Moisture Content Ratio Research Articles

An Approach to Evaluate Dehydration of Apples (Malus Domestica L) with the Effect of Temperature and Time Interval under the Response Surface Method

ABSTRACT Moisture content is an important quality feature that directly influences the storability of fruits and vegetables. The main goal of the present study was to estimate the drying behavior of apple slices (Malus Domestica) in a laboratory dryer at the drying temperatures of (40.9, 45, 55, and 65°C) and the time interval of (155.2, 180, 240, 300 and 324.9 minutes) with response surface method. The response surface methodology is used to optimize the dehydration of apple slices, and three thin-layer drying models are applied to the drying data. The effect of drying temperature and time interval tested at three levels on the percentage of moisture content, drying rate, hardness, and rehydration ratio were determined, with R2 values of 0.0761, 0.0519, 0.0564, and 0.2341, respectively. From the results, the actual optimum drying temperature with a time interval of 55°C and 240 min was better suited for the dehydration of apple slices. Therefore, the exact values of moisture content, drying rate, hardness, and rehydration ratio were noted in 11.40%, 0.030 (gwater. gdry. matter −1 cm−2 min−1), 2.35 N m, and 1.03 with a run factor of seven, respectively. Newton, Henderson & Pabis, and Page mathematical models are applied to the drying data, and consistent quality of the proposed models determined by using the calculation of the coefficient of determination (R2), reduced chi-square (X2), and root mean square error (RMSE). Further, from the results, it was conducted that the Newton model was better describing the data with R2, X2, and RMSE values of 0.9989, 0.00014, and 0.0145, respectively, of the apple slices. This manuscript will be helpful for researchers working on commercializing Apple slice processes in China as well as in other countries.

Estimation of Soil Cohesion Using Machine Learning Method: A Random Forest Approach

Soil cohesion (C) is one of the critical soil properties and is closely related to basic soil properties such as particle size distribution, pore size, and shear strength. Hence, it is mainly determined by experimental methods. However, the experimental methods are often time‐consuming and costly. Therefore, developing an alternative approach based on machine learning (ML) techniques to solve this problem is highly recommended. In this study, machine learning models, namely, support vector machine (SVM), Gaussian regression process (GPR), and random forest (RF), were built based on a data set of 145 soil samples collected from the Da Nang‐Quang Ngai expressway project, Vietnam. The database also includes six input parameters, that is, clay content, moisture content, liquid limit, plastic limit, specific gravity, and void ratio. The performance of the model was assessed by three statistical criteria, namely, the correlation coefficient (R), mean absolute error (MAE), and root mean square error (RMSE). The results demonstrated that the proposed RF model could accurately predict soil cohesion with high accuracy (R = 0.891) and low error (RMSE = 3.323 and MAE = 2.511), and its predictive capability is better than SVM and GPR. Therefore, the RF model can be used as a cost‐effective approach in predicting soil cohesion forces used in the design and inspection of constructions.

Heat of Combustion Experiment Based on the Ratio of Moisture Content of Infected and Non-Infected Bursaphelenchus Xylophilus

Heat of Combustion Experiment Based on the Ratio of Moisture Content of Infected and Non-Infected Bursaphelenchus Xylophilus

Effect of different drying methods on drying characteristics, appearance and active components of Belamcandae Rhizoma

In order to explore the effect of different drying methods(drying-in-the-shade, sun-drying, and hot air drying) on appearance characteristics, internal structure and composition of Belamcandae Rhizoma, so as to provide a theoretical basis for screening out suitable drying methods for primary processing. In this study, the Belamcandae Rhizoma's dynamic changes of the moisture content ratio and drying rate with different drying time under different drying methods, as well as the effects of different drying methods on the appearance, drying rate, density, ash, extractives and the contents of six flavonoids(mangiferin, tectoridin, iridin, tectorigenin, irigenin, irisflorentin) were compared. The results showed that fresh Belamcandae Rhizoma consumed the longest time to reach the water balance point by traditional dry drying in the shade, whiche was about 311 h; that by sun drying was 19.3%, which was shorter than drying in the shade; both drying curves were smoother. The section color of the sun drying samples was the closest to that of fresh samples, but the interior is full of holes, with a low density and loose structure. Hot air drying(40, 60, 80 ℃) could save about 27% to 88% of the drying time, which was greatly shorter, with less pores, a larger density and compact structure. Compared with the traditional drying method, the drying rate of hot air drying was reduced by 13.7%. Ash was affected by temperature, the drying conditions under 40 ℃ and below were not significantly different from those of conventional drying. The ash content decreased by 7.73% to 18.5% compared with conventional drying at 60,80 ℃. After conventional drying and 40 ℃ hot air drying, the contents of tectoridin and iridin(glycosides) in the samples were significantly higher than those in 60,80 ℃ hot air drying, while the contents of tectorigenin, irigenin and irisflorentin(aglycones) dried at 60 ℃ were the best. Therefore, considering comprehensive appearance characteristics and content of medicinal ingredients, traditional Chinese medicinal materials after 60 ℃ hot air drying show a solid texture, tight internal structure, good appearance, appropriate reduction of toxic parasides and higher aglycone content.

Study on the Influence of Diatomite with Different Shapes on the Moisture Absorption and Release Performance in Changbai Region of Jilin Province

In this paper, different morphologies of diatomaceous earth (disc, cylindrical) were purified, and characterized by SEM, BET and pore size distribution, and moisture absorption and desorption tests were carried out. The results show that the humidity control performance of the cylindrical diatomite sample is better than that of the disc-shaped diatomite sample. Its 24h moisture absorption, 24h moisture release, volumetric moisture content ratio, average volumetric moisture content and other indicators all exceed Disc-shaped diatomite samples; the specific surface area of cylindrical diatomite samples is higher than that of disc-shaped diatomite samples, and the pore size distribution is more reasonable. Combined with the analysis of humidity control performance, cylindrical diatomite samples are more suitable As an excellent humidity control material.

Process optimization for dehydration of shelled peas by osmosis and three‐stage convective drying for enhanced quality

Peas are highly seasonal and perishable in nature, thereby requiring suitable preservation methods to be available throughout the year. Osmotic drying is one of the suitable methods for preserving perishable and semi-perishable produce. Osmotic drying of green peas was carried out in ternary solutions of water, sodium chloride (NaCl), and sucrose having different solution concentrations and osmotic temperatures. Three-stage drying of osmotically pretreated green peas was carried out in convective tray dryer at air temperatures of 70°C (for first 3 hr), 60°C (for next 2 hr), and 50°C (till final moisture content of below 10% wb). The samples were analyzed for moisture content, color change, sphericity, hardness, and rehydration ratio (RR). The osmotic drying process was optimized using response surface methodology (RSM). The optimized process conditions for maximum sphericity, hardness, and RR and for minimum moisture content and color change were determined as sodium chloride solution (10% w/w) and osmotic temperature of 34.41°C. Practical applications Osmotic drying of foods is advantageous when used in combination with other drying techniques as it reduces total drying time, inhibits enzymatic browning, and also reduces energy costs. This study would help to understand the effect of osmotic solution concentration and osmotic temperature on quality of osmo-convective dried peas. Optimization of process parameters would provide the best combination of osmotic solution concentration and osmotic temperature for achieving better product quality in terms of moisture content, color, hardness, rehydration ratio, and sphericity. The high-quality product hence obtained using optimized process parameters will find utilization not only in soup mixes, ready-to-eat snack foods but also as fresh-like peas upon rehydration during off-seasons.

Influence of flocculant on flow behavior and undrained shear strength of fine coal refuse

The stability of impounded slurry materials in part depends on the potential for flow and undrained shear strength. The purpose of this study is to investigate the effect of an added flocculant on the flow behavior and undrained shear strength of fine coal refuse (FCR). Specimens were formed from fresh FCR slurry samples obtained from an active impoundment slurry discharge pipe, as well as solids recovered from the same slurry mixed with either distilled water or a dispersant solution. Specimens were consolidated over a range of low stresses with different initial void ratios and moisture contents. Flow table and vane shear tests were performed to investigate the influence of background solution type on flow behavior and undrained shear strength. The background solution chemistry has a significant impact on the FCR void ratio, flowability, and the undrained shear strength. The flocculant present in the FCR slurry contributes to higher flow resistance and shear strength at higher values of moisture content and void ratios. A reasonable correlation was observed between flowability and undrained shear strength. For the materials tested in this study, the results indicate an estimate of undrained shear strength may be determined indirectly by conducting a modified flow table test.

Mineralization of Urea-Formaldehyde Fertilizer and Its Availability to Oil Palm Seedling under the Tropical Environment

Easily dissolved fertilizers release nutrient in excess amount to be assimilated by plant roots. Some portions these fertilizers leach out from the root zone and adversely impact the environment. Controlled-release fertilizers are more favorable to reduce fertilizer loss, labor cost, and environmental impact. Urea-formaldehyde (UF) was synthesized by polymerization of urea and 40% formaldehyde solution using H3PO4 as a catalyst. Three mole ratios of urea:formaldehyde, namely, 1.0:1.0, 1.5:1.0 and 2.0:1.0 were synthesized. Mineralization of the UF was conducted using eight different mixtures, four different moisture, and four incubation periods. The experiment included soil alone, soil with compost, soil with UF (1.0:1.0), soil with UF (1.5:1.0), soil with UF (2.0:1.0), soil with UF (1.0:1.0) and compost, soil with UF (1.5:1.0) and compost, and soil with UF (2.0:1.0) and compost. Moisture of the mixtures was adjusted to 20%, 40% 60% and 80% water holding capacity (WHC) of the soil. The mixtures were incubated at room temperature for 1, 2, 4 and 8 weeks, the released NH4+ and NO3- were extracted by 1 M KCl and analyzed via a distillation method. Rates of mineralization increased with mole ratio of urea and moisture content of the soil. N loss increased with the moisture content. The best performance for the compromised condition was a mole ratio less than 1.5:1.0 (urea:formaldehyde) at 60% WHC. Availability of UF and serpentine-phosphate for oil palm seedlings was conducted using 10 treatments. The experiment consisted of soil without amendment; soil with Multicote; soil with cow manure; soil with cow manure and urea; soil with cow manure and UF (1.0:1.0); soil with cow manure and UF (1.5:1.0); soil with cow manure, MgHPO4 and UF (1.0:1.0); soil with cow manure, MgHPO4 and UF (1.5:1.0); soil with cow manure, serpentine-phosphate and UF (1.0:1.0); and soil with cow manure, serpentine-phosphate and UF (1.5:1.0). All amended soils increased vegetative growth of oil palm seedlings compared with the non-amended soils. Urea and UF increased the N content in seedling leaves, while Multicote, cow manure, MgHPO4, and serpentine-phosphate increased the Mg content. The best performance was found in the combination of cow manure, serpentine-phosphate and the UF with mole ratio of 1.0:1.0.

Compositional analysis and phase relations of soil mass from the active landslides of Babai River watershed, Siwalik zone of Nepal

The present study focuses on the compositional analysis and phase relationship of soil mass and their role to trigger landslides in the Babai River watershed, Siwalik zone of Nepal. A total of 76 landslides are selected for sampling and further analysis among 769 active landslides from the total study area. For the classification of soil, the Unified Soil Classification System (USCS) is adopted by using both the sieve and hydrometer analysis. The centered log-ratio (clr) and mean component fraction of sand, silt, and clay are obtained from the compositional analysis by using R and CoDapac v.2.02.21 software. Correlation of phase relationships like moisture content, unit weight, specific gravity, void ratio, porosity, and degree of saturation of each soil samples are obtained. The results indicate that the degree of saturation is highly correlated with moisture content and void ratio but less correlated with the specific gravity and dry density. Furthermore, the highly correlated variables are checked by multiple regression analysis and the best-fitted regression equation was obtained from the phase relation. The centered log-ratio and mean log of silt/clay fraction indicate that silt and clay constituents in the soil are responsible for the landslide initiation in the study area.

Soil Unconfined Compressive Strength Prediction Using Random Forest (RF) Machine Learning Model

Aims: Understanding the mechanical performance and applicability of soils is crucial in geotechnical engineering applications. This study investigated the possibility of application of the Random Forest (RF) algorithm – a popular machine learning method to predict the soil unconfined compressive strength (UCS), which is one of the most important mechanical properties of soils. Methods: A total number of 118 samples collected and their tests derived from the laboratorial experiments carried out under the Long Phu 1 power plant project, Vietnam. Data used for modeling includes clay content, moisture content, specific gravity, void ratio, liquid limit and plastic limit as input variables, whereas the target is the UCS. Several assessment criteria were used for evaluating the RF model, namely the correlation coefficient (R), root mean squared error (RMSE) and mean absolute error (MAE). Results: The results showed that RF exhibited a strong capability to predict the UCS, with the R value of 0.914 and 0.848 for the training and testing datasets, respectively. Finally, a sensitivity analysis was conducted to reveal the importance of input parameters to the prediction of UCS using RF. The specific gravity was found as the most affecting variable, following by clay content, liquid limit, plastic limit, moisture content and void ratio. Conclusion: This study might help in the accurate and quick prediction of the UCS for practice purpose.

Physiological and agrometeorology indices of machine harvestable chickpea genotypes in different planting density under rainfed ecosystem

The physiological and agrometeorological indices are the most precise and straightforward method to evaluate the contribution of different processes in plant development and prediction of yield. The field experiment conducted at ICRISAT, Patancheru, for two years. The results of pooled data revealed that the genotype JG-11 recorded higher SPAD values (62.27 and 63.42 at 30 and 60 days after sowing, respectively), soil moisture content (13.88%) and light absorption ratio (86.44%) and lower light transmission ratio (13.56%) as compared to tall/erect chickpea genotypes. Whereas, tall/erect genotype ICCV-11604 recorded a higher leaf relative water content (66.57 and 32.26%, respectively) at 40 and 70 days after sowing. The indices like SPAD value, leaf relative water content, and soil moisture content progressively and significantly decreased with an increase in plant density to either 20 percent or 40 percent higher than normal, and it was higher with normal plant density of 3.33 lakh ha-1. On the contrary, the light absorption ratio increased with an increase in plant density as evidence of decreased light transmission through the plant canopies. A higher density of 4.66 lakh ha-1 noticed a higher light absorption ratio and lowered light transmission ratio (82.03 and 17.97%, respectively). However, the interaction effect of genotype and plant densities on relative water content, light absorption ratio, light transmission ratio, and soil moisture content found significant, but chlorophyll content found not significant. These indices play an important role in the final contribution to the crop yield, which helps in the selection of suitable genotypes and planting density for maximizing the chickpea production.

Nutrient Content and Drying Quality Characteristics of <i>Achras zapota</i> (Sapota) Pulp Powder Stored in Different Packages

The present study was embarked to understand the nutrient content and drying quality of Achras zapota (sapota) using different drying methods namely shade drying, cabinet drying, vacuum drying and freeze-drying. Fresh and unbruised sapota fruits were collected from the local farms of Gandhigram, Dindigul District. The fruits were cleaned, washed, peeled, deseeded and cut into uniform size and subjected to drying. The samples were coded as A, B, C and D for shade dried, cabinet dried, vacuum dried and freeze-dried respectively and stored in airtight container and zip lock packs (LDPE). The dried samples were used to detect the moisture content, dehydration and rehydration ratio, nutrient content and shelf life using standard procedure. From the results, it is understood that freeze-dried sample had the lowest moisture content. Rehydration ratio of freeze-dried samples stored in an airtight container was (17.68:5), zip lock packs (17.62:5) and dehydration ratio of freeze-dried samples was low when compared to other methods. Nutrient content namely calcium (14.57 ± 0.07 mg, 14.57 ± 0.06 mg) and vitamin C (43.81 ± 0.1 mg, 43.85 ± 0.13 mg) was of highest amount in freeze-dried samples stored in airtight and zip lock packs when compared to other methods of drying. Freeze dried samples had highest Total Soluble Solids (22 ± 0° Brix) and titratable acidity (0.273 ± 0.004, 0.279 ± 0.001 %) stored in airtight container and zip lock packs respectively. The airtight container and zip lock packed freeze-dried powders had a longer shelf life of 30 days than other methods of drying. Thus, it was concluded from the study that, freeze drying method is best suited for drying sapota and it can help to extend the shelf life and retain its nutrient quality after drying.

Sorption behavior and storage stability of microencapsulated transglutaminase by ultrasonic spray–freeze–drying

Adsorption isotherms at 25 °C and 38 °C for microencapsulated microbial transglutaminase (mTG) powder produced by ultrasonic spray–freeze–drying (USFD), conventional spray drying (CSD), and conventional freeze–drying (CFD) methods and USFD–crude (without coating materials) were obtained using the standard static gravimetric method, and experimental data were fitted to the mathematical models. The sorption isotherms exhibited type III behavior, and the Ferro–Fontán model was selected as the best fit, having an R 2 of 0.920–0.995. The sorption isotherms of mTG powder depended on temperature and drying methods. The equilibrium moisture content decreased with increasing temperature, and the monolayer moisture content of the USFD sample was lower than other microencapsulated samples (M 0 = 0.133 kg/kg dry solids for 25 °C and M 0 = 0.080 kg/kg dry solids for 38 °C from Guggenheim–Anderson–deBoer model), followed by CFD and CSD. Furthermore, the storage stability of mTG powders produced by different methods in terms of quality parameters including enzyme activity, moisture content, water activity, color, density, porosity, flowability, and caking degree value was studied in aluminum-laminated polyethylene (ALPE) pouches under storage conditions of 25 °C, 50% relative humidity (RH) for 180 days and 38 °C, 90% RH for 90 days. Inactivation kinetics, the effect of drying methods, and application of the microencapsulation process were also examined on mTG powder during the storage period. The first-order kinetic reaction was successfully applied to the relative activity values of all samples for both storage conditions. Both the drying method and application of microencapsulation showed a significant effect on enzyme activity. When comparing the drying techniques, the USFD samples were the most stable, having 816 and 465 days of half-life times for both storage conditions, respectively. Storage at 25 °C, 50% RH increased the half-life twofold compared with that of the USFD samples kept at 38 °C, 90% RH. The physical properties of mTG powder obtained either USFD, USFD–crude, CFD, or CSD showed that moisture content and wettability values increased, while caking degree and enzyme activity values decreased during storage. USFD samples had the lowest moisture content (5.48%) and Hausner ratio (1.12) and the highest relative activity (86.2%) compared with other samples after 180 days storage at 25 °C, 50% RH. When all quality characteristics and enzyme stability were considered, the USFD method was superior to others, and it was determined to be the best method for the production of microencapsulated mTG powders. mTG powders stored at 25 °C, 50% RH exhibited a longer shelf life.

Cabya (Piper retrofractum Vahl) fruit under open sun drying: drying behavior and modeling of thin layer drying kinetics

Cabya (Piper retrofractum Vahl) fruit is one of Piper species, which indigenously grown in East Java Province, Indonesia, has huge utilizations but lacks postharvest processing investigation. The present study aimed to quantify moisture removal characteristic as well as to determine thin layer drying kinetics model, which represent the drying behavior of cabya fruit under open sun drying. The effect of blanching pre-treatment on the drying behavior of cabya fruit was also evaluated. The cabya fruit at the red edible maturity stage with 68.57±2.20% (wb) of average moisture content were used as raw material. The moisture content, drying rate, and moisture ratio during drying (18 and 24 h in three and four days) were measured and calculated. The calculated moisture ratio data were fitted to the twelve commonly used thin drying kinetics models. The results indicated that blanching pre-treatment affected greatly on drying behavior, i.e., final moisture content, drying rate, and drying kinetics. From all twelve drying kinetics models investigated, Midilli et al. model is found as the best one to depict cabya fruit drying kinetics in both blanching treated and untreated, based on its coefficient of correlation (R), root mean square error (RMSE) and reduced chi-square (χ 2).

The Physico-Chemical Properties of Bovine and Buffalo Whey Proteins Milk by Using Ultrafiltration Membrane Technology

The current study aims to prepare whey from bovine and buffalo fresh milk to make three types of cheese, namely: thermal, acidic and enzymatic. Afterward, whey proteins have been separated, then the concentration process of whey proteins has been conducted by using ultrafiltration membrane technology. Through the previous step, two products have been obtained; first, concentrated whey proteins which is called (Retentate), while the other is called (Permeate). Applying rotary evaporator, whey proteins are concentrated and then drying in two methods: spray-drying and freeze-drying in a form of white and soft powder. The chemical composition has been studied at each phase. The results show the separation, purification, and concentration of bovine and buffalo whey proteins by using ultrafiltration membrane technology. The results show that buffalo whey proteins produced by the method of enzymatic and dried with spray-drying are better than bovine whey protein. Finally, the results show a low ratio of lactose, salts and moisture content at the stages of filtration and concentration. The results present a high proportion of protein to 80 .and low ratio lactose and salt.

Encapsulation of oregano essential oil (Origanum vulgare) by complex coacervation between gelatin and chia mucilage and its properties after spray drying

Oregano essential oil (OEO) was encapsulated by complex coacervation between gelatin and chia mucilage (mass ratio 2:1, solids concentration 0.2% w/w). It was compared with a system of gelatin-arabic gum (GE-GA) as encapsulating agents. Two essential oil concentrations (5 and 7.5% w/w) were studied to determine its effect in the formation of complex coacervates by its encapsulation efficiency (EE). To characterize the complex coacervates Fourier-transform infrared spectroscopy (FTIR), particle size and morphology were determined. FTIR spectrum of complex coacervates showed characteristics peaks of carvacrol, one of the majority components present in OEO. OEO concentration and emulsifier added influenced the particle size and morphology of the coacervates, being the sample with gelatin-chia mucilage (GE-ChM) and 7.5% of OEO, the complex with the highest EE obtained (91.79 ± 0.05%). Complex coacervates with the highest EE were spray dried, testing two inlet temperatures (180 and 160 °C) and two feeding rates (5 and 7.5 g/min). Dried coacervates were characterized in moisture content, solid yield, EE, particle size, bulk density, tapped density, compressibility index, and Hausner ratio. Inlet temperature and feeding rate affected the physical properties studied, being the sample with GE-ChM (160 °C and 5 g/min) the one with the highest encapsulation efficiency observed (95.6 ± 0.39%). Moreover, GE-ChM powders had the best flow properties (compressibility index and Hausner ratio). Therefore, GE-ChM resulted in a better system than GE-GA to encapsulate OEO, being an alternative as encapsulating agents.

SOIL STABILIZATION AND IMPROVEMENT OF MARINE CLAYS USING CEMENT AND LIME IN A MARSHLAND

This study assesses the stabilization of marine clay soil using cement and lime to improve on the subgrade material. The tests conducted include: the natural moisture content, specific gravity, sieve analysis, Atterberg limit, compaction and California Bearing Ratio (CBR). The types of stabilization used were mechanical and chemical. The results obtained were classified using AASHTO classification system and based on the results the soil corresponds to group A-6 soils. The highest CBR values of 33.24% and 424.35% were obtained at 20% cement content for unsoaked and soaked and for lime the highest CBR values were 5.07 and 10.46 for 11% lime content for both unsoaked and unsoaked. Based on the results obtained, the addition of cement and lime to clay soil in the presence of water improved the CBR values for soft clay stabilization for highway construction with low traffic volume. It is therefore concluded that the addition of cement and lime to clay soil improved the bearing capacity and the maximum dry density of the clay soil. Further research should be carried out to examine the effects of industrial by-products on effective clay soil stabilization.

Rapid detection of moisture content and shrinkage ratio of dried carrot slices by using a multispectral imaging system

Carrot has high nutritional value and health-promoting effects and is popular among consumers. Real-time quality detection of dried carrot slices allows producers to adjust the process parameters of the drying device in time, thereby ensuring the final product quality and realizing energy conservation. Traditional methods of detecting moisture content and shrinkage ratio usually require a long measurement time, which is difficult to meet the needs of practical application. This investigated a rapid method based on a novel multispectral imaging system for acquiring multispectral images of samples in 25 wavebands over the spectral region between 675 and 975 nm at one time to detect moisture content and shrinkage ratio of dried carrot slices. The multispectral images of 600 carrot slice samples, which were dried at different times, were acquired using the multispectral imaging system. After extracting the spectral and GLCM features of the samples, prediction models were developed based on partial-least squares regression (PLSR) and least squares-support vector machines (LS-SVM) by using different feature combinations. Compared with PLSR models, LS-SVM models achieved better detection accuracy for moisture content and shrinkage ratio. The LS-SVM model obtained the following best results: coefficient of determination in prediction (Rp) = 0.942, root mean square error of prediction (RMSEP) = 0.0808%, and residual predictive deviation (RPD) = 2.636 for shrinkage ratio as well as Rp = 0.953, RMSEP = 0.0902%, and RPD = 3.271 for moisture content under static condition (without movement). The detection accuracy decreased with increasing movement speed of the test sample. When the movement speed of the sample was lower than 30 mm/s, the moisture content detected achieved satisfactory accuracy, with Rp = 0.941, RMSEP = 0.0981%, and RPD = 3.001. The novel multispectral imaging system shows potential for real-time detection of moisture and shrinkage of products during drying.

Understanding puffing in a domestic microwave oven

AbstractThis work is intended to develop an overall understanding of puffing of a starch‐based snack in a home microwave oven, using primarily the microwave energy. Combination of experimental measurements was used, including dynamic mechanical thermal analysis, CT‐Scan, SEM, image processing, and measurement of temperature, moisture content, and expansion ratio. Effects of various product and process parameters on puffing, including those of pretreatment to produce the half product, were studied. Experimental data showed that the physicochemical processes contributing to crust formation were gelatinization of starch, migration of soluble ingredients to the surface, and shrinkage at the surface. A thicker material was harder to puff due to its increased mechanical resistance. Higher microwave power, leading to higher rate of evaporation, increased expansion. Evolution of mechanical properties of the crust greatly affected the final shape of the puffed product. In overall understanding, critical determinants of a puffing process were attributed to three material factors (reduced surface permeability, optimal moisture content, and deformability) and two process factors (intense heat and higher internal pressure from evaporation).

Osmo-solar drying of bottle gourd (Legeneria Siceraria)

The bottle gourd is a common vegetable in India subcontinental. Osmotic dehydration increases the storage ability of fruits and vegetables making them available throughout the year. Dehydrated products also play a great role in processed foods of all kinds and the way to achieve high quality dehydrated products are desired. The combination of osmosis with solar drying has been put forward, mainly for tropical fruit. A 24-hour cycle has been suggested combining osmodehydration, performed during the night, solar drying during the day. The well washed bottle gourd fruits were then peeled off with help of stainless-steel hand peeler. Pieces of bottle gourd cubes (1cmx1cmx1cm) were then cut out using a ruler and knife. The salt solution with 5, 10, 15, 20, and 25% (w/w) concentration were prepared. Bottle gourd cubes were immersed in the osmotic reagents with a fruit to osmotic solution mass ratio of 10:1, 20:1 and 30:1 soaking experiments were conducted at 400C, 500C and 600C in a 500 mi capacity water bath. The osmotic dehydration was done for a period of 1, 3, 5, 7 and 9 h and replicated thrice. The dependent variable studied was moisture content after dehydration. Moisture content of sample was determined by standard air oven method (Ranganna, 1995). The minimum moisture content was 46.9% (wb) for samples osmotically dehydrated at 600C for 9 h at 30:1 fruit to osmotic solution at 25% concentration. The moisture content of bottle gourd cubes observed decreases with higher concentration, temperature and mass ratio. Solar drying characteristics of 9 h bottle gourd cubes at 600C are determined by solar tray dryer. During the process of solar drying of 9 h bottle gourds cubes, the air temperature inside the cabinet varies 44 to 810C. and relative humidity inside the chamber was measures 34 to 58 percent. The minimum value of final moisture content of osmo-solar dried bottle gourd cubes was 8.3% at 600C for sample of 10:1 mass ratio and maximum value of final moisture content was 24.4% of at 600C for 30:1 sample.