Nondestructive measurement of intramuscular fat content of fresh beef meat by a hand-held magnetic resonance sensor

Fast non-destructive measurement of intramuscular fat in Australian beef and lamb using nuclear magnetic resonance (NMR) technologies

Nuclear magnetic resonance (NMR) is an excellent technique for non-destructive analysis of meat because it has high accuracy, a linear response, and insignificant drift over time, which removes the need for recalibration. Furthermore, single-side NMR devices have open geometries that enable measurements of subsections of larger samples without taking sub-samples. Here we demonstrated long-term reproducibility in a benchtop device and the utility of a single-sided NMR device. We validated long-term reproducibility of NMR measurements of lamb intramuscular fat (IMF%) in a commercial processor boning room years after the original model was created. It was hypothesised that the NMR IMF% model would retain precision and accuracy on independent validation. The root mean squared (RMS) error of prediction of lamb IMF was 0.79 %. The R2 between reference measurements, predicted IMF% was 0.74, the slope of the chemical IMF% vs NMR predictions was 0.989, and the bias was 0.53 % IMF%. In the second example, we showed that IMF% measurements of high value beef striploins could be measured off a commercial processing belt and returned without damaging the product. It was hypothesised that a commercial prototype single-sided NMR system would predict IMF% in beef M. longissimus thoracis et lumborum. Here the RMS error of the correlation was 1.58 % IMF% and R2 was 0.97. The long-term stability, high accuracy, and nondestructive nature make unilateral NMR devices ideal for applications in the red meat industry where IMF% contributes to product value.

1H NMR Sensor for Nondestructive Characterization of Organic and Inorganic Materials

Nuclear magnetic resonance relaxation of the proton spins of liquid molecules and their evolution during processes such as drying, fluid flow, and phase change of a sample can be monitored in a nondestructive way. A unilateral 1H NMR sensor made with a permanent magnet array, inspired by the NMR MOUSE, with an RF coil tuned to 11.71 MHz was developed. This creates a sensitive homogeneous measuring volume parallel to the sensor surface and located 14 mm from its surface, allowing contactless measurements from the sample's interior. As this sensitive volume is moved across the sample using a semi-automatic linear displacement mechanism with millimetric precision, spatial T2 lifetime and signal intensity 1D profiles can be obtained. To characterize the sensor's sensitive volume, eraser samples were used. To evaluate the sensor's ability to characterize different materials, cement paste samples containing ordinary and white Portland cement were prepared and measured at seven days of age. In addition, measurements were made on organic samples such as a Hass avocado and beef steak. Based on the results, a 1 mm spatial resolution of the sensor was achieved. The sensor was able to detect differences in T2 lifetimes in eraser specimens composed of layers of three different erasers. Also, a clear difference in T2 lifetimes and signal intensities was observed in cement pastes composed of white and ordinary Portland cement. On the other hand, it was possible to obtain signals from the peel and pulp of the avocado fruit, as well as from the fat and meat in a beef steak in a nondestructive way. The T2 lifetimes of the different materials agreed with those obtained using a commercial NMR spectrometer.

Intelligent System/Equipment for Quality Deterioration Detection of Fresh Food: Recent Advances and Application

The quality of fresh foods tends to deteriorate rapidly during harvesting, storage, and transportation. Intelligent detection equipment is designed to monitor and ensure product quality in the supply chain, measure appropriate food quality parameters in real time, and thus minimize quality degradation and potential financial losses. Through various available tracking devices, consumers can obtain actionable information about fresh food products. This paper reviews the recent progress in intelligent detection equipment for sensing the quality deterioration of fresh foods, including computer vision equipment, electronic nose, smart colorimetric films, hyperspectral imaging (HSI), near-infrared spectroscopy (NIR), nuclear magnetic resonance (NMR), ultrasonic non-destructive testing, and intelligent tracing equipment. These devices offer the advantages of high speed, non-destructive operation, precision, and high sensitivity.

Design and validation of a single-sided magnet with a constant gradient parallel to its surface

We present the design, validation, and testing of an optimized 5 MHz three-magnet array with a gradient parallel to the magnet surface. An approach to permanent magnet array design is explored with a genetic algorithm. The genetic algorithm was used to produce multiple designs based on an inventory of available block magnets. One three-magnet array was constructed for testing. Constant gradients of 205, 115, and 61 gauss/cm, parallel to the magnet surface are found at displacements of 1.5, 2.0, and 2.5 cm from the surface of the magnet, respectively. Regions of useful gradient are roughly 1 cm in length. We constructed and field plotted the three-magnet array and found good agreement between the experimental and simulated magnet fields. To test applicability, we performed T₁ and T₂ relaxation measurements on a cod liver oil sample, and a simple doped water flow measurement.