Search Results (36)

Dried lemon slices (LSs) have become increasingly popular as a healthful beverage when infused in hot water. This study examined the effects of freeze drying (FD), hot air drying (HAD), heat pump drying (HPD), and far-infrared drying (FID) on the quality of dried LSs and their brewed beverages. The results show that FD-LSs and their corresponding beverages have the most appealing appearance and maximum levels of ascorbic acid (2.47 and 0.80 mg/g, respectively), synephrine (8.15 and 0.94 mg/g, respectively), and the overwhelming majority of natural and available phenolic compounds, as well as the strongest antioxidant activity, although numerous volatile compounds in FD-LSs were in the lowest abundances. HPD-LSs exhibited similar trends to FD-LSs but contained the peak concentrations of limonene (2258.87 μg/g), γ-terpinene (704.19 μg/g), β-pinene (502.92 μg/g), and α-pinene (188.91 μg/g), which were the four most abundant volatile compounds in dried LSs. Additionally, active ingredients in HPD-LSs generally featured relative high levels of available amounts. In contrast, HAD- and FID-LSs typically displayed unfavorable coloration and low retention levels of natural and available active ingredients. Consequently, FD and HPD demonstrate superior suitability for the commercial-scale production of dried LSs. Full article

Background: Cold feet syndrome is characterized by hypersensitivity of sympathetic nerves to cold stimuli, resulting in vasoconstriction and reduced peripheral blood flow. This condition causes an intense cold sensation, particularly in the extremities. Although hormonal changes (e.g., during childbirth or menopause) and psychological stress have been implicated, the mechanisms and effective treatments remain unclear. Methods: Ninety adult volunteers were randomized into three groups based on the type of heating mat applied to the feet, with surface temperatures gradually increased from 20 °C to 50 °C. Group A (control) used non-FIR electric mats, Group B used carbon FIR mats, and Group C used loess bio-ball FIR mats. Blood flow (mL/min/100 g) and epidermal temperature (°C) in the left big toe (LBT) and right big toe (RBT) were measured before and after heating or FIR exposure using laser Doppler flowmetry and infrared thermometers. Results: No significant changes in blood flow or skin temperature were observed in Group A. In Group B, blood flow increased by 15.07 mL/min/100 g in the LBT (from 4.12 ± 2.22 to 19.19 ± 5.44) and by 14.55 mL/min/100 g in the RBT (from 4.26 ± 2.29 to 18.81 ± 4.29). In Group C, blood flow increased by 32.86 mL/min/100 g in the LBT (from 4.23 ± 1.64 to 37.09 ± 6.04) and by 32.63 mL/min/100 g in the RBT (from 4.20 ± 1.61 to 36.83 ± 6.48). Epidermal temperature also increased significantly in Group C. All changes in Groups B and C were statistically significant (p < 0.05), with Group C showing the most prominent enhancement. Conclusions: The loess bio-ball mat significantly increased both peripheral blood flow and epidermal temperature compared to the electric and carbon mats. These findings suggest that FIR emitted from loess bio-balls may enhance peripheral circulation through hypothalamus thermogenic response and nitric oxide (NO)-dependent pathways and could serve as a complementary and non-invasive intervention for individuals with poor blood flow. Full article

Star anise, a traditional seasoning, plays a significant role in influencing consumer preferences through its flavor release during cooking. This study examines how drying techniques—hot air drying (HAD), heat pump drying (HPD), Far-infrared drying (FIRD), and microwave vacuum drying (MVD)—affect the visual appearance and flavor release of star anise. Among these techniques, HAD required the longest drying time (20.5 h) and had the highest fracture rate (11.97%), while MVD achieved the shortest drying time (70 min) and FIRD had the lowest fracture rate (9.84%). Color analysis of dried star anise fruits revealed no significant differences among HAD, HPD, and FIRD (p* > 0.05), but MVD resulted in poorer color quality. Following boiling, 26 aroma compounds were identified, with trans-anethole and anisic aldehyde being the most prominent. Compared to other techniques, HPD exhibited the highest volatile oil content and trans-anethole levels in star anise after cooking. Overall, HPD produces star anise with superior visual quality and enhanced flavor release during cooking, making it a more suitable option for large-scale drying. Full article

In this study, figs were dried by hot air drying (HD), vacuum freeze-drying (FD), vacuum drying (VD) and far-infrared drying (FID). Four fig polysaccharides (FPs) were extracted from different dried figs, and the corresponding names were FPH, FPF, FPV and FPFI. The effects of different drying methods on the structural properties, rheological properties and biological activities of FPs were compared. The result shows that the extraction rate of polysaccharides after FD (2.49%) treatment was 58.60%, 50% and 28.35% higher than that of HD (1.57%), VD (1.66%) and FID (1.94%), respectively. Drying methods result in varying molar ratios of monosaccharides. FPFI has more stable gel properties. HD, VD and FID caused damage to the surface structure of the polysaccharides. FPF exhibited the highest uronic acid content (25.56%), along with relatively low apparent viscosity and molecular weight (1.45 × 10⁵ Da), which contributed to its superior antioxidant and lipid-lowering activities. Therefore, FD is a drying method to obtain fig polysaccharide with high antioxidant and hypolipidemic activity. The results provided a scientific basis for the drying process of fig polysaccharide and a reference for the development of potential hypolipidemic products of fig polysaccharide. Full article

Background: Oryza sativa L. is one of the main staple crops in the South Korea. While rice production has remained stable over the past decades, rice consumption has gradually declined, leading to a rapid stockpile in rice inventory. Conventional rice storage methods often fail to preserve functional properties and long-term stability, necessitating innovative processing techniques. Methods: To address this issue, we developed a grain stabilization technique (GST) to enhance the functionality and shelf life of white rice (WR), brown rice (BR), and rice germ (RG). The GST process was conducted in a single-batch system, integrating a controlled temperature cycle (65~85 °C) with 60 rpm rotation, far-infrared (26,400 W/m²), and ultraviolet (254 nm, 60,880 J/m²) irradiation in an enclosed chamber equipped with an exhaust system for moisture, odor, and impurity removal. The process was followed by air drying (25 °C, 15 h) to ensure stability. Results: The GST significantly increased resistant starch content in BR and WR by 214% and 27%, respectively, but not in RG. Additionally, GST enhanced the contents of campesterol, stigmasterol, β-sitosterol, and octacosanol in BR and RG, but not significantly in WR. Furthermore, this technique markedly reduced moisture content, acidity, and bacterial counts over a 90-day storage period and kept mycotoxin levels within safe limits in WR, BR, and RG. GST also altered the microstructures of WR and BR, indicating gelatinization and amorphization of starch granules. Conclusions: These findings contribute to advancing food science by presenting GST as a transformative method to extend shelf life and improve the nutritional profile of rice, aligning with global efforts to reduce food waste, improve dietary health, and develop sustainable food processing technologies. Full article

In the background of high frequency and intensity forest fires driven by future warming and a drying climate, early detection and effective control of fires are extremely important to reduce losses. Meteorological satellite imagery is commonly used for near-real-time forest fire monitoring, thanks to its high temporal resolution. To address the misjudgments and omissions caused by solely relying on changes in infrared band brightness values and a single image in forest fire early discrimination, this paper constructs the angle slope indexes ANIR, AMIR, AMNIR, ∆ANIR, and ∆AMIR based on the reflectance of the red band and near-infrared band, the brightness temperature of the mid-infrared and far-infrared band, the difference between the AMIR and ANIR, and the index difference between time-series images. These indexes integrate the strong inter-band correlations and the reflectance characteristics of visible and short-wave infrared bands to simultaneously monitor smoke and fuel biomass changes in forest fires. We also used the decomposed three-dimensional OTSU (maximum inter-class variance method) algorithm to calculate the segmentation threshold of the sub-regions constructed from the AMNIR data to address the different discrimination thresholds caused by different time and space backgrounds. In this paper, the Himawari-8 satellite imagery was used to detect forest fires based on the angle slope indices thresholds algorithm (ASITR), and the fusion of the decomposed three-dimensional OTSU and ASITR algorithm (FDOA). Results show that, compared with ASITR, the accuracy of FDOA decreased by 3.41% (0.88 vs. 0.85), the omission error decreased by 52.94% (0.17 vs. 0.08), and the overall evaluation increased by 3.53% (0.85 vs. 0.88). The ASITR has higher accuracy, and the fusion of decomposed three-dimensional OTSU and angle slope indexes can reduce forest fire omission error and improve the overall evaluation. Full article

An emerging drying method, far-infrared radiation heating-assisted pulsed vacuum drying (FIR-PVD), was employed to dry raspberries. In this study, the impacts of FIR-PVD, freeze drying (FD), and hot air drying (HAD) on drying characteristics and quality attributes, including color, rehydration ratio, content of total phenolics (TP), content of total monomeric anthocyanins (TMA), antioxidant activity, and microstructural attributes of dried raspberries, were examined. Results indicated that FIR-PVD notably shortened the drying time by 47.78% compared to HAD and by 73.89% compared to FD. The FIR-PVD samples exhibited the highest TP content, DPPH radical scavenging activity, and FRAP value, which were 17.73%, 6.09%, and 38.16% higher than those of the FD samples, respectively, and 2.78%, 2.77%, and 18.74% higher than those of the HAD samples. Significant correlations (p < 0.05) were observed between antioxidant capacity, as measured by DPPH and FRAP assays, and TP content. However, FD at a low temperature led to a higher TMA content than FIR-PVD and HAD. FIR-PVD resulted in the highest ΔE values of dried products due to the lightness enhancement. In addition, the dried products obtained by FIR-PVD had better rehydration capacity. These findings indicate that FIR-PVD presents a promising alternative method for drying raspberries, as it enhances drying efficiency and improves the quality attributes of the dried products. Full article

To clarify the effects of far-infrared drying technology on the drying kinetics and quality of broccoli rhizomes, broccoli rhizomes were dehydrated at 60, 65, 70, 75 and 80 °C, respectively. Eight thin-layer drying mathematical models were used to explore the drying kinetic characteristics and comprehensively evaluate their quality. The results showed that the higher the drying temperature, the shorter the time required to dry the broccoli rhizomes to the endpoint, and the higher the drying rate. The drying temperature was 80 °C, the shortest drying time was 360 min, and the average drying rate was 4.72 g·g⁻¹·min⁻¹. The longest drying time at 60 °C was 660 min, and the minimum average drying rate was 1.99 g·g⁻¹·min⁻¹. The effective diffusion coefficients of moisture at different drying temperatures were 1.22 × 10⁻⁶, 1.25 × 10⁻⁶, 1.34 × 10⁻⁶, 1.46 × 10⁻⁶ and 1.55 × 10⁻⁶ m²/min, respectively. The activation energy was calculated to be 12.26 kJ/mol by the linear relationship between the effective moisture diffusion coefficient and time. From the thermodynamic parameters, the drying of broccoli rhizomes is a non-spontaneous process, and it is necessary to absorb heat from the medium to achieve dehydration. With an increase in the drying temperature, the drying effect is better. The fitting results of eight mathematical models showed that Modified Page, Page, and Wang and Singh were the best mathematical models for the far-infrared drying kinetics of the broccoli rhizomes. The membership function method comprehensively evaluated the quality of the broccoli rhizome dry products. The comprehensive order was 60 °C > 65 °C > 75 °C > 70 °C > 80 °C. When the temperature was 60 °C, the physicochemical properties and nutritional quality of broccoli rhizome were well preserved, and the quality was the best. Therefore, 60 °C is the best temperature for broccoli rhizome drying. The results provide a theoretical reference for further improving the far-infrared drying quality of broccoli rhizomes. Full article

Satellite rainfall estimates (SREs) play a crucial role in weather monitoring, forecasting and modeling, particularly in regions where ground-based observations may be limited. This study presents a comprehensive evaluation of three commonly used SREs—African Rainfall Climatology version 2 (ARC2), Climate Hazards Group Infrared Precipitation with Station data (CHIRPS) and Tropical Application of Meteorology using SATellite data and ground-based observation (TAMSAT)— with respect to their performance in detecting rainfall patterns in Nigeria at daily scales from 2002 to 2022. Observed data obtained from the Nigeria Meteorological Agency (NiMet) are used as reference data. Evaluation metrics such as correlation coefficient, root mean square error, mean error, bias, probability of detection (POD), false alarm ratio (FAR), and critical success index (CSI) are employed to assess the performance of the SREs. The results show that all the SREs exhibit low bias during the major rainfall season from May to October, and the products significantly overestimate observed rainfall during the dry period from November to March in the Sahel and Savannah Zones. Similarly, over the Guinea Zone, all the products indicate overestimation in the dry season. The underperformance of SREs in dry seasons could be attributed to the rainfall retrieval algorithms, intensity of rainfall occurrence and spatial-temporal resolution. These factors could potentially lead to the accuracy of the rainfall retrieval being reduced due to intense stratiform clouds. However, all the SREs indicated better detection capabilities and less false alarms during the wet season than in dry periods. CHIRPS and TAMSAT exhibited high POD and CSI values with the least FAR across agro-climatic zones during dry periods. Generally, CHIRPS turned out to be the best SRE and, as such, would provide a useful dataset for research and operational use in Nigeria. Full article

XRD diffraction and IR absorption were investigated for raw loess powder and heat-treated loess powder. Raw loess retains its useful minerals, but loses their beneficial properties when calcined at 850 °C and 1050 °C. To utilize the useful minerals, loess balls were made using a low-temperature wet-drying method. The radiant energy and transmittance were measured for the loess balls. Far-infrared ray (FIR) emitted from loess bio-balls is selectively absorbed as higher vibrational energy by water molecules. FIR can raise the body’s core temperature, thereby improving blood flow through the body’s thermoregulatory mechanism. In an exploratory study with 40 participants, when the set temperature of the loess ball mat was increased from 25 °C to 50 °C, blood flow increased by 39.01%, from 37.48 mL/min to 52.11 mL/min, in the left middle finger; in addition, it increased by 39.62%, from 37.15 mL/min to 51.87 mL/min, in the right middle finger. The FIR emitted from loess balls can be widely applied, in various forms, to diseases related to blood flow, such as cold hands and feet, diabetic foot, muscle pain, and menstrual pain. Full article

This study applied direct-contact ultrasound-assisted Vacuum Far-Infrared (VFIR) to dry Cistanche slices, investigating the influence of radiation temperature (45 °C, 55 °C, 65 °C), ultrasonic frequency (20 kHz, 40 kHz, 60 kHz) and ultrasonic power (72 W, 96 W, 120 W) on the physicochemical properties, drying characteristics, and microstructure of Cistanche slices. The results showed that the application of ultrasound had a significant enhancement effect on the drying process, with drying time decreasing as radiation temperature, ultrasonic power, and ultrasonic frequency increased. The drying rate curves under three experimental factors exhibited a brief acceleration stage followed by a deceleration stage. Under different drying conditions, the contents of Iridoid and phenylethanoid glycosides in dried products were higher than those under natural drying (ND). Specifically, the content of catalpol at 55 °C, 96 W, 40 kHz (0.56 mg/g) and the content of Leonuride at 55 °C, 96 W, 60 kHz (0.67 mg/g) increased by 1.81 and 1.9 times, compared to ND. The rest of the nutrient content and antioxidant activity increased with the increase in ultrasonic frequency. Compared to ND, ultrasonic-assisted VFIR drying improved the color and rehydration capacity of dried products. Observation of the microstructure revealed that the application of ultrasound made the interior of Cistanche slices loose and porous. In summary, ultrasonic-assisted VFIR drying not only enhances the drying rate but also improves the quality of dried products. Full article

In this study, the effects of ultrasonic power, drying temperature, and slice thickness on the drying rate, chromatism, water migration law, gingerol content, flavor, and antioxidant activity of ginger were investigated by using a direct-contact ultrasound and far infrared combined drying technology. The results showed that compared with single far infrared drying, direct-contact ultrasound and far infrared combined drying accelerated the free water migration rate of ginger (7.1~38.1%), shortened the drying time (from 280 min to 160 min), reduced the loss of volatile components in ginger, and significantly increased the antioxidant activity of ginger (p < 0.05). Furthermore, after ultrasound intervention, the gingerol content decreased in slices of 4 mm thickness (0.1226 ± 0.0189 mg/g to 0.1177 ± 0.0837 mg/g) but increased in slices of 6 mm thickness (0.1104 ± 0.0162 mg/g to 0.1268 ± 0.0112 mg/g). This drying technology has a certain reference significance for the drying process of ginger slices. Full article

Accurate thermal infrared (TIR) fast-forward models are critical for weather forecasting via numerical weather prediction (NWP) satellite radiance assimilation and operational environmental data record (EDR) retrieval algorithms. The thermodynamic and compositional data about the surface and lower troposphere are derived from semi-transparent TIR window bands (i.e., surface-sensitive channels) that can span into the far-infrared (FIR) region under dry polar conditions. To model the satellite observed radiance within these bands, an accurate a priori emissivity is necessary for the surface in question, usually provided in the form of a physical or empirical model. To address the needs of hyperspectral TIR satellite radiance assimilation, this paper discusses the research, development, and preliminary validation of a physically based snow/ice emissivity model designed for practical implementation within operational fast-forward models such as the U.S. National Oceanic and Atmospheric Administration (NOAA) Community Radiative Transfer Model (CRTM). To accommodate the range of snow grain sizes, a hybrid modeling approach is adopted, combining a layer scattering model based on the Mie theory (viz., the Wiscombe–Warren 1980 snow albedo model, its complete derivation provided in the Appendices) with a specular facet model. The Mie-scattering model is valid for the smallest snow grain sizes typical of fresh snow and frost, whereas the specular facet model is better suited for the larger sizes and welded snow surfaces typical of aged snow. Comparisons of the model against the previously published spectral emissivity measurements show reasonable agreement across zenith observing angles and snow grain sizes, and preliminary observing system experiments (OSEs) have revealed notable improvements in snow/ice surface window channel calculations versus hyperspectral TIR satellite observations within the NOAA NWP radiance assimilation system. Full article

The effects of far infrared radiation drying (FID) on physical properties (drying kinetics, color, shrinkage ratio, rehydration ratio, and microstructural characterization) and volatile odor characteristics (volatile odor profile distinction and volatile compounds) of shiitake mushrooms were evaluated in this study. During the FID, the drying time decreased with the increase in drying temperature, and it had a less significant effect in the lower temperature range. The increase in drying temperature led to increasing shrinkage and collapse in the microstructure, resulting in a decreased rehydration rate and highlighting the influence of microstructure characteristics on macroscopic properties. Higher drying temperatures employed in the FID process were found to be associated with a decreasing L* value and an increasing ΔE value. The application of principal component analysis can effectively distinguish the significant effect of FID on the volatile odor profiles of shiitake mushrooms. Compared to raw shiitake mushrooms, FID treatment has endowed samples with a greater variety of volatile compounds. After processing with FID, there have been increases in volatile components such as sulfur compounds, acids, nitrogen compounds, and aldehydes, while volatile components like alcohols, ketones, and hydrocarbons have shown decreases. Full article

Nowadays, adulteration of traditional food products is a very important field in the general food authenticity sector. Moreover, it is important to create databases with authentic traditional products. In Cyprus, research about the traditional dairy products is scarce. Anari is predominantly made from goat’s and sheep’s milk, but milk from cows can also be used. It is produced during the process of Halloumi cheese making. Classification of Halloumi and Anari cheese took place in two classes, thus per cheese type, and after that in milk species subclasses such as cow and goat-sheep origins for each cheese type. This research study aims to enlighten the field of food authenticity in terms of traditional Cypriot dairy products. The first step of the methodology is the freeze-drying process for lyophilization of samples. Forty-four samples have been analyzed thus far, including both Halloumi and Anari cheese. Measurements for each sample were obtained by using Fourier Transformed Infrared (FTIR) Spectroscopy. Interpretation of the extensive data was undertaken via Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA), and through the SIMCA chemometrics package. Characterization of Anari cheese by applying FTIR took place. In terms of cheese type, Halloumi and Anari cheese samples were classified correctly. In addition, Anari samples were classified correctly regarding the milk species’ origin. The proposed experimental procedure along with chemometrics allow the detection of the milk species’ origin of traditional Anari samples, highlighting the importance of FTIR spectroscopy in combination with chemometrics in food authenticity. Creation of a database with Anari samples from Cyprus has started, and this is a very important step towards authenticity of traditional dairy products of Cyprus. Full article