scholarly journals Effect of Wood Vinegar Substitutes on Acetic Acid for Coagulating Natural Para Rubber Sheets during the Drying Process

2021 ◽  
Vol 11 (17) ◽  
pp. 7891
Author(s):  
Wachara Kalasee ◽  
Panya Dangwilailux

The coagulating properties of wood vinegar from para rubber wood, bamboo, and coconut shell used as a substitute for acetic acid in the production process of natural rubber (NR) sheets were investigated and considered. For the dirt and volatile content, the tensile strength at break, the percentage of elongation at break, and the 300% modulus, the results showed that the types of wood vinegar coagulants were not significantly different from acetic acid. However, the Mooney viscosity and plasticity retention index (PRI) properties were significantly different from those of acetic acid. The NR sheet temperature increased rapidly during the first hour after the drying process started due to heat transfer from the hot air. Afterward, the temperature of the NR sheet samples began to stabilize. When the drying process started, the drying temperature was increased, so the trend was reducing the drying time. For the yellowness index (YI) value, the increase in the YI value was related to the type of coagulating material, the increase in the airspeed, and the drying temperature. The dried sheet samples using para rubber wood vinegar as the coagulating material had a color value at the same level as acetic acid and the referent. However, the bamboo and coconut shell wood vinegars were at a lower level. In comparing the YI value data between the experimental results and prediction values, the second-degree model had a better fit in prediction than the zero-degree and first-degree models. This result was confirmed by the higher mean of the coefficient of determination. The dried sheet product coagulated by using wood vinegar had fungus growth prior to supplying it to the customer.

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.


Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 389-395
Author(s):  
Rahmawati Rahmawati ◽  
D. Hunaefi ◽  
I. Basriman ◽  
Dede Saputra ◽  
A.A. Apriliani ◽  
...  

The study was conducted to obtain an optimal combination of time and temperature of the drying process of indigenous cocktail yeast mold culture using RSM. The cocktail yeast mold culture was dried using an oven. The cocktail cultures contain Penicillium citrinum, Aspergillus niger, Acremonium strictum, and Candida famata, namely AC (Amylolytic Culture). The Response Surface Methods (RSM) with Design-Expert® 7.00 software, namely Mixture design with D-optimal was performed. The drying time was between 24- 48 hrs and the drying temperature was between 40-50oC. The total of 16 formulas of the combination of drying time and temperature for processing the dried cultures were produced by RSM. The response chosen was total viability of mold and yeast, water content, water activity, and pH. The result of optimization and verification was obtained by the model: pH (AC) = -0.058A - 1.56 x 10-003B + 7.13, where A = drying temperature ( oC), B = drying time (hr). The AC optimization was achieved at a combination of drying temperatures and time of 50oC for 48 hrs. Desirability values were 0.729. The optimum formula for AC has viability of total yeast mold of 7.39 x 106 CFU/g, moisture content of 5.62%, aw 0.303, and pH 4.18.


Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 343
Author(s):  
Luis Puente-Díaz ◽  
Oliver Spolmann ◽  
Diego Nocetti ◽  
Liliana Zura-Bravo ◽  
Roberto Lemus-Mondaca

The objective of this work was to study the influence of the drying temperature, infrared (IR) radiation assistance, and the Mylar™ film thickness during Physalis fruit purée drying by the Refractance Window™ (RW™) method. For this, a RW™ dryer layout with a regulated bath at working temperatures of 60, 75, and 90 °C, Mylar™ thicknesses of 0.19, 0.25, 0.30 mm and IR radiation of 250 W for assisting RW™ drying process was used. Experimental curves data were expressed in moisture ratio (MR) in order to obtain moisture effective diffusivities (non-assisted RW™: Deff = 2.7–10.1 × 10−10 m2/s and IR-assisted RW™: Deff = 4.2–13.4 × 10−10 m2/s) and further drying curves modeling (Page, Henderson–Pabis, Modified Henderson–Pabis, Two-Term, and Midilli–Kucuk models). The Midilli–Kucuk model obtained the best-fit quality on experimental curves regarding statistical tests applied (Coefficient of Determination (R2), Chi-Square (χ2) and Root Mean Square Error (RMSE). Microscopical observations were carried out to study the RW™ drying conditions effect on microstructural changes of Physalis fruit purée. The main findings of this work indicated that the use of IR-assisted RW™ drying effectively accelerates the drying process, which achieved a decrease drying time around 60%. Thus, this combined RW™ process is strongly influenced by the working temperature and IR-power applied, and slightly by Mylar™ thickness.


Author(s):  
Ángel Hernández Moreno ◽  
Rafael Hernández-Maqueda ◽  
Isabel Ballesterios ◽  
Carlos Torres-Miño

Previous studies on the microwave drying of corn seeds have shown that the process parameters employed play a very important role in determining the properties and quality of this grain (Gürsoy et al, 2013). Among these parameters, the drying temperature has a fundamental role (Nair et al, 2011). The main objective of this work is to evaluate the effect of temperature on drying time, energy consumption and germination rate of corn seeds after they have been dried with microwave energy. To achieve the proposed objective, the drying process of these seeds was carried out in a rotating turntable domestic microwave oven (LACOR Model 69330), with a capacity of 30 liters and a total output power of 900 W, fitted with a PID temperature controller Eurotherm 3216 L. In this oven, 100 g of corn seeds, with an initial humidity of approximately 20%, was heated up to 3 drying temperatures (35, 55 and 75 °C). The seeds were weighed every 30 minutes and the drying process was considered completed when a humidity of 12 % was obtained. For each drying temperature studied, the experiments were carried out in duplicate. In each experiment, the electrical energy consumption was measured using a FLUKE 1735 energy analyzer. A sample of the dried seeds was subject to germination tests in a petri dish using filter paper and a volume of distillate water of 20mL to achieve sufficient humidity for them to sprout. Table 1 shows the average values obtained from the variables evaluated for each drying temperature.   Table 1. Results of the microwave drying experiments of the corn seeds at different temperatures and their germination tests. Drying temperature (ºC) Drying time to reach a humidity of 12% (min) Energy consumption (Wh) Germination rate (%) 35 345,0 880,3 90,0 55 118,5 330,0 81,3 75 73,5 183,9 12,0   As can be seen in Table 1, the temperature exerts a significant influence on the drying process and the germination rate of the corn seeds. An increase in the drying temperature causes a simultaneous decrease in drying time (∿ 78%) and in energy consumption (∿ 79%), which are very positive aspects. However, there is also an unacceptable decrease (∿ 87%) in the germination rate of the corn seeds.   References Gürsoy, S., Choudhary, R., Watson, D.G. Int. J Agric. & Biol. Eng., 2013, 6, 1, 90–99.Nair, G.R., Li, Z., Gariepy, Y., Raghavan, V. Drying Technology, 2011, 29, 11, 1291-1296.


2020 ◽  
Vol 7 (2) ◽  
pp. 147-155
Author(s):  
Adi Saputra

One way to process pineapples, pineapples are classified as highly perishable and rotten foods. For this reason, it is necessary to handle fruit to save the abundance of fruit that occurs during harvest. One example of what the community has done is dealing with the abundant harvest of pineapples by making fruit as a daily snack, namely getting dry fruit products that are ready to eat by making pineapple chips. The production of fruit kiripik is usually done by frying which is done by frying which contains oil which is usually called conventional frying. Therefore, with this oven drying machine, it can help the community in making pineapple chips. The purpose of this study was to determine the moisture content in the manufacture of pineapple chips in a drying oven machine, to analyze the ratio of temperature settings that were set 95 to 110 in the drying process. The fastest drying time is achieved at drying at a drying temperature of 110 ° C.  


2020 ◽  
Vol 12 (1) ◽  
pp. 403
Author(s):  
Xuanyang Li ◽  
Baoming Li ◽  
Qin Tong

Exhaust air from the poultry houses or ambient hot air are normally utilized to dry the laying hen manure extensively in the summer in China. The drying process can not only reduce the moisture of lay hen manure but can also have a degerming effect. However, the ammonia emission is considered as one of the major issues of laying hen manure drying and air pollution scouse. Then, it is not clear that whether the ammonia emission increased using the hot ambient air to dry laying hen manure in summer and whether increasing the temperature can inactivate more bacteria during low temperature drying process. Therefore, the main works of this study were to investigate the evolution of ammonium nitrogen (NH4-N) content, organic nitrogen (Org-N) content, and total bacteria count vs. time during the low-temperature drying process of laying hen manure at different drying temperatures. The results showed that increasing drying temperature can reduce the energy consumption of the manure drying system, but can increase the loss of NH4-N. The Org-N content among the three drying temperatures within same drying time was not significantly different (p > 0.05), which suggested that increasing the temperature did not accelerate the degradation of Org-N during low-temperature drying process. Low-temperature drying had weak destruction of bacteria in laying hen manure and the end dried manure still had a great number of bacteria.


2021 ◽  
Vol 12 (3) ◽  
pp. 3559-3571

Asparagus roots were dried in four selected driers vacuum, fluidized bed, tray, and solar dryer at temperatures starting from 40 to 70 °C. The drying kinetics of asparagus roots was studied with the analysis of the influence of all stated drying conditions on the drying rate, dehydration ratio, rehydration characteristic, color characteristics, and energy consumption. With an increase in the temperature required for drying asparagus, there is an increasing trend of dehydration ratio (DR) and decreasing trend of drying time. The rehydration characteristics are found to be increases with a decrease in drying temperature from 70-60 °C but decrease with a further decrease in drying temperature from 60-40 °C. The energy consumption based on the drying conditions showed great thermal sensitivity and was found higher for low-temperature drying. The results of color characteristics (Chroma, hue angle, and ΔE) showed that the cream color of roots was relatively unaffected by drying. However, the brightness of roots was observed to be increased. Eleven thin-layered drying mathematical models were applied to experimental data of different drying conditions, and the model best describing its behavior was selected based on the coefficient of determination (R2), sum square error (SSE), and root mean square error (RMSE). All selected models give good fitting results (R2 > 0.96) and found the cubic model as the most suitable model for all treatments (R2 > 0.99).


Food Research ◽  
2021 ◽  
Vol 5 (5) ◽  
pp. 244-249
Author(s):  
N.V. Tai ◽  
M.N. Linh ◽  
N.M. Thuy

In Vietnam, banana peels have been discarded as waste which is a potential source of raw material for food and other bioprocessing industries. Drying the peel offers opportunities for value addition into novel products, thus reducing waste from the fruit processing operations. This study presented the mathematical models of the thin-layer drying behaviour of banana peels using three air temperatures (60oC, 70oC and 80oC). The effect of drying temperature on the reduction of moisture content and drying rate of the banana peel was evaluated. A total of eight commonly drying models were used for choosing the best fitness model for describing the oven drying process. The effective moisture diffusivity and activation energy were calculated using Fick’s diffusion equation. The obtained results showed that increasing drying temperature accelerate the drying process, as well as, increasing drying rate and effective diffusivity. The goodness of fit tests base on the criterion indicated that the Page model gave the best fit to experimental results. The effective diffusivity varied from 2.29×10-8 – 3.25×10-8 m 2 /s. Effective diffusivity was satisfactorily by an Arrhenius relationship with activation energy within the 60-80°C temperature range. The obtained activation energy was 16.98 kJ/mol with a high coefficient of determination (R2 = 0.903).


Author(s):  
Samuel Enahoro Agarry

The objective of this study was to investigate the effect of pre-treatment and drying temperature on the drying kinetics and nutritional quality of tomato (Lycopersicon esculantum L.) under hot air drying. Tomato samples were blanched at 80oC and osmotically dehydrated using 20% w/w sodium chloride solutions at 30oC for 20 min. The blanch-osmotic pre-treated and untreated tomato slices were dried at temperature of 40, 50, 60, 70 and 80oC, respectively in a hot air-dryer. The results showed that blanch-osmotic pre-treatment offered a higher drying rate and lower or faster drying time than untreated condition. The tomato drying regime was characteristically in the constant and falling rate period. The tomato drying rate curve showed characteristics of porous hygroscopic solids. The optimum drying temperature for tomato was found to be 60oC. Four semi-empirical drying models of Newton, Page, Henderson and Pabis, and Logarithmic were fitted to the drying data using non-linear regression analysis. The most appropriate model was selected using the coefficient of determination (R2) and root mean square error (RMSE). The Page model has shown a better fit to the drying kinetics data of tomato in comparison with other tested models. Transport of moisture during drying was described by Fick’s diffusion model application and the effective moisture diffusivity (Deff) thus estimated. The Deff at 60oC was 4.43 × 10-11m2/s and 6.33 × 10-11m2/s for blanch-osmotic pre-treated and untreated tomato slices, respectively.


2020 ◽  
Vol 25 ◽  
pp. 54-82
Author(s):  
E. Rodrigues Mangueira ◽  
J. de Assis Cavalcante ◽  
N. Alves Costa ◽  
A.G. Barbosa de Lima

The foam-mat dryingprocessof egg white, developed in the food industry, promotes a porous product, brittle and easy to grind. The powderedegg white has a good rehydration properties, safer consumption and storage conditions than fresh product, keeping the high level of proteins and vitamins contained in the egg. In this way, the objective of this work is to study, through numerical computational simulation, the physical aspects of the duck egg white foam-matdrying process. For this, the foam was characterized by its density, percentage of expansion, air over run, stability and moisture. Temperature (50, 60 and 70°C), stirring rate (levels 6, 7 and 8) and stirring time (4, 5 and 6 minutes) are taken as input conditions and the product final moisture and drying time are the output variables. Drying was performed based on the complete factorial 23 + 3 central point experimental design in this procedure. It has been observed that the time and stirring rate significantly influence the product final moisture and that the drying temperature is predominant for the total process time. From the foam moisturedata, adjustments of empirical mathematical models were made; evidencing that theModifiedPage and the Page models provided the best results, with a standard deviation lower than 0.01 and the coefficient of determination above 0.99. For this analysis, the case where the drying temperature, time and the stirring rate were, respectively, 70 °C, 6 minutes and 8 level, presented the best results.


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