Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies

This study evaluated the changes in physicochemical properties and appearance quality of long-grain rice during the grinding process using image technologies and aimed to provide reference for future research. The brown rice milling process was divided into three stages, and flatbed scanning, scanni...

Full description

Saved in:
Bibliographic Details
Main Authors: Xiwu Jia, Rong Dong, Xuan Chen, Zhan Wang, Hongjian Zhang, Wangyang Shen
Format: Article
Language:English
Published: MDPI AG 2024-09-01
Series:Foods
Subjects:
Online Access:https://www.mdpi.com/2304-8158/13/19/3033
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850185032284504064
author Xiwu Jia
Rong Dong
Xuan Chen
Zhan Wang
Hongjian Zhang
Wangyang Shen
author_facet Xiwu Jia
Rong Dong
Xuan Chen
Zhan Wang
Hongjian Zhang
Wangyang Shen
author_sort Xiwu Jia
collection DOAJ
description This study evaluated the changes in physicochemical properties and appearance quality of long-grain rice during the grinding process using image technologies and aimed to provide reference for future research. The brown rice milling process was divided into three stages, and flatbed scanning, scanning electron microscopy (SEM), X-ray micro-computed tomography (micro-CT), low-field nuclear magic resonance (LF-NMR), and headspace–gas chromatography–ion mobility spectrometry (HS–GC–IMS) were employed to examine the physicochemical and volatile properties of the samples. Results revealed a continuous increase in the degree of milling, with a broken rice rate and a whiteness value increasing by 50.84% and 21.13%, respectively, compared with those during the initial stage; dietary fiber and vitamin B1 contents were reduced by 54.41% and 66.67%, respectively. The image results visualized showed that the cortex of brown rice was gradually peeled off with the increase in milling degree; the cortical thickness was gradually reduced, the endosperm was gradually exposed, and the surface was smoother and shinier. T<sub>2</sub> populations exhibited a shift toward longer relaxation times, followed by a decrease in relaxation time during the milling process. Additionally, 31 target compounds impacting rice flavor, mainly ketones, alcohols, and esters, were identified, and the concentration of volatile substances in the B region decreased with the reduction in the bran layer; the concentration of volatile substances in the C region provided rice flavor, which increased with the milling process. This study showed changes in the physicochemical properties and appearance quality of long-grain brown rice during milling. Furthermore, the use of various image processing techniques offers significant insights for optimizing processing parameters and enhancing overall quality and taste.
format Article
id doaj-art-cad4cc9400f84dd38cfe3a00a7f838ca
institution OA Journals
issn 2304-8158
language English
publishDate 2024-09-01
publisher MDPI AG
record_format Article
series Foods
spelling doaj-art-cad4cc9400f84dd38cfe3a00a7f838ca2025-08-20T02:16:50ZengMDPI AGFoods2304-81582024-09-011319303310.3390/foods13193033Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization TechnologiesXiwu Jia0Rong Dong1Xuan Chen2Zhan Wang3Hongjian Zhang4Wangyang Shen5Department of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaDepartment of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaDepartment of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaDepartment of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaHainan Institute of Grain and Oil Science, Qionghai 571400, ChinaDepartment of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, ChinaThis study evaluated the changes in physicochemical properties and appearance quality of long-grain rice during the grinding process using image technologies and aimed to provide reference for future research. The brown rice milling process was divided into three stages, and flatbed scanning, scanning electron microscopy (SEM), X-ray micro-computed tomography (micro-CT), low-field nuclear magic resonance (LF-NMR), and headspace–gas chromatography–ion mobility spectrometry (HS–GC–IMS) were employed to examine the physicochemical and volatile properties of the samples. Results revealed a continuous increase in the degree of milling, with a broken rice rate and a whiteness value increasing by 50.84% and 21.13%, respectively, compared with those during the initial stage; dietary fiber and vitamin B1 contents were reduced by 54.41% and 66.67%, respectively. The image results visualized showed that the cortex of brown rice was gradually peeled off with the increase in milling degree; the cortical thickness was gradually reduced, the endosperm was gradually exposed, and the surface was smoother and shinier. T<sub>2</sub> populations exhibited a shift toward longer relaxation times, followed by a decrease in relaxation time during the milling process. Additionally, 31 target compounds impacting rice flavor, mainly ketones, alcohols, and esters, were identified, and the concentration of volatile substances in the B region decreased with the reduction in the bran layer; the concentration of volatile substances in the C region provided rice flavor, which increased with the milling process. This study showed changes in the physicochemical properties and appearance quality of long-grain brown rice during milling. Furthermore, the use of various image processing techniques offers significant insights for optimizing processing parameters and enhancing overall quality and taste.https://www.mdpi.com/2304-8158/13/19/3033degree of millingappearance qualitymicro-CTvolatile compounds
spellingShingle Xiwu Jia
Rong Dong
Xuan Chen
Zhan Wang
Hongjian Zhang
Wangyang Shen
Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
Foods
degree of milling
appearance quality
micro-CT
volatile compounds
title Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
title_full Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
title_fullStr Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
title_full_unstemmed Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
title_short Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies
title_sort physicochemical and morphological changes in long grain brown rice milling a study using image visualization technologies
topic degree of milling
appearance quality
micro-CT
volatile compounds
url https://www.mdpi.com/2304-8158/13/19/3033
work_keys_str_mv AT xiwujia physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies
AT rongdong physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies
AT xuanchen physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies
AT zhanwang physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies
AT hongjianzhang physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies
AT wangyangshen physicochemicalandmorphologicalchangesinlonggrainbrownricemillingastudyusingimagevisualizationtechnologies