates the preparation of black radish using a cyclic method involving alternating 75 °C baking and 100 °C steam treatment for 10 cycles. Compared to fresh radish, black radish contains higher concentrations of quinolines and amino acids, giving it a rich taste and caramel aroma. Black radish extract contains quinoline and ornithine levels that are 198.92 times and 94.48 times greater, respectively, than those in fresh radish extract. Black radish extract demonstrates superior performance in reducing fat accumulation and enhancing antioxidant capacity. At a concentration of 10 μg/mL, black radish extract reduces the relative Oil Red O intensity in Caenorhabditis elegans to 13.42%. At a concentration of 1000 μg/mL, black radish extract achieves a 24.93% inhibition rate of reactive oxygen species. Additionally, the black radish extract does not exhibit significant toxic effects on various physiological functions of C. elegans and notably enhances their lifespan.

High Performance Organic Mixed Ionic‐electronic Polymeric Conductor with Stability to Autoclave Sterilization

We present a series of newly developed donor‐acceptor (D‐A) polymers designed specifically for organic electrochemical transistors (OECTs) synthesized by a straightforward route. All polymers exhibited accumulation mode behavior in OECT devices, and tuning of the donor comonomer resulted in a three‐order‐of‐magnitude increase in transconductance. The best polymer gFBT‐g2T, exhibited normalized peak transconductance (gm,norm) of 298±10.4 S cm‐1 with a corresponding product of charge‐carrier mobility and volumetric capacitance, μC*, of 847 F V‐1 cm‐1 s‐1 and a μ of 5.76 cm2 V‐1 s‐1, amongst the highest reported to date. Furthermore, gFBT‐g2T exhibited exceptional temperature stability, maintaining the outstanding electrochemical performance even after undergoing a standard (autoclave) high pressure steam sterilization procedure. Steam treatment was also found to promote film porosity, with the formation of circular 200 – 400 nm voids. These results demonstrate the potential of gFBT‐g2T in p‐type accumulation mode OECTs, and pave the way for the use in implantable bioelectronics for medical applications.

High Performance Organic Mixed Ionic-Electronic Polymeric Conductor with Stability to Autoclave Sterilization.

We present a series of newly developed donor-acceptor (D-A) polymers designed specifically for organic electrochemical transistors (OECTs) synthesized by a straightforward route. All polymers exhibited accumulation mode behavior in OECT devices, and tuning of the donor comonomer resulted in a three-order-of-magnitude increase in transconductance. The best polymer gFBT-g2T, exhibited normalized peak transconductance (gm,norm) of 298±10.4 S cm-1 with a corresponding product of charge-carrier mobility and volumetric capacitance, μC*, of 847 F V-1 cm-1 s-1 and a μ of 5.76 cm2 V-1 s-1, amongst the highest reported to date. Furthermore, gFBT-g2T exhibited exceptional temperature stability, maintaining the outstanding electrochemical performance even after undergoing a standard (autoclave) high pressure steam sterilization procedure. Steam treatment was also found to promote film porosity, with the formation of circular 200-400 nm voids. These results demonstrate the potential of gFBT-g2T in p-type accumulation mode OECTs, and pave the way for the use in implantable bioelectronics for medical applications.

Effects of different thermal processing methods on amino acid, fatty acid, and volatile flavor substance contents of Aohan millet (Golden seedling millet)

AbstractAohan millet has been cultivated for 8000 years and has rich nutritional value, such as high‐quality fatty acids and amino acids. Thermal processing is a conventional approach to food preparation. However, the effect of thermal processing on the formation of flavor substances in millet has not been clarified. Therefore, in this study, the effects of three different thermal processing techniques, namely, steaming, stir‐frying, and puffing, on the amino acids, fatty acids, and volatile flavor substances of Aohan millet were investigated using high‐speed automatic amino acid analyzer, headspace solid‐phase microextraction method, combined with gas chromatography–mass spectrometry (HS‐SPME/GC–MS) and gas chromatography (GC) with Aohan millet from Inner Mongolia as the raw material. All three thermal processing methods notably reduced the levels of protein, starch, polyphenols, and flavonoids in Aohan millet when compared to the raw millet (p &lt; .05). Amino acid and fatty acid contents demonstrated an increase in fried and puffed millet relative to steamed millet, with notable distinctions in amino acid and fatty acid contents between these two groups. Following the steaming process, there was a significant increase in the flavor compounds of Aohan millet, rising from 53 to 80, while this increase was not observed in the other two groups. The correlation analysis suggested that the formation of flavor compounds was predominantly influenced by the types and levels of amino acids. The study suggested that different heat treatments affected the amino acid, fatty acid, and more significantly flavor material content and composition of Aohan millet. In conclusion, steaming treatment could retain more nutrients and richer flavor substances; while puffing treatment would enhance amino acid and fatty acid content, which provides a fundamental basis for scientifically guided processing and rational culinary application of Aohan millet.

Integration of volatile and non-volatile metabolite profile, and in vitro digestion reveals the differences between different preparation methods on physico-chemical and biological properties of Gastrodia elata

Gastrodia elata Blume (G. elata) is a traditional medicinal and edible plant whose quality is significantly influenced by post-harvest processing. To obtain an optimal post-harvest processing method for G. elata, this study employed sensory evaluation, scanning electron microscopy (SEM), gas chromatography-ion mobility spectrometry (GC-IMS), and non-targeted metabolomics, in conjunction with an in vitro digestion model, to assess the impact of different processing and drying methods on the quality of G. elata. The findings showed that the steam treatment followed by heat pump drying resulted in the highest levels of total phenols, total flavonoids, and polysaccharides in G. elata, and caused more pronounced damage to its microstructure. This treatment also maintained the highest antioxidant activities and optimal acetylcholinesterase (AChE) inhibition capacity throughout in vitro digestion, meanwhile, effectively eliminating the unpleasant odor and achieving the highest sensory scores. Furthermore, non-targeted metabolomic analysis revealed noteworthy alterations in the metabolite profile of G. elata, mainly related to purine metabolism and the biosynthesis of amino acids pathways. This study provides valuable insights into the post-harvest processing of G. elata.

Evaluation of the Rehabilitation Effect of Nanometric Ion Medicine Steam Combined with Facial Muscle Training in the Treatment of Post-Stroke Peripheral Facial Nerve Palsy

This work aimed to investigate the rehabilitation effect of nanometer ion medicine steaming combined with facial muscle training in the treatment of post-stroke peripheral facial nerve palsy (PFNP), and to analyze the therapeutic effect of artificial skin continuous negative pressure drainage on stroke pressure ulcers. 120 patients with post-stroke PFNP who were admitted to Qilu Hospital (Qingdao), Cheeloo College of Medicine were recruited and rolled into the medicine steaming group (MS group, nanometer ion medicine steam) and the joint group (J group, nanometer ion medicine steam plus facial muscle training). The treatment effects, facial functional recovery, and pressure ulcer treatment outcomes were compared between patients in different groups. Results: After treatment, the facial disability index scores and facial nerve function scores of both groups of patients greatly increased, with a more drastic increase in J group (P &lt; 0.05), so did the scores of various traditional Chinese medicine symptoms (P &lt; 0.05). Furthermore, the proportion of patients in J group with facial function classified as level I or level II was obviously higher (P &lt; 0.05). The treatment effectiveness and satisfaction rate in J group were dramatically superior to in MS group (P &lt; 0.05). Conclusion: the joint treatment of nanometer ion medicine steam and facial muscle training has a significant effect in the rehabilitation of post-stroke PFNP, with faster facial functional recovery and higher patient acceptance.

Innovative Hurdle Strategies for Listeria Control on Food-Contact Surfaces: A Peroxyacetic Acid-Steam Approach.

The persistence of Listeria monocytogenes biofilms on equipment surfaces poses a significant risk of cross-contamination, necessitating effective surface decontamination strategies. This study assessed the effectiveness of hurdle treatments combining peroxyacetic acid (PAA) and saturated steam against 7-day-old L. innocua (a non-pathogenic surrogate for L. monocytogenes) biofilms on stainless steel (SS), polyester (PET), and rubber surfaces. Results demonstrated >6 log10 CFU/coupon L. innocua reductions on SS and PET surfaces after PAA (40 ppm, 1 min) followed by steam treatment (100 °C, 6 s). On rubber surfaces, PAA (80 ppm, 1 min) followed by steam treatment (100 °C, 6 s) resulted in ~5 log10 CFU/coupon L. innocua reduction. The presence of apple juice soil reduced the efficacy of hurdle treatments, with PAA (40 ppm, 1 min) and steam exposure (6 s) resulting in 5.6, 5.8, and 4.2 log10 CFU/coupon reductions of L. innocua on SS, PET, and rubber, respectively. The efficacy of this antimicrobial combination was further reduced by surface defects, especially in the presence of organic matter. Nevertheless, the treatment still achieved >5 log10 CFU/coupon reductions of L. innocua on worn SS and PET soiled with apple juice and ~4.5 log10 CFU/coupon reduction on worn, soiled rubber surfaces. These findings highlight that PAA treatments followed by a brief steam exposure are effective strategies for controlling Listeria on food-contact surfaces.

Experimental investigation on cyclic steam stimulation assisted modified THAI to enhance oil recovery in steam-treated heavy oil

Steam injection is well accepted as a main method for heavy oil reservoirs. Currently, most heavy oil reservoirs have reached the late stage of steam treatment and encountered various challenges thus alternative methods are needed to develop the remaining oil. CSS1 Assisted Modified THAI2 (CSSAMT) is proposed to be an effective follow-up method in heavy oil reservoirs treated by steam. CSSAMT combines the benefits of ISC3 and steam, with steam acting as a protective agent for production wells threatened by combustion as well as a restrainer for oxygen breakthrough. A 3-dimensional physical model was conducted for the experiment to simulate the process and investigate the mechanism. The result demonstrates the feasibility of the CSSAMT process with a high oxygen availability of 99.8% and an average apparent H/C ratio of 0.71, achieving an oil recovery factor of 44.01%. Optimal steam injection parameters were determined as a 0.03 T (dimensionless time)-soak period followed by a 0.06 T production period. Additionally, oil upgrading results were quantitatively described through the carbon number variations, and a prediction formula correlating the sweep efficiency and the carbon number variations was proposed, showing a correlation coefficient of 0.9.

Preparation of MAZ-Type Zeolite with High Silica.

The Si/Al molar ratio of MAZ aluminosilicate zeolite prepared by the direct hydrothermal method is generally less than five, thus giving rise to poor thermal and hydrothermal stability for this low-silica zeolite. With the purpose of enhancing the Si/Al molar ratio of MAZ zeolite, post-synthesized methods including acetic acid treatment and steaming treatment, as well as interzeolite transformation from FAU zeolite, were employed to prepare MAZ zeolite with high silica. It was found that steaming treatment was more effective in increasing the Si/Al molar ratio in comparison with acetic acid treatment, affording a maximum Si/Al molar ratio of 16.9 along with a preserved crystallinity of approximately 75%. Additionally, high-silica MAZ zeolite with a Si/Al molar ratio of up to 7.3 was also capable of being directly hydrothermally synthesized using interzeolite transformation from FAU zeolite.

Effect of superheated steam treatment on rice starch: study on in vitro digestibility and morphostructural, thermal and functional changes

Effect of superheated steam treatment on rice starch: study on in vitro digestibility and morphostructural, thermal and functional changes