Separation and Detection of Sugar in Raw Milk for Dairy Applications

The primary objective of this project is to develop a simple, low-cost, and effective system for the separation and detection of sugar in raw milk. The project aims to address the growing health concerns related to diabetes, lactose intolerance, and obesity by producing lowsugar, high-protein milk. Specific goals include: (i) separating lactose and other naturally occurring sugars from whole milk using a semipermeable ultrafiltration membrane, (ii) accurately detecting and measuring sugar concentration levels before and after filtration using a conductivity-based method, (iii) retaining essential milk proteins, nutrients, and bioactive compounds during the filtration process, and (iv) designing a fully functional, low-cost prototype accessible to small-scale dairy farmers, rural cooperatives, and households. The system is completely hardware-based and requires no microcontroller or programming, making it easy to use and replicate. The project employs two core methodologies: detection and separation. For detection, a conductivity-based circuit is designed using two copper probes inserted into the milk sample. When adulterants such as sugar, water, or detergent are present, the electrical conductivity of the milk changes. This variation generates a small electrical signal between the probes, which is then amplified using a BC547 NPN transistor. The output is displayed through an LED, where brightness varies according to the level of adulteration— brighter glow indicates higher adulteration. For separation, the project utilizes an ultrafiltration membrane that selectively allows smaller sugar molecules (lactose) to pass through while retaining larger proteins, vitamins, and minerals. The membrane operates at room temperature to preserve heat-sensitive nutrients. The detection circuit is assembled on a breadboard using resistors (10k? and 220?), a BC547 transistor, copper probes, an LED, and a DC power supply (5–12V). Testing is conducted using pure and adulterated milk samples, with LED brightness recorded for comparisons. Lactose is a reducing sugar present in milk. When heated with Fehling’s solution, lactose reduces cupric ions (Cu²?) to cuprous oxide (Cu?O), forming a brick-red precipitate. The amount of lactose present is determined by titrating the milk solution against Fehling’s solution using volumetric analysis.