Search Results (1,192)

This work presents a combined numerical and experimental investigation into the laser machining of aluminum alloy Al 1050 H14 using a high-power Continuous Wave (CW) fiber laser. Advanced three-dimensional, coupled thermal–structural Finite Element Method (FEM) simulations are developed to model key laser–material interaction processes, including laser-induced plastic deformation, laser etching, and engraving. Cases for both static single-shot and dynamic linear scanning laser beams are investigated. The developed numerical models incorporate a Gaussian heat source and the Johnson–Cook constitutive model to capture elastoplastic, damage, and thermal effects. The simulation results, which provide detailed insights into temperature gradients, displacement fields, and stress–strain evolution, are rigorously validated against experimental data. The experiments are conducted on an integrated setup comprising a 2 kW TRUMPF CW fiber laser hosted on a 3-axis CNC milling machine, with diagnostics including thermal imaging, thermocouples, white-light interferometry, and strain gauges. The strong agreement between simulations and measurements confirms the predictive capability of the developed FEM framework. Overall, this research establishes a reliable computational approach for optimizing laser parameters, such as power, dwell time, and scanning speed, to achieve precise control in metal surface treatment and modification applications. Full article

This work presents the design, modeling, and experimental validation of an innovative, highly autonomous, and economically viable photovoltaic solar cooker, integrating a robust battery storage system. The system combines 1200 Wp photovoltaic panels, a control block with DC/DC power converters and digital control for intelligent energy management, and a thermally insulated heating plate equipped with two resistors. The objective of the system is to reduce dependence on conventional fuels while overcoming the limitations of existing solar cookers, particularly insufficient cooking temperatures, the need for continuous solar orientation, and significant thermal losses. The optimization of thermal insulation using a ceramic fiber and glass wool configuration significantly reduces heat losses and increases the thermal efficiency to 64%, nearly double that of the non-insulated case (34%). This improvement enables cooking temperatures of 100–122 °C, heating element surface temperatures of 185–464 °C, and fast cooking times ranging from 20 to 58 min, depending on the prepared dish. Thermal modeling takes into account sheet metal, strengths, and food. The experimental results show excellent agreement between simulation and measurements (deviation < 5%), and high converter efficiencies (84–97%). The integration of the batteries guarantees an autonomy of 6 to 12 days and a very low depth of discharge (1–3%), allowing continuous cooking even without direct solar radiation. Crucially, the techno-economic analysis confirmed the system’s strong market competitiveness. Despite an Initial Investment Cost (CAPEX) of USD 1141.2, the high performance and low operational expenditure lead to a highly favorable Return on Investment (ROI) of only 4.31 years. Compared to existing conventional and solar cookers, the developed system offers superior energy efficiency and optimized cooking times, and demonstrates rapid profitability. This makes it a sustainable, reliable, and energy-efficient home solution, representing a major technological leap for domestic cooking in rural areas. Full article

Background: The decline in traditional cooking practices and the increased consumption of ready-to-eat meals have raised concerns about dietary quality and health, especially among university students. Nutrition students, despite their academic training, often struggle to translate theoretical knowledge into healthy eating practices. Culinary classes in academic settings have emerged as promising strategies to enhance both cooking skills (CS) and eating competence (EC). Objectives: This study aimed to evaluate the impact of a 12-month cooking class program on the development of culinary skills and eating competence among nutrition students at a public university in Brazil. Methods: A longitudinal study was conducted with 42 nutrition students who completed a structured questionnaire at three time points: baseline, after 6 months, and after 1 year of participation in sequential cooking-related subjects. Data were collected using the Brazilian Cooking Skills and Healthy Eating Questionnaire (QBHC) and the Brazilian version of the Satter Eating Competence Inventory (ecSI2.0™BR). Statistical analyses included a repeated-measures ANOVA and a Pearson correlation. Bonferroni post hoc comparisons were conducted following the repeated-measures ANOVA to identify the time points at which significant differences occurred. Results: Participants, predominantly young females (78.6%, mean age 21.07 ± 2.71 years), demonstrated high CS at baseline and showed significant improvements over time (p < 0.05). At baseline, 59.5% of participants (n = 25) were considered competent eaters (EC ≥ 32). Knowledge in cooking terms and techniques increased after one year (p = 0.023). EC mean scores classified participants as competent eaters at the beginning and after one year, with an increase in the internal regulation domain. Improvements in technical culinary knowledge were associated with gains in contextual skills. Conclusions: Participation in structured cooking classes positively influenced the development of CS and EC internal regulation among nutrition students. Full article

Biodiesel, which is a blend of fatty acid methyl esters (FAME), has garnered significant attention as a promising alternative to petroleum-based diesel fuel. Nevertheless, the commercial production of biodiesel faces challenges due to the high costs associated with feedstock and the non-recyclable homogeneous catalyst system. To address these issues, a solid catalyst derived from construction industry waste cement was synthesized and utilized for biodiesel production from waste cooking oil (WCO). The catalyst’s surface and physical characteristics were analyzed through various techniques, including Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier Transform Infrared Spectroscopy (FTIR). The waste-cement catalyst demonstrated remarkable catalytic performance and reusability in the transesterification of WCO with methanol for biodiesel synthesis. A maximum biodiesel yield of 98.1% was obtained under the optimal reaction conditions of reaction temperature 65 °C; methanol/WCO molar ratio 16:1; calcined cement dosage 3 g; and reaction time 8 h. The apparent activation energy (Ea) from the reaction kinetic study is 35.78 KJ·mol⁻¹, suggesting that the transesterification reaction is governed by kinetic control rather than diffusion. The biodiesel produced exhibited high-quality properties and can be utilized in existing diesel engines without any modifications. This research presents a scalable, environmentally benign pathway for WCO transesterification, thereby contributing significantly to the economic viability and long-term sustainability of the global biodiesel industry. Full article

A lens-coupled high-speed X-ray camera, “Hayaka”, was developed for quick imaging of X-ray absorption fine structure (XAFS) and time-resolved high-speed computed tomography (CT) using synchrotron radiation (SR). This camera is a lens-coupled type, composed of a scintillator, an imaging lens system, and a high-speed visible light sCMOS, capable of imaging with a minimum exposure time of 1 μs and a maximum frame rate of 5000 frames/s (fps). A feasibility study using white and monochromatic SR at the beamline BL07 of the SAGA Light Source showed that fine X-ray images with a spatial resolution of 77 μm can be captured with an exposure time of 10 μs. Furthermore, quick imaging XAFS, combined with high-speed energy scanning of a small Ge double crystal monochromator of the same beamline, enabled spectral image data to be acquired near the Cu K-edge in a minimum of 0.5 s. Additionally, an in coquendo 4DCT (time-resolved 3D observation of cooking processes) observation combined with a high-speed rotation table revealed the boiling process of Japanese somen noodles over 150 s with a time resolution of 0.5 s. Full article

Sensory evaluation is essential for analyzing fish quality, as it describes its organoleptic profile and reflects consumer perception. Attributes such as appearance, smell, taste, and texture can vary depending on the origin of the fish, its diet, and thermal processing. In order to obtain reproducible results, it is necessary to control factors such as temperature, cooking time, and portion thickness during fish sample preparation for testing. This study develops a standardized guide for the sensory evaluation of cooked fish, particularly Sparus aurata. The guide includes detailed preparation protocols, a structured descriptive method, and a tasting sheet to ensure objective, reproducible evaluations that are applicable in research, industry, training, and quality control. Full article

Solid-state microwave technology has emerged as an alternative to conventional magnetron-based microwave systems due to its precise frequency control and potential to improve heating uniformity. The objective of this study was to evaluate the effects of solid-state microwave cooking at 912–913 MHz on the quality characteristics of beef steak and minced beef in comparison with conventional oven cooking and traditional microwave cooking (2450 MHz). Meat samples were cooked to an internal temperature of 75 °C, and cooking time, weight loss, moisture content, lipid oxidation (TBARS), total soluble protein (TSP), color attributes, and texture properties were evaluated. Solid-state microwave cooking resulted in shorter cooking times compared to conventional oven cooking. However, it caused significantly higher cooking loss in beef steak (48.1%) compared to conventional (34.8%) and microwave cooking (42.4%) (p ≤ 0.05). In minced beef, solid-state microwave cooking led to significantly higher TBARS values (1.56 mg MDA/kg) than conventional cooking (1.07 mg MDA/kg) (p ≤ 0.05), indicating increased lipid oxidation. No significant differences were observed among cooking methods for total soluble protein content and several texture parameters (p > 0.05). Solid-state microwave cooking produced improved color development compared to traditional microwave cooking. Overall, solid-state microwave cooking shows potential advantages in processing time and color formation; however, increased cooking loss and lipid oxidation indicate that optimization of processing conditions is necessary to limit undesirable quality changes. Full article

To test whether fructooligosaccharide (FOS) and inulin (INU) molecules can improve the hardness of cooked rice through forming a hydrogel network, we added FOS or INU at 0%, 3%, 5%, 7%, and 10% concentrations to two cooking japonica rice and compared the cooking and textural parameters, the pasting, thermal, and thermo-mechanical properties, and the microstructure of the cooked rice. General Linear Model Univariate (GLMU) analysis revealed that, compared with no oligofructose addition, both FOS and INU addition reduced the rice cooking time and increased the gruel solid loss. The addition of these dietary fibers (DFs) to cooking rice lowered the hardness, adhesiveness, springiness, gumminess, and chewiness of the rice, but maintained the cohesiveness and increased the resilience. Compared with no oligofructose addition, FOS and INU addition improved the smell, taste, and total sensory score of cooked rice. The addition of these DFs significantly decreased the trough, peak, final, breakdown, and setback viscosities, but increased the pasting temperature and peak time. Both FOS and INU addition decreased the enthalpy of gelatinization but increased the peak and conclusion temperature of gelatinization of rice flour paste. After the retrograded flour pastes were kept at 4 °C for 21 days, both FOS and INU significantly increased amylopectin aging compared with no oligofructose addition. The FOS-added and INU-added rice doughs had a higher dough development time and stability time, gelatinization peak torque, setback torque, and gelatinization speed, with a lower protein weakening degree, amylase activity, breakdown torque, heating speed, and enzymatic hydrolysis speed. Compared with no oligofructose addition, both FOS and INU addition reduced the amorphous region of starch and β-sheet percentage, but increased the percentages of random coils, α-helixes, and β-turns in cooked rice. Principal component analysis (PCA) further demonstrated that the gruel solid loss, cooked rice hardness, chewiness, gumminess, taste, and the peak, trough, breakdown, final, and setback viscosities were sensitive parameters for evaluating the effects of species and the amount of oligofructose addition on rice quality. The microstructure showed that FOS or INU addition induced thickening of the matrix walls and an increase in the pore size, forming a soft and evenly swollen structure. These results suggest that FOS or INU addition inhibits amylose recrystallization but maintains amylopectin recrystallization in cooked rice, with INU addition producing greater improvements in the texture and sensory scores of cooked rice compared withFOS addition. This study provides evidence of the advantages of adding DFs and probiotics such as INU and FOS to cooked rice. Full article

A systematic understanding of the overall flavor and taste characteristics across different white radish varieties is still lacking. This study selected six white radish varieties and analyzed their texture, taste, and flavor profiles. The results showed that JYHX had excellent hardness and chewiness, and CKJRM had the highest brittleness. The total sugar content of XY418 was the highest, and the sweetness was the most prominent. The umami and bitterness of CKXY and XY477 contributed significantly. A total of 43 volatile compounds were detected by gas chromatography–mass spectrometry (GC-MS), and CKFM12 had the highest content of sulfur-containing compounds. Dimethyl trisulfide and erucin were the key substances for the characteristic flavor of white radish. In this study, the texture, taste, and flavor characteristics of several white radish varieties and their potential biochemical components (cell wall substances, amino acids, volatile compounds) were comprehensively compared and analyzed for the first time. These findings provide a scientific basis for targeted quality evaluation, flavor improvement, and variety selection based on specific cooking applications and processing needs. Full article

This study aimed to characterize the physicochemical, structural, and volatile compound changes in commercially sterilized pre-cooked braised chicken (PBC) during storage at 25 °C, using analyses conducted every 30 days from 30 to 180 days. Assessed parameters included microstructure, color, texture, pH, malondialdehyde (MDA) content, Ca²⁺-ATPase activity, and volatile organic compounds (VOCs). Significant quality changes occurred during storage. Specifically, the L* value decreased, and the a* value increased, while hardness, springiness, chewiness, and Ca²⁺-ATPase activity declined. pH increased from 6.01 to 6.59, and MDA content rose from 10.16 to 23.42 nmol/g. 91 VOCs were identified by gas chromatography-ion mobility spectrometry (GC-IMS), comprising 13 alcohols, 18 aldehydes, 18 ketones, 3 acids, 9 esters, 12 hydrocarbons, 6 aromatics, and 12 others. VOC profiles shifted dynamically: key aldehydes and ketones decreased initially, then increased, whereas alcohols, esters, hydrocarbons, and sulfur-containing compounds increased, then decreased. Prolonged storage significantly deteriorated the quality and altered the flavor profile, providing insights for PBC storage. Full article

Astaxanthin, a potent antioxidant, has attracted growing interest for its applications in the food, pharmaceutical, and cosmetic industries. This study aims to optimize the green extraction of astaxanthin from shrimp (Parapenaeus longirostris) by-products using ultrasound-assisted extraction (UAE) with extra virgin olive oil (EVOO) as a sustainable solvent, and explore its application in trahana fortification, a traditional Greek fermented cereal-based product. Response Surface Methodology (RSM) was applied to optimize astaxanthin extraction conditions (extraction time, liquid-to-solid (L/S) ratio, and ultrasound amplitude). Fatty acid analysis was performed with gas chromatography (GC-FID), and sensory analysis was conducted using a 7-point hedonic scale for sensory attributes. The optimal UAE conditions for astaxanthin, determined by RSM, were 228 min extraction time, a 65:1 liquid-to-solid ratio, and 41% ultrasound amplitude, predicting 83.50 μg astaxanthin/g by-product. At the optimal conditions, the experimentally obtained yield of 76.75 ± 1.17 μg astaxanthin/g by-product fell within the 95% confidence interval of the predicted value. The enriched trahanas retained nutritionally relevant levels after cooking (46.35 ± 0.60 μg astaxanthin per 60 g serving). Accelerated storage testing at 65 °C for six days was used to assess the thermal stability of astaxanthin in enriched trahanas. Based on first-order degradation kinetics and Arrhenius-based extrapolation of literature-derived activation energy values, astaxanthin retention above 80% at 25 °C was estimated to be maintained for approximately 27–51 days. Thereafter, progressive degradation is expected, with the estimated half-life ranging from 85 to 159 days. GC-FID analysis revealed favorable incorporation of bioactive lipids, including omega-3 fatty acids (EPA and DHA). Sensory evaluation demonstrated enhanced consumer acceptability, with enriched samples scoring significantly higher in appearance, aroma, and overall acceptance compared to traditional trahanas. These findings highlight UAE as an efficient and environmentally friendly strategy for recovering astaxanthin from seafood by-products and for developing functional cereal-based foods that align with sustainability. This work demonstrates the effective use of extra virgin olive oil as a green extraction solvent that also serves as a nutritional carrier, enabling the enrichment of trahanas with astaxanthin. The approach ensures both nutritional stability and consumer acceptability, providing a practical pathway for the development of sustainable, functional cereal-based foods. Full article

Valorization of environmental waste into sustainable energy and value-added products offers a strategic pathway for advancing circular economic development and resource sustainability. In this study, waste cooking oil was converted into biodiesel using biogenically generated CaO, prepared thermally at 900 °C. The reaction process was modeled and optimized with a Taguchi orthogonal array L9(3⁴), considering four factors at three levels to yield nine experimental conditions. The model reliability was statistically validated through analysis of variance (ANOVA) at 95% confidence level (p < 0.05), achieving a high determination coefficient (R²) of 0.9965. The maximum biodiesel yield of 91.08% was obtained under the optimal conditions of the methanol to oil ratio of 15:1, a catalyst loading of 4.5 wt%, a reaction time of 90 min, a temperature of 65 °C, and a constant stirring speed of 650 rpm. The fuel property analysis confirmed compliance with international biodiesel and diesel standards). Economic evaluation of the process showed that integrating waste cooking oil with reusable seashell-derived catalysts enabled the production of high-quality biodiesel at R23.20 (~USD 1.39)/L, highlighting a sustainable and cost-competitive alternative to conventional feedstock. The study contributes to advancing waste-to-energy technologies and supports the transition towards a circular and sustainable energy future. Full article

The impact of cooking method (stir frying, sugar stir-frying, baking, steaming, and boiling) on the physicochemical and sensory properties of Chinese chestnuts was evaluated. Dry heat treatment (stir frying, sugar stir-frying, and baking) increased hardness and chewiness because of water loss. Moist heat treatment (steaming and boiling) resulted in a softer texture and brighter color as a result of water absorption and starch gelatinization. Samples cooked with stir frying and boiling had a 50.82–54.17% reduction in resistant starch content. In contrast, the stir-frying, sugar stir-frying, and baking samples experienced a decrease of 37.16–47.18%. Concurrent changes in the glycemic index were observed. The polyphenol content and antioxidant activity were highest in the samples cooked using sugar stir-frying. A total of 34 volatile compounds were identified, but only 8 were key in the olfactory analysis (hexanal, (E)-2-hexenal, 3-methylbutanal, ethyl 3-methylbutyrate, ethyl acetate, 2-pentanone, 3-hydroxy-2-butanone, and 2-pentylfuran). At the same time, combined with sensory evaluation, sugar stir-frying can highlight the caramel and sweetness of chestnut; then baking can bring a strong aroma of nuts, and sugar stir-frying is a more popular method. Full article

Background: Dysphagia negatively impacts quality of life and requires diets with specifically modified textures. The IDDSI (International Dysphagia Diet Standardization Initiative) scale provides standardized criteria to ensure food safety. This research aims to explore and validate the IDDSI scale adapted to the consumption of foods developed with 3D printing in patients with dysphagia. Methodology: Different dishes were designed and validated using 3D printing and were evaluated by both healthcare professionals and people with dysphagia. In the second phase, participants analyzed their texture using the IDDSI scale. A mixed methodological approach was applied, combining quantitative data (from validated scales) and qualitative data (obtained through interviews and focus groups), ensuring methodological triangulation. Methods: In the first phase of the study, different dishes were cooked and designed using 3D printing technology and were previously evaluated by both healthcare professionals and people with dysphagia. In the second phase, all the dishes validated in the first phase were analyzed and classified according to their texture using the IDDSI. Results: A total of 24 dishes, backed by 204 validations, were determined to be suitable for people with dysphagia and compatible with 3D printing. According to the IDDSI analysis, 36% of these dishes were classified as level 3 (soft texture) and 64% as level 4 (thick purée), levels internationally recognized as safe and suitable for people with dysphagia and suitable for 3D printing. The application of the IDDSI scale eliminated ambiguities in the description of textures, facilitating clear communication between healthcare professionals, caregivers, people with dysphagia, and companies that produce 3D-printed foods, as well as the standardization of 3D food printing processes related to textures. The application of the IDDSI scale eliminated ambiguities in the description of textures, facilitating clear communication between healthcare professionals, caregivers, people with dysphagia, and companies producing 3D-printed food products. This enabled the standardization of 3D food printing processes and the definition of their textures. At the same time, 3D printing proved to be a viable and effective tool for customizing meals that are safe, appropriate, and sensorially appealing. Conclusions: The feasibility of combining the IDDSI scale with 3D printing to develop diets tailored to the needs of people with dysphagia is confirmed. This integrative approach represents an innovation in the field of nutrition for people with swallowing problems, especially in contexts with limited scientific evidence, combining the validation of modified textures with 3D printing technology. There are effective tools for producing safe, suitable and sensorially appealing meals. Full article

This study aimed to evaluate the impact of green coffee flour (GCF) addition (2–8%) and drying method (convective versus microwave-vacuum drying) on the physicochemical, textural, and bioactive properties of pasta. Both factors were found to significantly influence the assessed parameters. Green coffee had no observable effect on the microstructure of convectively dried pasta, whereas microwave-vacuum drying caused visible cracks and a heterogeneous starch-protein matrix even at a 2% supplementation level. Microwave-vacuum-dried pasta exhibited a shorter optimal cooking time and higher water absorption compared with convectively dried samples, while increasing the level of GCF prolonged cooking time and increased cooking losses. Texture analysis revealed that convectively dried pasta showed decreased elasticity and cohesiveness with increasing GCF content, whereas microwave -vacuum-dried pasta maintained a relatively uniform texture regardless of supplementation. The incorporation of GCF enhanced the antioxidant capacity of pasta, with the most pronounced effect at 2% addition, while higher levels showed reduced benefits. Similarly, fortification increased the content of phenolic acids, particularly chlorogenic acid and its isomers, with convectively dried samples exhibiting higher levels than microwave-vacuum-dried pasta. Consumer acceptance was highest for convectively dried pasta without GCF and for samples containing 2%, while pasta with higher GCF levels or microwave-vacuum-dried samples received lower scores. Full article