Oven-dried Samples Research Articles

The Effect of Different Drying Methods on Primary and Secondary Metabolites in Korean Mint Flower

Edible flowers have been used in the food and beverage industries because of their high nutritional value, flavor, and scent. For the storage of edible flowers used in these industries, drying is a necessity to store the materials more easily and prevent the damage of metabolites in the flowers. However, drying may affect metabolite retention because drying conditions can differ according to the various methods. In this study, Agastache rugosa flowers were dried using four different methods (oven drying at 25 ± 1 °C, 50 ± 1 °C, 80 ± 1 °C, and freeze drying) and primary and secondary metabolites were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). Freeze-dried flower samples contained higher levels of carotenoids (lutein, 13Z-β-carotene, β-carotene, and 9Z-β-carotene) and phenolics (rosmarinic acid, ferulic acid, and sinapic acid). Contrarily, the 80 °C oven-dried flower samples contained higher levels of most amino acids and flavonoids (including acacetin and tilianin) and at 25 °C and 50 °C contained higher levels of carbohydrates. Therefore, freeze-drying is a suitable method for retaining carotenoids and phenolics. In contrast, oven drying at 50 °C was highly recommended to retain amino acids and flavonoids.

Effect of different drying methods and storage conditions on physical, nutritional, bioactive compounds and antioxidant properties of doum (Hyphaene thebaica) fruits

The present study reports effect of various drying and storage conditions on physical, bioactive compounds, and antioxidant properties of doum (H. thebaica) fruit for the first time. Three types of fruit are used such as fresh, dried from tree, and dried fruits purchased from local market. Pulp of fresh fruit was dried using sun, shade and oven at different temperatures and stored under different conditions for three months. Samples were analysed before and after drying and storage. The results showed significantly (p < 0.01) higher dry matter (98.73 g/100g), pH (7.09), tannins (27.64 mg/g), flavonoids (19.90 mg/g) and total polyphenols (7.13 mg/g) contents in pericarp than other parts of fruit. The pulp without pericarp exhibited higher ash, amino acids, proteins and vitamin C contents, however pulp of whole fresh fruit had higher Ca (1.67 mg/g), Na (640.26 mg/g) and Zn (11.63 μg/g). Pulp of fruit purchased from local market showed significantly stronger antioxidant activities (DPPH and ABTS). All parameters evaluated were significantly (p < 0.01) affected in comparison with pulp of fresh fruit but varied with respect to drying methods and storage conditions. The shade-dried samples showed higher proteins, amino acids, vitamin C, ash, fibres and acidity contents than other drying methods. Polyphenols and antioxidant activities are higher in oven-dried samples at low temperature (40 °C) as compared to others. The highest DPPH and ABTS scavenging activities are observed after drying and storage conditions for three months. Significant and positive (p < 0.01) correlations are found between antioxidant compounds and antioxidant activities. Thus, drying methods and storage conditions can preserve pulp of doum fruit with high physicochemical, bioactive compounds and antioxidant capacities for human well-being up to three months, however shade-drying followed by oven-drying are highly promising process that must be considered as suitable drying methods for doum fruits.

Characterization of freeze-dried, oven-dried and blanched house crickets (Acheta domesticus) and Jamaican field crickets (Gryllus assimilis) by means of their physicochemical properties and volatile compounds

Edible insects are repeatedly being considered as underutilized food candidate due to their high nutritional value. Although frequent acceptance of whole insects to consumer is still challenging, incorporation of insects in food as powder or paste has been suggested to increase their acceptability. Hence, Acheta domesticus and Gryllus assimilis were subjected to freeze drying, oven drying, and blanching to acquire a clear insight on the impact of the processing methods on the nutritional and physical properties of both species. Result showed that these three methods had limited effects on the proximate composition, fatty acid and amino acid profile but had significant impact on other parameters for both species. Vitamin B12 in A. domesticus did not change but G. assimilis changed due to the treatment. Freeze drying showed better lightness (L* value) and lower browning index for both cricket species. Oven drying and blanching resulted in lower lipid oxidation values than freeze drying for both cricket species; though lipid oxidation was in all cases well below the rejection limit. Esters were the predominant group of volatile compound in freeze and oven-dried cricket while least amount of volatiles were found in blanched cricket. The volatiles resulted from fatty acid oxidation were higher in freeze-dried crickets, while Maillard reaction products were found in oven-dried samples. Although freeze drying showed higher colour quality, oven drying exerted superior effect in terms of nutritional and flavour characteristics followed by blanching treatment.

Use of near-infrared spectroscopy for prediction of chemical composition of Tifton 85 grass

The reduction in the quality, consumption, and digestibility of forage can cause a decrease in animal performance, resulting in losses to the rural producer. Thus, it is important to monitor these characteristics in forage plants to devise strategies or practices that optimize production systems. The aim of this study was to develop and validate prediction models using near-infrared spectroscopy (NIRS) to determine the chemical composition of Tifton 85 grass. Samples of green grass, its morphological structures (whole plant, leaf blade, stem + sheath, and senescent material) and hay, totaling 105 samples were used. Conventional chemical analysis was performed to determine the content of oven-dried samples (ODS), mineral matter (MM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose (CEL), hemicellulose (HEM), and in vitro dry matter digestibility (IVDMD). Subsequently, all the samples were scanned using a Vis-NIR spectrometer to collect spectral data. Principal component analysis (PCA) was applied to the data set, and modified partial least squares was used to correlate reference values to spectral data. The coefficients of determination (R2) were 0.74, 0.85, 0.98, 0.75, 0.85, 0.71, 0.82, 0.77, and 0.93, and the ratio of performance deviations (RPD) obtained were 1.99, 2.71, 6.46, 2.05, 2.58, 3.84, 1.86, 2.35, 2.09, and 3.84 for ODS, MM, CP, NDF, ADF, ADL, CEL, HEM, and IVDMD, respectively. The prediction models obtained, in general, were considered to be of excellent quality, and demonstrated that the determination of the chemical composition of Tifton 85 grass can be performed using NIRS technology, replacing conventional analysis.

Applicability of cosmic-ray neutron sensing for measuring soil water content to heterogeneous landscapes under subtropical hydroclimatic conditions

Cosmic-ray neutron sensing (CRNS) is one of the few techniques that can directly acquire information about the temporal dynamics of soil water content (SWC) at a hectometer scale. The performance of CRNS depends on the climate, soil and conditions of the underlying surface. The region of red soil in China is characterized by heterogeneous land uses (combination of upland and paddy fields), distinct dry-wet periods and low contents of soil organic carbon. The applicability of CRNS has not yet been evaluated under the subtropical hydroclimatic conditions of this region. We therefore compared spatially averaged SWC measured using CRNS with point-scale data measured using time domain reflectometry (TDR) at five locations and oven-dried soil samples collected at 27 locations across the CRNS footprint in an agricultural ecosystem of the red-soil region between March 2019 and February 2020. The footprint of CRNS varied with time. The horizontal radius of CRNS varied between 175 m in July and 215 m in October, with a mean of 194 m, and the measuring depth varied between 16 cm in March and 23 cm in August, with a mean of 19 cm. The relative contribution of rainfed cropland, citrus land and paddy fields were 86.7, 10.7 and 2.6%, respectively. The differences of the relative contribution among land uses were determined by the distance to the sensor and the area, which were less affected by the types of land use. The neutron count rate (N0, counts/h) was weakly temporally variable, with a mean coefficient of variation of 3%. The influence of its variation on the accuracy of CRNS, however, should not be ignored. Both the timing and frequency of sampling affected the calculation of N0. Occasional sampling in the dry season is a recommended strategy to acquire an accurate N0 of a region. CRNS performed well for determining the dynamics of spatially averaged SWC in heterogeneous landscapes. More specifically, the accuracy of CRNS was comparable with those using the oven-drying method, with R2, root mean square error and Nash-Sutcliffe model efficiency coefficient of 0.86, 0.026 cm3/cm3 and 0.81, respectively. This study evaluated the applicability of CRNS in a region with complex climatic, hydrological and underlying-surface conditions. These results are useful for developing a reasonable sampling strategy for acquiring an accurate N0 and calibrating the CRNS. Future studies, however, should focus on the application of the CRNS technique to resolve the eco-environmental issues of the region.

Profiling beneficial phytochemicals in a potato somatic hybrid for tuber peels processing: phenolic acids and anthocyanins composition.

The purpose of this study was to characterize the peels of a CN1 somatic hybrid obtained from two dihaploid potato lines (Cardinal H14 and Nicola H1) in terms of the health‐promoting phenolic compounds (phenolic acids and anthocyanins). The CN1 hybrid is defined by a pink tuber skin color making it different from the light‐yellow‐skinned “Spunta,” which is the most commonly grown potato cultivar in Tunisia. Oven‐dried peel samples derived from CN1 hybrid and cv. Spunta were ground, and phenolic compounds were extracted with water or methanol for quantification. Lyophilized peels were used for the phenolic acid and anthocyanin analyses. Higher total quantities of phenolic compounds were recovered in methanol extracts compared with water extracts. A slightly higher concentration of phenolic acids (100 mg/100 g DW) was obtained in the lyophilized peels extract of CN1 hybrid than in the cv. Spunta corresponding sample (83 mg/100 g DW). The profiles of the chlorogenic acid isomers were almost identical in both of CN1 hybrid and cv. Spunta. Caffeic acid (CA) and three caffeoylquinic acids (CQAs): 3‐CQA, 4‐CQA, and 5‐CQA, were identified from both genotypes, 5‐CQA being the dominant form in both potatoes. Since the CN1 hybrid has a pink skin color, its anthocyanin profile was also determined. The anthocyanin quantity in the CN1 peels was 5.07 mg/100 g DW, involving six different anthocyanins that were identified within the extract, namely, Pelargonidin‐3‐rutinoside‐5‐glucoside, peonidin‐3‐rutinoside‐5‐glucoside, coumaroyl ester of pelargonidin‐3‐rutinoside‐5‐glucoside, coumaroyl ester of peonidin‐3‐rutinoside‐5‐glucoside, feruloyl ester of pelargonidin‐3‐rutinoside‐5‐glucoside, and feruloyl ester of peonidin‐3‐rutinoside‐5‐glucoside. These results suggest that the peel waste of CN1 somatic hybrid can be considered as a promising source of high‐value compounds for food industry.

Utjecaj različitih metoda sušenja na sadržaj polifenolnih spojeva u kožicama crnih sorata grožđa

The aim of this work was to determine the effect of different drying treatments: freeze-drying, room-drying, and oven-drying on the grape phenolic composition of the 'Regent' and 'Cabernet Sauvignon' varieties. After drying, the samples were grounded, submerged to ultrasound-assisted extraction, and analyzed with high-performance liquid chromatography (HPLC). This study demonstrated that the use of different drying methods significantly affects the content of polyphenols in grape skins extracts. The greatest content of anthocyanins-diglucoside was preserved using freeze-drying, i.e. 15706.86 mg/kg for 'Regent', while the content of anthocyanins-monoglucoside was best preserved by room-drying, i.e. 216778.68 and 9220.30 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively. The highest content of flavonol glycosides (2583.04 and 1429.64 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively), hydroxycinnamic acids (1303.31 and 544.88 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively), and stilbene (2321.52 and 79.36 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively) was observed in the oven-dried samples. By applying freeze-drying the most optimal content of flavan-3-ol was preserved. Contents of polyphenolic compounds in oven-dried samples after 6 months of storage were almost identical to those in the samples analyzed immediately after drying. The greatest rate of degradation was observed in the room-dried samples while it was moderate in the freeze-dried ones. The results of this experiment demonstrate that it is necessary to dry samples in different ways to obtain the highest content of a certain polyphenolic group of compounds. The application of a drying method is determined by the goal of the final dried product in terms of content and composition of different polyphenolic compounds; thus, the obtained results could have an application in scientific research and for commercial purposes as well.

Comparison of smartphone and lab-grade NIR spectrometers to measure chemical composition of lamb and beef

Context Near-infrared reflectance spectroscopy (NIRS) has been extensively investigated for non-destructive and rapid determination of pH and chemical composition of meat including water, crude protein, intramuscular fat (IMF) and stable isotopes. Smaller, cheaper NIRS sensors that connect to a smartphone could enhance the accessibility and uptake of this technology by consumers. However, the limited wavelength range of these sensors could restrict the accuracy of predictions compared with benchtop laboratory NIRS models. Aims To compare the precision and accuracy metrics of predicting pH, water, crude protein and IMF of three sample presentations and two sensors. Methods Fresh intact (FI) store-bought beef and lamb steak samples (n = 43) were ground and freeze-dried (FD), and then oven-dried to create freeze-dried oven-dried (FDOD) samples. All three forms of sample presentation (FI, FD, FDOD) were scanned using the smartphone and benchtop NIRS sensors. Key results The IMF was the best predicted trait in FD and FDOD forms by the smartphone NIRS (R2 &gt;0.75; RPD &gt;1.40) with limited differences between the two sensors. However, predictions on FI meat were poorer for all traits regardless of the NIRS scanner used (R2 ≤ 0.67; RPD ≤ 1.58) and not suitable for use in research or industry. Conclusion The smartphone NIRS sensor showed accuracy and precision comparable to benchtop NIRS to predict meat composition. However, these preliminary results found that neither of the two sensors reliably predicted quality attributes for industry or consumer applications. Implications Miniaturised NIRS sensors connected to smartphones could provide a practical solution to measure some meat quality attributes such as IMF, but the accuracy depends on sample presentation.

Shear Strength and Consolidation Characteristics of Lateritic Soils: A Case of Asela Town, Oromia Regional State, Ethiopia

The most important engineering properties that determine the bearing capacity of soils are shear strength or ability to resist sliding along internal surfaces within a soil mass and the consolidation characteristics. Thus, in this study the shear strength and consolidation characteristics of Asela lateritic soil is studied. The shear strength parameters (i.e. Cohesion (C) and internal friction angle (Ф)) and consolidation parameters are determined using UU triaxial and 1-D odometer tests, respectively, on disturbed soil samples remolded with different densities and water contents in order to simulate the field condition. The shear strength test was done on the cylindrical samples of 38mm in diameter and a height of twice the diameter and the consolidation test were done on the samples of 75mm diameter and thickness of 20mm. In addition, the index test (specific gravity, grain size distribution, Atterberg limits and free swell tests) also conducted on air and oven-dried samples to understand the behavior and classification of the soils. The moisture content of the studied soil ranges between 17.35 – 32.51%, plasticity Index ranges between 11.8-26.4%, clay fraction ranges between 25.5-61.2, free swell ranges between 20-50% and specific gravity ranges between 2.59-2.95. The shear strength parameter, C and ɸ range from 89.63 to 161.48 Kpa and 17º-24º, respectively. The consolidation parameters: coefficient of compression ranges 0.193 to 0.581; coefficient of consolidation ranges 0.11 to 1.06 cm²/sec, coefficient of volume compressibility ranges 0.021 to 0.34m²/MN.

Chemical Composition of Aromas and Lipophilic Extracts from Black Morel (Morchella importuna) Grown in China

Morels (Morchella spp.) are valuable medicinal and edible mushrooms. In this study, chemical profiles of aromas and lipophilic extracts of black morel (Morchella importuna) grown in China were analyzed by gas chromatography/mass spectroscopy, along with the evaluation of antioxidant and antimicrobial activities for the lipophilic extracts. Sixty-five compounds in total were identified from the aromas, and 1-octen-3-ol was the main component for aromas of fresh (34.40%) and freeze-dried (68.61%) black morels, while the most abundant compound for the aroma of the oven-dried sample was 2(5H)-furanone (13.95%). From the lipophilic extracts, 29 compounds were identified with linoleic acid as the main compound for fresh (77.37%) and freeze-dried (56.46%) black morels and steroids (92.41%) as the main constituent for an oven-dried sample. All three lipophilic extracts showed moderate antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) with the IC50 values ranging 7.56 ∼ 17.52 mg/mL and 5.75 ∼ 9.73 mg/mL, respectively, and no obvious antimicrobial activity was observed for lipophilic extracts. The drying methods affect the chemical profile of black morel, and freeze-drying was favorable for retaining nutrients and morel smell. This is the first report on the aroma and lipophilic extracts of M. importuna grown in China.

Influence of drying methods on the structure and properties of cellulose formate and its application as a reducing agent

Cellulose formate (CF) with surface formyl groups can be prepared through the esterification between cellulose and formic acid (FA). The properties of CF are sensitive to temperature, which is of great importance for its end application. In this work, the effect of four drying methods on the structure and properties of the resultant CF was investigated. Results showed that the CF samples as special cellulose nanofibrils with cellulose II crystal form and fibrous structure were sensitive to drying temperature and drying time. The freeze-dried CF sample maintained its original structure, while the air-dried and oven-dried CF samples with amorphous structure showed the aggregation state. Furthermore, the CF/Ag composites were prepared using silver mirror reaction where the never dried CF was used as a reducing agent. SEM and TEM images exhibited a large number of Ag nanoparticles with the diameter of 20–50 nm on the surface of CF samples. As expected, the fabricated CF/Ag composites showed strong antibacterial activity against both Escherichia coli and Bacillus subtilis, and thus the prepared composites have great potential applications in antibacterial daily necessities and medical supplies.

Influence of some pre and post-harvest practices on quality of saffron stigmata

Saffron (Crocus sativus L.) yield and quality are affected by many pre and post-harvest activities. Therefore, four separate experiments were carried out to investigate the effect of some agronomic (irrigation, fertilization, and organic/ conventional cultivation) and post-harvest practices on color parameters (L, a, b, h°, and C) and apocarotenoid content (crocin, picrocrocin, and safranal) in stigmata. Required plots for the first and the second experiments were constructed in September 2013 and again in 2014 for corm planting. Sampling of the first experiment was done one year after each planting. When two years passed since corm planting, sampling was done for the second experiment. In the first study, the combined effect of the production system (one-year-old organic or conventional fields) and drying temperature (25 °C at shade; 55 and 75 °C in the electric oven) were evaluated during two flowering seasons of 2014 and 2015. In both production systems, oven-dried samples at 55 °C had better quality. In the second experiment, the organic and non-organic stigmata (obtained from two-year-old fields in flowering seasons of 2015 and 2016) were stored for 1, 2, or 3 years under room temperature in a dark place. Color coordinates (a, a/b, and C) increased by longer storage duration. The maximum crocin and safranal contents were obtained from organic samples, which were being stored for less than one year. In the third experiment, the effect of irrigation level (3600, 4200, and 4600 m3 ha−1) and fertilization (humic acid, Rhizophagus irregularis, and unfertilized control) was evaluated during two flowering seasons (2016 and 2017) on saffron yield and quality. Deficit irrigation treatment (3600 m3 ha−1), associated with the use of humic acid, had the highest yields of flower and stigmata. However, the effect of mycorrhizal inoculation was negative on flowering. Lower water availability plus mycorrhizal inoculation had the highest picrocrocin and safranal content but the lowest C, a/b, and a color parameters. In the fourth experiment, 48 stigmata samples were collected, and then the relationships between color parameters and apocarotenoids content were evaluated using correlation and regression procedures. Safranal had a correlation with a (-0.411**), b (0.295*), a/b (-0.454**) and h° (0.410**). Similarly, crocin had a positive correlation with b and h°, but a negative one with a and a/b indexes. Overall, the results of four separate experiments revealed that saffron stigmata quality is highly affected by pre and post-harvest practices. It was also concluded that stigmata quality assessment is somewhat possible through measurement of color parameters as a quick and cheap method.

Effect of ultrasound, high-pressure processing, and enzymatic hydrolysis on carbohydrate hydrolyzing enzymes and antioxidant activity of lemon (Citrus limon) flavedo

Lemon (Citrus limon) flavedo, an outer green layer of lemon peel, is used in the bakery for its good smell and attractive color. However, most of the research has been focused lemon peel bioactivities. Currently, there are no data exist on flavedo individual bioactive compounds. Therefore, we compared three extraction processes (ultrasound-assisted extraction (UAE; 20 min), high-pressure processing (HPP; 400 MPa/10 min), and enzymatic hydrolysis (EH)) on two dried samples (oven-dried (OD); essential oil residues (EOR)) to understand the effect of flavedo extracts on the inhibition of carbohydrate hydrolyzing enzymes and their bioactive compounds. EH-treated samples exhibited higher carbohydrate hydrolyzing enzymes inhibition compared to UAE and HPP-treated samples (α-amylase inhibition of 25.83–93.77% for UAE and EH-treated OD samples, respectively). The phenolics in OD-EH was higher than EOR samples (3688 mg GAE/100 g and 2306 mg GAE/100 g) and SOD-like activity (3505 U/g and 2815 U/g). Moreover, sinapic acid (47.33% and 59.59%) and esculetin (16.85% and 18.31%) were the major compounds of the total phenolics in OD and EOR samples that may regulate obesity and blood sugar, respectively. Therefore, lemon flavedo might be considered as a potential source in the development of functional foods.

Electrohydrodynamic, oven and natural drying of mint leaves and effects on the physiochemical indices of the leaves

Electrohydrodynamics (EHD) enhanced the thin-layer drying of mint (Mentha Spicata Huds) leaves using multiple point-to-plate electrodes. Its configurations were carried out under DC high voltage and its effects were compared to oven drying at 40 °C and open-air-drying with natural convection at 25 °C. The EHD was run in an optimum electric field of 3.2 kV·cm&lt;sup&gt;–1 &lt;/sup&gt;using positive ionising conical needles to a plate electrode covered by a steel screen grid to prevent the leaves drifting. The samples subjected to the EHD and oven exhibited faster drying kinetics than natural convection. Compared to the oven drying, the EHD electrical power consumption was negligible. The EHD method developed fewer undesirable changes in the colour features and the leaves’ total chlorophyll, whereas the oven-dried sample colour underwent a significant change in colour. The samples dried by EHD had lower active microorganisms. The empirical modelling, based on the maximum value of R&lt;sup&gt;2&lt;/sup&gt; and the minimum value of RMSE and SSE between the experimental and predicted moisture ratios, showed that the diffusion and logarithmic models were the best models for describing the EHD and oven drying behaviour of the mint leaves.

Comparative of Different Drying Methods on the Phytochemical and Some Nutrient Components of Scent Leaf (Ocimum gratissimum)

The effect of air, sun, and oven drying methods on scent leaf (Ocimum gratissimum) and the organic and dietary elemental composition of its leaves was evaluated using standard analytical procedures. Drying increased significantly and the concentration of organic constituents evaluated. The ash content was markedly enhanced by drying and it range from 2% in the fresh sample to 11.5% in the oven-dried sample, the fiber content range from 1.5% in the fresh sample to 5.5% in the air-dried sample, also the lipid content from 0.5% in fresh sample to 2.5% in both air-dried and oven-dried sample, the moisture content was markedly low in the drying method compared to the fresh, the carbohydrate content range from 9.46% in the fresh sample to 76.20% in the sun-dried sample, the protein content ranging from 1.54% in the fresh sample to 2.80% in the sun-dried sample. Preserving Ocimum gratissimum leaves in a more hygienic way and ensure its all-year round availability and possible elimination of most nutrient deficiencies. A significant increase in mineral content was observed upon drying except for K and Ca whose concentration was found to be high (2050±0.003 mg/kg and 1.50±0.003 mg/kg) in the fresh sample and observed low in the dried samples. All the results are expressed in MEAN±SEM (Standard Error of Mean) and a significant difference was observed among the drying methods. The result of this study suggest that drying methods increase the concentration of organic and dietary elemental compositions.

Quality Evaluation of ‘Fufu’ Produced from Sweet Cassava (Manihot Esculenta) and Guinea Corn (Sorghum Bicolor) Flour

ABSTRACT Sweet cassava and guinea corn were processed into flour using two different drying methods (sun and oven) to produce unfermented enriched fufu. Experimental design from which ten blends were selected for analyzes, sample F (100% traditional processed fufu) and sample C (commercial market sample – semolina) were used as control. In-vitro starch digestibility, glycemic index/load, antioxidant potential, and sensory attributes were evaluated, analyzed and mean were separated using Duncan New Multiple Range (DNMR) test at p ≤ 0.05. In-vitro starch digestibility of the experimental samples were significantly (p ≤ 0.05) higher than 8.91% obtained for sample F in both sun- and oven-dried samples. Results of the estimated glycemic index/load of the experimental samples showed that enriched fufu can be classified as low glycemic foods and are significantly (p ≤ 0.05) higher than sample F (55%) and glucose (100%). The samples also had better ability to scavenge free radicals against DPPH and ABTS.

Effect of Processing Method on Proximate Composition, Physicochemical Analysis and Mineral Content of Milk-Bush Seed (Thevetia peruviana)

This study examined proximate composition, physicochemical analysis and mineral content of thevetia peruviana seed. The seeds (sun dried, oven dried and air dried) were ground into very fine powder. AOAC 2005 (Standard method) was used to analyse all the parameters used in the study. However, for mineral analysis, AOAC 2005 and Shumaila and Mahpara (Pak J Nutr 8(9):1456–1460, 2009) were used. The result of the proximate composition revealed that the moisture content was (4.59 ± 0.12, 2.78 ± 0.12 and 4.21 ± 0.12), ash content was (2.75 ± 0.12, 1.73 ± 0.07 and 1.22 ± 0.00), crude fibre content was (1.17 ± 0.00, 1.31 ± 0.00 and 1.42 ± 0.20), crude fat content was (66.84 ± 0.00, 66.67 ± 0.20 and 42.92 ± 0.00), crude protein content was (20.53 ± 0.12, 23.41 ± 0.12 and 24.72 ± 0.12), carbohydrate content was (28.04 ± 0.00, 4.10 ± 0.25 and 1.59 ± 0.00) and energy (597.504 ± 1.79 kcal/kg, 728.766 ± 1.19 kcal/kg and 725.430 ± 0.48 kcal/kg) for sun dried, oven dried and air dried seeds respectively. Meanwhile, the results for physicochemical analysis of the oven dried, air dried and sun dried samples were saponification value (mgKOH/g): 88.20 ± 0.00, 85.40 ± 0.00 and 77.00 ± 0.00, peroxide value (meq/kg): 6.00 ± 1.15, 1.53 ± 0.12 and 10.60 ± 0.12, acid value (mgKOH/g): 2.86 ± 0.06, 1.85 ± 0.12 and 2.85 ± 0.06, free fatty acid (% as oleic acid): 1.43 ± 0.12, 0.92 ± 0.12 and 0.83 ± 0.09, density (g/dm3): 0.91 ± 0.04, 0.87 ± 0.00 and 0.83 ± 0.01, specific-gravity:0.90 ± 0.12, 0.90 ± 0.00 and 0.87 ± 0.12, viscosity (pal/sec @25 °C): 24.99 ± 0.00, 20.48 ± 0.09 and 20.66 ± 0.00, iodine value (meq/kg): 13.51 ± 0.06, 11.59 ± 0.12 and 9.79 ± 0.06. The mineral contents of the sun dried, air dried and oven dried seed samples were in increasing order of K > Ca > Na > Mg > Zn > Fe > Cu > Pb > Ni. The study concluded that oven-dried sample of the seed of thevetia peruviana has greater effect on proximate composition than the other process.

Water saturation effects on dynamic behavior and microstructure damage of sandstone: Phenomena and mechanisms

Underground rock structures are frequently subjected to water erosion and dynamic disturbance simultaneously. Herein, in order to study the coupled effects of water and high strain rate on the mechanical behavior and microstructures of sandstone, we conducted a series of dynamic unconfined compressive tests on oven-dried and water-saturated sandstone core samples using a split Hopkinson pressure bar. Test results revealed that, three macroscopic final patterns, namely unbroken, axial split and pulverization, were observed. At given strain rates, the presence of water weakens the dynamic peak stress and the dissipated energy density (the ratio of energy dissipation to residual axial strain) of rock sample but enhances the elastic modulus regardless of the failure pattern. Additionally, the saturated sample owns a higher rate dependence of dynamic strength compared to the dry one under the explored range of strain rate (43.9–156.7 s−1), which indicates that water-weakening on rock strength gradually attenuates with the increase of strain rate. Interestingly, thin sections analysis microscopically showed that the failure of dry samples is characterized by the intra-granular fracturing in larger quartz grains while that of saturated samples by the inter-granular fracturing. The underlying mechanisms were interpreted with two micro-mechanical damage models.

Removal of oil from ferrous grinding swarf of automobile industry by aqueous washing process

This research focused on the recovery of valuable materials from ferrous grinding swarf. We received the sample from the automobile industry. The sample has consisted of approximately 20 wt% moisture and 80 wt% residue (oil and soild). The chemical composition of the oven-dried sample was approximately 87 wt% iron. In this study, aqueous washing process for oil removal from ferrous grinding swarf was investigated with two different commercial reagents, Micro-90 and Detergent 8. Three different amounts of solids (2, 3, and 4 g) were mixed with 20 mL of diluted reagents for the aqueous washing. In the Micro-90 solution, about 80% of the oil was removed after three washing cycles at a solids content less than 3 g/20 mL. On the other hand, when using Detergent 8, 100% oil was removed after three washing cycles at a solids content of less than 3 g/20 mL. Pulp density was an important factor in determining oil removal efficiency. For the scale-up experiment, different washing methods such as ultrasonication and overhead stirrer were examined. The preliminary reuse test of the Detergent 8 solution was also conducted for the feasibility of the aqueous washing process.

Non-destructive genotypes classification and oil content prediction using near-infrared spectroscopy and chemometric tools in soybean breeding program

In soybean (Glycine max L.) breeding programs, segregation is normally observed, and it is not possible to have replicates of individuals because each genotype is a unique copy. Therefore, near-infrared spectroscopy (NIRS) was used as a non-destructive tool to classify soybeans by genotypes and to predict oil content. A total of 260 soybean genotypes were divided into five classes, which were composed of 32, 52, 82, 46, and 49 samples of the BV, BVV, EB, JAB, and L class, respectively. NIR spectra were obtained using oven-dried samples (80 g) in a reflectance mode. A successive projection algorithm and genetic algorithm with linear discriminant analysis discriminated genotypes of the low (L class) from the high (EB class) for oil content (88.89% accuracy). The partial least square regression models for oil content were considered good (root mean square error of prediction of 0.96%). Therefore, NIRS can be used as a non-destructive tool in soybean breeding programs, but further investigation is necessary to improve the robustness of the models. It is important to note that to use the models, it is necessary to collect NIR spectra from dry soybean samples.