Roasting Method Research Articles

Preparation of Microelectrolysis Filler Using Coal Slag for the Removal of Hazardous Substances in Contaminated Water.

Presently, the utilization of gasification slag in the context of wastewater treatment is constrained. Furthermore, the presence of dye wastewater and wastewater containing hazardous metals represents a significant threat to human health. Accordingly, the present study prepared a microelectrolytic filler (MF) from gasification slag via a high-temperature roasting method and evaluated its degradation performance in water containing organic matter and harmful metal ions. The impact of varying preparation conditions, including initial solution pH and MF dose, on the degradation process was examined. The removal of methyl blue was found to be 92.21% at an initial pH of 2, a reaction time of 300 min and a dosage of 40 g L-1. The removal of Cu(II), Cd(II), and Pb(II) metal ions was 97.32, 96.58, and 99.38%, respectively, at an initial pH of 4, a reaction time of 180 min, and a dosage of 10 g L-1. Following five cycles, the MF process demonstrated continued efficacy in the removal of dyes and heavy metals from the wastewater. A mechanistic analysis revealed that the water treatment process is not a single adsorption process. Instead, it was found that organic macromolecules undergo chain-breaking reactions, while heavy metal ions undergo redox reactions. The wastewater treatment process comprises a number of distinct strategies, including electrochemical reactions, adsorption, flocculation, and precipitation. These findings illustrate the potential of a gasification slag green recycling approach to treat waste with waste, in alignment with the principles of sustainable development.

Sustainable innovation for fermented cassava roasting: Examining the potential of parabolic dish solar collectors and thermal energy storage

Fermented cassava roasting is an energy-intensive process that is commonly used to produce gari, a popular food in Nigeria made from cassava. Traditional roasting methods use firewood as an energy source, which is inefficient and harmful to the health of those who inhale the smoke (mainly women and children in rural communities) and contributes to deforestation. This work aims to investigate a developed fermented cassava roasting system driven by a concentrated parabolic solar collector. Important data on the gari production food chain was obtained from a work-study in a rural community: temperatures and moisture content. The roasting temperatures range between 85oC - 100oC. The parabolic dish solar collector was designed and fabricated to achieve temperatures between 118oC-154oC at optimum tilt angles at Port Harcourt (4°54′ 22.86″N, 6°55′ 27.52″E) climatic conditions. The focal length ranges between 50 mm and 80 mm, and the fluctuation of the focal point position was considered for the thermal storage system design. Gravel was used as a thermal storage, and heat transfer was enhanced through small internally placed mild steel rods. The experimentally obtained average total fry/roast time per batch (40g) was 24 min, which is greater than the theoretically obtained value of 8.5 min. The fermented cassava roasting experiment was conducted for three days with favourable weather conditions, achieving a maximum temperature of 101oC. This innovation is important in addressing the health risks associated with traditional fermented cassava roasting methods and moving towards zero-emission and zero-poverty innovative systems.

Sensory profile of beverages produced from fermented coffee under different time and temperature conditions

Coffee, one of the most globally consumed beverages, exhibits varied economic values influenced by bean quality, prompting ongoing research for enhancement. This study aimed to assess the impact of coffee fermentation on sensory properties. Arabica beans (Catuaí Amarelo variety) were inoculated with Saccharomyces cerevisiae yeast at diverse times and temperatures, following a Central Composite Rotational Planning. Additionally, two roasting methods were examined. Sensory evaluation, conducted by a panel of 8 trained and certified tasters, focused on flavor, aroma, aftertaste, acidity, body, uniformity, balance, cleanliness, sweetness, and overall impression. While fermentation conditions and roasting methods did not significantly alter attributes like aroma, uniformity, cleanliness, and sweetness, improvements were noted in flavor, acidity, body, aftertaste, balance, and overall impression for coffees fermented at 22.5 °C for 30 h. However, increasing roasting intensity adversely affected sensory quality. Findings suggest that the studied fermentation parameters and roasting methods yielded marginal enhancements in sensory quality.

Effects of Different Roasting Methods on the Quality of Roasted Large Yellow Croaker (Larimichthys crocea).

This study investigated the effects of different roasting methods (45% light wave and 55% microwave roasting, 70% light wave and 30% microwave roasting, 100% light wave roasting, far-infrared roasting, and oven roasting) on the quality of roasted large yellow croaker. The quality was evaluated using sensory evaluation, texture characteristics, color differences, moisture content, and volatile flavor substances. In this context, different roasting methods can affect the color, taste, and flavor of large yellow croaker fish, significantly improving the overall acceptance of roasted fish. The results showed that after 45% light wave and 55% microwave roasting, the elasticity of fish meat was maintained, the hardness of fish meat was reduced, the moisture content and distribution were changed, and the taste was the best. Far-infrared roasting and 45% light wave and 55% microwave roasting had a significant effect on the color of large yellow croaker samples and improved the sensory evaluation score. Forty-six volatile compounds were detected using gas chromatography-mass spectrometry. After roasting, the oxidation and Maillard reactions of lipids and proteins were increased, with the 45% light wave and 55% microwave roasting giving the highest variety of volatile flavor substance products.

Response surface methodology was used to optimize the defluorination process of steam-enhanced microwave roasting waste cathode carbon

As a typical hazardous solid waste, improper treatment of waste cathode carbon (WCC) will cause great harm to animals and plants and their living environment. In order to make the treatment of WCC more simple, efficient and clean, this paper mainly adopts the method of microwave roasting and introducing water vapor to make the fluoride in WCC melt at high temperature and be absorbed by water vapor. The effects of water flow rate, reaction temperature, reaction time, material particle size and other important factors on the defluorination efficiency of WCC were studied by single factor experiment. In this paper, the response surface method (RSM) was used to obtain and verify the best results of the experiment, and the optimum process conditions of water vapor enhanced microwave roasting WCC defluorination were determined: the reaction temperature was 1100 °C, the reaction time was 2.8 h, and the water flow rate was 3.2 mL·min−1. Under this condition, the defluorination effect of WCC is the best. The predicted value of defluorination efficiency of WCC is 99.85 %, and the actual value is 99.8 %.

Comprehensive recovery of valuable metals from spent LiCoO2 cathode material by a method of NH4HSO4 roasting- (NH₄)₂S leaching

With the retirement of rechargeable lithium-ion batteries (LIBs) entering peak period, the recycling of LiCoO2 has become a hot topic. The spent LiCoO2 batteries are rich in carcinogenic metal Co and high-value metal Li, so they are needed to be recovered in time before causing serious environmental pollution and resource waste. Thus, a clean and efficient process is proposed for the comprehensive recovery of Li, Co, and Mn from the spent LiCoO2 cathode material. It is an integrated pyro-hydrometallurgical process, mainly consisting of sulfation roasting with NH4HSO4 and selective sulfurizing leaching with (NH4)2S solution. Using low melting point ammonium salt as roasting auxiliary, 99.7 %, 99.1 %, and 99.8 % of Li, Co, and Mn in the spent LiCoO2 powder can be converted into sulfate when roasting under 400 ℃ for 75 min. Then 99.5 % of Li in the sulfation roasting product can be selectively leached with an aqueous (NH4)2S solution, which is also a precipitator for Co, Mn, and impurity Al. In addition, 96.4 % of Co and 96.0 % of Mn in the sulfurized precipitate can be separated with impurity elements Al and C via oxidation roasting–water leaching process. Compared to traditional recycling, this method can achieve a higher Li leaching rate at a low roasting temperature, and the recovery of Co and Mn can be realized without adding any acid/base reagents or impurity cations. More importantly, the circulation of NH3/NH4+ and S element in the recycling system has been taken into account, making it an environmental-friendly and economical process. In this study, the sulfation reduction roasting and selective sulfurizing leaching mechanisms were both revealed in details, and the behavior of the valuable elements was also elucidated.

Differences in the aroma quality of large-leaf yellow tea subjected to different roasting methods

Roasting is a key process in the production of large-leaf yellow tea (LYT) and substantially affects the formation of its aroma. In order to investigate the effect of roasting method on the aroma of large-leaf yellow tea and to identify the potential causes. In this study, guided by molecular sensory science, the aroma components of charcoal-roasted, electric-roasted and drum-roasted LYTs were analyzed using headspace solid phase microextraction and solvent-assisted flavor evaporation in conjunction with gas chromatography-mass spectrometry, and the data were visualized and analyzed using SMICA, SPSS and Origin. The results of quantitative descriptive analysis revealed that rice crust, burnt, corn and floral aromas were significantly different between the three samples. The results of aroma extract dilution and odor activity value analyses revealed that 2,4,5-trimethyloxazole, 1-ethylpyrrole-2-carboxaldehyde, 2-ethyl-3,5-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine, linalool, 2,3-diethyl-5-methylpyrazine, 3,5-diethyl-2-methylpyrazine, β-damascenone, and (E)-β-ionone were the main compounds responsible for differences in the aroma of LYT subjected to different roasting methods. Aroma recombination and addition experiments verified these findings. All in all, charcoal roasting enhances the rice crust and burnt aromas of LYT, and drum roasting facilitates the presentation of floral and corn aromas. This study provides a theoretical basis for the processing of high-quality LYT.

Oxygen-doped defects modified C3N5 in enhanced molecule oxygen photoactivation for tetracycline hydrochloride degradation and H2O2 in situ production: Double pathways of 1O2 and O2–· high yield

The study aims to investigate the mechanism by which O-doped defect engineering in C3N5 enhances molecular oxygen photoactivation. A feasible one-step roasting method was adopted to synthesize a novel C3N5 with multiple O-doped defects sites (O-C3N5). The experimental characterizations and DFT analysis reveal that O atoms were doped into the in-plane structure of C3N5 to form O-doped defects located at both linked and terminal positions on triazine units. The O-doped defects transform C3N5 morphologies and diminish the band gap, favoring charge migration and electron accumulation under visible-light irradiation. Furthermore, O-doped defects improve the adsorption performance for molecular oxygen, which provides the prerequisite for photoactivating molecular oxygen. The prominent photoelectric property can high effectively photoactivate the adsorbed O2 to directly generate 1O2 in the energy transfer-mediated pathway and O2–· in the electron oxygen reduction reaction pathway. In addition, the well photoelectric property also facilitates the interconversion between 1O2 and O2–·, which enables diverse reaction applications to be achieved. Hence, the outstanding performance of O-C3N5 can be verified in photoactivating molecular oxygen for TC degradation and H2O2 in situ production. The results not only demonstrate the universality and feasibility of utilizing O-C3N5 photoactivating molecular oxygen for the advanced treatment of the complicated sewage, but also provide a comprehensive understanding on the enhanced molecule oxygen photoactivation of C3N5 through O-doped defects.

The effect of fixed and rotary roasting methods on the oxidative stability of pistachio oil

Today, the demand for vegetable oils has increased. Unsaturated fatty acids in pistachio oil are an important component in promoting the health of the human diet. The purpose of this study was to evaluate the oxidative properties of roasted pistachio oil in two fixed and rotary roasters at 160 °C for 15 min during 0, 3, and 6 months of storage. The heat used has led to the destruction of the oil in the roasted pistachios, and with the increase in the storage time, the peroxide value of the samples increased from 0.06 to 0.57 meq/kg in the fixed method and from 0.03 to 0.07 meq/kg in the rotating method, respectively. Free fatty acids and acid value increased from 0.34 to 1.34 % and 0.69 to 2.68 mg KOH/g in the fixed method and from 0.3 to 1.11 % and 0.6 to 2.20 mg KOH/g in the rotating method as a result of storage time for 6 months and lipolysis reactions. Under the effect of roasting heat, the Maillard reaction products played an important role in the thermal stability of the oil (P<0.05). The roasted samples at zero storage time have the highest inhibitory percentage of DPPH and the lowest IC50 (3.66 % in the fixed method and 6.9 % in the rotary method). In spite of the fact that the changes made during 6 months of storage in both roasting methods are within the standard range, but due to the fact that in the samples of roasted pistachios in the fixed method, the peroxide value increased and the oxidative stability decreased significantly, it is suggested to use the rotary method in roasting of pistachios.

Effect of cooking conditions and storage on phenolic contents of bottled Capia red pepper

Cooking (traditional and industrial-type roasting) and storage (bottling) can affect fresh Capia red peppers' (CRP) total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (AA). The present work aimed to determine the effect of cooking methods and storage on phenolic and flavonoid contents, and the change in antioxidant activity of samples. The changes in phenolic, flavonoid, and antioxidant activity of (1) fresh mature CRP pericarp of fruit, (2a) industrial fire roasted-bottled CRP pericarp at 700°C at 30 s, (2b) after 12-week storage at 4°C, (3a) traditional roasted-bottled CRP pericarp at 550°C at 10’, and (3b) after 12-week storage at 4°C were investigated. Fresh CRPs’ mean TPC and TFC were 118.57 mg GAE/g and 34.68 µg QE/g, respectively. Traditional bottled CRPs initial and post-storage mean TPC and TFC were 137.8 and 81.90 GAE/g, and 58.87 and 107.56 µg QE/g (p &lt; 0.05), respectively. Industrial bottled CRPs' initial and post-storage mean TPC and TFC were 73.89 and 46.26 GAE/g, and 25.19 and 87.0µg QE/g (p &lt; 0.05). AA decreased due to both traditional and industrial roasting methods after 12-week storage based on CUPRAC (p &lt; 0.05). In traditional roasting method, 12-week storage negatively affected CRPs TPC. However, TFC positively affected more than industrial roasting method (p &lt; 0.05). In traditional roasted method, 12-week storage negatively affected TPC. However, TFC positively affected more than industrial roasting.

Effect of different roasting methods on clove bud extracted oil

This research aims to study the effect of hotplate and microwave roasting at different time,temperature/power on extracted clove bud oil.In this study, oils extracted from clove buds were subjected to hotplate roasting at different times (10, 20, and 15 min) and temperatures (80,100, and 1800 C) and microwave roasting at different power levels (450, 600, 840 W) and time (30 s and 1 min) were evaluated. Physical property parameters color, density, and refractive index; and chemical quality parameters antioxidant properties, chemical composition analysis, functional group analysis, and antimicrobial activity were carried out.Analysis showed that under these conditions there was change in the yield of oil, chemical composition in the spice.The antioxidant properties, chemical composition, antimicrobial activities, and presence of functional groups in clove bud oil increased with microwave power and time up to 600 W and 1 min, for hot plate roasting at 180oC and 10 min, respectively. Based on these findings, roasting clove buds in the microwave with moderate power and short treatment times might be a feasible choice. Both roasting processes may generate new compounds as natural food preservatives

Characterization of lamb shashliks with different roasting methods by intelligent sensory technologies and GC–MS to simulate human muti-sensation: Based on multimodal deep learning

To simulate the functions of olfaction, gustation, vision, and oral touch, intelligent sensory technologies have been developed. Headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC/MS) with electronic noses (E-noses), electronic tongues (E-tongues), computer vision (CVs), and texture analyzers (TAs) was applied for sensory characterization of lamb shashliks (LSs) with various roasting methods. A total of 56 VOCs in lamb shashliks with five roasting methods were identified by HS-SPME/GC–MS, and 21 VOCs were identified as key compounds based on OAV (>1). Cross-channel sensory Transformer (CCST) was also proposed and used to predict 19 sensory attributes and their lamb shashlik scores with different roasting methods. The model achieved satisfactory results in the prediction set (R2 = 0.964). This study shows that a multimodal deep learning model can be used to simulate assessor, and it is feasible to guide and correct sensory evaluation.

In-situ hydrothermal roasting of Ni-based oxide as efficient oxygen evolution reaction catalysts

Oxygen evolution reaction (OER) is the key reaction in the water splitting and CO2 electrochemical reduction. However, the current catalysts for OER still suffer from high potentials and poor stability. Herein, hierarchical self-supporting Ni-based oxides (NiMOx)/Ni–V/Ni foam (NF) (M = Fe, Co, Cu, Mo) catalysts are directly grown on NF by in-situ hydrothermal roasting method. The OER activity of a series of Ni-based oxide catalysts doped with different metal are investigated. The results demonstrate that the NiFeOx/Ni–V/NF exhibits the best OER activity. At the current density of 10 mA cm−2, a smaller overpotential for OER of 270 mV is achieved in 1.0 M KOH electrolyte. No obvious decay in performances is observed after constant electrolysis of about 25 h, demonstrating its outstanding stability. The formation of new oxides compounds and the structure changes due to the addition of Fe, Co, Cu, Mo to the NiOx contribute to the improvements in activity.

Impact of some Ghanaian local roasting methods on aflatoxin reduction in groundnuts (Arachis hypogaea L)

Groundnut (Arachis hypogaea L) is an important cash crop in Ghana and a key component of many Ghanaians' diets. Groundnuts are mostly infected with aflatoxin, a secondary metabolite of the fungal species Aspergillus. The most popular form of traditional food processing of groundnuts is the application of heat, which involves boiling, baking, canning, frying, and roasting. This study characterized the effect of various local processing methods on aflatoxin levels in groundnut. Groundnut samples purchased from vendors in the Ho central market, Volta Region of Ghana, were processed by various local roasting methods viz- a- vis raw contaminated (control). High-Performance Liquid Chromatography connected to a fluorescence detector (HPLC-FLD) was used to determine the aflatoxin levels in the samples. The results revealed that through a combination of roasting + sand + pretreatment methods, the highest percentage of aflatoxin reduction of 97.38% was obtained. This was followed by the combination of roasting + sand – pretreatment (95.79%). Roasting + gari (a fermented partially gelatinized granular product) + pretreatment combination resulted in a percentage reduction of aflatoxins to 82.51%. Roasting + gari – pretreatment combination resulted in a percentage reduction of aflatoxins of 72.81% while Roasting with neither sand nor gari and without pretreatment resulted in an aflatoxin reduction of 43.62%. It was observed that the extent of aflatoxin reduction depended upon the duration of roasting of groundnuts as well as the type of roasting method used. The results of this research offer us the idea and extent of decontamination of aflatoxins in our foods by our local processing methods which will inform policymakers of the areas of prioritization when it comes to Food Safety.

Biomass as a clean reductant for recovery of zinc from zinc leaching residue

Detoxification and utilization of zinc leaching residue (ZLR) is a critical urgent problem for the zinc metallurgical industry. Traditional roasting methods relying on fossil fuels as reducing agents not only increase the operating cost but also contribute to environmental pollution. This work investigates the effectiveness of using biomass as the reducing agent for decomposing zinc ferrite in the process of ZLR roasting. Analysis methods including XRD, TG-DTG-DSC, and SEM-EDS are used to analyze the pyrolysis of biomass and the phase transformation and microstructural evolution of ZLR. The mechanism that biomass pyrolysis gas promotes the reduction of zinc ferrite in ZLR also is elucidated. The reduction rate of zinc ferrite can reach 43.87% under optimal reduction conditions when pine powder is used as the reducing agent. These optimal conditions include a reduction temperature of 750 °C, a biomass addition ratio of 0.75, and a reduction time of 90 min. It's believed that the reduction process mainly proceeds in the path of ZnFe2O4→Fe3O4→FeO→Fe. By using acid leaching, the extraction of zinc and iron from the reduction roast achieved 89.62% and 58.90%, respectively. During the biomass reduction process, loosely structured with abundant microcracks are obtained probably due to the reaction between the reducing gas and zinc ferrite particles. This study offers precious insights into the utilization of biomass for reductive roasting of ZLR with potential energy conservation and emission reduction.

Study on microwave selective treatment of mercury-containing acid mud

The subject of this paper is acid mud, a hazardous waste containing mercury. The current treatment process for acid mud involves high temperatures and extended roasting times. In order to address this issue, a new method utilizing microwave-assisted treatment was proposed. This method has demonstrated the effectiveness of microwave heating for acid mud treatment. The results of the study indicate that acid mud consists of PbSO4, HgS, HgSe, and HgCl2, with the main microwave absorbing material being the mercury-containing phase. A schematic diagram illustrating the microwave heating process is proposed in this study. After subjecting the acid mud to microwave treatment at a temperature of 600 ℃ for 30min, the volatilization rate of mercury was found to reach 99.94%. This rate is 6.55% higher compared to conventional roasting methods. Additionally, the microwave roasting slag exhibited increased pore size and specific surface area, indicating that microwave energy provided an improved channel for volatilization. These observations support the conclusion that microwave heating selectively targets the mercury-containing components in acid mud, thereby enhancing the volatilization rate of mercury.

From Silica Leachate of Laterite Nickel Ore to Silicate Cathode Material: Preparation of Li2MnSiO4/C as Lithium-ion Battery Cathode Material by Two-Stage Roasting Method

From Silica Leachate of Laterite Nickel Ore to Silicate Cathode Material: Preparation of Li2MnSiO4/C as Lithium-ion Battery Cathode Material by Two-Stage Roasting Method

The Effects of Different Roasting Methods on the Phenolic Contents, Antioxidant Potential, and In Vitro Inhibitory Activities of Sacha Inchi Seeds.

Roasted sacha inchi seeds are now commercialized as a health food product, but the influence of roasting methods on their proclaimed health effects has yet to be explored. This study investigated the total phenolic contents (TPCs), antioxidant potential, and inhibitory activities of raw and roasted sacha inchi seeds in vitro. Individual phenolics in raw seeds were also identified in an attempt to explain the bioactivities of the seeds. The results suggested that roasting in a cooking pan, vacuum oven, and tray dryer had distinct impact on TPC in sacha inchi seeds, and thus differentially altered their antioxidant and inhibitory properties. Seeds that underwent roasting exhibited 1.5-2.7-fold higher antioxidant potentials than raw seeds. Certain roasting methods provided the products with anti-α-amylase and anti-cholinesterase activities, while inhibitions of these enzymes were not detected in raw seeds. Roasted seeds also possessed superior anti-lipase and anti-glycation activities when compared with raw seeds (up to 1.7- and 4.8-fold, respectively). The inhibitory properties observed in the seed samples might be attributed to their p-coumaric acid, ferulic acid, and quercetin, as these potential enzyme inhibitors were predominant in raw seeds. The overall results showed that pan-roasting could be used to obtain relatively high health benefits from the antioxidant and inhibitory activities of sacha inchi seeds. The information obtained from this study may serve as the basis for the proper processing of sacha inchi seeds to optimize their functional food and nutraceutical applications.

Determination of caffeine in Robusta coffee beans with different roasting method using UV-Vis spectrophotometry

Caffeine is one of the substances in coffee. Several factors affect the caffeine content in coffee, such as harvesting, post-harvesting, roasting, drying, and storage. This study aimed to compare the roasting methods to caffeine content from two samples of robusta coffee beans (from two different areas in east Java, Indonesia) and determine the caffeine using UV-Vis spectrophotometry. Light (180°C), medium (210°C), and dark (240°C) roast profiles were used. This method was validated pertaining to linearity, precision and accuracy studies, limit of detection (LOD) and limit of quantification (LOQ). The result of the validation method showed the specificity of caffeine in coffee with dichloromethane as solvent at a Wavelength of 275 nm. The linearity showed linear results at a concentration of 5-40 ppm. The linear correlation coefficient (r2 ) was 0.9997. The LOD and LOQ were 0.57 ppm and 1.90 ppm, respectively. The accuracy method showed % recovery in the range of 97.9-99.6%. The precision results showed % relative standard deviation of between 0.9-1.0%. The result showed that the highest caffeine content was found in the light roast profile up to 8%. Based on the statistical test, there is no difference in caffeine content between the two samples (p&gt;0.05). In conclusion, the different roasting methods affect the caffeine content (p&lt;0.05). The caffeine content will decrease as the roasting temperature increases. The method was established to be simple, linear, precise, accurate as well as sensitive and can be applied to determining the caffeine content in coffee.

Predicting VOCs content and roasting methods of lamb shashliks using deep learning combined with chemometrics and sensory evaluation.

A comparison was made between the traditional charcoal-grilled lamb shashliks (T) and four new methods, namely electric oven heating (D), electric grill heating (L), microwave heating (W), and air fryer treatment (K). Using E-nose, E-tongue, quantitative descriptive analysis (QDA), and HS-GC-IMS and HS-SPME-GC-MS, lamb shashliks prepared using various roasting methods were characterized. Results showed that QDA, E-nose, and E-tongue could differentiate lamb shashliks with different roasting methods. A total of 43 and 79 volatile organic compounds (VOCs) were identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. Unsaturated aldehydes, ketones, and esters were more prevalent in samples treated with the K and L method. As a comparison to the RF, SVM, 5-layer DNN and XGBoost models, the CNN-SVM model performed best in predicting the VOC content of lamb shashliks (accuracy rate all over 0.95) and identifying various roasting methods (accuracy rate all over 0.92).