Blanching of Peanut Kernels As Affected By Repeated Rewetting-Drying Cycles1

1977 ◽  
Vol 4 (2) ◽  
pp. 63-66 ◽  
Author(s):  
S. M. Farouk ◽  
G. H. Brusewitz ◽  
M. R. Paulsen

Abstract Shelled Spanish peanut kernels were subjected to repeated cycles of rewetting and drying at three levels of drying relative humidity (20%, 40% and 60%) and a single level of rewetting humidity (90%). Temperature was constant at 40 °C for all the experiments. Effects of relative humidity, number of rewetting-drying cycles, and the level of moisture content on the percentage of blanching were observed and analyzed. The number of rewetting-drying cycles, and the relative humidity of the drying air were found to be highly significant. Univariate models predicting blanching percentage as a function of the number of cycles of operation at fixed relative humidity levels, and bivariate model predicting blanching percentage as a function of drying relative humidity and number of cycles were fit to the experimental data. Skin moisture content and moisture history are suggested as important factors in peanut kernel blanching.

2007 ◽  
Vol 13 (3) ◽  
pp. 231-238 ◽  
Author(s):  
P.C. Corrêa ◽  
A.L.D. Goneli ◽  
C. Jaren ◽  
D.M. Ribeiro ◽  
O. Resende

This study was carried out to evaluate the sorption isotherms of peanut pods, kernels and hulls for several temperature and humidity conditions and to fit different mathematical models to the experimental data, selecting the one best fitting the phenomenon. The dynamic method was applied to obtain the hygroscopic equilibrium moisture content. The environmental conditions were provided by means of an atmospheric conditioning unit, in which removable perforated trays were placed to allow air to pass through peanut mass, each one containing 50 g of the product. The mathematical models frequently used for the representation of hygroscopicity of agricultural products were fit to the experimental data. Based on those results, it was concluded that peanut pods, kernels and hulls presented differentiated hygroscopicity. The equilibrium moisture content for peanut pods, kernels and hulls increased with an increase in the relative humidity at any particular temperature and decreased with increase in temperature at constant relative humidity. At a constant water activity, peanut hulls samples had higher equilibrium moisture content than the pods and kernels samples. Based on statistical parameters, the modified Henderson and Chung-Pfost models were found to adequately describe the sorption characteristics of peanut pods, kernels and hulls. Isosteric heat of desorption were evaluated by applying the Clausius—Clapeyron equation to experimental isotherms and decreased with increasing moisture content. The peanut hulls had higher isosteric heat of sorption than that peanut pods and kernels.


2021 ◽  
Vol 10 (14) ◽  
pp. e184101420930
Author(s):  
Mariana Aparecida Nunes ◽  
Camila Alves Moreira ◽  
Lenilton Santos Soares ◽  
Marta Fernanda Zotarelli ◽  
Marieli de Lima

This study aimed to produce quail egg powder by freeze-drying and to evaluate its stability in different types of flexible packages (low-density polyethylene, polypropylene and pigmented polypropylene) in high relative humidity (approximately 81%) at 25 °C during 59 days. The packages were evaluated for water vapor permeability and freeze-dried egg was characterized as to bulk density and hygroscopicity (initial time), and moisture, water activity, pH and color (until the end of storage). GAB, BET and Peleg sorption isotherm models were adjusted to the experimental data to predict monolayer moisture content in the powdered eggs. The freeze-dried quail eggs presented a little oscillation in color coordinates, reduction in pH, and increase in moisture content and water activity during storage for all packages used. No evaluated packaging was sufficiently effective as a moisture barrier. GAB and BET models fitted better to the experimental data for the freeze-dried quail egg, and the estimated monolayer moisture values were 0.0333 and 0.0227 g H2O/g solids, respectively. The powdered quail egg has industrial potential, however, it is susceptible to significant changes throughout storage when exposed to high relative humidity and conditioned in the tested packages. Commercially, as this product can be sold in regions with different temperatures and relative humidity, it is essential to consider the use of preservatives or anti-wetting agents.


2018 ◽  
Vol 38 (1) ◽  
pp. 45
Author(s):  
Widya Eka Prayitno ◽  
Harsi Dewantari Kusumaningrum ◽  
Hanifah Nuryani Lioe

Factors affecting contamination on peanut kernel marketed in Jakarta has not been investigated yet. The purpose of the research was to investigate and evaluate the storage condition and the behavior of retailers on the way of peanuts storage and also to investigate the presence of Aspergillus flavus infection in the peanuts. The research was conducted at traditional market with 15 peanut retailers as respondents (n=15). The research stages included survey at retailer area including interview, observation, temperature and relative humidity measurements as well as peanuts analysis including moisture content, defective seeds and presence of A. flavus. The results of research revealed that the average temperature of peanut storage area at retail stalls range from 29.6 to 31.2 °C which is not in accordance with the Codex Alimentarius Commission (CAC) recommendation, while the average of storage room RH ranged between 53.6–73.1% and moisture content of peanuts of 6.23–7.86% were mostly in accordance to CAC recommendation. The percentage of damage, shrivelled and splitted seeds ranged between 3.9–19.1%, 5.4–32.3% and 0.2–8.8%, respectively. The range of mean of total molds and A. flavus were 2.5–5.6 log cfu/g and 1.3–4.0 log cfu/g, respectively. Total molds had a strong correlation to damage kernels (r = 0.74), and had a moderate correlation to the temperature (r = 0.41), moisture content (r = 0.42) and behavior of retailers, especially in cleaning the ceiling (r = 0.44) and placing the storage container (r = 0.44). The presence of A. flavus had a slight correlation to relative humidity on storage (r = 0.26), and had no significant correlation to peanuts damage and all storage conditions. ABSTRAKFaktor-faktor yang mempengaruhi cemaran aflatoksin pada biji kacang tanah atau ose di wilayah Jakarta belum pernah dilaporkan. Penelitian ini dilakukan di pasar tradisional dengan 15 pedagang pengecer kacang tanah sebagai responden (n=15). Tujuan penelitian adalah mengidentifikasi dan mengevaluasi kondisi penyimpanan dan perilaku pengecer dalam menyimpan kacang tanah serta mengidentifikasi potensi cemaran Aspergillus flavus pada kacang tanah. Tahap penelitian meliputi survei di area pengecer (wawancara, pengamatan langsung dan pengukuran suhu serta kelembaban relatif (RH) di area penyimpanan) serta analisis kacang tanah (kadar air, biji cacat, dan keberadaan A. flavus). Hasil studi menunjukkan rata-rata kisaran suhu area penyimpanan kacang tanah di kios pengecer berkisar antara 29,6–31,2 °C. Hal ini tidak sesuai dengan rekomendasi Codex Alimentarius Commission (CAC), meskipun sebagian besar rata-rata kisaran RH area penyimpanan berkisar antara 53,6–73,1% dan kadar air kacang tanah sebesar 6,23–7,86% yang sesuai dengan rekomendasi CAC. Rata-rata biji rusak, biji keriput dan biji belah ditemukan pada kisaran, berturut-turut, 3,9-19,1%, 5,4–32,3% dan 0,2–8,8%. Rata-rata total kapang dan A. flavus pada sampel kacang tanah, masing-masing, ditemukan berkisar antara 2,5–5,6 log cfu/g dan 1,3–4,0 log cfu/g. Total kapang pada sampel kacang tanah memiliki korelasi positif yang kuat dengan biji rusak (r = 0,74), dan berkorelasi positif pada tingkat sedang dengan suhu (r = 0,41), kadar air (r = 0,42) dan perilaku pengecer dalam pembersihan langit-langit kios (r = 0,44) serta penempatan wadah simpan kacang tanah (r = 0,44). Studi ini menunjukkan bahwa keberadaan A. flavus pada sampel kacang tanah berkorelasi positif lemah dengan kelembaban relatif di area penyimpanan (r = 0,26) dan tidak memiliki korelasi secara signifikan dengan biji rusak maupun semua kondisi penyimpanan lainnya.  


2000 ◽  
Vol 18 (No. 3) ◽  
pp. 86-90 ◽  
Author(s):  
N.D. Menkov ◽  
D.I. Gelyazkov

The equilibrium moisture contents were determined for millet seeds of two cultivars using the gravimetric static method at 10, 25 and 40°C over a range of relative humidities from 0.112 to 0.868. The sorption capacity of the seeds decreased with an increase in temperature at constant relative humidity. The hysteresis effect is not distinctly expressed but statistically significant. The differences between equilibrium moisture contents of the cultivars are small. Four models were applied for analyzing the experimental data using the following equations: modified Chung-Pfost, modified Halsey, modified Oswin, and modified Henderson. The modified Chung-Pfost model was found to be the most suitable for describing the relationship between equilibrium moisture content, relative humidity and temperature.


2020 ◽  
Vol 44 ◽  
Author(s):  
Paulo Cesar Corrêa ◽  
Juliana Soares Zeymer ◽  
Gabriel Henrique Horta de Oliveira ◽  
Marcos Eduardo Viana de Araujo ◽  
Camilla Sena da Silva

ABSTRACT It is necessary to determine the sorption isotherms of seeds to develop adequate systems of storage and drying. The chemical composition of a product affects the sorption process; products with a high oil content adsorb a lower amount of moisture from the environment than products with a high carbohydrate content. Given the importance of the hygroscopicity of different agricultural products, this work aimed to determine, model and evaluate the difference between desorption isotherms of ryegrass and flax seeds grown at different temperature and relative humidity conditions. Ryegrass and flax seeds, which contained initial moisture contents of 10.4 and 8.7% (db), respectively, were used. The equilibrium moisture content of the seeds was determined using a static-gravimetric method at different temperatures (10, 20, 30, 40, and 50 ± 1 °C) and relative humidity values (between 11 and 96 ± 2%), in three replicates. Seven mathematical models were adjusted to the equilibrium moisture content experimental data of the seeds. The Chung Pfost model best fit the experimental data of ryegrass seeds, whereas the Smith model was determined to be the best fit for flax seeds. The equilibrium moisture content of the seeds was found to decrease as the temperature increased when the value of water activity was constant. The desorption isotherms of ryegrass seeds (Type II) and flax seeds (Type III) are different, according to Brunauer’s classification, which is caused by the composition (starch and oil content) of each product.


2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.


2019 ◽  
Vol 111 ◽  
pp. 02044
Author(s):  
Akemi Iwaki ◽  
Takashi Akimoto ◽  
Naho Misumi ◽  
Takuya Furuhashi

This study focused on the thermal comfort of air circulation-type whole-house air-conditioning ventilation systems. We studied the influence of 24-h continuous whole-house air-conditioning on the living environment in which the occupant is sleeping. A survey was conducted in the summer of 2016 and winter of 2017 to ascertain the influence on the sleeping environment, skin moisture content, and blood pressure. We then compared the results with those of the sleeping environment of residents in air-conditioned housing surveyed the previous year. The sleeping environment when using a personal humidifier around the occupant’s head was examined during winter when the humidity is low. The results indicated that sleep latency was significantly shortened in the 24-h continuous whole-house air-conditioning ventilation system in both summer and winter because the temperature control of the bedroom before going to bed affects the sleep latency. Subjectively, no participants felt dryer than the values measured in the bedroom environment. The results implied that the comfort of the entire building was improved with continuous air-conditioned housing.


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