Edible Oils and Fats Analysis

Edible oils and fats are lipid materials that are generally soluble in organic solvents but insoluble in water. While oils and fats are chemically similar in that both are composed of triglycerides, the distinction between them is that fats are solid at room temperature, while oils remain liquid.

Edible oils and fats including cooking oils are an essential part of everyday life and can be derived from animal, vegetable or even synthetic sources, and their consumption enables the fulfillment of both structural and metabolic functions in the body. They can be ingested directly or as components of prepared foods, to which they may lend flavor or texture. Edible oils and fats may find additional use in the production of soaps and other skin care products, candles, and perfumes.

When processing oils and fats, robust quality control is a must. METTLER TOLEDO supports you in the development of robust analytical techniques by providing innovative laboratory and industrial solutions to support various steps in the oils and fats value chain from testing the purity of raw materials to avoid adulteration, to final product testing to help ensure taste, shelf-life, and more.

The first step in the production of oils and fats is extraction, which typically involves mechanical pressing, solvent extraction or autoclaving of a natural oil-producing product (such as a nut, seed or fruit such as olives). Obtained oils and fats then normally go through subsequent purification processes to adjust their physicochemical properties for the desired purpose.

Schematic of an oil solvent extraction system:

Extractor – mechanically pressed ground/roasted

Bran roaster to get solvent free bran

Continuous evaporator to get crude oil

Solvent condenser to get solvent reservoir

Several analytical parameters can be used through the extraction process to ensure desired properties are maintained. Prior oil extraction is important to analyze the quality of a seed or nut batch, especially if it has been stored for a length of time. It is also recommended to verify moisture content to avoid issues such as bacteria or mold growth. As periodic moisture analysis during storage is required, a moisture analyzer offers a simple yet accurate way to monitor moisture content over time.

Other analyses that are important for ensuring quality depending on the oil and its intended use include titration, pH measurement, conductivity measurement, near-infrared spectroscopy, and refractive index. Several of these analytical techniques for the testing of edible fat and oil quality are described in the sections that follow.

One of the important processes applied to oils and fats to obtain edible products is refining. As recently as the end of the 19th century, oil was obtained by simple sedimentation. Today, the vast majority of oils and fats for human consumption are subjected to chemical refining and/or physical refining.

Impurity removal is the primary reason oils and fats are refined. Crude oil contains impurities, such as free fatty acids, mono- and diglycerides, pigments, metals, tocopherols, waxes and more. Chemicals used in the extraction process can also leave behind solvents and sediments that negatively affect a product’s odor and flavor. Therefore, the refining process aims to improve the appearance, odor, flavor, and other properties of oils by removing components that impair quality.

The processing stages of oil refining depend on the initial quality of the raw or unrefined oil available and the intended application of the final oil product.

Simplified edible oil refining process flow chart:

Crude edible oil

Degumming (enzymatic or chemical): aims to remove colloidal impurities

Deacidification: aims to neutralize free fatty acids

Washing: aims to eliminate residual alkaline substances

Decolorization: aims to remove pigments and improve quality

Deodorization: aims to eliminate volatiles, carotenoids and free fatty acids

Filtration: ensures any remaining particulates are removed

Refined edible oil

Below, we offer a representative list of the types of analytical techniques used for research and development, process monitoring and quality control in the production of edible oils and fats.

Almost all analytical methods require the use of calibration reference standard solutions of varying concentrations. Samples, reference standards and calibration standards must be weighed and diluted with extreme accuracy. The number of calculations required to determine the purity of each final component adds to the complexity of each analysis. Ensuring data traceability is also demanding, requiring each weighing result, calculation, and dilution step to be meticulously documented.

The exceptional weighing performance and low minimum weights of METTLER TOLEDO’s Automatic Balance and Excellence level analytical balances support the preparation of highly accurate standard solutions. Useful features, including stored weighing methods, the results notepad, and easy connection to peripheral devices such as printers and barcode readers, help to simplify and speed up processes.

With the automatic balance, substances and solvents are dispensed automatically directly into a container on the balance with a level of accuracy that cannot be matched by manual procedures. Precise concentrations are achieved by dispensing the exact amount of solvent according to the actual dosed amount of substance. A dilution factor of up to 10,000 can be achieved in one single step.

Furthermore, by connecting balances to LabX™ laboratory software, edible fats and oils producers can benefit from comprehensive data management, automatic calculations, and sample tracking.

Discover efficient sample and standard preparation by reading about two important analytical methods used in the testing of fats and oils:

When filling thousands of containers or bottles of edible oils every day, overfilling by just one gram can result in tons of wasted material. A statistical quality control (SQC) solution can show you the result of the filling process for every controlled container, allowing you to reduce overfilling and material costs. METTLER TOLEDO’s options for filling control are:

FreeWeigh.Net
This powerful, networked SQC system provides factory-wide data acquisition and features MS SQL database. The modular system offers several methods of process optimization and can grow with your edible oil and fat production capacity.

IND930SQC
IND930SQC is a complete standalone solution containing everything you need for single station SQC. No IT infrastructure or skilled technical personnel are needed to fulfil legal requirements. The touchscreen terminal is IP69k protected and can withstand harsh cleaning processes.

Learn more about controlling fill quantity to comply with legal requirements, monitor quality in edible fats and oils filling processes, and increase productivity.

There are several important regulations that guide the production of edible oils and fats, including the refining of popular oils such as olive, canola and soy and the production of fats like cacao butter.