Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product
Extrusion can lead to an expanded product or to a slightly expanded pellet, known as a third-generation (3G) snack. In this case, expansion occurs subsequently, in an independent thermal device (e.g., oven), out of the extruded pellet. During both processes, several structural changes occur which ar...
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MDPI AG
2022-01-01
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Series: | Foods |
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Online Access: | https://www.mdpi.com/2304-8158/11/2/198 |
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author | Yadira Zambrano Ingrid Contardo María Carolina Moreno Pedro Bouchon |
author_facet | Yadira Zambrano Ingrid Contardo María Carolina Moreno Pedro Bouchon |
author_sort | Yadira Zambrano |
collection | DOAJ |
description | Extrusion can lead to an expanded product or to a slightly expanded pellet, known as a third-generation (3G) snack. In this case, expansion occurs subsequently, in an independent thermal device (e.g., oven), out of the extruded pellet. During both processes, several structural changes occur which are linked to processing conditions, including cooking temperature, screw speed, formulation, and initial moisture content. However, a clear relationship between processing variables and the structure of pellets and expanded products has not yet been identified. Accordingly, this work aimed to study the effect of extrusion temperature (110, 135, and 150 °C) and moisture content (27, 29, and 31%) in rice-flour pellets and their microwave expansion, through a microstructural approach using micro-CT. The results showed that the lowest moisture content (27%) and the highest extrusion temperature (150 °C) led to the highest pellet volume and the highest wall thickness, which in turn led to the highest expansion after microwave heating (50 s, 800 W). Interestingly, no significant differences were observed when analyzing the ratio between the volume of the expanded products and the volume of the pellet (~2.4) when using the different processing conditions. |
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issn | 2304-8158 |
language | English |
last_indexed | 2024-03-10T01:29:03Z |
publishDate | 2022-01-01 |
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spelling | doaj.art-bf7f57f83f7c42ae81cb467f2a9c40a42023-11-23T13:45:21ZengMDPI AGFoods2304-81582022-01-0111219810.3390/foods11020198Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded ProductYadira Zambrano0Ingrid Contardo1María Carolina Moreno2Pedro Bouchon3Department of Chemical and Bioprocess Engineering, Faculty of Engineering, Pontificia Universidad Católica de Chile, Macul 6904411, ChileDepartment of Chemical and Bioprocess Engineering, Faculty of Engineering, Pontificia Universidad Católica de Chile, Macul 6904411, ChileDepartment of Chemical and Bioprocess Engineering, Faculty of Engineering, Pontificia Universidad Católica de Chile, Macul 6904411, ChileDepartment of Chemical and Bioprocess Engineering, Faculty of Engineering, Pontificia Universidad Católica de Chile, Macul 6904411, ChileExtrusion can lead to an expanded product or to a slightly expanded pellet, known as a third-generation (3G) snack. In this case, expansion occurs subsequently, in an independent thermal device (e.g., oven), out of the extruded pellet. During both processes, several structural changes occur which are linked to processing conditions, including cooking temperature, screw speed, formulation, and initial moisture content. However, a clear relationship between processing variables and the structure of pellets and expanded products has not yet been identified. Accordingly, this work aimed to study the effect of extrusion temperature (110, 135, and 150 °C) and moisture content (27, 29, and 31%) in rice-flour pellets and their microwave expansion, through a microstructural approach using micro-CT. The results showed that the lowest moisture content (27%) and the highest extrusion temperature (150 °C) led to the highest pellet volume and the highest wall thickness, which in turn led to the highest expansion after microwave heating (50 s, 800 W). Interestingly, no significant differences were observed when analyzing the ratio between the volume of the expanded products and the volume of the pellet (~2.4) when using the different processing conditions.https://www.mdpi.com/2304-8158/11/2/1983G snacksextrusionriceX-raymicro-CTmicrostructure |
spellingShingle | Yadira Zambrano Ingrid Contardo María Carolina Moreno Pedro Bouchon Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product Foods 3G snacks extrusion rice X-ray micro-CT microstructure |
title | Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product |
title_full | Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product |
title_fullStr | Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product |
title_full_unstemmed | Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product |
title_short | Effect of Extrusion Temperature and Feed Moisture Content on the Microstructural Properties of Rice-Flour Pellets and Their Impact on the Expanded Product |
title_sort | effect of extrusion temperature and feed moisture content on the microstructural properties of rice flour pellets and their impact on the expanded product |
topic | 3G snacks extrusion rice X-ray micro-CT microstructure |
url | https://www.mdpi.com/2304-8158/11/2/198 |
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