Volume 9, Issue 4 -

The aim of this work was to study the convective drying of anchovy ( Engraulis anchoita ) fillets and to evaluate the final product characteristics through its biochemical and functional properties. The drying temperatures were of 50, 60 and 70°C, and the fillet samples were dried with the skins down (with air flow one or the two sides) and skins up (with air flow one side). The drying experimental data were analyzed by Henderson–Pabis model, which showed a good fit ( R 2 > 0.99 and REQM < 0.05). The moisture effective diffusivity values ranged from 4.1 × 10 –10 to 8.6 × 10 –10 m 2 s −1 with the skin down and 2.2 × 10 –10 to 5.5 × 10 –10 m 2 s −1 with the skin up, and the activation energy values were 32.2 and 38.4 kJ mol −1 , respectively. The product characteristics were significantly affected ( p < 0.05) by drying operation conditions. The lower change was in drying at 60°C with air flow for two sides of the samples and skin up. In this condition, the product showed solubility 22.3%; in vitro digestibility 87.4%; contents of available lysine and methionine 7.21 and 2.64 g 100 g −1 , respectively; TBA value 1.16 mg MDA kg −1 ; specific antioxidant activity was 1.91 mM DPPH g −1 min −1 , and variation total color was 10.72.

This work was made aiming at studying the best model for the rheological properties of Cupuassu ( Theobroma grandiflorum , Schum) pulps with 14 (in nature), 17, 19, 23 and 25°Brix of total soluble solids (TSS) which were measured at 20, 30, 40, 50 and 60°C temperature using a concentric cylinder rheometer. The results were adjusted to the following nine models: Ostwald-de-Waele (power law), Bingham, Casson, Generalized Casson, Heinz–Casson, Herschel–Bulkley, Mizrahi–Berk, Schulmann–Haroske–Reher and Windhab. The parameters of the best model were correlated with pulp temperature and TSS by polynomial regression analysis and were kept in the regression equation only those parameters that contributed more than 1% to the variation of the independent variable. The results indicate that the rheological behavior of Cupuassu pulp in different concentrations and temperatures can be modeled by the Windhab model, although other models can be used in a narrower band of shear stress.

The objective of this work was to study the convective drying process used for cylindrical samples of two different pear varieties, one originating from Europe ( Pyrus communis ) and the other from Asia ( Pyrus pyrifolia ), submitted to two blanching treatments, as well as determine some coefficients referring to heat and mass transfer and thermodynamic parameters of the process, being: enthalpy (Δ H *), entropy (Δ S *) and Gibbs energy of activation (Δ G *). All samples were dried in a forced air oven at temperatures of (62, 76, 84 and 92)°C until reaching a constant mass. The heat and mass transfer coefficients referring to the constant and falling-rate drying periods were obtained by adjusting the experimental data to wet bulb temperature and liquid diffusion models, respectively. The heat and mass transfer coefficients varied linearly with temperature. Blanching altered the drying behavior of the two varieties in relation to the non-blanched samples, mainly at the elevated drying temperatures of 84°C and 92°C. Δ H * and Δ S * decreased while Δ G * increased with the elevation of drying temperature; therefore, it was possible to verify that variation in the diffusion process in pears during drying is dependent on energetic contributions of the environment.

In this study, drying characteristics of canola seeds were determined using heated ambient air at 40, 50 and 60°C, relative humidity of 20, 40 and 60% and constant velocity of 3 m/s. To select a suitable drying curve, six thin-layer drying models were fitted to experimental data. The models were compared according to three statistical parameters: R 2 , reduced chi-square ( χ 2 ) and root mean square error. Using some experimental data, an Artificial neural network model, trained by Feed Forward Back-Propagation algorithm, was developed to predict moisture ratio values based on the three input variables. Different activation functions and several rules were used to assess percentage error between the desired and predicted values. According to the results, the approximation of diffusion drying model had better agreement with the drying data. The artificial neural network model was able to predict the moisture ratio quite well with R 2 of 0.9994. The predicted mean square error was obtained as 0.00012575.

Rice grain conditions within the sun-drying bed predicted by a mathematical model during drying were used to relate drying parameters to the head rice yield (HRY) which is the key rice quality metric. A number of parameters were derived to characterise the mechanisms of grain fissures and breakage postulated in the literature, and the model was used to estimate these parameters. These parameters were then regressed against the HRY experimental data to determine the contributing mechanisms. An increase in bed temperature, the maximum temperature at the top of the bed, the size of the moisture content gradients within a rice grain and the difference from the critical point for drying were all found to negatively affect HRY. By stirring the bed regularly and covering and shading the bed during the hottest parts of the day, HRY can be significantly increased leading to better returns to the farmer.

In this research, the experiment is done by a dryer. It could provide any desired drying air temperature between 20 and 120°C and air relative humidity between 5 and 95% and air velocity between 0.1 and 5.0 m/s with high accuracy, and the drying experiment was conducted at five air temperatures of 40, 50, 60, 70 and 80°C and at three relative humidity 20, 40 and 60% and air velocity of 1.5, 2 and 2.5 m/s to dry Basil leaves. Then with developed Program in MATLAB software and by Genetic Algorithm could find the best Feed-Forward Neural Network (FFNN) structure to model the moisture content of dried Basil in each condition; anyway the result of best network by GA had only one hidden layer with 11 neurons. This network could predict moisture content of dried basil leaves with correlation coefficient of 0.99.

The influence of operating pressure during osmotic dehydration on mass transfer and mechanical properties in pineapple fruits was analyzed. Dehydration trials were performed at atmospheric pressure (OD) and by applying a vacuum pulse (VPOD), in sucrose solution at 60°Brix and 40°C for 300 min. Seven operation conditions were implemented with a vacuum pulse of 100 mbar or 250 mbar for 0, 5, 15 or 25 min at the beginning of the process. The decrease of pressure favored the solute uptake, but the water loss has not been significantly affected. No significant effect of vacuum time was observed. However, solute uptake in trials with vacuum pulse of 100 mbar was significantly higher than in OD process. In general, mechanical properties and shrinkage were not affected by operation conditions. Osmotic dehydration process (both OD and VPOD) originates a more resistant tissue structure than the one in fresh pineapple fruit.

: The possibility of using raw glycerol as a substrate for yeast biomass production as a source of proteins was investigated. Biomass concentration, protein content and total protein content of four yeasts ( Yarrowia lipolytica NRRL YB-423, Candida lipolytica NRRL Y-1095, Candida utilis NRRL Y-900 and Candida rugosa NRRL Y-95) were determinate, comparing analytical grade glycerol and raw glycerol. Y. lipolytica NRRL YB-423 has been selected as promising for cultivation in a raw glycerol-based medium, mainly due to the higher biomass concentration in relation to the other strains. For this strain, four different culture media were tested. The best results were obtained with 50 g/L glycerol, 5.5 g/L ammonium phosphate, 5.5 potassium dihydrogen phosphate, 1 g/L ammonium sulphate, 0.25 g/L magnesium sulphate, 0.021 g/L calcium chloride dehydrate, 1 g/L yeast extract, 1 g/L peptone, pH adjusted to 5.5. In these conditions, it was possible to obtain 17.8 ± 0.6 g/L maximum biomass concentration, 18.2 ± 1.0% protein content and 3.1 ± 0.1 g/L total protein production. These results represent a 1.2-fold increase in biomass concentration, a 1.5-fold increase in protein content and a 1.9-fold increase in total protein production in relation to the results obtained with the previously medium composition.

In this research, effects of aminoethoxyvinylglycine (AVG) and methyl jasmonate (MeJA) applied 2 weeks ahead of estimated harvest date on fruit color, firmness and individual phenolic compounds of three plum varieties wereinvestigated during the cold storage. Fruits of “BlackAmber”, “Black Beauty” and “Fortune” were kept at 0 ± 0.5 ° C temperature and 90 ± 5% relative humidity for 4 weeks. During the storage, decreases in L *, chroma and hue angle values were observed. AVG treatments differed significantly ( p < 0.05) by control and MeJA treatment. In all plum varieties, AVG treatment resulted in significant increases in flesh firmness at the end of storage. MeJA increased significantly the firmness of “Black Beauty” and “Fortune” fruit at the end of storage. Chlorogenic acid was detected as major phenolic compound in plum varieties. AVG treatment to “Black Amber” fruit increased the contents of chlorogenic and p -coumaric acid during storage, whereas it reduced chlorogenic and p -coumaric acid content in “Fortune” fruit. MeJA treatment led to not only increase the contents of rutin, ferulic acid and naringenin in the fruits of “Black Beauty” and “Fortune” varieties during the storage but also significantly increase the kaempferol content in “Black Amber” and “Black Beauty” fruits. While AVG treatment compared to control significantly decreased the contents of chlorogenic acid, quercetin and naringenin in “Black Amber” fruits at the end of cold storage, it increased content of p -coumaric acid. At the end of storage, AVG and MeJA treatments reduced significantly the content of ferulic acid in “Black Beauty” fruits. In addition, MeJA treatment significantly increased chlorogenic acid, ferulic acid and kaempferol contents in “Fortune” fruits.

Passion fruit ( Passiflora edulis flavicarpa) is a seasonal, tropical, pulpy fruit, known for a rich source of Vitamin C, antioxidants, and delicate flavor. Presently, freezing technique has been used to preserve the pulp. This article reports alternate method of preservation by foam mat convective air drying of fruit pulp under moderate temperatures. The optimization of process parameters, particularly air temperature, was done with subsequent mathematical modeling of the process and assessment of quality parameters by retention of physicochemical properties and antioxidant capacity of the fruit powder. Sixty degree Celsius was found to be the optimum temperature, and Henderson and Pabis model showed best fit to the drying characteristics data (R 2 = 0.99). Diffusivity characteristics of moisture during drying were also studied. As drying temperature was increased, total color difference and rehydration ratio decreased, whereas non-enzymatic browning index, total phenolic content, and total antioxidant activity showed increase that was attributed to inhibition of oxidative enzymes and biochemical changes. Dried passion fruit powder showed overall acceptability in terms of organoleptic properties and total antioxidant activity.

In this research, we produced concentrates of banana juices from three different cultivars of bananas ( Enano gigante and two hybrids FHIA-17 and FHIA-23) by the freezing and thawing method. To track the cryoconcentration process, different parameters were monitored in the melted fractions, such as variation of the content of soluble solids, concentration of polyphenols (Folin–Ciocalteu), reducing sugar (DNS assay), minerals (K, Mg, Ca, P, Na, Mn, Cu and B) by inductively coupled plasma-optical emission spectroscopy and the main volatile compounds by headspace-GC–MS. It was found that the solution obtained during thawing showed higher concentrations than the original solution. The concentrations of polyphenols were duplicated in FHIA-17 cultivar (758.53 mg/100 ml), and the concentrates obtained in this study proved to be good sources of K and Mg 5,054.6 mg/l and 485.4 mg/l with around 70% and 40% of the recommended daily intake (RDI), respectively. In addition, the concentrates contained a very low level of Na around 1% of the RDI. Furthermore, the cryoconcentration process of the bioactive compounds presented a sigmoid behavior, and the inflexion point in the function was proposed as stop point of the process. Finally, the main volatile compounds reported as responsible for the banana aroma were identified, and its cryoconcentration proved. These results suggest that consumption of banana juice concentrates obtained by the freezing and thawing method can provide bioactive compounds needed for health.

Rheological property of defatted flaxseed-added wheat flour dispersions was investigated as a function of defatted flaxseed concentration (0–20%), NaCl concentration (0, 0.6, and 1.2%), sucrose concentration (0, 5, and 10%), and slurry concentration (33and 62.5%). Frequency sweep tests at 20°C and temperature sweep tests from 20 to 90°C were applied to the samples. The experimental measurements demonstrated that the viscoelastic moduli of samples increased with the increase in defatted flaxseed concentration from 0 to 20% and decreased with the increase in NaCl, sucrose, and water concentration at 20°C. The gelatinization temperatures of the defatted flaxseed-wheat slurry samples were delayed with the addition of defatted flaxseed, NaCl, and sucrose but hastened with the addition of water.

Plant diseases cause major losses to several agricultural and horticultural crops around the World. Therefore, methods for proper diagnosis of diseases found in any parts of the plant body play a crucial role in disease management. In the past few decades, many methods and techniques of image processing and soft computing are applied on a number of plants to diagnose and treat variety of plant diseases. Hence, the present work is aimed to develop an automated system that results in three major outcomes for a leaf image. They are disease identification, disease grading and treatment advisory. The methodology begins with capturing of samples of healthy and diseased leaf images of Pomegranate plant. All the images are made to undergo pre-processing steps and different features are extracted and stored in the database. Analysis is done on the extracted features to determine those features that constitute a disease in the leaf. Later, a query image is taken and is tested to determine whether that image is healthy or diseased one. If the query image is found to be diseased, then the grade of the disease is determined. Finally, a treatment advisory module is built which ultimately helps agriculturists/farmers.

The aim of this work was to select models of mass transfer to estimate effective mass diffusion coefficients during the dehydration of Rosa eglanteria fruits with air at 70°C. Fruits were pretreated chemically and mechanically (dipping it in NaOH and ethyl oleate solutions and cutting or perforating the fruit cuticle). Selected models were those of Becker and Fick’s second law, considering fruit shrinkage during drying. Both models satisfactorily predict the fruit drying, and the different pretreatments, to total or partially remove this waxen cuticle, noticeably improved water diffusion, reducing the time of processing from 28% (NaOH) to 52% (oleate and mechanical pretreatments). Mechanical pretreatments were the more effective, because oleate presents quality problems.

In this study, four tuber sizes (28S1 45mm, 45S255mm, 55S365 mm and S465 mm) and three potato cultivars (Jelly, Milva and Sante) were used to assess the variations of physico-mechanical, chemical and colour properties depending on tuber size and potato cultivars. Physico-mechanical properties (geometric mean diameter, sphericity, surface area, bulk and tuber densities, volume, static coefficient of friction, puncture force and deformation), chemical properties (pH, total acidity [TA] and total soluble solid content [TSSC]), and colour characteristics ( L , a , b ) were determined. The physico-mechanical (geometric properties and puncture force) and chemical properties of potatoes were significantly affected by tuber sizes and cultivars, respectively. pH, TA and TSSC of potato tuber were higher in Milva, TA was higher in Jelly and TSSC was higher in Sante than in those of the other cultivars, respectively.

The moisture sorption characteristics of dakuwa at 10, 20, 30 and 400°C were studied. The experimental sorption data obtained were applied to BET, GAB, Oswin and Henderson equations to test fitness of the equations to moisture sorption of dakuwa . The sorption isotherms of dakuwa were type III isotherms (J shaped), and the equilibrium moisture content increased with increasing water activity but decreased with increasing temperature. The BET and GAB monolayer moisture contents all decreased with increasing temperature. For adsorption, the BET monolayer was higher (3.163–4.158 g/100 g solid) than that of GAB (2.931–3.728 g/100 g solid), but for desorption, the GAB monolayer (4.792–7.741 g/100 g solid) was higher than that of BET (3.962–4.480 g/100 g solid). Evaluation of goodness of fit of models revealed that moisture sorption of dakuwa was best modelled by GAB equation.

Currently, food industries need rapidly available information related to food production while most lab-based instrumentation techniques are often complicated and expensive for real-time application. Studies show that the measurement of rheological characteristics of dough is a relevant control variable for the proper formulation of ingredients and bread-making additives. It is in this context that this work aims to present an alternative method for real-time monitoring of the evolution of the dough behavior during processing with telemetry form. The dough behavior is monitored through the changes in the electrical properties of the motor as affected by the properties of the machine torque that makes the mixture. Results of this work showed that it is possible to record dough deformation during mixing in real time and also demonstrated how wireless technology can contribute to the quality control of a food processing system.