Multivariate Modelling Based on Isotopic, Elemental, and Fatty Acid Profiles to Distinguish the Backyard and Barn...

Area of Science:

• Food Science
• Analytical Chemistry
• Nutritional Science

Background:

• Backyard-raised eggs command higher market prices than barn-raised eggs.
• Authenticating egg origin is crucial for consumer trust and value.
• Dietary and rearing systems significantly influence egg composition.

Purpose of the Study:

• To differentiate between backyard and barn-raised eggs.
• To analyze isotopic, elemental, and fatty acid profiles for origin tracing.
• To evaluate the nutritional quality of backyard eggs.

Main Methods:

• Analysis of 90 egg yolk samples for isotopic (δ18O), elemental, and fatty acid profiles.
• Statistical analysis using Student's t-test to identify significant differences.
• Application of pattern recognition methods: Linear Discriminant Analysis (LDA), k-Nearest Neighbor (k-NN), and Multilayer Perceptron Artificial Neural Networks (MLP-ANN) for classification.

Main Results:

• Significant differences were observed in δ18O, multiple elements (Mg, K, Sc, Mn, Fe, Ni, Cu, Zn, As, Cd, Ba, Pb), and various fatty acids.
• Backyard eggs showed a lower n-6 polyunsaturated fatty acid content and a more favorable n-6 to n-3 ratio.
• LDA achieved 98.9% accuracy, k-NN 85.7%, and MLP-ANN 92.3% in cross-validation for production system classification.

Conclusions:

• Fusion of isotopic, elemental, and fatty acid profiles effectively distinguishes backyard from barn eggs.
• Backyard rearing systems are associated with enhanced nutritional profiles in eggs.
• The analytical and classification methods provide a reliable approach for egg origin verification.