scholarly journals The Effect of Drying Temperature on Nitrogen Loss and Pathogen Removal in Laying Hen Manure

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.

2020 ◽  
Vol 194 ◽  
pp. 02014
Author(s):  
Xiu Fangtao ◽  
Zhu Hongguang ◽  
Xu Yupeng

For the biogas project which does not have the ability to return to the field nearby, the outlet of biogas residue is one of the important bottlenecks restricting the development of biogas engineering. Deep dehydration and drying is a reliable basis for commercial utilization of biogas residue, especially combined with waste heat utilization of cogeneration of biogas. Therefore, three kinds of biogas residue raw materials were dried at low temperature by hot drying method in this paper. The drying temperature, the thickness of biogas residue and the backmixing amount of dry biogas residue were selected as three influencing factors. The drying time, drying rate and residual water ratio were taken as dependent variables. The drying characteristic curve of biogas residue was obtained, and the influence of each factor on the drying process of biogas residue was analyzed and compared. The results showed that the drying time of three kinds of biogas residue decreased with the increase of drying temperature. At the same temperature, the drying time decreases with the decrease of thickness. The dry biogas residue backmixing can’t optimize the drying characteristics and even increase the drying energy consumption.


Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 375
Author(s):  
Timilehin Martins Oyinloye ◽  
Won Byong Yoon

We investigated the effect of chlorine dioxide (ClO2) under low temperature drying to suppress rice cake stickiness during the cutting process by initiating the onset of retrogradation until the stickiness is minimized for shelf-life extension. The intermittent ClO2 application at low-temperature drying was conducted at 10 °C for different drying periods (0, 6, 12, 18, and 24 h). Texture analysis showed significant differences with increasing values of hardness (901.39 ± 53.87 to 12,653 ± 1689.35 g) and reduced values of modified adhesiveness (3614.37 ±578.23 to 534.81 ± 89.37 g). The evaluation of rice cake stickiness during the cutting process revealed an optimum drying period of 18 h with no significant difference (p ≤ 0.05) compared to the 24 h drying process. Microbial contamination during the drying process increased, with microbial load from 6.39 ± 0.37 to 7.94 ± 0.29 CFU/g. Intermittent ClO2 application at 22 ppm successfully reduced the microbial load by 63% during drying process. The inhibitory property of ClO2 was further analyzed on a sample with high initial microbial load (3.01 ± 0.14 CFU/g) using primary and modified secondary growth models fitted to all experimental storage temperatures (5–25 °C) with R2 values > 0.99. The model demonstrated a strong inhibition by ClO2 with microbial growth not exceeding the accepted population threshold (106 CFU/g) for toxin production. The shelf-life of rice cake was increased by 86 h and 432 h at room temperature (25 °C) and 5 °C respectively. Microbial inactivation via ClO2 treatment is a novel method for improved food storage without additional thermal sterilization or the use of an additional processing unit.


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.


Author(s):  
H. T. Sabarez ◽  
S. Keuhbauch ◽  
K. Knoerzer

An ultrasonic design based on the indirect transmission of ultrasonic energy from the ultrasound emitter through to the material to be dried was investigated to assist in low temperature drying of food materials. The application of the improved design tested in this work was found to enhance the low temperature drying by shortening the overall drying time of up to 45% (i.e., lower energy consumption and may enable better retention of product quality). This offers a promising approach towards a better applicability of ultrasound in industrial operation, since no direct contact between the sample and the ultrasonic emitter is needed. Keywords: ultrasound; drying; low temperature; drying intensification 


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.  


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