Equilibrium Moisture Content of Kabuli Chickpea, Black Sesame, and White Sesame Seeds

Abstract

Abstract. Sesame and chickpea are important crops in Ethiopia because both are major export crops that generate much revenue for both small farmers and the country as a whole. However, there is a lack of information about the fundamental equilibrium moisture content (EMC) relationships among these crops, which would help facilitate better monitoring and storage. Therefore, EMC adsorption and desorption prediction models based on temperature (T) and relative humidity (RH) were developed for the modified Chung-Pfost and modified Henderson models for Kabuli chickpea (KC), black sesame (BS), and white sesame (WS) seeds. The samples for conducting the adsorption and desorption tests were conditioned to various moisture content (MC) levels for the EMC test models. The samples (~500 g) were placed in multiple sealed enclosures equipped with T and RH sensors, which were placed in an environmental chamber where they were exposed to three temperatures (15°C, 25°C, and 35°C). The MCdb ranges used for model development for adsorption and desorption were, respectively, 11.6% to 19.5% and 8.9% to 16.9% for KC samples, 5.0% to 8.7% and 4.3% to 6.9% for BS, and 4.2% to 8.7% and 3.5% to 7.6% for WS. Nonlinear regression was used to determine the model coefficients for the modified Henderson and modified Chung-Pfost equations. The prediction statistics for the adsorption and desorption models yielded an SEE of, respectively, 0.53% and 0.68% MCdb for KC, 0.23% and 0.13% for BS, and 0.28% and 0.25% for WS. The model coefficients obtained in this study will be used in a moisture meter based on EMC measurement, which is currently being used as part of a USAID postharvest project in various African and Asian countries. These EMC models may also be important for other grain operations, which include harvesting, drying, storage, conditioning, and processing. Keywords: Adsorption, Chickpea, Desorption, EMC, Equilibrium moisture content, Sesame.

Mathematical Modeling and Hysteresis of Sorption Isotherms for Paddy Rice Grains

“…According to Ullmann et al (2016), the Chung Pfost model has been used for starchy products, being the model chosen to represent the hygroscopicity of sweet sorghum seeds. This model also fitted satisfactorily to hygroscopic equilibrium of okra (Goneli et al, 2010), wheat (Li, 2012), cotton (Oliveira et al, 2013), sugar beet (Corrêa et al, 2016), kalibu chickpea, black sesame and white sesame (Armstrong et al, 2017) and red kidney beans (Jian & Jayas, 2018) seeds.…”

Impact of storage technologies and duration on insect pest population, post‐harvest losses, and seed quality of stored chickpea in Ethiopia

“…The recommended safe storage moisture content for chickpeas is generally reported to be below 14%. At the beginning of the trial in this study, the seed moisture content was assessed to be safe at 14.78% 6,26 . However, as storage time progressed, the jute and PP bags showed a significant increase in moisture content.…”

“…To measure intergranular temperature, seed moisture, and RH, the USAID Feed the Future Innovation Lab for the Reduction of Post‐Harvest Loss moisture meter (PHL‐IL, KSU, USA) was utilized 26 . The moisture meter was placed within the grain mass and allowed to stabilize for 2–4 min.…”

“…2.6 Parameters recorded 2.6.1 Intergranular temperature, moisture content, and RH To measure intergranular temperature, seed moisture, and RH, the USAID Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss moisture meter (PHL-IL, KSU, USA) was utilized. 26 The moisture meter was placed within the grain mass and allowed to stabilize for 2-4 min. The equilibrium intergranular temperature (°C), equilibrium wet basis moisture content (% wb), and equilibrium RH were recorded from the meter display.…”

Effects of Storage Duration and Structures on Sesame Seed Germination, Mold Growth, and Mycotoxin Accumulation

“…Dried commodities stored in such porous woven bags can gain moisture from environments with high relative humidity, allowing for fungal infections and the accumulation of mycotoxins [ 3 , 4 ]. Sesame is a widely cultivated oilseed crop and is the second leading Ethiopian export crop behind coffee [ 5 ]. Sesame accounts for over 90% of the value of oilseed exports and more than 30% of the total oilseed production [ 6 , 7 ].…”