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

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.

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

Polyphenols accumulation effects on surface color variation in apple slices hot air drying process

LWT ◽  
2019 ◽  
Vol 108 ◽  
pp. 421-428 ◽  
Author(s):  
Xuan Li ◽  
Xinye Wu ◽  
Jinfeng Bi ◽  
Xuan Liu ◽  
Xiao Li ◽  
...  
Keyword(s):  
Color Variation ◽  
Drying Process ◽  
Surface Color ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Apple Slices

Hot Air Drying and Vacuum Drying Characteristics of Scarlet Runner Beans

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Yoshiki Muramatsu ◽  
Eiichiro Sakaguchi ◽  
Takahiro Orikasa ◽  
Akio Tagawa
Keyword(s):  
Diffusion Coefficient ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Vacuum Drying ◽  
Drying Method ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Drying Characteristics ◽  
Hot Air

Abstract The drying characteristics and volume changes of scarlet runner beans were measured under various conditions to obtain useful basic information for the optimum drying method and conditions. The sample was dried using two drying methods: hot air drying and vacuum drying. The measured changes in moisture content of the sample with the hot air drying process were in good agreement with the exact solution of the infinite plane sheet model. The estimated diffusion coefficients were 3.8×10 -7 -7.4×10 -7 (m 2 h -1) for hot air drying and were related to absolute temperature by an Arrhenius-type equation. The hull of the scarlet runner bean is hard and thick, and the drying rate of the sample was much slower than that of other beans. To establish an efficient drying method without the quality loss, the vacuum drying characteristics of the sample were measured at several levels for temperature and initial moisture content. For the vacuum drying process, an exponential model could be used to estimate the changes in moisture content of the sample. The values of diffusion coefficient for vacuum drying were approximately twice as much as the values of diffusion coefficient for hot air drying at the same temperature. The effects of drying method, temperature, and initial moisture content on the sample quality were investigated, and the optimum drying method and conditions for scarlet runner beans were proposed. Volumetric changes in the sample were determined by measuring particle density. The specific volume of the sample was represented as a linear function of moisture content.

Characteristics and Process Optimization of Hot-Air Drying Pepper

2012 ◽  
Vol 490-495 ◽  
pp. 3074-3078
Author(s):  
Chun Shan Liu ◽  
Wen Fu Wu ◽  
Jia Song ◽  
Ya Qiu Zhang ◽  
Jun Xing Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
Moisture Content ◽  
Air Temperature ◽  
Drying Process ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Primary Parameter ◽  
Hot Air ◽  
Pre Treatment

In order to solve the drying problems in the deep-processing of pepper, peppers were dried through blanching pre-treatment and hot-air drying process. Orthogonal test designs were carried out to investigate factors influencing the quality and moisture content of pepper. The results showed that the whole drying process was a reduction speed drying, hot-air temperature and wind speed have significantly affected on the drying rate of pepper, but the impact of hot-air temperature was more prominent than wind speed; hot-air temperature was found to be the primary parameter to affect the quality of the pepper, wind speed was the secondary one and followed by packing thickness; drying time was found to be the primary parameter to affect the moisture content of the pepper in the drying process, the best drying conditions were as follows: wind temperature was 80°C, wind speed was 10 m/s, packing thickness was 80 cm, drying time was 12 h after 100°C steam blanching pre-treatment

Low-cost optical approach for noncontact predicting moisture content of apple slices during hot air drying

2017 ◽  
Vol 35 (12) ◽  
pp. 1530-1542 ◽  
Author(s):  
Mansoureh Mozaffari ◽  
Asghar Mahmoudi ◽  
Kaveh Mollazade ◽  
Bahareh Jamshidi
Keyword(s):  
Moisture Content ◽  
Low Cost ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Apple Slices

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.

Experimental Study on Hot-air Drying Process Parameters Optimization of Chinese Jujubes

2013 ◽  
Vol 12 (21) ◽  
pp. 6154-6158
Author(s):  
Xiao Kang-Yi ◽  
Chuan Feng-Li ◽  
Shu Gang-Li ◽  
He Lei Cui ◽  
Wen Fu-Wu
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Parameters Optimization ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Process Parameters Optimization ◽  
Hot Air
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