Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions

During the rice milling process, single and continuous compression occurs between brown rice and the processing parts. When the external load exceeds the yield limit of brown rice, brown rice kernels are damaged; with an increase in compression deformation or the extent of compression, the amount of...

Full description

Bibliographic Details
Main Authors: Xiaopeng Liu, Ziang Shi, Yonglin Zhang, Hui Li, Houchang Pei, Hongjun Yang
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Foods
Subjects:
Online Access:https://www.mdpi.com/2304-8158/13/7/1069
_version_ 1797212595942326272
author Xiaopeng Liu
Ziang Shi
Yonglin Zhang
Hui Li
Houchang Pei
Hongjun Yang
author_facet Xiaopeng Liu
Ziang Shi
Yonglin Zhang
Hui Li
Houchang Pei
Hongjun Yang
author_sort Xiaopeng Liu
collection DOAJ
description During the rice milling process, single and continuous compression occurs between brown rice and the processing parts. When the external load exceeds the yield limit of brown rice, brown rice kernels are damaged; with an increase in compression deformation or the extent of compression, the amount of damage to the kernels expands and accumulates, ultimately leading to the fracture and breakage of kernels. In order to investigate the mechanical compression damage characteristics of brown rice kernels under real-world working conditions, this study constructs an elastic–plastic compression model and a continuous damage model of brown rice kernels based on Hertz theory and continuous damage theory; the accuracy of this model is verified through experiments, and the relevant processing critical parameters are calculated. In this study, three varieties of brown rice kernels are taken as the research object, and mechanical compression tests are carried out using a texture apparatus; finally, the test data are analysed and calculated by combining them with the theoretical model to obtain the relevant critical parameters of damage. The results of the single compression crushing test of brown rice kernels showed that the maximum destructive forces <i>F</i><sub>c</sub> in the single compression of Hunan Early indica 45, Hunan Glutinous 28, and Southern Japonica 518 kernels were 134.77 ± 11.20 N, 115.64 ± 4.35 N, and 115.84 ± 5.89 N, respectively; the maximum crushing deformations <i>α</i><sub>c</sub> in the single compression crushing test were 0.51 ± 0.04 mm, 0.43 ± 0.01 mm, and 0.48 ± 0.17 mm, respectively; and the critical average deformations <i>α</i><sub>s</sub> of elasticity–plasticity deformation were 0.224 mm, 0.267 mm, and 0.280 mm, respectively. The results of the continuous compression crushing test of brown rice kernels showed that the critical deformations <i>α</i><sub>d</sub> of successive compression damage formation were 0.224 mm, 0.267 mm, and 0.280 mm, and the deformation ratios <i>δ</i> of compression damage were 12.24%, 14.35%, and 12.84%. From the test results, it can be seen that the continuous application of compression load does not result in the crushing of kernels if the compression deformation is less than <i>α</i><sub>d</sub> during mechanical compression. The continuous application of compressive loads can lead to fragmentation of the kernels if the compressive deformation exceeds <i>α</i><sub>d</sub>; the larger the compression variant, the less compression is required for crushing. If the compression deformation exceeds <i>α</i><sub>c</sub>, then a single compressive load can directly fragment the kernels. Therefore, the load employed during rice milling should be based on the variety of brown rice used in order to prevent brown rice deformation, which should be less than <i>α</i><sub>d</sub>, and the maximum load should not exceed <i>F</i><sub>c</sub>. The results of this study provide a theoretical reference for the structure and parameter optimisation of a rice milling machine.
first_indexed 2024-04-24T10:44:53Z
format Article
id doaj.art-c5b74e383e3947da8d4fc741a1729643
institution Directory Open Access Journal
issn 2304-8158
language English
last_indexed 2024-04-24T10:44:53Z
publishDate 2024-03-01
publisher MDPI AG
record_format Article
series Foods
spelling doaj.art-c5b74e383e3947da8d4fc741a17296432024-04-12T13:18:36ZengMDPI AGFoods2304-81582024-03-01137106910.3390/foods13071069Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression ConditionsXiaopeng Liu0Ziang Shi1Yonglin Zhang2Hui Li3Houchang Pei4Hongjun Yang5School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaSchool of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaSchool of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaSchool of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaSchool of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaSchool of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaDuring the rice milling process, single and continuous compression occurs between brown rice and the processing parts. When the external load exceeds the yield limit of brown rice, brown rice kernels are damaged; with an increase in compression deformation or the extent of compression, the amount of damage to the kernels expands and accumulates, ultimately leading to the fracture and breakage of kernels. In order to investigate the mechanical compression damage characteristics of brown rice kernels under real-world working conditions, this study constructs an elastic–plastic compression model and a continuous damage model of brown rice kernels based on Hertz theory and continuous damage theory; the accuracy of this model is verified through experiments, and the relevant processing critical parameters are calculated. In this study, three varieties of brown rice kernels are taken as the research object, and mechanical compression tests are carried out using a texture apparatus; finally, the test data are analysed and calculated by combining them with the theoretical model to obtain the relevant critical parameters of damage. The results of the single compression crushing test of brown rice kernels showed that the maximum destructive forces <i>F</i><sub>c</sub> in the single compression of Hunan Early indica 45, Hunan Glutinous 28, and Southern Japonica 518 kernels were 134.77 ± 11.20 N, 115.64 ± 4.35 N, and 115.84 ± 5.89 N, respectively; the maximum crushing deformations <i>α</i><sub>c</sub> in the single compression crushing test were 0.51 ± 0.04 mm, 0.43 ± 0.01 mm, and 0.48 ± 0.17 mm, respectively; and the critical average deformations <i>α</i><sub>s</sub> of elasticity–plasticity deformation were 0.224 mm, 0.267 mm, and 0.280 mm, respectively. The results of the continuous compression crushing test of brown rice kernels showed that the critical deformations <i>α</i><sub>d</sub> of successive compression damage formation were 0.224 mm, 0.267 mm, and 0.280 mm, and the deformation ratios <i>δ</i> of compression damage were 12.24%, 14.35%, and 12.84%. From the test results, it can be seen that the continuous application of compression load does not result in the crushing of kernels if the compression deformation is less than <i>α</i><sub>d</sub> during mechanical compression. The continuous application of compressive loads can lead to fragmentation of the kernels if the compressive deformation exceeds <i>α</i><sub>d</sub>; the larger the compression variant, the less compression is required for crushing. If the compression deformation exceeds <i>α</i><sub>c</sub>, then a single compressive load can directly fragment the kernels. Therefore, the load employed during rice milling should be based on the variety of brown rice used in order to prevent brown rice deformation, which should be less than <i>α</i><sub>d</sub>, and the maximum load should not exceed <i>F</i><sub>c</sub>. The results of this study provide a theoretical reference for the structure and parameter optimisation of a rice milling machine.https://www.mdpi.com/2304-8158/13/7/1069brown rice kernelsrice millingelastic–plastic contactcontinuum damageHertz theory
spellingShingle Xiaopeng Liu
Ziang Shi
Yonglin Zhang
Hui Li
Houchang Pei
Hongjun Yang
Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
Foods
brown rice kernels
rice milling
elastic–plastic contact
continuum damage
Hertz theory
title Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
title_full Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
title_fullStr Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
title_full_unstemmed Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
title_short Characteristics of Damage to Brown Rice Kernels under Single and Continuous Mechanical Compression Conditions
title_sort characteristics of damage to brown rice kernels under single and continuous mechanical compression conditions
topic brown rice kernels
rice milling
elastic–plastic contact
continuum damage
Hertz theory
url https://www.mdpi.com/2304-8158/13/7/1069
work_keys_str_mv AT xiaopengliu characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions
AT ziangshi characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions
AT yonglinzhang characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions
AT huili characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions
AT houchangpei characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions
AT hongjunyang characteristicsofdamagetobrownricekernelsundersingleandcontinuousmechanicalcompressionconditions