Optical characterization of emulsions and applications in the dairy industry

Abstract

Milk and milk products are an integral part of diet for a major segment of human population. Safety and quality of the industry's products is therefore essential as it directly affects human health and wellbeing. The present thesis discusses work towards developing analytical technologies and methods for the dairy industry in India, to improve product safety and quality and eventually consumer health. A user-centric product design and development approach has been followed in the project. The needs and opportunities have been identified through repeated stakeholder interactions. Proposed concepts have been shortlisted based on value and impact, commercial potential, and technological feasibility. The thesis introduces a novel digital imaging based method of online spectrophotometric measurements on raw milk without any sample preparation. Multiple LED's of different emission spectra are used as discrete light sources and a digital CMOS camera is used as an image sensor. The absorption and scattering characteristics of samples are derived from captured images. Despite of the presence of multiple scattering, the extinction of incident radiation can be unequivocally quantified using the proposed method. The dependence of multiple scattering on power of incident radiation is exploited to quantify scattering. These can be related to the fat concentrations and globule sizes of samples. The method has been validated by conducting experiments for the spectrophotometric response of milk with varying fat concentrations and fat globule sizes.