scholarly journals Effects of Hydrocolloid Injection on the Eating Quality of Pork Analyzed Based on Low-Field Nuclear Magnetic Resonance (LF-NMR)

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Shengmei Gai ◽  
Zhonghui Zhang ◽  
Yufeng Zou ◽  
Dengyong Liu
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Water Distribution ◽  
Free Water ◽  
Color Difference ◽  
Eating Quality ◽  
Low Field ◽  
Lf Nmr ◽  
Nuclear Magnetic

This study investigated the effects of hydrocolloid injection on the eating quality of porcine meat based on low-field nuclear magnetic resonance (LF-NMR). The eating quality and water distribution of hydrocolloid-injected pork were compared with control, and the principle component analysis (PCA) was applied for the identification of hydrocolloid-injected pork. Total color difference (ΔE∗), cooking loss, and moisture content of hydrocolloid-injected pork were significantly increased compared with the control (p<0.05). LF-NMR indicated that significant differences in the relaxation time and peak area proportion of immobilized water (T21, P21) and free water (T22, P22) were detected among hydrocolloid-injected samples and the control (p<0.05). The first two principal components (PCs) of PCA accounted for 54.07% and 33.56% of the observed variation, respectively. Based on the two PCs, the hydrocolloid-injected pork could be differentiated from the control. Therefore, LF-NMR combined with PCA offers an effective method for the analysis and detection of hydrocolloid-injected pork.

Influence of Freezing–Thawing Cycle on Water Dynamics of Turbot Flesh Assessed by Low-Field Nuclear Magnetic Resonance and Magnetic Resonance Imaging

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Jiaqi Li ◽  
Kexin Xia ◽  
Yao Li ◽  
Mingqian Tan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Water Dynamics ◽  
Resonance Imaging ◽  
Low Field ◽  
Meat Spoilage ◽  
Thawing Process ◽  
Lf Nmr ◽  
Nuclear Magnetic

AbstractTurbot is a valuable commercial species due to its high nutrient content. Moisture is an important indicator of meat spoilage. This study elucidated distinctive water dynamics in turbot flesh in the freezing–thawing process by nondestructive low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) techniques.T2relaxation spectra were utilized to describe the mobility and content of different types of water. Principal component analysis (PCA) revealed a clear discrimination of various freezing–thawing cycles.T1- andT2-weighted MRI provided further visualization of internal information for turbot flesh. Microscopic examination clearly identified protein denaturation and structural shrinkage. Furthermore, NMR parameters and conventional physicochemical parameters of color, shear force and thiobarbituric acid-reactive substances showed good correlations. To sum up, the study revealed that LF-NMR and MRI are promising techniques to portray the relationship between the water dynamics and changes of turbot quality properties during the freezing–thawing process.

scholarly journals Effects of Glazing with Preservatives on the Quality Changes of Squid during Frozen Storage

2019 ◽  
Vol 9 (18) ◽  
pp. 3847 ◽  
Author(s):  
Mingtang Tan ◽  
Peiyun Li ◽  
Wenhui Yu ◽  
Jinfeng Wang ◽  
Jing Xie
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Shelf Life ◽  
Fluorescence Intensity ◽  
Frozen Storage ◽  
Intrinsic Fluorescence ◽  
Quality Changes ◽  
Low Field ◽  
Lf Nmr

This study aimed to investigate the effects of glazing with sodium polyacrylate (SP) and D-sodium erythorbate (DSE) on the quality changes of squid during frozen storage. Frozen squid samples were randomly divided into seven groups: (1) CK (unglazed); (2) WG (distilled water-glazed); (3) SG (0.1% SP -glazed); (4) SG-1DSE (0.1% SP with 0.1% DSE -glazed); (5) SG-3DSE (0.1% SP with 0.3% DSE-glazed); (6) SG-5DSE (0.1% SP with 0.5% DSE-glazed); (7) WG-1DSE (0.1% DSE-glazed). The efficacy of the different coatings was evaluated using various indicators, such as water holding capacity (WHC), pH value, low field nuclear magnetic resonance (LF-NMR), color, malondialdehyde (MDA) content value, free amino acids (FAAs) content, intrinsic fluorescence intensity (IFI) and the total sulfhydryl content (SH) content. Intrinsic fluorescence intensity (IFI) and low field nuclear magnetic resonance (LF-NMR) were used as fast monitoring techniques to monitor changes in quality of squid samples. The results showed that compared with the CK and WG groups, coating with either SG or DSE alone resulted in reduced rate of moisture loss (p < 0.05), lipid oxidation (p < 0.05) protein degradation (p < 0.05) and prolonged its shelf-life. The combination of glazing treatment with SG and DSE (groups SG-1DSE, SG-3DSE and SG-5DSE) further improved the protective effects of coating, particularly in the SG-3DSE group. Therefore, the glazing of SG-3DSE is recommended to be used to control the quality of frozen squid and to prolong its shelf-life during frozen storage.

Monitoring a typical fermentation process of natto by low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) techniques

2016 ◽  
Vol 8 (39) ◽  
pp. 7135-7140 ◽  
Author(s):  
Jing Wu ◽  
Yanru Li ◽  
Xingsheng Gao
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Fermentation Process ◽  
Resonance Imaging ◽  
Low Field ◽  
Magnetic Resonance Imaging Mri ◽  
Lf Nmr ◽  
Nuclear Magnetic

Unique insights into the monitoring of a typical fermentation process of natto based on low field nuclear magnetic resonance (LF-NMR) associated with magnetic resonance imaging (MRI).

scholarly journals Sensor Configuration and Algorithms for Power-Line Interference Suppression in Low Field Nuclear Magnetic Resonance

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3566 ◽  
Author(s):  
Xiaolei Huang ◽  
Hui Dong ◽  
Quan Tao ◽  
Mengmeng Yu ◽  
Yongqiang Li ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Power Line ◽  
Computational Time ◽  
Frequency Noise ◽  
Low Field ◽  
J Coupling ◽  
Sensor Configuration ◽  
Lf Nmr ◽  
Nuclear Magnetic

Low field (LF) nuclear magnetic resonance (NMR) shows potential advantages to study pure heteronuclear J-coupling and observe the fine structure of matter. Power-line harmonics interferences and fixed-frequency noise peaks might introduce discrete noise peaks into the LF-NMR spectrum in an open environment or in a conductively shielded room, which might disturb J-coupling spectra of matter recorded at LF. In this paper, we describe a multi-channel sensor configuration of superconducting quantum interference devices, and measure the multiple peaks of the 2,2,2-trifluoroethanol J-coupling spectrum. For the case of low signal to noise ratio (SNR) < 1, we suggest two noise suppression algorithms using discrete wavelet analysis (DWA), combined with either least squares method (LSM) or gradient descent (GD). The de-noising methods are based on spatial correlation of the interferences among the superconducting sensors, and are experimentally demonstrated. The DWA-LSM algorithm shows a significant effect in the noise reduction and recovers SNR > 1 for most of the signal peaks. The DWA-GD algorithm improves the SNR further, but takes more computational time. Depending on whether the accuracy or the speed of the de-noising process is more important in LF-NMR applications, the choice of algorithm should be made.

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