Microwave dielectric spectroscopy for the determination of pork meat quality

Cost-Effective Open-Ended Coaxial Technique for Liquid Food Characterization by Using the Reflection Method for Industrial Applications

A cheap technique based on an open-ended coaxial probe together with a vector network analyzer was set up. The vector network analyzer NanoVNA, a very tiny handheld device, is the affordable component that gives the instrumental chain a cost-effective perspective. The open-ended coaxial probe is a cable with an SMA gold-plated termination. User-friendly programs can be used to calibrate the instrument, carry out the measurements, and save data on PC. Simple liquid solutions (sodium chloride, citric acids, and saccharose) and more complex liquid food (milk, egg products, and fruit juice) were investigated. In addition, the temperature on the electric measurement of milk was measured to evaluate a possible influence for refrigerated storage products. The reflection parameters, such as the real and imaginary parts of S11, were used to build univariate and multivariate models. The best results in terms of coefficient of determination and related error were 0.997 (RMSE 0.05%) for sodium chloride and 0.965 (RMSE 0.71 °Brix) for fruit juice considering the univariate model, and 0.997 (RMSE 0.04%) for sodium chloride and 0.981 (RMSE 4.44%) for yolk using multivariate analysis. The proposed solution is non-destructive, cheap, rapid, and very attractive for potential lab and industrial applications.

Analysis of Apple Candying by Microwave Spectroscopy

Process control in the industry requires fast, safe and easily applicable methods. In this sense, the use of dielectric spectroscopy in the microwave range can be a great opportunity to monitor processes in which the mobility and quantity of water is the main property to produce a quality and safety product. The candying of fruits is an operation in which the samples are first osmotically dehydrated and then exposed to a hot air-drying operation. This process produces changes in both the structure of the tissue and the relationships between water, the solid matrix and the added soluble solids. The aim of this paper is to develop a dielectric tool to predict the water/sucrose states throughout the candying of apple, by considering the complexity of the tissue and describing the different transport phenomena and the different transition processes of the sucrose inside the sample.

Detection of Artificially Water-Injected Frozen Octopus minor (Sasaki) Using Dielectric Properties

A few importers of marine products have practiced the fraud of artificially injecting water into Octopus minor for increasing their weights prior to the freezing process. These rampant practices have recently become a serious social issue and threaten public health. Therefore, it is necessary to develop the detection method for artificially water-injected frozen Octopus minor. This study was conducted to develop the nondestructive method for verifying adulterated Octopus minor by measuring dielectric properties using the coaxial probe method. Regardless of weight and measurement locations, a significant difference between ε values from normal octopuses was not observed. The ε values of Octopus minor were decreased in the microwave frequency range between 500 and 3000 MHz. The ε values of water-injected octopuses also showed similar trend with normal octopuses; however, the dielectric loss factor (ε″) values of adulterated octopuses were much lower than normal octopuses. After thawing normal, adulterated, and imported frozen Octopus minor, the ε values measured at the trunk part from these octopuses were compared and statistically analyzed. The ε″ values from normal frozen octopus were significantly different from adulterated and imported frozen octopuses. In addition, the ε″ values from the adulterated frozen octopus group that weight gain rate was less than 20% was significantly different from other adulterated octopus groups with higher weight gain rate than 20%. The ε″ values from adulterated frozen octopus groups with the range of weight gain rate between 20 and 30% were quite similar to imported frozen octopuses. Therefore, it was found that the measurement of ε″ values from Octopus minor has a great possibility to distinguish normal frozen octopuses and artificially water-injected frozen octopuses.

Theoretical Basis and Application for Measuring Pork Loin Drip Loss Using Microwave Spectroscopy

During cutting and processing of meat, the loss of water is critical in determining both product quality and value. From the point of slaughter until packaging, water is lost due to the hanging, movement, handling, and cutting of the carcass, with every 1% of lost water having the potential to cost a large meat processing plant somewhere in the region of €50,000 per day. Currently the options for monitoring the loss of water from meat, or determining its drip loss, are limited to destructive tests which take 24–72 h to complete. This paper presents results from work which has led to the development of a novel microwave cavity sensor capable of providing an indication of drip loss within 6 min, while demonstrating good correlation with the well-known EZ-Driploss method (R² = 0.896).

A Microwave Ring-Resonator Sensor for Non-Invasive Assessment of Meat Aging

The assessment of moisture loss from meat during the aging period is a critical issue for the meat industry. In this article, a non-invasive microwave ring-resonator sensor is presented to evaluate the moisture content, or more precisely water holding capacity (WHC) of broiler meat over a four-week period. The developed sensor has shown significant changes in its resonance frequency and return loss due to reduction in WHC in the studied duration. The obtained results are also confirmed by physical measurements. Further, these results are evaluated using the Fricke model, which provides a good fit for electric circuit components in biological tissue. Significant changes were observed in membrane integrity, where the corresponding capacitance decreases 30% in the early aging (0D-7D) period. Similarly, the losses associated with intracellular and extracellular fluids exhibit changed up to 42% and 53%, respectively. Ultimately, empirical polynomial models are developed to predict the electrical component values for a better understanding of aging effects. The measured and calculated values are found to be in good agreement.

Evolution of the complex permittivity of biological tissue at microwaves ranges: correlation study with burn depth

The evolution of the muscle tissue's complex permittivity represents a growing interest in terms of characterization in medicine and biology. The influence of a burned part on the permittivity is not very developed. In this work, an estimation of the complex permittivity of biological tissues is performed as a function of the depth of burn tissues. The sensor, an open-ended coaxial probe, is placed directly against each sample. The evolution of the complex permittivity is studied for two measurements conditions (in the air and in a physiological solution). A correlation study is attempted with the depth of burn tissue.