Roasted Samples Research Articles

Corylus avellana L. Natural Signature: Chiral Recognition of Selected Informative Components in the Volatilome of High-Quality Hazelnuts.

The volatile fraction of plant-based foods provides useful functional information concerning sample-related variables such as plant genotype and phenotype expression, pedoclimatic and harvest conditions, transformation/processing technologies, and can be informative about the sensory quality. In this respect, the enantiomeric recognition of the chiral compounds increases the level of information in profiling studies, being the biosynthesis of native compounds often stereo-guided. Chiral native volatiles mostly show an enantiomeric excess that enables origin authentication or support correlation studies between chemical patterns and sensory profiles. This study focuses, for the first time, on the enantiomeric composition of a large set of chiral compounds within the complex volatilome of Corylus avellana L. belonging to different cultivars (Tonda Gentile Romana, Tonda Gentile Trilobata, Anakliuri) and harvested in different geographical areas (Italian and Georgian). Besides native components profiled in raw kernels, volatiles formed after technological treatment (i.e., roasting) are also considered. Headspace solid-phase microextraction combined with enantioselective gas chromatography–mass spectrometry enables the accurate tracking and annotation of about 150 compounds across many samples. The results show that chiral compounds have diagnostic distribution patterns within hazelnut volatilome with cultivar and harvest region playing the major role. Moreover, being some of these chiral molecules also key-aromas, their distribution has a decisive impact on the sensory properties of the product. In particular, the enantiomeric composition of (E)-5-methyl-2-hepten-4-one (filbertone) resulted to be discriminant for origin authentication. The enantiomeric distribution showed, according to literature, an excess of the (S)-enantiomer in both raw and roasted samples volatilome with larger differences in raw samples. The amount of both (R) and (S)-filbertone increases during roasting; the most marked increase for (R)-enantiomer is observed in Italian samples, thus supporting evidence of better hedonic properties and more pleasant odor and aroma.

Microwave roasting induced structural, morphological, antioxidant, and functional attributes of Quinoa ( Chenopodium quinoa Willd)

The present study focused on impact of microwave heat treatment on the morphological, functional, thermal, and antioxidant properties of quinoa. Microwave roasting significantly (p < .05) varied the WAC (1.04 to 1.41 g/g), OAC (1.09 to 0.96 g/g), FC (6.66% to 4.62%), EC (57.06% to 43.18%), and pasting properties of quinoa. Roasted quinoa samples are rich in TPC (78.54 to 105.9 mg GAE/100 g) and AOA (68.95% to 81.84%). In contrast, higher reduction in gelatinization temperature and destruction of crystalline structure (amylopectin content: 85.23% to 80.78%) in starch molecule were observed in highly roasted samples. Microwave roasted samples showed a significant reduction in ordered structure (β-sheet and α-helix) and converted into unordered and flexible structure. Practical applications This study will add scientific knowledge in the field of microwave roasting of quinoa and help to understand the effect of microwave power and roasting time. The result will help in identifying the best roasting condition to achieve the desirable quality for snack production or formulation of new functional foods.

Impact of roasting on the phenolic and volatile compounds in coffee beans.

Phenolic compounds present in coffee beans could generate flavor and bring benefits to health. This study aimed to evaluate the impacts of commercial roasting levels (light, medium, and dark) on phenolic content and antioxidant potential of Arabica coffee beans (Coffea arabica) comprehensively via antioxidant assays. The phenolic compounds in roasted samples were characterized via liquid chromatography–electrospray ionization quadrupole time‐of‐flight mass spectrometry (LC‐ESI‐QTOF‐MS/MS). Furthermore, the coffee volatile compounds were identified and semi‐quantified by headspace/gas chromatography–mass spectrometry (HS‐SPME‐GC‐MS). Generally, for phenolic and antioxidant potential estimation, light roasted samples exhibited the highest TPC (free: 23.97 ± 0.60 mg GAE/g; bound: 19.32 ± 1.29 mg GAE/g), DPPH, and FRAP. The medium roasted beans performed the second high in all assays but the highest ABTS+ radicals scavenging capacity (free: 102.37 ± 8.10 mg TE/g; bound: 69.51 ± 4.20 mg TE/g). Totally, 23 phenolic compounds were tentatively characterized through LC‐ESI‐QTOF‐MS/MS, which is mainly adopted by 15 phenolic acid and 5 other polyphenols. The majority of phenolic compounds were detected in the medium roasted samples, followed by the light. Regarding GC‐MS, a total of 20 volatile compounds were identified and semi‐quantified which exhibited the highest in the dark followed by the medium. Overall, this study confirmed that phenolic compounds in coffee beans would be reduced with intensive roasting, whereas their antioxidant capacity could be maintained or improved. Commercial medium roasted coffee beans exhibit relatively better nutritional value and organoleptic properties. Our results could narrow down previous conflicts and be practical evidence for coffee manufacturing in food industries.

Selective leaching of Li from spent LiNi0.8Co0.1Mn0.1O2 cathode material by sulfation roast with NaHSO4‧H2O and water leach

Extensive research efforts have been made in recycling spent lithium-ion batteries; however, there has been little focus on the selective recovery of lithium from spent lithium-ion batteries. In this paper, we report a new process for selective extraction of lithium from spent lithium-ion power batteries by roasting a mixture of LiNi0.8Co0.1Mn0.1O2 and NaHSO4·H2O followed by water leaching. The most suitable conditions included roasting LiNi0.8Co0.1Mn0.1O2:NaHSO4·H2O at 600 °C for 30 min in a mass ratio of 1:1.40, followed by water leaching at 60 °C for 30 min with a liquid/solid ratio of 25:1 (mL/g). Under the optimal conditions, extraction efficiencies of 99.3%, 0.01%, 3.69%, and 3.90% for Li, Mn, Co, and Ni, respectively, were obtained. X-ray diffraction, in situ X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry–differential scanning calorimetry, and thermogravimetry–mass spectrometry were performed to investigate the transformation of Li, Ni, Co, and Mn in the LiNi0.8Co0.1Mn0.1O2–NaHSO4·H2O roasting system. The results demonstrated that the SO3 produced by thermal decomposition of NaHSO4·H2O considerably affected the transformation of Li, Ni, Co, and Mn in the LiNi0.8Co0.1Mn0.1O2. The surface morphology of the roasted samples showed evidence of sintering and agglomeration. The thermodynamic analysis indicated that the roasting reaction is feasible and that the selective extraction of Li can be achieved by controlling the additive ratio of NaHSO4·H2O.

Effects of roasting on storage degradability and processing suitability of brown rice powder

To screen the best roasting condition for development of new roasted brown rice products, c.f., roasted brown rice slurry, the storage stability and processing suitability of roasted brown rice powder were studied. In this study, roasted brown rice (BR) powders were prepared with different roasting levels of raw, light roast, medium roast and dark roast. Analyses of roasted BR powder's color, degradability (moisture content, water activity, and acid value), antioxidant activity, processing properties (pasting properties and thermal properties) were carried out. Lower L* value and higher a* value was observed with higher roasting levels. Degradability significantly improved in roasted samples and dark roasted sample showed the lowest water content and acid value though water activity value was the most favorable in light roasted sample (0.2<aw <0.4). Furthermore, antioxidant activity became significantly higher in roasted samples and dark roast showed the highest activity even after 4 wk of storage (21.1–25.9%). In terms of processing suitability, the increased pasting temperature and decreased peak viscosity were observed upon roasting. Advantageously, dark roasted sample showed highest cooling and heating stability. Overall, dark roasted sample showed the best storage stability and functionality, thus, selected as an optimal roasting level.

Determination of Antioxidant and Antibacterial Activities of Yirgacheffe Arbica Coffee Leaves

The use of coffee plants is more focused on the coffee beans as a brewing drink or as a food additive. Parts of the coffee plant, such as leaves, are considered as waste and have not been properly utilized. The current study investigates the antioxidant activities and antibacterial activities of Arabica coffee leaves from Yirgacheffe, Gidio Zone, Ethiopia. As a reference, the crude extracts of green/raw and medium roasted beans of coffee were screened for their in vitro antioxidant properties and antibacterial activities. Antioxidant activities were measured by DPPH assay and the reducing power. The findings of this research show that the coffee leaves possessed the highest antioxidant activities in both DPPH and reducing power assays. A linear correlation between concentrations of coffee extract of the leaves and reducing power was observed with a coefficient of y = 0.00312x + 0.0802, (R2 = 0.99472). These results indicated the extract of leaves of coffee has a strongest antioxidant activities compared with green and medium roasted coffee extracts. Moreover, coffee extract has found to be more effective against gram positive bacteria; S.aureus than negative bacteria strains; E. coil. Antioxidant activities for leaf of coffee samples were slightly higher than for the corresponding green and roasted samples while antibacterial activities was significantly lower in leaf of coffee compared to that of green and roasted samples (p &lt; 0.05). Thus, coffee leaf is a very promising resource in the areas of food and pharmaceutical industry, especially, in the beverage industry.

Mineralogical and Chemical Changes after Reduction Roasting of Xinjiang Iron Ore, China

The mineralogical and chemical changes in Chinese Xinjiang iron ore containing impurities, lead, and zinc as a result of reduction roasting were studied via chemical analysis, optical microscopy, X-ray fluorescence (XRF), electron probe microanalysis (EPMA), and energy-dispersive spectroscopy (EDS). Analysis showed that hematite was the main iron-bearing mineral, with small amounts of magnetite and iron silicate; lead impurities were mainly lead oxide and lead–iron alum, while zinc oxide was the main zinc impurity. X-ray fluorescence analysis for raw samples indicated the presence of quartz, hematite, magnetite, chlorite, calcite, and dolomite. The results of the analysis of roasted samples showed an increase in hematite at temperatures of 750 °C and 950 °C, while the elemental iron increased at a temperature of 1200 °C, along with the conversion of galena to lead oxide and sphalerite to zinc oxide, with a stable quartz ratio. The chemical analysis of the raw sample showed that the TFe grade of the sample was 47.04%, while the contents of harmful Pb and Zn impurities were 0.39% and 0.30%, respectively, both of which exceed the index (less than 0.10%) required by the iron industry for raw materials. The content of harmful sulfur impurities was also high, at 1.19%, which needs to be eliminated or reduced. The results of EPMA and EDS analysis of pre-roasting raw samples showed that chemical compositions vary in different locations in the hematite, magnetite, sphalerite, and galena micro-zones. It has also been observed that quartz is mostly diffused with magnetite and hematite, and sulfur appears in small quantities in most regions. The analysis after roasting showed that the percentages of lead, zinc, and sulfur impurities decreased by a large rate. It is clear that the roasting process plays a major role in removing impurities such as sulfur, which appears in a small percentage after the roasting process, and also helps in oxidizing the impurities of lead and zinc, which helps in removing them.

Assessment of ochratoxin A exposure risk from the consumption of coffee beans in Phnom Penh, Cambodia

ABSTRACT This survey aimed to determine OTA contamination in roasted coffee samples commercialised in Phnom Penh, Cambodia and to assess the potential health risk from OTA exposure. Forty locally grown and imported coffee samples were collected and analysed. Analytical validation methods were fully performed. In 3 of 40 samples (7.5%), the results showed detectable levels of OTA, ranging from 0.19 to 1.12 µg kg−1, with an overall average of 0.26 µg kg−1 and an average over the LOQ (n = 3) at 0.81 µg kg−1. OTA estimated daily intake (EDI) of both values were 0.05 (overall average) and 0.17 ng/kg bw/day (the worst-case scenario) with the calculated risk of OTA exposure expressed as a Hazard Quotient at 0.003 and 0.01, respectively. This result could imply a low health risk to Cambodian coffee consumers.

Efekti metoda prerade na funkcionalna svojstva i mineralni sastav brašna od zrna indijskog oraha

This research determined the effects of processing methods on the functional properties and mineral composition of cashew kernel flour. Three varieties of cashew nut were processed to flour using three methods. The oven-dried, hot oil bathed and roasted cashew nuts were cracked using a wooden mallet to obtain whole cashew kernel. The covering testa was removed by hand and winnowed to obtain whole cashew nuts. The samples were then milled separately using a manually operated attrition mill machine and sieved through a 200 mm aperture mesh screen to obtain flours with uniform particle sizes. The processed samples of flour were taken to the laboratory where functional properties and mineral composition were determined. The result showed that the functional properties of cashew flour processed with a hot oil bath, oven-dried, and roasted varied significantly at (p&gt;0.05). Foaming capacity, emulsification capacity and foaming stability for a hot oil bath, oven-dried and roasted samples respectively were found to be higher in the roasted samples. Water absorption capacity and oil absorption capacity for a hot oil bath, oven-dried and roasted were found to be higher in hot oil bath samples. Swelling capacity and solubility for a hot oil bath, oven-dried and roasted samples respectively, were observed to be higher in oven-dried samples. The mineral composition of cashew flour samples processed using a hot oil bath, oven-dried and roasting were varied significantly at (p&gt;0.05) across the varieties and processing methods. Phosphorus, Ca, Mg, K, Mn, Cu, Zn for hot oil bath, Oven-dried and roasted samples respectively, were significant in hot oil bath samples while Na and iron for hot oil bath, Oven-dried and roasted samples respectively were dominant in oven-dried flour samples. Generally, it was observed that the processing methods adopted significantly influenced mineral and functional properties of cashew kernel flour at (p&gt;0.05). The cashew kernel flour displayed good characteristics of functional and mineral properties. Therefore, flour can serve as a functional ingredient in the formulation of snack products as an alternative to legumes/wheat flour.

Thermodynamics and mechanisms of silver tailings roasting processes

To separate and extract all the useful components of tailings, taking silver tailings as the object, the thermodynamics of silver tailings during the roasting processes was investigated, and the phases transformation mechanism of major minerals were obtained. Based on the mineralogy characteristics of silver tailings, the standard Gibbs free energy changes for the chemical reactions in the roasting processes were calculated; the thermal chemical behaviors and the mineral phases transformation were investigated using TG/DTG-DSC and XRD; and the microstructure changes with chemical composition of microregions were characterized through SEM-EDS. The thermochemical reaction characteristics for the roasting activation of tailings and sodium carbonate at different temperatures were as follows: at 450–650 °C, the ankerite, siderite and sulfide in tailings were oxidized and decomposed, while the crystal transformation of quartz and chlorite occurred; at 650–750 °C, quartz, muscovite and chlorite decomposed to form soluble sodium silicate, sodium aluminum silicate, diopside, sodium ferrite and copper ferrite etc; at 750–800 °C, due to the increase in products with low melting point, the roasted samples melted. During the roasting processes, the surface of minerals depressed and the structures were destroyed. These results can provide a theoretical foundation for thoroughly resource utilization of tailings.

Effects of the Deacetylation Degree of Chitosan on 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) Formation in Chemical Models and Beef Patties

The effects of the deacetylation degree (DD) of chitosan on heterocyclic aromatic amine formation were investigated in chemical models and beef patties. The results in model systems showed that at lower addition levels (10 mg), chitosan with 85% DD showed the strongest inhibitory effect against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation, while chitosan with a higher DD (95%) or a lower DD (72 and 50%) did not show any significantly inhibitory effect. Further mechanism study showed that chitosan addition reduced the content of Maillard reaction intermediates including phenylacetaldehyde and the aldol condensation product but increased the PhIP precursor creatinine residue in the chemical model, indicating that chitosan at least partially competed with creatinine to react with phenylacetaldehyde to inhibit PhIP formation. In roast beef patties, 0.15% (w/w) chitosan (85% DD) significantly reduced the formation of PhIP, MeIQx, 4,8-DiMeIQx, Harman, and Norharman by 56.21, 33.32, 31.35, 25.14, and 28.12%, respectively. Moreover, chitosan significantly inhibited the formation of aldehydes in roast beef patties, further confirming the above-mentioned inhibition mechanism. However, the addition of chitosan might promote fatty acid oxidation. In addition, chitosan addition below 0.15% (w/w) had no significant effect on the textural properties of the roast samples.

Effect of boiling and oven roasting on some physicochemical properties of sunflower seeds produced in Far North, Cameroon.

The effects of different processing methods on proximate composition, total phenolic content, antioxidant activity, lipid oxidation, and mineral contents of sunflower seeds produced in Far North Region of Cameroon were evaluated. Mean moisture, ash, lipid, protein, fiber, and carbohydrate contents of raw sunflower seeds were 6.60%, 2.55%, 44.65%, 20.17%, 4.08%, and 21.25%, respectively. The changes in moisture, ash (excepted in boiled samples), lipid, protein, fiber, and carbohydrate (excepted in roasted samples) were found to be significant for all cooking methods. Ash and lipid contents of samples roasted at 120°C were found to be significant when compared with other cooking methods. Antioxidant activity increased with treatment. After processing, the acid, peroxide, and thiobarbituric acid values increased significantly, whereas iodine value decreased. The roasting process improved the induction time, and samples roasted at 120°C were found to have the highest induction time (2.29 ± 0.09 hr). Raw sunflower seeds were good sources of potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn), and manganese (Mn). Increase in contents of Ca, Mg, Zn, Cu, and Fe was observed during processing. Roasting compared with boiling appeared to be the best cooking method of sunflower seeds concerning nutrient content, antioxidant stability, and lipid stability.

Volatile aroma component of natural and roasted hazelnut varieties using solid-phase microextraction gas chromatography/mass spectrometry

Hazelnut is a very important nutrient in terms of human health. It is widely consumed as natural and roasted. Aromatic components could be used as marker for export criteria in hazelnut. Thus, this study aimed preliminary to compare the aroma profile of some hazelnut varieties and to determine the effect of roasting on aroma component in natural hazelnuts. Hazelnut varieties (18 Turkish and 2 foreign varieties) were obtained and then roasted at 135°C for 30 min. The volatile aroma components of hazelnuts were characterized via solid phase microextraction-gas chromatography-mass spectrometry (SPME/GC-MS). A total of 20 and 29 aroma compounds were detected by SPME/GC-MS in natural and roasted hazelnuts, respectively. Concerning natural hazelnut samples, the highest values among the Turkish and foreign varieties were obtained from nonanal in ‛Kalınkara’, ‛Kan’ and ‛Negret-N9’, which are mainly characterized by citrus, rosy, fatty flavor. In roasted samples, 2(3H)-furanone was determined in highest level in ‛Cavcava’, ‛Mincane’ and ‛Negret-N9’ and the flavor attributes of these varieties were oily-nut-like. In particular, Turkish hazelnut varieties such as ‛Acı’ and ‛Kalınkara’ could be promising in terms of the highest amount of aromatic components in roasted hazelnuts.

Investigation of Different Post-Harvest Treatments on the Quality of Almond Kernels during Ambient Storage

Maintaining almond kernel quality during and after harvest is crucial in producing premium kernel product for Australian and international markets. In this study, we investigated the effects of different post-harvest treatments on changes in moisture content, texture, colour, nutritional profile and flavour of almond kernels over a storage period of 9 months under ambient conditions. Post-harvest treatments included steam pasteurization, volumetric heating pasteurization, oven roasting and dry roasting, which were compared with raw kernels. Moisture and texture analysis revealed that the average values within each treatment group did not change significantly over 9 months, although the breaking force required to create an initial crack in the kernel structure were markedly lower for Steam Pasteurized (SP) and Oven Roasted (OR) samples after 9 months. Sensory analysis conducted by a trained panel of experts revealed that the chewiness of raw samples increased over time, and both toasted and roasted characteristics were low. For OR and Dry Roasted (DR) samples the chewiness was low and roasted and toasted properties were higher. Average overall enjoyment score given to samples as a part of sensory testing was higher for Volumetric Heating Pasteurization (VHP) and DR at start of the storage (control) and stayed higher than others after 6 and 9 month of storage. Testing of nutritional content of samples showed changes in alpha tocopherol content in roasted samples. However, DR samples had higher content in comparison with OR samples. Volumetric heating treatment didn’t diminish tocopherol content of samples in comparison with raw samples while the average alpha tocopherol content of SP over first 3 month of storage was lower. Both SP and OR samples showed lower fat percentage in comparison with raw, VHP and DR. A reduction was observed in Lightness (L*) values for all samples tested. Among the tested treatments OR samples had darker kernels and Raw and VHP samples had lightest colours. The testing results showed the potential of volumetric heating pasteurization and roasting in maintaining quality of kernel over bulk storage period.

The influence of processing conditions on proximate, mineral and phytochemical properties of tiger nut (Cyperus esculentus) flour

Processing of agricultural produce is carried out to improve its nutritional value and consumer acceptability.&nbsp; Different processing operations are used to process cereals and legumes and these include fermentation, germination and roasting. These techniques are important in improving the nutritive values, palatability, digestibility and shelf life. Data on the influence of these processing conditions on nutrients and anti-nutrients of tiger-nut are scanty. The influence of these processing techniques on proximate composition, mineral and anti-nutritional contents of tiger nuts were determined using standard procedures. Fermentation germination and roasting caused significant (p≤0.05) increases in protein from 2.69% to 18.65%, sodium from 6 to 12 mg/100g, potassium from 402 to 517 mg/100g, calcium from 6 to 16 mg/100g and iron from 5 to 12 mg/100g and a significant (p≤0.05) decrease in ash contents. There were also significant decreases in tannin from 0.76 to 0.22 mg/g, phytate from 0.46 t0 0.15 mg/g, saponin from 2.04 to 1.18 mg/g and alkaloids from 1.93 to 1.29 mg/g in fermentation, 1.74mg/g in germination and 1.77 mg/g in roasting, but there occur marginal increases in alkaloids and saponin in freshly germinated and dry roasted samples. Increases or decreases were not observed in magnesium and zinc contents in any of the processing techniques.&nbsp;

Single Origin Coffee Aroma: From Optimized Flavor Protocols and Coffee Customization to Instrumental Volatile Characterization and Chemometrics.

In this study, the aroma profile of 10 single origin Arabica coffees originating from eight different growing locations, from Central America to Indonesia, was analyzed using Headspace SPME-GC-MS as the analytical method. Their roasting was performed under temperature–time conditions, customized for each sample to reach specific sensory brew characteristics in an attempt to underline the customization of roast profiles and implementation of separate roastings followed by subsequent blending as a means to tailor cup quality. A total of 138 volatile compounds were identified in all coffee samples, mainly furan (~24–41%) and pyrazine (~25–39%) derivatives, many of which are recognized as coffee key odorants, while the main formation mechanism was the Maillard reaction. Volatile compounds’ composition data were also chemometrically processed using the HCA Heatmap, PCA and HCA aiming to explore if they meet the expected aroma quality attributes and if they can be an indicator of coffee origin. The desired brew characteristics of the samples were satisfactorily captured from the volatile compounds formed, contributing to the aroma potential of each sample. Furthermore, the volatile compounds presented a strong variation with the applied roasting conditions, meaning lighter roasted samples were efficiently differentiated from darker roasted samples, while roasting degree exceeded the geographical origin of the coffee. The coffee samples were distinguished into two groups, with the first two PCs accounting for 73.66% of the total variation, attributed mainly to the presence of higher quantities of furans and pyrazines, as well as to other chemical classes (e.g., dihydrofuranone and phenol derivatives), while HCA confirmed the above results rendering roasting conditions as the underlying criterion for differentiation.

INCIDENCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN ROASTED PLANTAINS OBTAINED WITHIN OSOGBO METROPOLIS, NIGERIA

The present study was conducted to assess the carcinogenic and non-carcinogenic health risks of PAHs contamination in roasted plantain collected from three different locations within Osogbo metropolis, Nigeria. The PAHs were extracted using Soxhlet extraction technique with n-hexane and dichloromethane (3:1) as the extracting solvent. A column, packed with silica gel, was used for clean-up process and the levels of the targeted PAHs were determined by a gas chromatograph–flame ionization detector (GC-FID). The result revealed that the concentrations of total PAHs detected in the roasted samples at location A, B, C were 3.958 μg/kg, 3.654 μg/kg and 3.217 μg/kg. The HMW carcinogenic PAHs constitute about 32% of the total PAHs in the roasted plantain samples where benzo(a)pyrene, which is a marker for carcinogenicity, was found to be 9%. Comparing these results with the regulatory limits, all the analyzed roasted plantain samples were found below the maximum residual limit (MRL) of 5 μg/kg, but the calculated carcinogenic risk (CR) presented value greater than 1×10-4, signifying health risk associated with the consumption of the roasted plantain. The major source of the PAHs using diagnostic ratios (Fla/Pyr and Ph/Ant) showed that the charcoal used in roasting is a major contributing factor to the high levels of PAHs detected in the roasted plantain samples.

Assessment of technological characteristics and microbiological quality of marinated turkey meat with the use of dairy products and lemon juice.

ObjectiveThe aim of this study was to evaluate the effect of marinating turkey meat with buttermilk and acid whey on the technological traits and microbiological quality of the product.MethodsSlices of turkey meat muscles were marinated for 12 hours in buttermilk (n = 30), acid whey (n = 30) and comparatively, in lemon juice (n = 30). The control group (n = 30) consisted of unmarinated slices of turkey breast muscles. Physical parameters (pH, water holding capacity, colour L*a*b*, shear force, weight loss) were assessed and quantitative and qualitative microbiological evaluation of raw and roasted products was performed. The microbiological parameters were determined as the total viable counts of mesophilic aerobic bacteria, of the Enterobacteriaceae family, and Pseudomonas spp. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.ResultsMarinating turkey meat in buttermilk and whey compared to marinating in lemon juice and the control sample resulted in a higher (p<0.05) degree of yellow color saturation (b*) and a reduction (p<0.05) in the number of mesophilic aerobic bacteria, Pseudomonas spp. and Enterobacteriaceae family as well as the number of identified mesophilic aerobic bacteria in both raw and roasted samples. The lowest (p<0.05) shear force values were found in products marinated in whey.ConclusionThe use of buttermilk and acid whey as a marinade for meat increases the microbiological safety of the product compared to marinating in lemon juice, while maintaining good technological features of the product.

Thermal Decomposition Kinetics of Rare Earth Minerals in Tailings with Addition of MgO

Due to the advantage in deactivating fluorine and enhancing the decomposition of rare earth (RE) minerals, MgO was applied to the magnetizing roasting of Bayan Obo tailings in this work. The effects of MgO dosages, roasting temperature, and holding time on the decomposition rate of RE minerals were experimentally studied. With a MgO dosage of 10 wt.%, the decomposition rate of RE minerals reached 98.09% at 750 °C. The phase composition of roasted samples was characterized by XRD and SEM-EDS. The incomplete decomposition rate was investigated with the observation of leaching residual by SEM-EDS. The decomposition kinetics of the RE minerals with the addition of MgO was analyzed with the Ginstling-Brundshtein model, where the reaction rate was controlled by chemical reaction.

Effects of air temperature on the physicochemical properties and flavor compounds of roasted red ginseng lateral roots in a jet impingement fluidized bed roaster

This study aimed to improve the availability of red ginseng lateral roots by applying air jet impingement fluidized bed roasting as a novel processing technology. The effects of air temperature (150 °C, 160 °C, 170 °C, 180 °C, 190 °C, and 200 °C) on the physicochemical properties and flavor compounds of red ginseng lateral roots were investigated. The air roasting time and velocity of the jet impingement fluidized bed roaster were 10 min and 21.68 m s−1, respectively. The moisture content and bulk density significantly decreased, while the total weight loss, expansion index and specific volume significantly increased as the temperature increased (p < 0.05). The extraction yields significantly increased by 38.34% at 200 °C compared with unroasted samples (p < 0.05). The high-temperature roasted sample had larger and more porous structures on their surfaces than the unroasted sample in the scanning electron microscope images. The major ginsenosides (Re, Rg1, Rb1, Rc, Rb2 and Rd) peaked at 150 °C or 160 °C, whereas the minor ginsenosides (Rh1 and Rg2) peaked at 190 °C or 200 °C. Furfural and maltol increased >444 and >10 times in the roasted samples at 200 °C and 170 °C, respectively, when compared with the unroasted samples.