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Abstract Challenge tests with eight brands of fresh ricotta showed rapid growth of Listeria monocytogenes and significant variability in physical-chemical characteristics. Thus, two cardinal parameters models were developed for the growth of L. monocytogenes in ricotta including, respectively, terms for temperature (Model 1) and temperature and pH (Model 2). Also an extensive, existing growth model including the effect of organic acids (Model 3) was product recalibrated to predict growth of L. monocytogenes in ricotta. Interestingly, a lack of anti-listerial effect of organic acids in ricotta was observed in this study. The range of applicability of Models 1 and 2 in ricotta (characterized by absence of competitive microbiota) included storage at temperatures from 4.1 to 20.6 °C, pH from 5.5 to 6.6, moisture contents from 72% to 82%, NaCl from 0.38% to 0.60%, concentrations of acetic acid from 579 to 1559 ppm in the water phase, citric acid from 14,774 to 46,116 ppm in the water phase, and lactic acid from 0 to 4146 ppm in the water phase. Comparing observed and predicted maximum specific growth rates of L. monocytogenes in ricotta showed a bias-factor significantly above 1, for existing models developed for broth and these models were thus fail-safe with predicted growth being faster than observed, while typically below 1 for models developed for other food types. The models developed in the present study showed bias-factors of 1.10, 1.06 and 0.78, respectively, for Model 1, 2, and 3. In particular, Model 1 and 2 developed and successfully validated could allow an easy determination of safe shelf-life of ricotta and facilitated the reformulation the product with the aim to increase shelf-life or safety. Highlights • Eighteen challenge tests showed evident growth of Listeria monocytogenes in fresh ricotta. • A new product specific model predicted with good performance the growth of L. monocytogenes in ricotta (Bf = 1.10). • Temperature and pH models facilitated product reformulation to prevent growth of L. monocytogenes in ricotta. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A reliable method for the analysis of 30 elements in honey samples is described. • Method performances were verified by inter-techniques comparison (ICP-MS/ICP-OES). • Four typical quality parameters of Lazio honeys were measured, they have good quality. • Several toxic elements, sugar and moisture didn't discriminate the production sites. • Results show that honey is not a reliable biomonitor of environmental contamination. Abstract The levels of 30 elements (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, U, V, Zn) and some typical quality parameters were measured in 40 honey samples from the Lazio region (Italy). The main purpose of this study was to enhance the information variety. The mean values for the quality parameters were: pH, 4.0; sugar, 80.9 °brix; moisture, 17.4%; electrical conductivity 0.63 mS cm-1. Mineral elements were quantified by ICP-OES and ICP-MS and compared with literature data. The most abundant minerals decreased in the following order (mean - μg g-1): K: 1450 > S: 107 > Ca: 86 > P: 75 > Na: 45 > Mg: 34. Chemometrics was applied in order to detect significant differences among the five provinces of honeys production. Overall, several elements (As, Cd, Cr, Cu, Fe, Ni, P, Pb, Sb, Se, Sn, V, Zn), sugar and moisture did not discriminate the Lazio provinces. This strongly agrees with our previous findings that honey is not a reliable biomonitor of environmental contamination. There are no evident signs of pollution for the Lazio honeys confirming their good quality and safety. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of different encapsulating agents (maltodextrin, whey protein isolate and the modified starch Capsul ® ) on the physicochemical properties and lycopene stability of a tomato concentrate microencapsulated by spray drying. Different formulations were produced according to an experimental mixture simplex-lattice design, where the independent variables were the concentrations of each encapsulating agent. Physical properties (moisture content, solubility and hygroscopicity), lycopene concentration and the antioxidant capacity of particles immediately after drying, as well as lycopene stability during storage, were analyzed as responses. Particles presented initial lycopene content between 333 and 494 μg/g. The powders produced with maltodextrin and modified starch presented the highest concentrations of this carotenoid and greater antioxidant capacity. These two responses showed high degree of correlation with each other. Maltodextrin and modified starch also led to lower lycopene degradation rates during storage and, therefore, these encapsulating agents were considered the most suitable for the tomato concentrate encapsulation. [ABSTRACT FROM AUTHOR]

The live fuel moisture content is an important factor in estimating the risk of forest fires and their rate of spread. However, due to a lack of research, the FMC values in the Mediterranean region of Andalusia, Spain, must be obtained by sample collection. This study is therefore the first to provide tools for estimating the moisture content of the most widespread plant species in Andalusia. First, samples were collected to estimate the moisture content of the plants; these data were collected from May 2007 to the present. Each species has its own range of moistures that depend on the time of year and the physiological state in which they are found. Secondly, an extensive database was obtained for each day of sample collection from the nearest weather station with free access. The statistics are performed at 12 solar hours on the day of sample collection and 24 h before collection, and then at 7 days, 14 days, 1 month, 3 months and 6 months before the day of collection. Finally, this database was statistically analyzed in two ways: Multiple linear regressions and random forest for each species. The predictive capacity of random forest is superior (R2 > 0.89) to that obtained in linear regression (R2 < 0.86). The highest root mean square error obtained in the case of the random forest is 0.74479 while in the linear regressions it was 1.29184. Consequently, uncertainty regarding fire behavior in the case of forest fires is reduced. • Moisture samples collected from May 2007 to April 2021. • Substantial improvement of the estimates of LFMC through Random Forest. • LFMC is a fundamental variable for flammability and rate of fire spread. [ABSTRACT FROM AUTHOR]

Woody biomass is currently sold on a weight basis, practical moisture sensors are essential for fair sales, especially in energy markets. To address this need, an 8-electrode electrical capacitance tomography (ECT) sensor was built and tested for predicting moisture content of wood chips and compared with the near infrared spectroscopy (NIR) method. The goal was to find an optimal means of measuring moisture content of woody biomass in the form of chips in two situations: individual chips and bulk samples. Tests were made on chips ranging in moisture content from 4% to 140% (d.b.). Results indicated that NIR had better performance in measuring moisture of single wood chips, while ECT was more accurate and rapid in bulk moisture determination. Knowledge of the mass of wood chips under test was required in the ECT moisture prediction model, unlike in the case of NIR. Both methods had the capability to measure moisture content of biomass while in motion. From a practical standpoint, however, only a portion of the material flowing past a near-infrared sensor could be practically scanned and the sub-sampled biomass would have to be representative of the entire population to be accurate. The ECT sensor, on the other hand, could likely be designed to scan the entirety of a large quantity of moving material and provide an accurate bulk average moisture content. Compared to a single paired-plate capacitance sensor, the ECT system also provided images, through its tomography function, that displayed permittivity distribution variability throughout bulk biomass samples. [ABSTRACT FROM AUTHOR]

Precisely estimating the top electrode voltage of a radio frequency (RF) system is important for computer simulation of sample temperatures. The goal of this study was to validate whether the developed equations can be applied to determine the top electrode for RF heated soybeans with different moisture contents. Soybeans with moisture contents of 6.7% and 8.7% (w.b.) were treated in a 27.12 MHz, 6 kW RF system under 5 electrode gaps. The results showed that the top electrode voltage increased almost linearly both with increasing moisture content and decreasing electrode gap. The maximum difference of the estimated top electrode voltages was less than 10% relative error between the anode current and the measured current in the same conditions. The temperature distributions in three representative layers from simulation were in good agreement with those from experiment, as was the average root mean square error (RMSE) of 1.6% for temperature profiles in three selected positions. The validation results demonstrated that the established equation using anode current was suitable for estimating the top electrode voltage when soybeans of different moisture contents were heated in RF systems. [ABSTRACT FROM AUTHOR]

The non-uniform temperature distribution created in the processed materials limits the wide application of microwave treatment. The non-uniform temperature also increases the chance of insects surviving or moving out from the treated materials. Wheat (14, 16 and 18% moisture contents, wet basis) with or without insects ( Cryptolestes ferrugineus (Stephens)) was continuously or intermittently treated inside a microwave oven for 30, 60 and 90 s. Three dimensional distributions were determined by measuring temperatures and moisture contents at 27 locations inside a 10 × 9 × 9 cm 3 plastic container. The adults and larvae of C. ferrugineus , which did not escape from the treated wheat, were sieved out or forced out using the Berlese funnel method. Temperatures and moisture contents had different mean, maximum and minimum values in different replicates when treatment time was 30 s. Long treatment time (90 s) generated a dry and hot spot at the same position even though the hot and dry spots were not at the same position in different replicates. Intermittent treatment did not generate more even distributions of temperatures and moisture contents in dry grain, while wet grain (>16% MC) did. Most of the introduced adults were extracted and there was no significant difference between intermittent or continuous treatment methods. Microwave treatment did not kill all insects, however the number of offspring decreased by >75%. Driving insects out of wheat could be an alternative method for insect disinfestation and detection. [ABSTRACT FROM AUTHOR]

The use of near-infrared spectroscopy for evaluation of moisture content of Jatropha curcas kernels and heating value of its residue after oil extraction were studied. In total, 100 samples of whole kernels from green, yellow and black fruits and oven-dried kernels scanned in diffuse reflection mode using a Fourier transform NIR spectrometer at wave numbers of 1,250,000–400,000 m −1 were used to develop moisture-predicting models. The corresponding residues after the oil extraction of the samples scanned in transflection mode using the same spectrometer and wave number range were used to develop the heating-value-predicting models. The models correlating the spectral data and the corresponding values measured using the reference method were developed by partial least squares regression and were validated using a test set. For the moisture content and heating value, coefficients of determination ( R 2 ) were 0.969 and 0.860, root mean square errors of prediction (RMSEP) were 4.0% wb and 360 J g −1 , biases were −0.7% wb and −17 J g −1 and ratios of prediction to deviation (RPD) were 5.7 and 2.6, respectively. In addition, vibration bands of fibre and cellulose had important effects on the prediction of the heating value. [ABSTRACT FROM AUTHOR]

The kinetics of the dehydration of alfalfa stems, leaves and the whole alfalfa plant ( Medicago sativa L) was studied experimentally at lab-scale using a fixed-bed dryer with warm air at 328, 333, 338 and 343 K. Following the evaluation of the influence of bed thickness, air mass rate and air temperature on the kinetics of drying, a kinetic model of globalised parameters is proposed. The kinetic model was designed to simulate the exchange of moisture between alfalfa and the surrounding air and the variation of temperature inside the substrates with time simultaneously. In a first step, the kinetic model was applied to stems and leaves separately. The model reproduced 94.4% and 70.1% of the moisture experimental results obtained for stems and leaves, respectively, within an error band of 15%. Moreover, 95% of the experimental results regarding the variation of temperature inside stems with time were simulated. The kinetic model was then applied to the whole alfalfa plant considering its content of stems (60% wet weight) and leaves (40% wet weight) using the same kinetic parameters and variables fixed for their single modelling. The model reproduced 82.2% of the moisture experimental results obtained for the drying of the whole alfalfa plant. This kinetic model could be a useful tool for the design of a drying device based on scientific evidence. [ABSTRACT FROM AUTHOR]

Abstract: Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9–392.9 rpm), feed moisture (10.9–21.0 g/100 g) and bean flour level (4.8–55.2 g/100 g) on the specific mechanical energy (SME), sectional expansion index (SEI), longitudinal expansion index (LEI), volumetric expansion index (VEI) and density (D) of the extrudates. The instrumental texture was also analyzed. The independent variables had significant effects on the physical properties (SEI, VEI and density) of extrudates, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (≥19 g/100 g) and lower screw speed (≤333 rpm), the results of the expanded product were not satisfactory. [Copyright &y& Elsevier]

Abstract: Phosphorus (P) is a scarce, nonrenewable resource; its acquisition by plants decreases when soil moisture declines, as anticipated under future climate-change scenarios. It is, therefore, important to understand plant responses and adaptations to dual moisture and P limitations, in order to maintain crop productivity and predict plant performance in natural ecosystems. We review current knowledge of the effect of simultaneous water and P shortage on plant function, and identify key knowledge gaps. Plants have developed a range of adaptations to ensure P uptake is adequate to maintain vital functions within a broad range, at least until a certain level of P and/or drought stress is exceeded. Differences in plant growth and amount of P taken up under dual moisture and P limitations greatly depend on the rate of soil drying and wetting, the severity and duration of drought cycles, plant uptake capacity, root system plasticity, presence and magnitude of hydraulic redistribution, P-resorption ability, and soil properties such as waterholding capacity, P diffusion rate, P mineralization and fixation rates, and the activity of arbuscular mycorrhizal (AM) symbioses. During the process of soil drying, both P fertilization and association with AM fungi may increase performance under drought, until a certain level of water stress is exceeded. A small number of previously reported contradictory results probably reflect differences/limitations in experimental approaches. When breeding crop varieties to increase the efficiency of P and water acquisition, and when examining performance of species in natural ecosystems, multiple and interacting processes, from the scale of cellular to whole plant, must be considered. [Copyright &y& Elsevier]

Abstract: Temporal environmental variation is a leading hypothesis for the coexistence of desert annual plants. Environmental variation is hypothesized to cause species-specific patterns of variation in germination, which then generates the storage effect coexistence mechanism. However, it has never been shown how sufficient species differences in germination patterns for multispecies coexistence can arise from a shared fluctuating environment. Here we show that nonlinear germination responses to a single fluctuating physical environmental factor can lead to sufficient differences between species in germination pattern for the storage effect to yield coexistence of multiple species. We derive these nonlinear germination responses from experimental data on the effects of varying soil moisture duration. Although these nonlinearities lead to strong species asymmetries in germination patterns, the relative nonlinearity coexistence mechanism is minor compared with the storage effect. However, these asymmetries mean that the storage effect can be negative for some species, which then only persist in the face of interspecific competition through average fitness advantages. This work shows how a low dimensional physical environment can nevertheless stabilize multispecies coexistence when the species have different nonlinear responses to common conditions, as supported by our experimental data. [Copyright &y& Elsevier]

Abstract: Using a spatially explicit mathematical model for water-limited vegetation we show that spatial instabilities of uniform states can lead to species coexistence under conditions where uniformly distributed species competitively exclude one another. Coexistence is made possible when water-rich patches formed by a pattern forming species provide habitats for a highly dispersive species that is a better competitor in uniform settings. [Copyright &y& Elsevier]

Abstract: Here we examined the response mechanisms and the strategies adopted to cope with drought stress in Jatropha curcas L. Response mechanisms to water stress were explored in three different accessions (from Brazil, Tanzania and Suriname) of J. curcas in terms of water and osmotic relations, gas exchange, PSII photochemistry, and growth performances. Plants were exposed to 18 days of water stress (irrigation was kept at 20% of water holding capacity) followed by 13 days of relief from stress. J. curcas withstands drought stress with a drought-avoidance mechanism through a water saving strategy. These responses include selective abscission of leaves, and marked decreases in net photosynthetic rates and water use efficiency. This allows plants to maintain an “above-lethal” water potential during stress, and to recover net assimilation rate promptly when water availability to the roots is resumed. The Suriname accession displayed greater reductions in net photosynthesis, maximal efficiency of PSII photochemistry (F v/F m), total leaf area and plant dry weight, as compared with both Tanzania and, particularly, the Brazil accession, during drought stress. Impairment of PSII photochemistry was also observed in the Suriname accession at the end of the relief period. Water-stressed J. curcas, irrespective of seed source, was capable to recover net photosynthesis to the level of the well watered counterparts by the end of the relief period. Our data allow to conclude that J. curcas may survive to drought spells of moderate intensities but, at the same time pose serious concerns for its profitable cultivation in arid/semi-arid regions worldwide. [Copyright &y& Elsevier]

Abstract: A plastic-like material can be obtained by thermomolding wheat gluten protein which consists of glutenin and gliadin. We studied the effect of molding temperature (130–170 °C), molding time (5–25 min) and initial wheat gluten moisture content (5.6–18.0%) on the gluten network. Almost no glutenins were extractable after thermomolding irrespective of the molding conditions. At the lowest molding temperature, the extractable gliadin content decreased with increasing molding times and moisture contents. This effect was more pronounced for the α- and γ-gliadins than for the ω-gliadins. Protein extractabilities under reducing conditions revealed that, at this molding temperature, the cross-linking was predominantly based on disulfide bonds. At higher molding temperatures, also non-disulfide bonds contributed to the gluten network. Decreasing cystine contents and increasing free sulfhydryl and dehydroalanine (DHA) contents with increasing molding temperatures and times revealed the occurrence of β-elimination reactions during thermomolding. Under the experimental conditions, the DHA derived cross-link lanthionine (LAN) was detected in all gluten samples thermomolded at 150 and 170 °C. LAN was also formed at 130 °C for gluten samples containing 18.0% moisture. Degradation was observed at 150 °C for samples thermomolded from gluten with 18.0% moisture content or thermomolded at 170 °C for all moisture contents. [Copyright &y& Elsevier]

Abstract: Using broken rice and rice bran as raw material, texturized rice (TR) was prepared by Improved Extrusion Cooking Technology (IECT) in which gelatinization is formed by means of low temperature and high pressure. The expansion of extrudate was hardly changed so that TR showed similar texture properties and shape with polished rices. The effect of rice bran addition (0% and 4%) and IECT conditions, including feed moisture content (26.6–33.4%), screw speed (20.1–32.6 rpm) and shearing compression metering zone temperature (SCMT, 69.8–120.2 °C) on the physicochemical, texture and nutritional characteristics of TR, were investigated by response surface methodology using Central Composite Design. When the bran addition was 4%, feed moisture content was 30%, screw speed was 26.6 rpm, SCMT was 95 °C, prepared TR contained 16.61 ± 0.02% of total dietary fiber, 9.40 ± 0.04% of protein, 3.68 ± 0.03% of fat, 2.42 ± 0.02 μg/g of thiamin, 0.52 ± 0.01 μg/g of riboflavin and 16.07 ± 0.12 mg/100 g of γ-oryzanol (dry matter content). The content increase of TDF for TR was 15.81% and the content increases of nutrients for thiamin, riboflavin, and γ-oryzanol were 1.39 μg/g, 0.24 μg/g, and 8.99 mg/g dry matter content, respectively, compared with those of polished rice. [Copyright &y& Elsevier]

Abstract: Distillers dried grains with solubles (DDGS), a major co-product from the corn ethanol industry, has high feed value for its chemical composition. The ratio of wet distillers grains (WDG) and condensed distillers solubles (CDS) added during the production process determines the chemical composition of DDGS. Effect of changing this ratio and the influence of moisture content on glass transition behavior of DDGS was studied. Five prediction models were evaluated to explain the glass transition of DDGS. The mixed trends in the result indicated the complex behavior of DDGS particles and revealed that both moisture content and chemical composition impact the glass transition behavior of DDGS. Onset glass transition temperature ranged from 20 to 30 °C depending on the chemical composition. Kwei equation predictions were better than the predictions by Gordon–Taylor equation. The glass transition temperature of DDGS can be mathematically explained by combining the moisture content and chemical components protein, fiber, glycerol, and sugar percent. The artificial neural network (ANN) model gave a better prediction of onset and midpoint glass transition temperature of DDGS and this might be due to the accurate mapping of the interaction between chemical components. [Copyright &y& Elsevier]

Abstract: This study reports the measurement of grain density and grain volume of barley grains using a gas displacement technique. The densities of single kernels were determined and were highly correlated with measurements of larger quantities of kernels (10, 25 or 800). Grain weight and volume were significantly correlated when measuring 800 kernels (0.99, P <0.001), 25 kernels (0.99, P <0.001), 10 kernels (0.98, P <0.001), and a single kernel (0.97, P <0.001), and the standard deviations were low for the five replicate measurements. The relationship between grain density and endosperm hardness was significantly correlated (0.57, P <0.001), as was the relationship between grain density and test weight (0.70, P <0.001). Grain density was negatively correlated to moisture content (−0.65, P <0.001), but not protein content. Endosperm hardness was positively correlated to protein content (0.45, P <0.001), but not moisture content. Although grain density and endosperm hardness are interdependent physico-chemical traits, different grain components appear to interact independently. Gas displacement technique could be applied to determine the distribution of grain density within a sample. Therefore, this technique will assist breeding programs to identify genomic regions associated with these physico-chemical traits, and produce superior malting and feed quality through uniform varieties with inherently denser, plumper grain. [Copyright &y& Elsevier]

The extraction of important phytochemicals such as carotenoids from sweet paprika using supercritical carbon dioxide (SC–CO 2) was discussed in this paper. The effect of particle size, moisture content, and composition of raw material on extraction efficiency, the content of carotenoid in the paprika extract and recovery of carotenoid were demonstrated. Results of SC-CO 2 extraction were compared to extraction using n-hexane. It was observed that increasing lipid content and reducing particle size led to an increase in extraction efficiency and also the increase in carotenoids recovery. The moisture content of paprika below 7.5 g/100 g did not have an effect on process efficiency and carotenoid extraction. However, higher content of water in paprika has an impact on the decrease of carotenoid recovery, and it necessitated the additional separation of water from the paprika extract. The optimal working parameters with respect to the extract yield and recovery of carotenoid was the extraction of paprika with the moisture content of 7.5 g/100 g and particle size of <0.2 mm using SC-CO 2 at 45 MPa and 50 °C. Image 1 • Pilot scale applied to study SC-CO 2 extraction of carotenoid from paprika. • The highest carotenoid recovery was achieved for the particle size of <0.2 mm. • The moisture content had a greater effect on carotenoid recovery than extract yield. • The optimal moisture to achieve high carotenoid recovery was 7.5 g H 2 O/100 g. [ABSTRACT FROM AUTHOR]