scholarly journals Effect of initial moisture content and relative humidity on the accumulation of afalatoxin in maize grains (Zea Mays)during storage

2001 ◽  
Vol 29 (1-2) ◽  
pp. 29 ◽  
Author(s):  
G. H. C. M. Hettiarachchi ◽  
Jaanaki Goonaratne ◽  
W.K. Hirimburegama
2018 ◽  
Vol 3 (2) ◽  
pp. 351-360
Author(s):  
Athul Fadhli ◽  
Diswandi Nurba ◽  
Raida Agustina

Abstrak. Jagung merupakan tanaman penghasil karbohidrat terpenting. Pengeringan jagung pipil menggunakan alat pengering merupakan proses untuk menghasilkan jagung pipil yang siap diolah untuk pembuatan tepung jagung dengan batas kadar air tertentu sehingga menghaslkan jagung pipil dengan kualitas yang baik. Tujuan penelitian ini adalah untuk mengkaji karakteristik pengeringan biji jagung menggunakan alat pengering surya Termodifikasi. Metode penelitian  menggunakan 3,15 kilogram jagung pipil dengan kadar air awal 22% untuk proses pengeringan. Parameter yang dianalisis terkait alat pengering kolektor surya yaitu temperatur, kelembaban relatif, kecepatan udara dan iradiasi surya, sedangkan parameter yang dianalisis terkait bahan yaitu kadar air, lama waktu pengeringan, laju pengeringan dan organoleptik. Prosedur penelitian terdiri dari pengujian kosong dan pengujian dengan menggunakan jagung pipil. Hasil penelitian menunjukkan bahwa temperatur rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 44,4oC, temperatur rata-rata setelah dilakukan modifikasi yaitu 55,5oC dan temperatur rata-rata rak pengering pada pengeringan menggunakan jagung pipil yaitu 46,96oC. Kelembaban relatif rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 40,1%, kelembaban relatif rata-rata dalam rak pengering setelah modifikasi yaitu 35,1% dan kelembaban relatif rata-rata pengeringan menggunakan jagung pipil yaitu 44,45%. Dari hasil pengukuran tersebut menunjukkan bahwa nilai temperatur dan kelembaban pada alat setelah modifikasi lebih baik dibandingkan sebelum alat dimodifikasi. Pengukuran temperatur dan kelembaban relatif terdiri dari 4 titik pengukuran yaitu rak 1A,1B dan rak 2A, 2B. Kecepatan udara rata-rata yang diukur konstan yaitu 0,7 m/s pada ruang pengering, sedangkan lingkungan 1,1 m/s. Total iradiasi surya selama pengeringan yaitu 1848,84 W/m2. Kadar air jagung pipil masing-masing rak yaitu rak 1A 14,29%, rak 1B 14,47%, rak 2A 13,91% dan rak 2B 14,1%. Hasil dari pengujian organoleptik, panelis agak menyukai jagung pipil yang dikeringkan menggunakan alat pengering tersebut.Characteristics of Seed Drying (Zea mays L.) Using a Modified Adriyarkara Solar DryerAbstract. Corn is the most important carbohydrate plant. Drying corn using a drying tool is a process to produce corn that are ready to be processed for making corn flour with a certain water content limit so as to produce corn with good quality. The purpose of this study was to examine the characteristics of drying of corn kernels using a modified solar dryer. The research method used 3,15 kilogram of corn milled with the initial moisture content of 22% for drying process. The parameters analyzed in relation to solar collector dryers are temperature, relative humidity, air velocity and solar irradiation, while the parameters analyzed are materials such as moisture content, drying time, drying rate and organoleptic. The research procedure consists of unloaded testing and testing using corn. The results showed that the average temperature in the dryer tray before modification was 44,4°C, the average temperature after modification was 55,5°C and the average temperature of the dryer tray on drying using corn was 46,96oC. The average relative humidity in the dryer tray before modification is 40,1%, the average relative humidity in the dryer tray after modification is 35,1% and the average relative humidity of drying using corn is 44,45%. From the measurement results show that the value of temperature and humidity in the tool after modification is better than before. Measurement of temperature and relative humidity consist of 4 point of measurement that is tray 1A, 1B and tray 2A, 2B. Average mean air velocity measured is 0,7 m/s at the dryer room, while the environment is 1,1 m/s. Total solar irradiation during drying is 1848,84 W/m2. Moisture level of corn each shelves tray 1A is 14,29%, tray 1B is 14.47%, tray 2A is 13,91% and tray 2B is 14,1%. As a result of organoleptic testing, panelists rather like dried corn using the dryer.


2019 ◽  
Vol 62 (3) ◽  
pp. 661-671 ◽  
Author(s):  
Jia Wu ◽  
Xiangyang Lin ◽  
Shengnan Lin ◽  
Paul Chen ◽  
Guangwei Huang ◽  
...  

Abstract. The effects of packaging and storage conditions on the moisture content and instrumental and sensory textural properties of raw and salty light roasted (SLR) California almonds were studied under different storage conditions. The controlled combinations included low, medium, and high temperatures and low and high relative humidity (RH). Almond samples were packaged in cartons or polyethylene (PE) bags with and without vacuum. Both absorption and desorption of moisture by almonds were observed during storage and were dependent on the packaging and storage conditions. In general, gradual changes were observed for samples with PE and vacuum PE packaging in most of the storage conditions, while the samples packed in cartons showed more dramatic changes because these unprotected samples were more vulnerable to seasonal changes in humidity. The SLR almonds showed consistent moisture gains, while the raw almonds tended to lose moisture content in most of the storage conditions. This may be attributed to the low initial moisture content of the SLR samples. All raw samples packed in cartons became softer over time. The softening tended to be enhanced by high storage humidity and temperature. The raw almonds packaged in PE bags were firmer than those packed in cartons but also became softer over time. The firmness of the SLR samples was generally lower than that of raw samples, probably because roasting reduced the density and mechanical strength of the kernels. The firmness of PE packaged SLR samples increased in uncontrolled storage conditions and in higher storage temperature and humidity conditions but decreased slightly in lower temperature and humidity conditions. Vacuum packaging did not affect the firmness much. Using PE packaging and maintaining the RH below 50% and the temperature below 25°C are effective in stabilizing both raw and processed almonds. Keywords: Almond, Firmness, Nonpareil, Packaging, Relative humidity, Sensory, Storage, Temperature, Texture.


2012 ◽  
Vol 622-623 ◽  
pp. 1580-1585
Author(s):  
A. Sae-Khow ◽  
S. Tirawanichakul ◽  
Y. Tirawanichakul

The objective of this research were to evaulate equilibrium moisture contents (EMC) of black pepper using the gravimetric-static method and to study the drying kinetics of pepper using 1-stage hot air (HA) drying, 1-stage infrared (IR) drying, 2-stages drying with microwave (MW) and IR and 2-stages drying with MW and HA including to the specific energy consumption determination. For the first objective, the five saturated salt solutions were used for providing equlibrate state between pepper and surrounding at temperature ranging of 40-65°C correlated to relative humidity ranging of 10-90%. The results showed that EMC value decreased with increasing temperature at constant relative humidity. To evaluate the EMC value, the experimental data was simulated by four conventional EMC models and the criteria of the best fiiting models were determined by the determination of coefficient (R2) and the root mean square error (RMSE) value. The results showed that the calculated value using the Modified Oswin model was the most suitable for describing the relationship among equilibrium moisture content, relative humidity and temperature. To study effect of drying condition on drying kinetics, the initial moisture content and final moisture content after drying of papper sample was in ranges of 300-400% dry-basis and 12-16% dry-basis, respectively. The experimetal data were simulsted using empirical drying models and the results showed that the drying temperature relatively affected to drying rate of pepper while the evolution of moisture transfer was in the drying falling ratefor all drying strategies. The 1-stage IR drying and 2-stages drying with MW and IR provided low specific energy consumption (SEC) (0.11-0.15 MJ/kg of water evaporated) compared to the other drying strategies (0.87-1.52 MJ/kg of water evaporated). Moreover, the SEC of pepper drying decreased with increasing of drying temperature.


2018 ◽  
Vol 6 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Hary Kurniawan ◽  
Nursigit Bintoro ◽  
Joko Nugroho W.K.

The purpose of this research was to determined the shelf life of packaged palm sugar at various temperatures and relative humidity (RH) storage using Arrhenius model based on changes in water content. The palm sugars were packed with 0.675 mm polyethylene packaging and stored at 15, 25, 30 and 35°C at RH of 77% and 98%. Measured parameters included the determination of critical parameters of palm sugar, initial moisture content and critical moisture content of palm sugar, changes in moisture content during storage. The Arrhenius model approach was used in this study to predict the shelf life period of palm sugar. The results showed that the texture was one of palm sugar critical parameters. Initial moisture content and critical moisture content of palm sugar were obtained at 1.51% (db) and 6.80% (db), respectively. Increase in moisture content of palm sugar occurred in various temperature variations and RH storage. The higher the storage temperature, the higher the moisture content of the palm sugar, which was characterized by the greater slope of moisture content relationship graph with respect to storage period at both RH 77% and 98%. The longest duration of palm sugar occurredat 15°C, RH 77%; the shortest duration occurred at 35°C, RH 98%. Keywords: palm sugar, packaging, relative humidity, temperature, shelf life   ABSTRAK Tujuan dari penelitian in adalah menentukan umur simpan gula semut dalam kemasan pada berbagai suhu dan RH penyimpanan mengunakan model Arrhenius berdasarkan perubahan kadar air. Gula semut dikemas menggunakan kemasan polietilen ketabalan 0,675 mm dan disimpan pada suhu 15, 25, 30 dan 35oC pada RH 77% dan 98%. Parameter yang diukur antara lain penetuan parameter kritis gula semut, kadar air awal dan kadar air kritis gula semut, perubahan kadar air selama penyimpanan. Pendekatan model Arrhenius digunakan dalam penelitan ini untuk memprediksi umur simpan gula semut. Hasil menunjukkan bahwa tekstur merupakan salah satu parameter kritis gula semut. Kadar air awal dan kadar air kritis gula semut diperoleh masing-masing 1,51 % (db) dan 6,80% (db). Terjadi peningkatan kadar air gula semut pada berbagai variasi suhu dan RH penyimpanan. Semakin tinggi suhu penyimpanan maka kenaiakn kadar air gula semut semakin besar yang ditandai dengan semakin besar kemiringan grafik hubungan kadar air terhadap waktu penyimpanan baik pada RH 77% dan 98%. Umur simpan gula semut paling lama terjadi pada suhu 15oC RH 77% dan umur simpan gula semut yang paling pendek terjadi pada suhu 35oC RH 98%.     Kata kunci: gula semut, kelembaban relatif, kemasan, temperatur, umur simpan


2017 ◽  
Vol 44 (2) ◽  
pp. 111-123 ◽  
Author(s):  
C.L. Butts ◽  
M.C. Lamb ◽  
R.B. Sorensen ◽  
S. Powell ◽  
D. Cowart ◽  
...  

ABSTRACT Studies were conducted in small chambers and commercial storage facilities to evaluate the effect of storing shelled peanuts at 3, 13, and 21 C (38, 55, 70 F) for one year. Shelled medium runner peanuts from the 2014 crop were placed in the three different environments in Feb 2015, sampled at 60-d intervals until Feb 2016 (364 days). Difficulty maintaining the desired relative humidity of 65% in the 3 C unit, led to unacceptable mold growth and severely degraded seed germination. Peanuts stored at 21 C developed an infestation of Indian meal moth after 238 d in storage rendering the samples unsuitable for sensory analysis from that point forward. The infestation most likely occurred due to hatches of eggs that were present in the original samples. Sensory analyses showed very little change in the intensity of the Roasted Peanut flavor characteristic in either storage environments. There were no unacceptable increases in free fatty acids or peroxide values during the 1-yr storage period for peanuts stored at 13 C. The percent free fatty acids in peanuts stored at 13 C remained well below 1% throughout the 1-yr study. Commercial studies were conducted from Feb 2015 through Mar 2016. Six 60-d runs were conducted where three totes of medium runner peanuts from the same manufacturing lot were placed in commercial cold storage facilities maintained at 3 and 13 C. There were no differences in the initial moisture content of peanuts when placed in the two storage environments. However, after 30 and 60-d storage, the peanuts stored at 13 C tended to be an average of 0.3% dryer than those stored at 3 C. The peanuts had the highest increase in moisture between June and August 2015, with the moisture content after 30 and 60 d storage at 3 C averaged 8.1 and 7.7%, respectively. The peanuts stored in the 13 C environment averaged 7.6 and 7.3% moisture content after 30 and 60 d in storage, respectively. This study has shown that shelled peanuts can be stored for up to one year with no detrimental effects at temperatures up to 13 C and relative humidity ranging from 55 to 70%. Based on this research, the recommended temperature for storing shelled peanuts can be increased to 13 C, while maintaining the relative humidity between 55 and 70%.


Holzforschung ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Lauri Rautkari ◽  
Callum A.S. Hill

Abstract The effects of initial moisture content (MC) on anti-swelling efficiency (ASE), mass loss (ML), and equilibrium MC (EMC) at 65% relative humidity of thermally modified Scots pine sapwood under saturated steam (TMSA) has been investigated. ML during the TMSA process was higher with the specimens containing moisture before modification compared with initially dry specimens. Surprisingly, the EMC of the modified specimens with initial moisture was higher than that observed with the modified wood that was initially dry before the modification process. Higher initial MC before thermal modification results in a lower ASE.


Author(s):  
L. Hübschen

AbstractThe present paper shows the detectable factors on which a sorption isotherm depends. Even if it is well-known that a sorption isotherm is most essentially conditioned by influences of the respective tobacco variety, other factors, such as temperature, initial moisture content, or fibre dimension, play a part as well. In general, a sorption isotherm constitutes a ''summation'' of such factors and, in the end, a combination of desorption and adsorption if the tobacco is dried or moistened from the average commercial moisture content. The tobacco hysteresis is experimentally investigated and discussed


Agrotek ◽  
2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Wilson Palelingan Aman

<em>A research about cocoa beans drying used solar tunnel dryer with photovoltaic module driven have conducted in Manokwari. Solar tunnel dryer used in this research adapted from type Hohenheim with photovoltaic module and integrated air heat collector has been installed at the Department of Agricultural Technology, Papua State University Manokwari to dried cocoa beans. The objectives of this research were to design solar tunnel dryer and evaluate it�s performance in dryed cocoa beans. The result obtained was a new construction of solar tunnel dryer for cocoa beans with dimensions 6 m of length and 0,9 m of wide. The dryer completed with photovoltaic module to drive the blowers of hot drying air. �Performance test of the dryer showed that drying of 10 kg of cocoa beans with initial moisture content about 70% wet basis needed 13 hours of drying time to achieved final moisture content about 7,17% wet basis. The drying time achieved was faster compared than traditional solar drying that needed 20 hours of drying time. The maximum temperature achieved in drying chamber was 60 <sup>o</sup>C.</em>


Sign in / Sign up

Export Citation Format

Share Document