U-bent plastic optical fiber probes as refractive index based fat sensor for milk quality monitoring

The present manuscript focuses on reviewing the optical techniques proposed to monitor milk quality in dairy farms to increase productivity and reduce costs. As is well known, the quality is linked to the fat and protein concentration; in addition, this issue is crucial to maintaining a healthy herd and preventing illnesses such as mastitis and ketosis. Usually, the quality of the milk is carried out with invasive methods employing chemical reagents that increase the time analysis. As a solution, several spectroscopy optical methods have been proposed, here, the benefits such as non-invasive measurement, online implementation, rapid estimation, and cost-effective execution. The most attractive optical methods to estimate fat and protein in cow’s milk are compared and discussed considering their performance. The analysis is divided considering the wavelength operation (ultraviolet, visible, and infrared). Moreover, the weaknesses and strengths of the methods are fully analyzed. Finally, we provide the trends and a recent technique based on spectroscopy in the visible wavelength.

Section: Spectroscopy Techniquesmentioning

confidence: 99%

Optical Methods Based on Ultraviolet, Visible, and Near-Infrared Spectra to Estimate Fat and Protein in Raw Milk: A Review

Gastélum-Barrios

Soto-Zarazúa

Escamilla-García

et al. 2020

“…As a basic optical parameter, the refractive index (RI) can be widely used to identify chemical substances in many analytical applications, including food safety [ 1 ], medical examination [ 2 , 3 ], and environmental monitoring [ 4 , 5 ]. In the past few decades, the fiber-based RI sensor has been extensively explored because of its advantages of low cost, multiplexing capability, and fast response.…”

Section: Introductionmentioning

confidence: 99%

Refractive Index Sensor Based on Double Side-Polished U-Shaped Plastic Optical Fiber

Wang

Zhang

et al. 2020

A U-shaped double-side polished plastic optical fiber (POF) is demonstrated as a liquid refractive index (RI) sensor. The refractive index of glycerinum solutions is identified by the intensity detection on the bending and evanescent wave loss change. Heat treatment and mechanical polishing are adopted to form the symmetrical side-polished POF probe. The processing parameters are experimentally optimized on the power transmittance. The sensitivity of 1541%/RIU (Refractive Index Unit) can be obtained with a resolution of 5.35 × 10−4 in the scope of 1.33–1.39. The favorable temperature characteristic is proved to offer stable RI sensing from 20 to 50 °C. This simple POF sensor has potentials in low-cost visible light intensity RI detection.

“…As a result, different milk properties are exploited. The use of optical fiber sensors has been increased since several reported techniques have assured that sensitivity can be improved [10]. Some of the reported works use an NIR source and the transmission spectra is analyzed [11,12], while other fiber optic works use the relationship between the refractive index (RI) and total fat content [10].…”

Section: Introductionmentioning

confidence: 99%

“…The use of optical fiber sensors has been increased since several reported techniques have assured that sensitivity can be improved [10]. Some of the reported works use an NIR source and the transmission spectra is analyzed [11,12], while other fiber optic works use the relationship between the refractive index (RI) and total fat content [10]. It is important to recall that the size of fat globules (average diameter of 3 µm) and protein particles (average diameter of 120 nm) produce scattering effects [11].…”

Section: Introductionmentioning

confidence: 99%

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A New Method for Total Fat Detection in Raw Milk Based on Dual Low-Coherence Interferometer

Gastélum-Barrios

Soto-Zarazúa

García‐Trejo

et al. 2019

The present work experimentally demonstrates a multimode fiber optic sensing setup for total fat detection in raw milk samples. The optical fiber arrangement incorporates a low-coherence Fabry–Perot cavity operating in dual response. The system provides a phase modulation for a total fat range from 0.97 to 4.36%. Here, the protein remains constant at ≈3%. The data indicate that maximum sensitivity close to 616 pm/%fat could be achieved at optimal wavelength operation (500 nm). In addition, the system presented a minimal repeatability error measurement of 0.08%, cross-sensitivity between protein and fat of 0.134, and a regression coefficient of r2=0.9763. A thermal analysis was also performed, which indicate the temperature immunity of the system. The proposed method represents a low-cost alternative to detect minimal fat variations in raw cow milk.