Extraction and ¹H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry

Abstract

The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a 1 H NMR analysis of the recovered fat to determine the levels of saturated, unsaturated, monounsaturated, and polyunsaturated fats in the food. Students compare their results to the information provided on the food package label. This experiment engages students in the learning process by connecting with their prior knowledge and familiarity of the foods used. Students learn several important concepts and techniques, such as fat characteristics and structure, solid−liquid extraction, structure−solubility relationships, vacuum filtration, and 1 H NMR spectroscopy.

Identification of Edible Oils by Principal Component Analysis of 1H NMR Spectra

“…Consequently, there has been a growing interest in employing spectroscopic techniques that do not require derivatization, yet provide results comparable to those obtained with GC. Spectroscopic characterization of oils by IR, − NIR, , Raman, , and NMR ,,,− methods has been reported. Because the spectroscopic signatures of many oils are quite similar, spectral data analysis often requires a multivariate statistical approach. − ,,− Recently, 1 H NMR spectroscopy has been used to characterize olive oils ,,, because NMR spectroscopy does not require sample pretreatment and offers a relatively large amount of information in a single spectrum …”

Implementation of picoSpin Benchtop NMR Instruments into Organic Chemistry Teaching Laboratories through Spectral Analysis of Fischer Esterification Products

“…As a consequence, students infrequently interpret crude spectra taken from student data on an NMR instrument. 1 H NMR suitable experiments have been published in this journal, but the advent of benchtop NMR instruments provided an opportunity for students to use recent NMR technology to obtain 1 H NMR spectra of products recovered or synthesized in the undergraduate instructional laboratory. − Students are able to see experimental signal integrations, determine signal multiplicity, and learn about solvent and reference signals in spectra.…”

A First Laboratory Utilizing NMR for Undergraduate Education: Characterization of Edible Fats and Oils by Quantitative 13C NMR

“…1 H NMR takes a prominent place in both papers. Complementary techniques such as IR and extraction plus gravimetric measurements are included. However, for our nonchemistry majors’ course, the combined set of lectures and laboratories that would be required is too involved.…”

“…We present a laboratory that provides 13 C NMR-based quantitative measurements of average chain length, degree of saturation, and average polyunsaturated fatty acid content of common edible oils. This work was inspired by publications by Crowther, and Hartel and Moore …”

“…1 H assignments can be made using the HSQC spectra for students curious about other methods (e.g., as described in refs and ). Inclusion of HSQC transitions an NMR-based laboratory suitable for nonchemistry majors into one suitable for chemistry majors and honors students.…”