Urea adulteration alters raw milk composition and induces renal tissue damage: a molecular and histopathological study

Abstract

This study investigates the impact of urea adulteration in raw milk on milk quality, safety, and renal tissue integrity, addressing a significant public health concern, particularly in low-to-middle-income countries where over 76.6% of milk samples have compromised quality and 77.89% are adulterated. Raw milk samples were analyzed for quality parameters, adulterants, and the presence of synthetic by-products using FTIR. In vivo studies in mice were conducted to assess the histopathological effects of urea-adulterated milk on renal and liver tissues. Results revealed that urea adulteration leads to significant alterations in milk composition, including changes in fat content from 5.73% to 0.6% in boiled milk, solids-not-fat from 9.11% to 12.84%, protein from 3.61% to 5.28%, and lactose content from 3.81% to 5.57%, alongside the formation of synthetic compounds such as lactose monohydrate and polyvinyl stearate. Histological examination of mice kidneys exposed to urea-adulterated milk demonstrated morphological, inflammatory, degenerative, congestive, and necrotic changes. This study highlights the cellular-level damage induced by urea adulteration, emphasizing its potential to induce neoplastic changes in renal tissues and underscoring the need for stringent monitoring of milk quality to safeguard public health.