Investigating light propagation and random lasing for assessing milk properties
Milk contributes to a healthy diet as it contains nutritional components such as fats, proteins, carbohydrates, calcium, and vitamins. Previous analysis of milk involves chemical reactions, optics, and machine learning, which are complicated and time consuming. Thus, this research aims to analyse mi...
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| Summary: | Milk contributes to a healthy diet as it contains nutritional components such as fats, proteins, carbohydrates, calcium, and vitamins. Previous analysis of milk involves chemical reactions, optics, and machine learning, which are complicated and time consuming. Thus, this research aims to analyse milk based on light propagation and random lasing for assessing optical properties of milk. The appearance of milk can be determined by the optical properties, which can be observed through light propagation. The light propagation in milk can be observed through absorbance, transmission, reflectance, and fluorescence spectra. The research is divided into three parts in order to achieve the following objectives: (1) to investigate and compare light propagation in milk using various spectrometers, (2) to analyse milk quality after fermentation using spectrometry technique and (3) to model random laser based on light propagation in various types of milk. The first part focuses on comparing light propagation in milk using near infra-red (NIR), visible (VIS) and Fourier transform infrared (FTIR) techniques. Three different spectrometry methods are utilized to analyse the milk fat contents based on absorbance and transmittance spectra. Full milk sample shows the highest absorbance due to high fat globule content compared to others. Higher photon count can be estimated through Monte Carlo modeling. The second part analyses the milk quality after fermentation using VIS-NIR spectrometer. Milk is kept in the room temperature for the fermentation process. The results show that the newly opened milk bottle has higher light absorbance and lower light transmission than the fermented milk. Modeling based on scattering theory is provided to compare light propagation in milk, water, and air. The third part aims to differentiate optical properties of milk from animal, plant and human sources based on light propagation and random lasing. The absorbance and fluorescence of various milk samples in the wavelength range 350 nm to 1650 nm are measured which shows the different results for each milk, due to different fat content. Statistical analysis using principal component analysis (PCA) is done to analyse the reliability and the validity of the absorbance and fluorescence data. On the other hand, random laser is modeled to study the effects of milk fat content on properties of random lasers. Higher fat content in milk can produce lower lasing threshold. Therefore, this research is important to assess optical properties of milk. This study can be further enhanced by setting up scattering and random laser experiments. |
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