Mean Moisture Content Research Articles

Assesment of some microbiological and chemical properties of pismaniye sweet

The objective of this research was to determine some microbiological and chemical properties of pismaniye sweet. A total of 47 plain and with cacao pismaniye samples were purchased from retail markets in the Marmara region, Turkey. Mean moisture, ash, fat and total sugar contents were found as 3.16 to 3.31, 0.18 to 0.23, 11.67 to 11.87 and 37.10 to 35.72%, for plain and with cacao, respectively. The microbial counts were in the range of 3.05 to 3.12 log cfu g -1 for total mesophilic aerobic bacteria (TMAB). 2.19 to 2.51 log cfu g -1 for yeast and mould, 0.17 to 0.59 log cfu g -1 for total Coliform group bacteria. It was observed that 51.06% of samples were contaminated by Staphylococcus types, 42.55% by Salmonella-Shigella and 10.64% by Escherichia coli. The microbiological findings showed the presence of high counts of microorganisms depending on poor sanitary practices due to empiric traditional manufacturing procedures.

Digital image analysis of radial shrinkage of fresh spruce (Picea abies L.) wood

Contact-free digital image analysis was performed of the radial shrinkage of fresh, fully saturated small spruce wood beams. An experimental test set-up was developed to ensure constant distance from the charge-coupled device camera to the sample surface as well as constant climate and light conditions during the whole experiment. Dimensional changes were observed immediately after the drying process began. An unexpected distinct effect could be observed which could not be explained by drying surface layers only. After a fast initial radial shrinkage a slowing down of the dimensional changes occurred at high mean moisture contents. A complete interruption of any dimensional changes followed. Finally, a recovery from shrinkage was even observed. It is assumed that strong negative pressure occurred in the fully saturated capillaries owing to dehydration which led to additional dimensional changes. As a consequence, the break of the water column and aeration in these capillaries finally resulted in a recovery period in the shrinkage rate due to the pressure release. After this effect, the dehydration was characterized by a phase of fast and almost linear shrinkage due to drying surface layers. Finally, the shrinkage slowed down to zero when reaching equilibrium moisture content.

Comparison of Nutritional Composition Between Palm Kernel Fibre and the Effect of the Supercritical Fluid Extraction on Its Quality

High fibre foods start to gain much attention in the industrial world, due to its importance in human health for treating and prevention wide range of diseases. Finding new and cheap source of dietary fibre is highly needed. Palm kernel cake which is wastes produced after oil extraction from palm kernels is increasing in volume as the oil palm industry expands in many parts of Asia and Africa. The aim of this study is to compare the nutritional composition of palm kernel fibre derived from PKC samples: Supercritical carbon dioxide - palm kernel cake with testa (SC-PKt), supercritical carbon dioxide-palm kernel cake without testa (SC-PK), and palm kernel cake from palm oil mill. Supercritical carbon dioxide was used to extract the residual oil from Palm kernel with and without testa at temperature of 80°C and pressure 41.36MPa. Total dietary fibre, crude fibre, crude protein, ash and moisture were determined in these samples and compared with palm kernel cake from palm oil mill. The results showed that the palm kernel with testa contains the highest amount of the total dietary fibre with 63.06g/100g sample, crude fibre 8.49g/100g, crude protein content 14.40g/100g, ash 4.43g/100g sample with p<0.05. The mean moisture content of the Palm Kernel with testa was 3.26 which is least than the other samples. The results of this study suggest that, extracting oil using supercritical can minimize the waste by producing a new and cheap source of fibre with good nutrition. Moreover, the defatted palm kernel with testa considered superior than the defatted palm kernel without testa and palm kernel cake, and could be used as a good and cheap source of dietary fibre for human consumption. However, others tests are still needed to confirm it validity for human consumption.

Qualidade de sementes de arroz irrigado produzidas com diferentes doses de silício

O arroz tem expressiva importância no cenário agrícola mundial, dada à extensão de áreas cultivadas e à sua produção. Sua importância e seu crescente consumo no mundo têm levado as instituições de pesquisa à busca cada vez maior por novas tecnologias que possam aumentar a produção de sementes de alta qualidade com um menor custo de produção. Assim, objetivou-se com este trabalho avaliar a influência da aplicação de diferentes doses de silicato de cálcio (0, 800, 1600 e 3200 kg ha-1) no plantio, sobre a qualidade fisiológica de sementes de arroz produzidas e armazenadas por 0, 3 e 6 meses. Foram utilizadas sementes da cultivar Jequitibá, produzidas sob sistema irrigado por inundação, nos municípios de Lambari e Leopoldina - MG. Avaliaram-se o teor de água, germinação, vigor pelo envelhecimento acelerado, emergência e índice de velocidade de emergência e a atividade isoenzimática. O teor de água das sementes de 11,5% permaneceu inalterado durante o armazenamento. Em Lambari, local de solos com baixo teor de Si, houve pequeno efeito favorável do silicato de cálcio aplicado, sobre a qualidade das sementes produzidas. Já em Leopoldina, local de solos com médio teor de Si, a aplicação de silicato de cálcio foi prejudicial à qualidade das sementes produzidas.

Fruit processing residues as an alternative fuel for drying in Northern Thailand

In this study, the fuel potential of residues from local fruit processing facilities in Northern Thailand was assessed. Facilities were surveyed to determine current processing and waste disposal strategies. In facilities handling large amounts of these fruits particularly, residues are currently disposed of in municipal dumps. Fresh processing refuse such as peels and seeds was sampled and analyzed for fuel properties. The results of proximate analysis showed mean moisture content of wastes were 35–75% wb with ash contents of about 2.2–7.1 wt.% db and high volatile matter ranging 67–73 wt.% db. Higher heating values ranged between 18.3 and 19.3 MJ kg −1. Therefore, wastes showed good fuel potential, but high moisture (>60% wb) and nitrogen (>0.6 wt.% db) contents require attention when considering potential fuel applications.

Modelagem matemática e determinação das propriedades termodinâmicas do café (Coffea arabica L.) durante o processo de secagem

A secagem de produtos agrícolas é largamente utilizada no mundo para o controle e a manutenção da qualidade dos produtos agrícolas. O objetivo do presente trabalho foi modelar o processo de secagem e obter os parâmetros termodinâmicos de frutos de café (Coffea Arabica L.), cultivar Catuaí Amarelo, para três diferentes condições de temperatura e umidade relativa (35 ºC e 32,1%; 45 ºC e 15,7%; e 55 ºC e 10,2%). Foram utilizados frutos de café colhidos manualmente com teor inicial de água de 1,25 (b.s.) e submetidos à secagem até atingirem o teor médio de 0,13 (b.s). Seis modelos matemáticos usualmente utilizados para a representação do processo de secagem de produtos agrícolas foram ajustados aos dados experimentais. A segunda lei de Fick foi utilizada para obter os coeficientes de difusão dos frutos de café por meio da cinética da secagem. A energia de ativação para a secagem dos frutos de café, bem como a entropia, entalpia e energia livre de Gibbs, foram obtidas. O modelo de Midili modificado foi o que melhor representou o fenômeno de secagem de frutos de café. Os valores do coeficiente de difusão obtidos foram 2,99 x 10-11, 2,39 x 10-11 e 5,98 x 10-11 m² s-1 para as temperaturas de 35, 45 e 55 ºC, respectivamente. A entalpia diminuiu com o aumento da temperatura do ar de secagem, bem como a entropia. A energia livre de Gibbs aumentou com o aumento da temperatura.

Effect of storage management on free fatty acid content in dry cocoa beans

Though not a quality parameter, it is expected that the free fatty acids (FFA) content must be less than 1.0% to meet the acceptable level of 1.75% in cocoa butter extracted from the dry cocoa beans. This study therefore investigates the FFA content of stored dry cocoa beans from Ghana that was generally low compared to that of Cote d’Ivoire. The FFA content of dry cocoa beans increases with storage time and this was evident for both countries. The mean FFA of Ghana’s cocoa beans was 2.03% in 1999 and 0.90% in 2008 while that of Cote d’Ivoire’s cocoa beans was 2.57% in 2002 and 1.43% in 2008. The low mean moisture content of 6.5% of Ghana cocoa beans and the mean moisture content 8.0% of Cote d’Ivoire cocoa beans might have influenced the differences in mean FFA levels. To evaluate the effect of insect infestation on increase of FFA, dry cocoa beans were infested with ten young adults of Lasioderma serricorne (Fabricus), Tribolium castaneum (Herbst), Cryptolestes ferrugineus (Stephens) and stored for 9 mo under dry condition at 30±2°C. The mean FFA of the insect-infested dry cocoa beans increased from 0.76% at the time of storage to 1.81% after 9 mo of storage. However, the mean FFA of the control dry cocoa beans increased from 0.79% at the time of storage to 0.93% after 9 mo of storage. It could therefore be inferred conclusively that FFA content in dry cocoa beans increases with insect infestation. Keywords : Cocoa beans, Free fatty acids, Storage management, Quality preservation, Insect infestation.

Microbiological and chemical profile of Lebanese qishta [heat-coagulated milk

Qishta is a popular Middle Eastern coagulated cream product, prepared using a traditional heating and skimming process. This study in Lebanon aimed to assess the microbiological and chemical profile of the product. Samples selected from 31 different manufacturers and outlets were analysed using standard methods. The plate counts for the various microorganisms were either of borderline acceptability or unacceptable for Escherichia coli, Salmonella spp. and Listeria monocytogenes (detected in 32%, 7% and 42% of the analysed samples respectively). Chemically, the mean moisture content [67.5 (SD 2.6) g/100 g] and pH (6.53) were relatively high. High counts of spoilage and pathogenic microorganisms and the nature of its chemical composition make qishta highly perishable.

Numerical study of the interaction among a pair of blunt plates subject to convective drying – A conjugate approach

The effect of the relative positioning of a pair of porous blunt plates, subject to convective drying, on heat/mass transfer phenomena is investigated numerically based on a combination of a flow-heat transfer simulation with a suitable drying model. The air flow is assumed incompressible, two-dimensional, laminar, confined in a channel and parallel to the plates. The finite volume method is used and the computed temporal and spatial variations of flow parameters, moisture content and temperature for different arrangements are analyzed. Several configurations are studied: Side-by-Side, Staggered and in-Tandem arrangements, in an attempt to find the optimum relative positioning which results in the highest reduction of the mean moisture content of the plates, as well as in a more uniform drying. It was found that the Side-by-Side arrangement shows the best overall drying behaviour among all arrangements considered, owing to the enhancement of heat/mass transfer caused by the blockage effect. The analysis of the parameters affecting the transport rates and the uniformity of drying as well as the discussion of the development of unfavorable aerodynamic or thermal effects due to the interaction of product units, may be valuable in optimizing the arrangement of the products in the dryer.

Effects of Soy and Corn Flour Addition on Batter Rheology and Quality of Deep Fat-Fried Shrimp Nuggets

In this paper, the effects of soy and corn flour (5 and 10% w/w) addition to the batter formulation on the quality of deep fat-fried shrimp nuggets were evaluated. Rheological properties of batters, coating pick-up, moisture content, and oil content of the samples were determined. Shrimp nuggets were fried at 150 °C, 170 °C, 190 °C, for 1, 2, 3, 4, and 5 min. The coating pick-up, oil and moisture content were found to be directly proportional to batter viscosity. All batters were found to show shear thinning behavior by exhibiting flow behavior index ≤ 1. The batters were modeled as power law fluids. Batter formulation, frying time, and temperature significantly (p < 0.01) affected moisture and oil content of shrimp nuggets. Soy flour added batters provided the highest consistency index, 7.595 and 10.635 Pa.sn for 5% and 10% soy flour added, respectively. Soy flour was found to be an effective ingredient in decreasing oil content of fried nuggets. Batters containing 5% corn flour showed the lowest moisture content and the highest oil content among all the formulations. The mean moisture and fat content of shrimp nuggets coated with batter contained 10% soy and 5% corn flour, fried at 190 °C, for 5 min were 0.59 ± 0.022, 0.480 ± 0.029 and 0.149 ± 0.035, 0.346 ± 0.024 (g/g db), respectively.

Internal friction measurement of tropical species by various acoustic methods

A batch of 54 tropical species was analyzed using free-vibration and forced-released vibration tests. The free-vibration tests were conducted by bending and compression using nylon thread or elastic thread as supports. The wood species used cover a broad spectrum of density values and were obtained from the CIRAD wood collection. Samples were stabilized at a mean moisture content of 11.1%. The goals of the study were (a) to observe the effects of nylon or elastic supports on the measurement of vibration damping, (b) to compare the damping measurements obtained through free vibration in bending and in compression, (c) to understand the relationship between temporal damping and internal friction based on free-vibration and forced-vibration bending tests, and (d) to observe the effect of frequency on bending free-vibration damping on a rosewood specimen (Dalbergia sp., Madagascar). In this study we were able to demonstrate that (a) the type of support has a significant influence on the measurement of the temporal damping, (b) the temporal damping measurements obtained during bending free vibration are linearly linked to those obtained during compression vibration, (c) the expression of internal friction η V according to temporal damping α was identical during compression and bending free vibration: η V = α/(πf), and (d) changes in temporal damping α according to frequency f can be modeled in the form α = β 1 f 2 - β 2 f 4. This form is theoretically justified as the first-order form obtained from the generalized differential equation of linear viscoelasticity.

Mould incidence and mycotoxin contamination in maize kernels from Swat Valley, North West Frontier Province of Pakistan

Mould incidence and aflatoxin B1 (AFB1) and ochratoxin A (OTA) contamination as well as proximate composition and minerals content of maize kernels from Swat Valley, North West Frontier Province of Pakistan was studied during the year, 2007. Results indicated that the mean moisture content of the kernels was within the recommended safe storage levels of ⩽15%. Across the whole valley, Aspergillus, Fusarium, Penicillium and Rhizopus were the most predominant fungal genera identified and amongst the mycotoxigenic species, Aspergillus flavus had the highest incidence. AFB1 content ranged from none to 30.92 μg/kg with the average values of 14.94 and 16.22 μg/kg for Upper and Lower Swat regions, respectively. Similar trend was observed for OTA with the contamination level ranged from <0.001 to 7.32 μg/kg. A significant numbers of samples contained AFB1 and OTA levels above the safe limits as recommended by the USFDA and EU but on the average the results were within the safe limit. These results indicate that maize consumers in Swat Valley may be exposed to the danger of aflatoxins and ochratoxins poisoning. Thus, there is a need for policy makers to establish and enforce maize quality standards and regulations related to moulds and mycotoxins across the area.

Effect of drying method as a pretreatment on CUAZ preservative impregnation in Japanese cedar logs

Green Japanese cedar logs 2 m in length and 18 cm in diameter were dried to a mean moisture content of less than 30% by either air drying or kiln drying. Dried logs were impregnated with copper azole (CUAZ) solution according to Japanese Industrial Standard (JIS) A9002. Preservative absorption was calculated from the log weight before and after preservative impregnation. Impregnated logs were then dried in the air and cut at the center to determine preservative penetration. The penetration area was determined after visualizing the preservative with chrome azurol S. The visualized area indicated that the preservative solution penetrated into the sapwood portion of almost all the air-dried logs. However, the kiln-dried logs did not show full penetration into the sapwood portion. The visualized area of some kiln-dried sapwood showed a penetration value of less than 80%, which is the minimum requirement set by the Japanese Agricultural Standard (JAS) for sawn timber. Statistical analysis showed that penetration in the air-dried sapwood was significantly better than that in the kiln-dried sapwood. It was concluded that air drying is more favorable than kiln drying as the predrying method for CUAZ impregnation. On the other hand, preservative absorption was not affected by the drying method.

The Cumulative Sum Chart for Moisture Control in Lumber Drying

Monitoring the moisture content of lumber is an important part of the manufacturing process. Lumber that is too wet or too dry will have a lower value than properly dried lumber. The cumulative sum (CUSUM) chart is proposed as an alternative to traditional control charts for detecting small sustained changes in the mean charge moisture content of kiln-dried lumber. Charts are presented and interpreted for two kilns. The CUSUM chart readily detected changes in the mean moisture content that were not detected with an X-chart. For the CUSUM chart to work well, the process must be in a good state of control with the mill’s average moisture content near the target moisture content.

Changes in the proximate composition of bluefin tuna (Thunnus thynnus) reared in the cages located on the Gulf of Antalya (Turkey's Western Mediterranean coast) during the fattening period

The aim of this study was to investigate the changes in the proximate composition of bluefin tuna (Thunnus thynnus) muscle reared in cages during the fattening period. Samples were taken from tunas at monthly intervals between July and October. Moisture, crude protein, crude fat and crude ash were analysed. The fat and ash contents increased, and the moisture content decreased during the fattening period. There were no significant differences in the protein content during this period. The mean protein concentration was 21% over this period. The highest levels of dry matter (40%), fat (15%) and ash (1.21%) were found in October. Baitfish (Sardina pilchardus, Sardinella aurita and Alosa fallax nilotica) were also analysed. There were no differences in the moisture, protein and fat contents between baitfish, but a lower ash content was found in sardine than in the others. The mean moisture, protein, fat and ash contents of baitfish were found to be 68.28%; 19.2%; 8.5%; and 1.4% respectively.

Water absorption, anti-swell efficiency, and dimensional stability properties of neem seed-oil treated wild grown Bambusa vulgaris Schard. ex J. C. Wendl. in southwest Nigeria

Bamboo culm is a hygroscopic lignocellulosic material. Hygroscopic properties may be disadvantageous in bamboo material if applied in certain applications and modes where and when extreme moisture variations are likely to occur. This study was aimed at evaluating the moisture absorption and resistance including dimensional stability properties of neem seed oil-treated split bamboo samples using two methods of treatment. Split bamboo samples from the same source were oven-dried at 103±2oC, conditioned to 11.76% mean moisture content, and treated by completely soaking them in oil at room temperature for 24 hours and by soaking in hot oil at 60oC for 4 hours, with untreated samples as control. Results showed that samples soaked in hot oil at 60oC for 4 hours had both the least percentage water absorption and higher anti-swell efficiency, followed by samples soaked in oil at room temperature for 24 hours. Shrinkage in the longitudinal, radial, and tangential directions also followed the same trend. Conclusions and recommendations were made in line with the outcome of the study.

Small‐scale variability in surface moisture on a fine‐grained beach: implications for modeling aeolian transport

AbstractSmall‐scale variations in surface moisture content were measured on a fine‐grained beach using a Delta‐T Theta probe. The resulting data set was used to examine the implications of small‐scale variability for estimating aeolian transport potential. Surface moisture measurements were collected on a 40 cm × 40 cm grid at 10 cm intervals, providing a total of 25 measurements for each grid data set. A total of 44 grid data sets were obtained from a representative set of beach sub‐environments. Measured moisture contents ranged from about 0% (dry) to 25% (saturated), by weight. The moisture content range within a grid data set was found to vary from less than 1% to almost 15%. The magnitude of within‐grid variability varied consistently with the mean moisture content of the grid sets, following an approximately normal distribution. Both very wet and very dry grid data sets exhibited little internal variability in moisture content, while intermediate moisture contents were associated with higher levels of variability. Thus, at intermediate moisture contents it was apparent that some portions of the beach surface could be dry enough to allow aeolian transport (i.e. moisture content is below the critical threshold), while adjacent portions are too wet for transport to occur. To examine the implications of this finding, cumulative distribution functions were calculated to model the relative proportions of beach surface area expected to be above or below specified threshold moisture levels (4%, 7%, and 14%). It was found that the implicit inclusion of small‐scale variability in surface moisture levels typically resulted in changes of less than 1% in the beach area available for transport, suggesting that this parameter can be ignored at larger spatial scales. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Comment on “Field observations of soil moisture variability across scales” by James S. Famiglietti et al.

[1] In a recent paper, Famiglietti et al. [2008] analyzed more than 36,000 ground-based soil moisture measurements to characterize soil moisture variability across spatial scales ranging from 2.5 m to 50 km. They concluded that the relationship between soil moisture standard deviation versus mean moisture content, sq (hqi), has a convex upward behavior with maximum values occurring at mean moisture contents of 0.17 cm cm 3 and 0.19 cm cm 3 for the 800-m and 50-km scale, respectively. On the basis of these data, they derived empirical relationships between the coefficient of variation and the mean soil moisture content in order to estimate the uncertainty in field observations of mean moisture content. The authors are to be commended for providing this valuable database to the scientific community. We agree with the authors that such data are important in improving our understanding about the importance of subgrid moisture variability in the parameterization and simulation of land surface processes. However, the authors limited themselves to an empirical description of the observed data by fitting exponential relationships to the mean moisture content versus coefficient of variation (CV) data. We feel that this is a missed opportunity and would like to argue that an interpretation based on established theories and concepts in soil hydrology and upscaling theories could provide alternative methods and new insights for interpreting such data sets. Specifically, it can be shown from soil physical concepts that for a homogeneous soil, the shape of the moisture retention curve can largely explain observed variations in surface soil moisture, at any specific observation scale. For heterogeneous soils, stochastic upscaling theories may be used to relate sq (hqi) to spatial variability in soil hydraulic properties. These theories can be used to predict sq (hqi) and to examine the sensitivity of this function with respect to soil hydraulic properties.

A Markov chain model for characterizing medium heterogeneity and sediment layering structure

By leveraging use of “soft” data (e.g., initial moisture content, θi), this study applies the transition probability (TP) based Markov chain (MC) model to sediment textural classes for characterizing the medium heterogeneity and sediment layering structure. The TP/MC method is evaluated by simulating the vadose zone moisture movement at a field site, where the stratigraphy consists of imperfectly stratified soil layers. Soil heterogeneity is characterized via spatial variability of the geometry of soil textural classes. When the θi measurements, which carry signature about medium heterogeneity and stratigraphy, are not included in the TP/MC model, it is not possible to identify the horizontal TP. The θi measurements, when transformed into soil classes, are necessary in mapping the soil layering structure prevalent at the site. The soil hydraulic parameters for each soil class are treated deterministically and are estimated on the basis of core samples. To evaluate uncertainty in characterizing geometry of the soil classes, multiple conditional realizations of the soil classes are generated. A Monte Carlo simulation shows that the simulated mean moisture contents agree well with corresponding field observations. The observed splitting of the moisture plume in a coarse sand layer that is sandwiched between two fine‐textured layers, the southeastward movement of the plume during the redistribution period, and the near‐zero fluid flux below the bottom fine layer are adequately simulated. Spatial variability of the field‐measured moisture content is sufficiently captured by the 95% confidence intervals calculated from the Monte Carlo simulations. Investigating the effect of data conditioning on the simulated results shows that a reduction of conditioning data does not necessarily deteriorate simulation results if other conditioning data exist within the mean length of the soil classes. The TP/MC method is flexible so that other types of site characterization data (e.g., geophysical data) can be incorporated as they become available.

Normalization of wood density in biomass estimates of Amazon forests

Wood density is an important variable in estimates of biomass and carbon flux in tropical regions. However, the Amazon region lacks large-scale wood-density datasets that employ a sampling methodology adequate for use in estimates of biomass and carbon emissions. Normalization of the available datasets is needed to avoid bias in estimates that combine previous studies of wood density that used wood sampling at diverse positions in the bole or with various methods of density determination. This paper examines the question of whether regressions for radial variation and for variation in wood density along the bole, both developed in dense forest in central Amazonia (CA), are suitable for the open forests in southern Amazonia (SA) that are currently the target of most of Amazonia's deforestation activity. The wood density of the heartwood and density of full disks or slices (bark, sapwood and heartwood) in each tree were measured to assess the radial variation. For variation along the length of the bole, wood densities at breast height and at the top of the bole were used. Moisture content of the bole was measured in SA and compared with values reported by studies from CA in similar dense forest. Comparing regressions that predict full-disk density from heartwood density, the pattern of radial variation differs slightly and significantly between the two forest types (ANCOVA p = 0.006); the slopes have similar values but the intercepts differ. Variation along the bole in the two forest types does not differ significantly ( p = 0.144), so the CA model for predicting mean bole density from the density of a slice at breast height gives an unbiased estimate of the mean bole density when applied to SA trees. In SA the mean moisture content of the bole was 0.416 (±0.068 S.D.; n = 223 trees). Moisture content of the bole had a strong inverse relationship with basic wood density ( r = −0.77), which explains the lower moisture content in the trees in CA relative to SA. A much weaker inverse relationship was found between moisture content and green wood density ( r = −0.292). The relationship between wood basic density and green (‘fresh’) density presented in this study provides an alternative means of obtaining basic wood density directly in the field when oven drying of samples is not possible.