# Applications of Mueller Matrix Polarimetry to Biological and Agricultural Diagnostics: A Review
Additionally, we want to draw attention to the ability of the MM to respond to biomolecular orientation, aggregation and assembly with nanoparticles, which need to be tracked in biotechnology. Another basic goal of this review is to outline promising directions for the development of MMP devices for agriculture, including the control of the quality and composition of agricultural materials and food and monitoring crop vegetation and soil conditions. Further, we present some examples of MMP applications. For instance, MMP was used to analyze blood for the presence of dengue virus [26]. MMP provides an efficient method for imaging localized structures, in particular for distinguishing the type of collagen organization [27]. In addition, MMP was employed to monitor changes in myocardial tissues and perform non-invasive measurement of glucose levels [28]. MMP, in combination with other various methods of quantitative analysis, can provide ample opportunities for the visualization of biological tissues; for example, it can distinguish between cancerous and healthy tissues, while being a cheaper method for the diagnostics of tissues before and after surgery, as shown in [29; 30]. MMP can be successfully applied when tracking colonies of microorganisms [31]. The imaging contrasts of MM-derived parameters media can be used to characterize the anisotropic and isotropic structures of tissues [32]. It was confirmed that optical coherence tomography (OCT) supplemented with MMP can record polarization contrast images of any biological sample, in particular, soft tissues [33]. A combination of OCT and MMP was used in a novel device for measuring the anisotropy and bulk properties of tissue [34]. Optical diagnostic methods, including those based on MMP, have some agricultural applications. For example, these methods are used for diagnostics of dairy products [35; 36; 37; 38; 39]. The size distributions of fat droplets and casein aggregates were reconstructed from the block-diagonal elements of a scattering matrix of milk samples diluted by volume with water [36]. Using the size histograms, fat content and protein and the protein-to-fat ratio were estimated. MMP is capable of characterizing and authenticating vegetable oils [40; 41]. MM imaging polarimetry can serve as a non-contact method for meat quality control [42]. MM spectropolarimetry around the absorption band of chlorophyll can be used for the non-destructive study of the molecular architecture of plant photosynthesis, which can be applied to vegetation monitoring [43]. In addition, MMP is suitable for determining the microphysical parameters of soils and soil suspensions. The ability of MMP to characterize soil suspensions was assessed with the aim to implement MMP as a unit for measuring the disperse composition in a robotic system for converting soil into a stable, high-performance, organic, chemical bioreactor for more controlled biomolecular interaction of nanoparticles and their adsorption by biological and mineral media [44]. A semi-empirical model of the averaged differential MM for microwave backscattering from bare soil surfaces in terms of moisture content and surface roughness was proposed in [45]. Measurements of polarized scattering of a carbon dioxide laser radiation from sandy soil enabled the retrieval of information about the dielectric constants and size of sand particles [46]. It is also worth noting the studies of protein solutions [47; 48]. Using laser ellipsometry, organic molecular films formed at the interface of solids as a result of adsorption of a protein solution were studied in [47]. The results of a correlative experiment that was carried out to compare the interaction of human serum albumin and immunoglobulin G with sodium dodecyl sulfonate using polarized synchronous light scattering were in good agreement with dynamic light scattering measurements [48].