CELEBES Agricultural 6.
: 66 - 77 February .
Research Article Characteristics of Passive Drying Model in BirdAos Eye Chili and Curly Chili Karakteristik Model Pengeringan Pasif pada Cabai Rawit dan Cabai Keriting Risal Nur Rahma Syahrir1*.
Asnidar Mastam1.
Yulismayanti1.
Andi Anggi Novergi2 Study Program of Agricultural Engineering.
Department of Agricultural Technology.
Faculty of Agriculture.
Sam Ratulangi University, 95115.
Manado Study Program of Agricultural Engineering.
Department of Agricultural Technology.
Faculty of Agriculture.
Hasanuddin University, 90245.
Makassar *email: risalnurrahma@unsrat.
Received: November, 2025 Accepted: April, 2026 Published: April, 2026 p-ISSN: 2723-7974 e-ISSN: 2723-7966 doi: 10.
52045/jca.
Website:
https://ojs.
id/index.
php/faperta Abstract: Chili is a commodity that is susceptible to damage, because of its highwater content, so it is necessary to carry out efficient and effective post-harvest actions through drying methods.
Chili drying aims to reduce the water content of the dried material.
The purpose of this study was to determine the pattern of water content reduction in birdAos eye chili and curly chili and the appropriate drying model to use for chili peppers.
The average drying temperature inside the chamber ranger from 39 until 75 C and the total drying time was 21 hours from each treatment.
The samples used were two types of chili peppers, namely birdAos eye chili and curly chili.
The models whose suitability was evaluated were the Newton.
Page.
Handreson & Pabris models.
The Page model showed the best performance in describing the drying behaviour of birdAos eye chili and curly chili, with R2 values of 0.
9952 and 0.
9971, respectively, which were higher than those obtained from the Newton and Henderson & Pabis model.
Keywords: Passive drying, cayenne pepper, dried chili, drying model Abstrak: Cabai merupakan komoditas yang rentan terhadap kerusakan, karena kadar air yang cukup tinggi sehingga perlu dilakukan tindakan pasca panen yang efisien dan efektif melalui metode pengeringan.
Pengeringan cabai bertujuan untuk mengurangi kadar air bahan yang dikeringkan.
Tujuan dari penelitian ini ialah untuk mengetahui pola penurunan kadar air cabai rawit dan cabai keriting serta model pengeringan yang tepat digunakan pada cabai.
Suhu pengeringan rata-rata didalam ruang pengering berkisar antara 39 sampai 75 C.
Sampel yang digunakan dua jenis cabai, yakni cabai keriting dan cabai Model yang dievaluasi kesesuainnya adalah model Newton.
Page.
Handreson & Pabris.
Model Page menunjukkan kinerja terbaik dalam menggambarkan perilaku pengeringan cabai rawit dan cabai keriting dengan nilai R2 masing-masing sebesar 0.
9952 dan 0.
9971, yang lebih tinggi dibandingkan dengan menggunakan model Newton dan Henderson & Pabis.
Kata Kunci: Pengeringan pasif.
Cabai Rawit.
Cabai Kering.
Model Pengeringan INTRODUCTION Red chili (Capsicum annuum L.
) is one of the vegetable commodities with a relatively high economic value due to its important role in meeting domestic needs as well as serving as an export commodity and a raw material for the food and pharmaceutical.
After being harvested, chili peppers continue to undergo respiration, a natural process that cannot be stopped, and they easily experience metabolic changes due to their highwater content.
Consequently, they cannot be stored for long in their fresh form (Ridwan et al.
, 2.
Citation:
Syahrir RNR.
Mastam A.
Yulismayanti.
Novergi AA.
Characteristics of Passive Drying Model in BirdAos Eye Chili and Curly Chili.
CELEBES Agricultural.
: 66-77.
doi: 10.
52045/jca.
CELEBES Agricultural Vol.
6 No.
February .
In general, chili peppers are still handled in a very simple manner after harvest, which leads to a high rate of damage (Afgani & Ariskanopitasari, 2.
This issue is caused by farmersAo limited understanding of postharvest management techniques and the lack of adequate technological infrastructure (Wulandari & Kurniati, 2.
Chili peppers contain a high level of moisture, making them highly perishable (Kusmali et al.
, 2.
The deterioration of chili peppers can be caused by internal factors within the chili itself or by external factors.
Farmers are often reluctant to take the risk of storing their chili harvest because of its perishable nature.
an efficient and effective postharvest handling method such as drying is necessary (Alhanannasir et al.
, 2.
BirdAos eye chili and curly chili were selected in this study because both commodities have different physical characteristics, particularly in size, skin thickness, and surface area, which may influence heat and mass transfer during drying.
The comparison of these two chili varieties is expected to provide information on the suitability of a drying model for different chili In addition, studies comparing thin-layer drying models of different chili varieties using a passive direct dryer are still limited.
Determination of an appropriate drying kinetic model is important as a fundamental reference for the design and scale-up of solar dryers for agricultural The novelty of this study lies in the simultaneous evaluation of two chili varieties dried in a passive dryer by considering different tray positions inside the drying chamber.
Based on the explanation above, it is necessary to conduct a study on the passive drying of birdAos eye chili and curly chili to determine the moisture reduction pattern of both types of chili and to identify the appropriate drying model that matches the characteristics of birdAos eye chili and curly chili.
MATERIALS AND METHODS
Materials and Tools The materials used in this study were birdAos eye chili and curly chili with an average weight 806 g for birdAos eye chili and 99.
783 g for curly chili.
The amount of material used was adjusted to the maximum tray capacity for each commodity being dried.
The equipment used in this study included a direct-type passive solar box dryer, a digital scale, a hygro-thermometer, a wire rack, a mobile phone camera, and a laptop.
Drying Process Preparation Procedure Research Data Processing Preparation The preparation carried out in this study included preparing the drying equipment, cleaning the birdAos eye chili and curly chili, and selecting chili samples that were as unifor as possible in terms of color, length, and diameter.
The trays measuring 25 y 10 cm were weighed using a digital scale before being filled with samples.
The chilies were then placed into four trays, consisting of two trays for birdAos eye chili and two trays for curly chili.
The experiment was conducted using a descriptive experimental design with two replications for each chili variety and tray position.
The analysis focused on the determination of drying kinetic model parameters and goodness-of-fit Syahrir et al.
Drying Models of BirdAos Eye and Curly Chili CELEBES Agricultural Vol.
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Drying Process The drying process was carried out following these procedures: The birdAos eye chili and curly chili to be dried were prepared, and the drying process was conducted from 9:00 a.
to 4:00 p.
The chilies were placed in the dryer with different positions for two replications.
The dryer was positioned under direct sunlight.
Every 30 minutes, the chilies were removed from the dryer and weighed to determine the sample weight, while the temperature inside the drying chamber was Once the weight reduction became constant, the chili samples were placed in an oven at 105 AC for 72 hours to obtain their dry weight.
After oven drying, the samples were removed and weighed again to determine the total dry weight.
Data Processing After obtaining the dry weight of the material .
he weight of the chili after being dried using a passive drye.
, the moisture content on a wet basis was then calculated using the following equation (Irwan et al.
, 2.
Kabb= Wt -Wd x 100% Kabb = Moisture content on a wet basis (%) = Initial weight of the material .
= Dry weight of the material .
After calculating the moisture content of the material, the Moisture Ratio (MR) was then determined using the following equation (Mukhlis et al.
, 2.
(Mt - W.
MR= (M0 -M.
= Moisture Ratio = Initial moisture content of the material = Moisture content at time t = Equilibrium moisture content .
fter reaching constant weigh.
The thin-layer drying model was obtained by determining the constants k, a, and n for each exponential form (Jassin et al.
, 2.
The constant values were determined using MS Excel Solver to obtain the coefficient of determination (RA), and the model with the highest RA value was selected as the best model representing the drying characteristics of birdAos eye chili and curly The drying models used in this study were the Newton.
Henderson & Pabis, and Page models (Mukmin et al.
, 2.
Syahrir et al.
Drying Models of BirdAos Eye and Curly Chili CELEBES Agricultural Vol.
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Research Flow Diagram Start Preparation of materials and equipment Preparating the cleaned birdAos eye chili and curly chili Weighing the empty tray Placing the birdAos eye chili and curly chili samples into the upper and middle drying chambers of the solar box dryer Measuring the temperature inside and outside the drying chamber Weighing the samples every 30 minutes Constant? Yes Oven drying the samples at 105o for 72 hours Processing the data by calculating the moisture content Calculating the moisture ratio Determining the drying models (Newton.
Henderson and Pabis & Pag.
Finish Figure 1.
Research flow diagram Syahrir et al.
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RESULTS AND DISCUSSION Drying Temperature Temperature .
C) --- Temperature --- Temperature Out Suhu In (AC) In suhu Time (Hour.
Figure 2.
Dryer Temperature Inside and Outside the Dryer in the First Treatment Based on the graph in Figure 2, it can be seen that the temperature inside the dryer .
nlet temperatur.
was consistently higher than the temperature outside the dryer .
utlet The internal temperature ranged from 39Ae75 AC, while the external temperature was in the range of 32Ae57 AC.
This condition indicates that the drying chamber was able to maintain a higher internal temperature compared to the surrounding environment (Soekarno et , 2.
The fluctuation of the internal temperature was quite noticeable, with peaks occurring at hours 5, 9, 12, and between 18Ae20.
This suggests that there was a significant variation in the incoming heat during the drying process (Sari et al.
, 2.
The temperature difference between the inside and outside remained relatively stable, allowing effective heat transfer and supporting the evaporation of moisture from the chilies.
Temperature .
C) --- Temperature In --- Temperature Out Figure 3.
9 10 11 12
Times (Hou.
Drying Temperature Inside and Outside the Dryer in the Second Treatment The graph in Figure 3 shows that the drying temperature pattern in the second treatment also indicated that the internal temperature .
was higher than the external temperature .
, although the difference was not as large as in the first treatment.
The internal temperature ranged from 39Ae72 AC, while the external temperature was between 39Ae68 AC.
Based on Figures 2 and 3, it can be observed that the temperature inside the drying chamber (In Temperatur.
was consistently higher than the temperature outside the drying chamber (Out Temperatur.
throughout the observation period.
This was due to the greenhouse effect of the solar box dryer, which trapped solar heat and increased the internal temperature, thereby accelerating the drying process.
In passive solar drying, the temperature of the material in both Syahrir et al.
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the first and second treatments increased immediately after being placed inside the drying chamber, with ambient temperatures of 50AC and 67AC, respectively.
However, the temperatures inside and outside the dryer were not stable but fluctuated over time due to the influence of sunlight (Irfan & Lestari, 2.
This fluctuation can be seen from the variation in temperature levels at each time interval, which occurred because the intensity of solar radiation received was not constant throughout the day.
Relative Humidity Relative Humadity (%) RH in Figure 4.
9 10 11 12 13 14 15 16 17 18 19 20 21
Time (Hour.
Relative Humidity (RH) Inside and Outside the Dryer in the First Treatment RH In Relative Humadity (%) RH Out RH Out 10 11 12 13 14 15 16 17 18 19 20 21 Times (Hou.
Figure 5.
Relative Humidity (RH) Inside and Outside the Dryer in the Second Treatment Figures 4 and 5 show the relationship between the relative humidity (RH) inside and outside the dryer for each treatment.
The results indicate that the relative humidity inside the drying chamber (RH I.
was consistently lower than the relative humidity outside the chamber (RH Ou.
This occurred due to the increase in temperature inside the drying chamber caused by the greenhouse effect of the solar box dryer.
As the internal temperature increased, the airAos capacity to hold water vapor also increased, resulting in a decrease in relative humidity within the chamber (Rahmah et al.
, 2.
The drier air inside the dryer had a greater ability to absorb moisture from the chili samples, thereby accelerating the drying process.
In both graphs, the relative humidity outside the dryer fluctuated over time, reflecting changes in environmental conditions such as sunlight intensity and ambient temperature.
Although the humidity inside the dryer also fluctuated, its values remained consistently lower than the external humidity.
Syahrir et al.
Drying Models of BirdAos Eye and Curly Chili CELEBES Agricultural Vol.
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confirming the effectiveness of the passive dryer in creating a more favorable drying environment for chilies.
Table 1.
Summary of drying air temperature and relative humadity Treatment Location Inside Dryer Outside Dryer Inside Dryer Outside Dryer Temperature 39Ae75 32Ae57 39Ae72 39Ae68 Relative Humadity 33,2Ae44,8 37, 6Ae67,7 32,4Ae41,1 37, 6Ae69,3 The summary of drying air conditions in Table 1.
indicates that the drying air temperature inside the dryer was consistently higher and the relative humidity was lower than those outside the dryer for both treatments.
Higher drying air temperature combined with lower relative humidity increased the driving force for heat and mass transfer and enhanced the moisture removal rate from the chili samples Moisture Content The results of the passive drying experiment showed that the chili samples were placed in the upper and middle sections of the drying chamber, with two replications conducted.
The following graph illustrates the moisture content reduction pattern of birdAos eye chili and curly Moisture Content (%) ---- MC Bird's Eye Chili
---- MC Curly Chili
10 11 12 13 14 15 16 17 18 19 20 21
Times (Hou.
Figure 6.
Moisture Content of BirdAos Eye Chili and Curly Chili in the First Treatment
Moisture Content (%) ---- MC Bird's Eye Chili
---- MC Curly Chili
10 11 12 13 14 15 16 17 18 19 20 21
Time (Hou.
Figure 7.
Moisture content of birdAos eye chili and curly chili in the second treatment.
Syahrir et al.
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Figure 6 shows the moisture content reduction pattern of curly chili and birdAos eye chili during the drying process, which exhibit similar characteristics.
In the initial stage, the moisture content of both chili types near the surface is still high, resulting in a faster rate of moisture reduction.
Over time, the drying rate decreases as the surface moisture diminishes.
This process causes water diffusion from the inner part of the chili toward the surface to take longer.
Based on the research findings, it can be concluded that the drying process using a solar box dryer effectively influences the moisture content of both birdAos eye chili and curly chili by evaporating and diffusing the water through the fruit surface into the air until a constant moisture level is This result is consistent with the study by (Cipta, 2.
which stated that drying aims to reduce the moisture content to a safe level so that the product can be stored longer and is less susceptible to damage.
In the first experiment, the initial moisture content of curly chili was approximately 80%, which decreased to a constant level of about 7%.
Meanwhile, birdAos eye chili in the same experiment had an initial moisture content of around 79% and reached a constant level of 5%.
the second experiment, curly chili had an initial moisture content of 80% and reached a constant moisture content of 6%, while birdAos eye chili started at 79% and stabilized at 5%.
Moisture content is an important factor to consider in the storage of agricultural products, including chili.
This is consistent with the statement of (Fadhilatunnur et al.
, 2.
, which explains that the drying process aims to reduce the moisture content to a safe limit so that the product can last longer during storage and is less prone to damage.
There was no significant comparison between the two
types of chili peppers Moisture Ratio Reduction Pattern
The drying process that has been carried out not only showed a decrease in the moisture content rate of birdAos eye chili and curly chili but also a reduction in the Moisture Ratio (MR) Moisture Rasio
---- MR Bird's Eye Chili
---- MR Curly Chili
10 11 12 13 14 15 16 17 18 19 20 21
Times (Hou.
Figure 8.
Moisture Ratio of Curly Chili and BirdAos Eye Chili in the First Treatment.
Based on Figures 8 and 9, which show the relationship between Moisture Ratio (MR) and time during the drying process, it can be concluded that the decrease pattern of MR for curly chili (MR C.
K) and birdAos eye chili (MR C.
R) is nearly identical.
As shown in the figures, the MR value starts at 1 and gradually decreases over time.
This result is consistent with the findings of (Ilham, 2.
who stated that as drying time increases, the MR value tends to decrease.
The decline occurs rapidly during the initial hours of drying, which aligns with the moisture content reduction Syahrir et al.
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After approximately 8Ae10 hours, the rate of MR decrease slows significantly until it approaches a value close to zero, indicating that the drying process has reached its final or equilibrium stage.
Moisture Rasio
10 11 12 13 14 15 16 17 18 19 20 21
Times (Hou.
Figure 9.
Moisture Ratio of Curly Chili and BirdAos Eye Chili in the Second Treatment.
The similar MR reduction patterns observed in both chili types indicate that they have comparable drying characteristics.
The MR values are then used to determine the most suitable drying model, where the model with the highest RA value is selected to represent the drying behavior of birdAos eye chili and curly chili (Yosika et al.
, 2.
Drying Model Evaluation Testing of the drying model on birdAos eye chili and curly chili was conducted using three models, namely Page.
Newton, and Henderson and Pabis.
Table 2.
Analysis results of the equation models for birdAos eye chili and curly chili.
Model Newton Page Equation MR=exp (-k.
MR=exp (-kt^.
Sample Curly chilies Curly chilies Average BirdAos Eye chili U1 BirdAos Eye chili U2 Average Curly chilies Curly chilies Average BirdAos Eye chili U1 BirdAos Eye chili U2 Syahrir et al.
Drying Models of BirdAos Eye and Curly Chili
0,190275
0,9530
0,325431
0,9821
0,257853
0,198656
0,96755
0,9531
0,414046
0,9773
0,306351
0,025175
2,108804
0,96520
0,9962
0,171097
1,486017
0,9979
0,098136
0,028568
1,79741
2,085289
0,99705
0,9948
0,228153
1,547439
0,9956
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Henderson Pabris MR= a exp(-k.
Average Curly chilies Curly chilies Average BirdAos Eye chili U1 BirdAos Eye chili U2 Average 1,186784 0,128361 0,219507 1,816364 0,99520 0,9584 1,096747 0,352532 0,9840 1,141765 1,17777 0,28602 0,227575 0,97120 0,9578 1,090225 0,445608 0,9789 1,133997 0,336592 0,96835 Table 2 shows the constant values for each of the tested models.
From the test results, it can be seen that the Page model has the highest RA value compared to the Newton and Henderson & Pabis models.
This indicates that the Page model is the best model to describe the decrease in moisture content and Moisture Ratio (MR) during the drying of birdAos eye chili and curly chili, in accordance with the study by (Irfan et al.
, 2.
, which stated that the Page model is the most suitable for representing the drying characteristics of chili.
After the coefficient of determination (RA) value is obtained, the root mean square error (RMSE) and chi-square (NA) values are calculated as additional parameters to evaluate the level of agreement between the moisture ratio values from observations and the model prediction results.
Table 3.
Value root mean-square error (RMSE) and chi-square (NA) Material RMSE
BirdAos Chili
0,0452
0,00214
Curly Chili
0,0336
0,00118
Based on the constants k, a, and n from Table 1, the predicted Moisture Ratio (MR) values were calculated for each sample .
irdAos eye chili and curly chil.
In addition to the coefficient of determination (RA), model validation was performed using the root mean square error (RMSE) and chi-square (NA).
The Page model produced low RMSE values of 0.
0336 for birdAos eye chili and 0452 for curly chili, with corresponding NA values of 0.
00118 and 0.
These results indicate a good agreement between the experimental and predicted moisture ratio data, confirming the suitability of the Page model to describe the drying behaviour of both chili varieties under passive drying conditions.
CONCLUSIONS
Based on the study conducted on birdAos eye chili and curly chili, it can be concluded that the moisture ratio reduction patterns of both types of chili during the drying process were relatively similar.
At the beginning of the drying process, the decrease in moisture content occurred rapidly due to the high initial water content, but the drying rate gradually slowed down as the moisture content within the chilies decreased.
Among the three drying models testedAi Page.
Newton, and Henderson & PabisAithe Page model was identified as the most suitable for representing the moisture reduction pattern of birdAos eye chili and curly chili, as it produced the highest coefficient of determination (RA) value.
Syahrir et al.
Drying Models of BirdAos Eye and Curly Chili CELEBES Agricultural Vol.
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REFERENCE