Non-Invasive Detection of Adulterated Olive Oil in Full Bottles Using Time-Domain NMR Relaxometry

Author(s)

Poliana M. Santos ^[1] ; Flávio Vinicius C. Kock ^[2] ; Maiara S. Santos ^[3] ; Carlos Manuel S. Lobo ^[4] ; André S. Carvalho ^[5] ; Luiz Alberto Colnago ^[6]

Affiliation

^[1] Universidade Tecnológica Federal do Paraná. Departamento Acadêmico de Química e Biologia - Brasil

^[2] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[3] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[4] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[5] Universidade de São Paulo. Instituto de Química de São Carlos - Brasil

^[6] Embrapa Instrumentação - Brasil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 28, n. 2, p. 385-390, 2017-02-00.

Abstract

A fast procedure using time-domain nuclear magnetic resonance (TD-NMR) to detect olive oil adulteration with polyunsaturated vegetable oils in filled bottles is proposed. The 1H transverse relaxation times (T2) of 37 commercial samples were measured using low-field nuclear magnetic resonance (LF-NMR) spectrometer and a unilateral nuclear magnetic resonance (UNMR) sensor. Results obtained with LF-NMR revealed better feasibility when compared with the UNMR sensor, with higher signal-to-noise (S/N) ratio and larger difference in the T2 decays. Principal component analysis (PCA) exhibited tight and well-separated clusters of pure olive oil (OO), pure soybean oil (SO), and blends of OO/SO (adulterated samples). Soft independent modeling of class analogies analysis (SIMCA) classification model indicated that five brands of olive oil commercialized in Brazil were adulterated with polyunsaturated fatty acids, further confirmed by high-resolution NMR. Overall, LF-NMR provided a fast procedure for screening olive oil authenticity directly in the sealed bottles. (AU)

• FAPESP's process: 11/11160-3 - Development of steady state free precession (SSFP) sequences with phase alternation for rapid acquisition of high resolution NMR spectra
• Grantee: Tiago Bueno de Moraes
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/23169-8 - In situ study of action of quitosan biopolymer in the decontamination of metals and herbicides in aqueous system by electrochemistry coupled to high and low field NMR
• Grantee: Flavio Vinicius Crizostomo Kock
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/03770-1 - Development and applications of pulses sequences with alternating phases in the time domain NMR
• Grantee: Tatiana Monaretto
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/22126-9 - Development of time domain NMR spectrometers and methods for chemical analyses in field
• Grantee: Luiz Alberto Colnago
• Support Opportunities: Regular Research Grants