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Oxford Instruments develops and manufactures benchtop QA instrumentation using a technique called nuclear magnetic resonance (NMR). Within the food industry, this means a method of quantitative quality assurance at a rate 250 times faster than wet chemistry extraction techniques, delivering numbers for oil, fat and moisture content in a broad range of products from raw materials to finished processed goods.

Benchtop NMR

Benchtop NMR is a clean, rapid and accurate technique for the measurement of oil content and is a viable alternative to traditional wet chemical techniques. NMR is easier to calibrate than near infrared spectroscopy (NIR) because NMR is not dependent on the product matrix. In fact it is often possible to calibrate NMR against a single 100% oil calibration sample.

Food and agriculture applications include:

  • Oil in snack food
  • Fat and oil in food
  • Oil in infant formula / milk powder
  • Fat in chocolate and cocoa products
  • Solid fat content of edible oils and fats (AOCS/ISO standard)
  • Oil and moisture in seeds / grain (ISO 10565)
  • Oil in olive paste

MQC systems – benchtop quantitative solutions

The most important requirements of laboratory instrument users relate to instrument performance and reliability, the availability of service and applications support, and bench-space. Oxford Instruments’ MQC systems have been designed to deliver against these expectations.

Benchtop NMR is now firmly established in many industries for quick and easy measurement of proton-bearing constituents such as water, oil and fat. Measurements by benchtop NMR have many advantages over traditional techniques such as Soxhlet (solvent) extraction, and NIR, including:

  • Minimal sample preparation
  • No solvents
  • Easy, robust calibration
  • Fast measurements
  • Reliability

Benchtop NMR analyser for measuring fat content

Recently, one of Europe’s leading independent testing laboratories was seeking an alternative to the standard solvent extraction/acid hydrolysis (Soxhlet) method for testing the amount of fat in a variety of foods. Oxford Instruments recommended its powerful but compact MQC benchtop NMR analyser. By converting from the wet chemistry method to an MQC benchtop NMR analyser for measuring the fat content of foods, the lab reaped significant economic and environmental benefits.

Key features of NMR:

  • Can be calibrated to cover a concentration range from 0.5% to 100% fat
  • Primary calibration can be produced using a single fat sample
  • Requires infrequent recalibration
  • Sample measurement time is short
  • Minimal sample preparation necessary
  • No solvents are required
  • Excellent for bulk measurements
  • Insensitive to sample granularity and product additives
  • Non-destructive, facilitating repeatability measurements

Measurement of oil content in dried snack foods

Measuring the oil content of dried snack foods is essential for quality control. Nuclear magnetic resonance (NMR) is well-established for measuring oil content for a broad range of applications. It is now becoming widely used for the measurement of oil content in snack foods. NMR has many advantages over other techniques:

  • It can be calibrated to cover a concentration range from 0% to 100% oil
  • NMR is very stable over the long term and rarely needs calibration adjustment
  • It is virtually insensitive to sample granularity and additives such as spices, flavours, colours and salt

NMR provides the most accurate measurement of the total amount of oil in a given volume of sample. A primary calibration can be produced using a single sample of oil. The measurement precision is typically better than 0.1% oil.

Determination of total fat content in chocolate

Cocoa beans are processed to extract cocoa liquor or cocoa butter, a major ingredient of dark and milk chocolate. It is important to quantify the fat content of the raw and intermediate materials to ensure consistency of the final product.

With NMR the measurement is very rapid and the total experimental time to result is about 15-20 minutes. NMR requires minimum sample preparation and it is environmentally friendly. The method calibration is very simple and the technique is non-destructive. The measurement precision is 0.1% fat or better.

NMR is internationally recognised, complying with all internationally-accepted official direct methods for SFC measurement: AOCS Cd 16b-93; ISO 8292-1; and IUPAC 2.150.

Benefits of using NMR for determination of fat and oil content in foodstuffs

Fat and oil content is an important measurement of nutritional value and product quality for many foodstuffs. Fat and oil content may significantly affect the texture, perceived quality and flavour of products. Accurate measurements enable manufacturers to achieve higher standards in nutritional characterisation and quality control of foodstuffs.

The benefits of benchtop NMR have been well demonstrated in many applications. Contact Oxford Instruments to find out how NMR can benefit your business.