Chemical compositions, contaminants, and residues of organic and conventional goat milk in Bogor District, Indonesia

Abstract

Aim: This study aimed to compare chemical composition and contaminants (pesticide residues, antibiotic residues, and heavy metal residues) between organic and conventional goat milk in Bogor District, West Java Province, Indonesia. Materials and Methods: Milk sampling was carried out from March to August 2018 at six goat farms. The chemical quality of milk was checked using the Lactoscan Ultrasonic Milk Analyzer device. Fatty acids were analyzed using gas chromatography (GC). Pesticide residues in goat's milk were analyzed using a GC-electron capture detector (GC-ECD). Antibiotic residues were analyzed using bioassay screening test method. The lead (Pb) and arsenic (As) residues were analyzed using the Atomic Absorption Spectrophotometer (AAS). Results: The content of fat, protein, and lactose showed that there was no difference in the composition of goat's milk between organic and conventional farms. Caprylic acid (C8:0) and capric acid (C10:0) of organic goat milk are higher than conventional goat milk. Stearic acid (C18:0) and linoleic acid (C18:2) of conventional goat milk are higher than organic goat milk. The total fatty acid of organic goat milk is higher than conventional goat milk. Organochlorine pesticide residues were not detected in organic goat milk and conventional goat milk. Tetracycline antibiotic residues were found in one sample (5.56%) of organic goat milk, and macrolides residues were found in two samples (11.11%) of conventional goat milk. Pb residue in organic goat milk is 50 ppb while conventional goat milk is 80 ppb. Residue As in organic goat milk is 70 ppb while conventional goat milk is 110 ppb. Conclusion: There was no chemical composition (fat, protein, and lactose) difference between organic and conventional goat milk. Saturated fatty acid (SFA) in organic goat milk is higher than conventional goat milk. Pesticide residues are not found in both organic and conventional goat milk. Tetracycline antibiotics were found in organic goat milk and macrolide antibiotic groups found in conventional goat milk. Pb and As residues were found in both organic goat milk and conventional goat milk. Keywords: antibiotic, chemical composition, goat milk, heavy metal, pesticide.