Stable Carbon and Nitrogen Isotope Analyses as a Potential Tool for Verifying Origin of Cattle Milk Produced in Different Agroclimatic Zones of Sri Lanka

Producing safe and high quality food is a prerequisite to ensure consumer health as well as being a vital aspect of food security. Cows' milk is vulnerable to a range of food safety hazards that may arise at any stage from production to marketing. Consequently, having analytical methods to identify the source of any potentially unsafe milk would be of great benefit in undertaking investigations or targeted recalls. The dairy sector contributes to the economy of Sri Lanka by way of employment generation and reducing nutritional poverty. This study was aimed at establishing a method to verify the origin of cattle milk using stable isotope data of defatted milk coming from different agroclimatic zones of Sri Lanka. A total of forty five milk samples were collected from five different agroclimatic zones in Sri Lanka, namely dry zone, coconut triangle, mid country, upcountry, and wet zone. Although the δ ¹³C and δ ¹⁵N values of defatted milk samples were not significantly different among the agroclimatic zones except for the dry zone, a multivariate discriminant analysis based on variables δ ¹³C, δ ¹⁵N, nitrogen%, carbon%, and carbon to nitrogen molecular ratio, achieved good discrimination among the milk produced in different agroclimatic zones of Sri Lanka. (author)