Status : Verified
| Personal Name | Cambangay, Janine N. |
|---|---|
| Resource Title | Moisture desorption isotherms of Pinilisa rice (Oryza sativa L.) with different degrees of milling and kernel fragment sizes |
| Date Issued | 30 January 2017 |
| Abstract | This study sought to investigate the effects of degree of milling (DOM) and kernel fragment size on moisture desorption of Pinilisa rice. Pinilisa paddy rice, dehulled (DOM: 0%) and milled―undermilled (DOM: 12%) and regularly milled (DOM: 14%) were used in the study. Dehulled, undermilled, and regular milled were tested in three fragment sizes: whole, broken, and ground. Samples were pretreated to at least 18% (w.b.) moisture content. Desorption isotherms were determined using static gravimetric method at 37⁰C at a water activity range of 0.0205-0.9566. Type II (sigmoidal) moisture desorption isotherms were generated from the equilibrium moisture content versus equilibrium water activity at the incubation temperature used. The monolayer moisture contents were estimated using Brunauer-Emmett-Teller (BET) equation and Guggenheim-Anderson-de Boer (GAB). The monolayer values of Pinilisa rice were found to be 0.0674-0.1199 g/g (d.b.) for BET and 0.0825-0.1662 g/g (d.b.) for GAB. The following mathematical models were fitted on the EMC data of samples: Guggenheim-Anderson-de Boer (GAB), Modified Henderson Equation (MHEE), Modified Chung-Pfost Equation (MCPE), Modified Halsey Equation (MHAE), and Modified Oswin Equation (MOSE). The equation most suitable for almost all Pinilisa rice samples was MCPE, followed by MHAE and MOSE. Inflection points of the MCPE curves were found at water activity values of 0.0124 and 0.7575, suggesting that the water binding capacity of Pinilisa rice changes at these water activity values. The effects of degree of milling and particle size on experimental equilibrium moisture content (EMC) were studied. The degree of milling, fragment size, and the interaction between degree of milling and fragment size were found to be significant except at water activity values of x 0.9566, 0.7575, 0.5770, and 0.1024. The fragment size was shown to have a larger effect on experimental EMC of rice compared to the degree of milling. Any effect of degree of |
| Degree Course | Bachelor of Science in Food Technology |
| Language | English |
| Keyword | Rice |
| Material Type | Thesis/Dissertation |
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