Potato Shrinkage During Hot Air Drying

2010 ◽  
Vol 16 (4) ◽  
pp. 337-341 ◽  
Author(s):  
A. Frías ◽  
G. Clemente ◽  
A. Mulet
Keyword(s):  
Image Analysis ◽  
Moisture Content ◽  
Volumetric Shrinkage ◽  
Air Velocity ◽  
Volume Changes ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Physical Changes

Shrinkage is one of the most important physical changes that occur during the dehydration of foods. In this work, the effect of the temperature (35, 40, 50, 60 and 70 °C) and air velocity (7, 8, 9 and 10 m/s) on bulk volumetric shrinkage was investigated. Volume changes were evaluated by image analysis. It was found that neither temperature nor air velocity had any significant effects on bulk shrinkage in this system. The bulk shrinkage of the potato cubes was well correlated with the moisture content of the sample during drying (R2 = 97.28). Volume varied linearly with the moisture content changes under the studied conditions. The volume of lost water and the decrease in volume of the samples during dehydration were similar.

scholarly journals Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo
Keyword(s):  
Moisture Content ◽  
Quadratic Model ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air

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.

Detection of moisture and carotenoid content in carrot slices during hot air drying based on multispectral imaging equipment with selected wavelengths

2021 ◽  
Vol 17 (9) ◽  
pp. 727-735
Author(s):  
Jiamei Long ◽  
Jia Yang ◽  
Jing Peng ◽  
Leiqing Pan ◽  
Kang Tu
Keyword(s):  
Moisture Content ◽  
Prediction Model ◽  
Multispectral Imaging ◽  
Prediction Models ◽  
Projection Algorithm ◽  
Carotenoid Content ◽  
Support Vector ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

Abstract Moisture content and carotenoid content are important indicators for evaluating the drying process of carrot slices. There are growing attention to develop non-destructive methods as effectively analytical tools in quality assurance of drying carrot slices. In this study, the characteristic wavelengths of moisture and carotenoid content in carrot slices during hot air drying were extracted based on hyperspectral imaging technology. A multispectral imaging equipment was built after that, and the wavelengths of filters were determined according to the characteristic wavelengths. Based on the successive projection algorithm (SPA), the optimal wavelengths of moisture and carotenoid content were further determined, and prediction models of both were established based on the system. There were 12 filters selected in this study. The results showed that a support vector machine (SVM) prediction model for moisture content was established based on seven optimal wavelengths with 0.991 for the coefficient of determination of prediction set (R 2 p ) and 10.318 for the residual prediction residual (RPD). Based on eight optimal wavelengths, a SVM prediction model for carotenoid content was also established with 0.968 for R 2 p and 5.337 for RPD. The prediction performance is close to or even better than that based on hyperspectral. The study confirmed the feasibility of using the multispectral imaging equipment to measure the moisture and carotenoid content of carrot slices during drying based on selected wavelengths, laying a foundation for the further preparation of a portable multispectral detector for the quality of dry products.

scholarly journals Effect of drying methods on properties of green curry powder

2018 ◽  
Vol 192 ◽  
pp. 03023
Author(s):  
Natthacha Chaloeichitratham ◽  
Pornkanya Mawilai ◽  
Thadchapong Pongsuttiyakorn ◽  
Pimpen Pornchalermpong
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Water Activity ◽  
Freeze Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Temperature ◽  
Hot Air

In this study, the effects of two drying methods: hot-air and freeze drying for Thai green curry paste in a terms of drying time and qualities have been investigated. The hot-air drying was carried out in tray dryer at temperature of 50, 60 and 70 °C. The freeze drying was carried out in freeze dryer at freezing temperature of -20°C, primary drying temperature of -10°C and secondary drying temperature of 50°C. Moisture content, water activity, colour, bulk density, and total phenolic content (TPC) were determined in samples. Freeze dried sample had significantly (p<0.05) lower moisture content, water activity, bulk density, total colour difference and browning index than hot air dried samples. For antioxidant activity, the results showed hot-air drying at 70°C effected highest TPC similar to freeze drying.

Analysis of Equilibrium moisture content and L-ascorbic acid during hot air drying for sweet potato

2008 ◽  
Author(s):  
Takahiro Orikasa ◽  
Daisuke Nei ◽  
Poritosh Roy ◽  
Nobutaka Nakamura ◽  
Takeo Shiina ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Moisture Content ◽  
Sweet Potato ◽  
Equilibrium Moisture Content ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

scholarly journals Optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices

2019 ◽  
Vol 50 (3) ◽  
pp. 150-158 ◽  
Author(s):  
Nnaemeka R. Nwakuba
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
High Energy ◽  
Slice Thickness ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Drying Conditions ◽  
Desirability Index

High-energy demand of convective crop dryers has prompted study on optimisation of dryer energy consumption for optimal and cost effective drying operation. This paper presents response surface optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices. Drying experiments were conducted with 1 kg batch of tomato samples using a 33 central composite design of Design Expert 7.0 Statistical Package. Three levels of air velocity (1.0, 1.5 and 2.0 ms–1), slice thickness (10, 15 and 20 mm) and air temperature (50, 60 and 70°C) were used to investigate their effects on energy consumption. A quadratic model was obtained with a high coefficient of determination (R2) of 0.9825. The model was validated using the statistical analysis of the experimental parameters and normal probability plot of the energy consumption residuals. Results obtained indicate that the process parameters had significant quadratic effects (P<0.05) on the energy consumption. The energy consumption varied between 5.42 kWh and 99.78 kWh; whereas the specific energy consumption varied between 5.53 kWhkg–1 and 150.61 kWhkg–1. The desirability index method was applied in predicting the ideal energy consumption and drying conditions for tomato slices in a solar-electric dryer. At optimum drying conditions of 1.94 ms–1 air velocity, 10.36 mm slice thickness and 68.4°C drying air temperature, the corresponding energy consumption was 5.6 8kWh for maximum desirability index of 0.989. Thermal utilisation efficiency (TUE) of the sliced tomato samples ranged between 15 ≤TUE ≤58%. The maximum TUE value was obtained at 70°C air temperature, 1.0 ms–1 air velocity and 10 mm slice thickness treatment combination, whereas the minimum TUE was obtained at 50°C air temperature, 2.0 ms–1 air velocity and 20 mm slice thickness. Recommendation and prospect for further improvement of the dryer system were stated.

Experiment on the Mechanics Properties of Hot-Pepper in the Process of Hot-Air Drying

2013 ◽  
Vol 395-396 ◽  
pp. 571-576
Author(s):  
Xue Bi Zhang ◽  
Si Yu Chen ◽  
Wen Fu Wu ◽  
Ya Qiu Zhang ◽  
Chun Shan Liu ◽  
...  
Keyword(s):  
Moisture Content ◽  
Tensile Strain ◽  
Maximum Load ◽  
Hot Pepper ◽  
Hot Air Drying ◽  
Air Drying ◽  
Damage Rate ◽  
Hot Air ◽  
Variation Tendency

In order to reduce the damage rate of hot-pepper in the process of drying and transportation, and to improve the quality of dried hot-pepper. In this paper, the mechanical properties of hot-pepper were studied in the process of hot-air drying. The experimental results showed that the hot-pepper’s compressive ability dropped with the decrease of moisture content after the moisture content reached the safe moisture content. With the moisture content decreasing, the variation tendency of the elastic modulus and tensile strain of hot-pepper were first increased and then decreased and finally tended to be stable when it reached 12％. Effect of hot-pepper’s shape on tensile strain is greater than on the maximum load and displacement in the process of drying.

Empirical Model and Artificial Neural Network Model Approach for Air Dried Sheets (ADS) Rubber

2012 ◽  
Vol 622-623 ◽  
pp. 69-74
Author(s):  
T. Ninchuewong ◽  
S. Tirawanichakul ◽  
Y. Tirawanichakul
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Moisture Content ◽  
Neural Network Model ◽  
Artificial Neural Network Model ◽  
Hot Air Drying ◽  
Air Drying ◽  
Rubber Sheet ◽  
Hot Air ◽  
Drying Behavior

The objective of this research was to predict drying behavior of hot air drying using an empirical model (EM) and an artificial neural network model (ANN). Rubber sheet with initial moisture content ranging of 23-40% dry-basis was dried by temperature ranging of 40-70°C and air flow rate of 0.7 m/s. The desired final moisture content was set at 0.15% dry-basis. The results showed that drying rate of rubber sheet dried with hot air convection was faster than conventional natural aeration. The EM and ANN were simulated to describe the drying behavior of products. Furthermore, prediction results between EM and ANN were compared with the experimental data. In this research, it was obviously found that ANN can describe the drying behavior effectively. Additionally, it was also found that predicted results of Multilayer feed forward Levenberg-Maqurdt’s Back-propagation ANN were good agreement with the experimental results compared to those results of EM. It is the optimum architecture for prediction the evolution of moisture transfer for hot air drying.

scholarly journals Hot air drying combined vacuum-filling nitrogen drying of apple slices: Drying characteristics and nutrients

2018 ◽  
Author(s):  
Xiaoli Huang ◽  
T. Li ◽  
S.N. Li ◽  
Z.H. Wu ◽  
J. Xue
Keyword(s):  
Moisture Content ◽  
Drying Rate ◽  
Slice Thickness ◽  
Relative Pressure ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Characteristics ◽  
Hot Air ◽  
Apple Slices ◽  
Apple Slice

In this paper, hot air drying (HAD) was applied when moisture content of apple slices range from 50% to 86%, and then vacuum-filling nitrogen drying (VFND) was used till moisture content reaching 7%. Results showed that, the drying rate of apple slice during VFND period increased with temperature increment and decreased with increment of slice thickness; compared to freezing dried samples,  samples dried in this research were owned lower Vc and higher flavonoid; when HAD (70℃,3.0m/s)+VFND(relative pressure 0.08MPa, 50℃) and thickness of 6.0mm, nutrients reached better levels: retentions of Vc, total phenolics and flavonoid were 1.63mg/100g, 4.07mg/100g and 2.10mg/100g, respectively. Keywords: apple slices, hot air drying, vacuum-filling nitrogen drying, drying rate, nutrients

scholarly journals Organic apples (cv. Elstar) quality evaluation during hot-air drying using Vis/NIR hyperspectral imaging

2018 ◽  
Author(s):  
Luna Shrestha ◽  
Roberto Moscetti ◽  
Stuart Crichton ◽  
Oliver Hensel ◽  
Barbara Sturm
Keyword(s):  
Moisture Content ◽  
Hyperspectral Imaging ◽  
Regression Models ◽  
Quality Evaluation ◽  
Pls Regression ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Apple Slices

Organic dried apples are common snacks fulfilling functional as well as nutritional aspects. However, appearance of dried slices does not always satisfy consumer requirements, thus, improvements are needed. In this study, partial least squares (PLS) regression models were successfully developed to monitor changes in colour and moisture content in apple slices during the drying process over the Vis/NIR spectral range. The regression vector analysis results suggested that features at 580, 750 and 970 nm are better for predicting moisture content, while 580 and 680 nm allow to measure the (a*/b*) colour ratio.   Keywords: Drying; Dried apple slices; Moisture content; Colour; PLSR modelling

Sign in / Sign up

Export Citation Format

Share Document