The global edible oils market is expected to register a CAGR of 5.1% and have an estimated value of $130.3 billion by 2024. One factor that contributes to these high projections is an overall increase in health concerns among consumers, which increases the demand for edible oils higher in unsaturated fatty acids like canola and olive oil. Quality assurance in edible oils production is critical not only for price and brand protection but also for safeguarding human health.
Moreover, consumer awareness of quality assurance amongst brands is a major factor in consumers’ decisions to purchase edible oil products. The implications of poor product quality spreading in today’s social media environment, as well as the financial consequences of a product recall, can be devastating to a company’s bottom line. These factors along with the large size of the global market have created a demand for new and objective quality control methods. Traditional methods are costly and time-consuming. Developing rapid, non-invasive, cost-effective, and environmentally sound methods for quality testing has become a priority for edible oil manufacturers. One such method with potential for both laboratory and industrial testing of edible oil products is NIR spectroscopy.
Quality assurance in edible oils production is critical not only for price and brand protection but also for safeguarding human health. Moreover, consumer awareness of quality assurance amongst brands is a major factor in consumers’ decisions to purchase edible oil products. The implications of poor product quality spreading in today’s social media environment, as well as the financial consequences of a product recall, can be devastating to a company’s bottom line. These factors along with the large size of the global market have created a demand for new and objective quality control methods. Traditional methods are costly and time-consuming. Developing rapid, non-invasive, cost-effective, and environmentally sound methods for quality testing has become a priority for edible oil manufacturers. One such method with potential for both laboratory and industrial testing of edible oil products is NIR spectroscopy.
Raw Material Testing
Edible oil comes from various parts of plants, usually from seeds (sunflower, palm kernel, safflower, cotton, sesame, and grapeseed) or nuts (peanut, soybean, almonds, and walnuts). In the case of olives, the oil comes from the olive fruit itself. Fish oil is especially known for its high nutritional value from Omega-3 fatty acids. Some studies have been conducted to analyze nutrients in olive leaves for optimal amounts of nitrogen, phosphorous, potassium, calcium, and magnesium are important because deficiencies reduce growth while excessive nutrients can inhibit adequate bloom and growth set. Physical and chemical parameters change during the ripening process, and these parameters are of high commercial importance because they affect the quality and shelf life of the finished product. Physical parameters in olives include yield point force and total deformation energy. Chemical parameters in all types of edible oils include moisture, oil content, sugar content, maturity index, fatty acid composition, phenols, tocopherols, and sterols. The established methods for measuring these parameters are time-consuming, expensive, and impractical for measuring large amounts of samples. There have been studies documenting the feasibility of measuring these parameters using NIR spectroscopy. While results vary from study to study, there is no question that NIR spectroscopy has the potential to replace laborious and often expensive wet chemistry methods to measure these parameters successfully. Possibilities available from current NIR spectroscopic instruments include hand-held instruments for field measurements, benchtop laboratory instruments, and online instruments as the raw material is fed for pressing. It is important to incorporate both a wide range of chemical composition variability and proper sample homogenization to create accurate calibration models for any parameter.
Paste, Mash, and Extractable Material Testing
All edible oil manufacturing begins with the preparation of the raw material to make it suitable for pressing. Exact preparation varies depending on the material used but all consist of material stripping and cleaning. Cotton seeds must be stripped of their lint and dehulled. Corn kernels must undergo milling to separate the germ. Stripped seeds and nuts are ground into coarse meal to increase the surface area. Olives are crushed into paste form to tear the flesh cells to facilitate the release of oil from the vacuoles. The next step is to separate the oil from the rest of the components. For seeds and nuts, the material is heated and fed continuously into a screw press, allowing the oil to be squeezed out and recovered. After the initial oil is recovered from the screw press, the remaining cake is processed by solvent extraction to attain the maximum yield. Evaporated solvent is often collected for reuse using a stripping column. The process for olives is slightly different and has evolved over time. Older olive oils facilities feed the olive paste into a press in a similar fashion to other oils, except the paste is not heated, hence the common terms “first press” and “cold press.” The extraneous material that is leftover from pressing is known as pomace. Newer olive oil facilities use centrifuges for the same purpose to separate oil, water, and solids separately. Most of the time, the oil coming out of a first centrifuge is further processed to eliminate any leftover water and solids by a second centrifuge. The oil is then tanked or barreled, and gravity will separate any leftover material in a process known as racking. As is the case with raw material analysis, moisture, oils, sugars, and fat are important to measure during the process of manufacturing edible oils. The optimal crushing of the raw material is important as well as choosing the correct parameters for the screw press or centrifuges. Pomace testing of fat and oils can help determine if the optimum extraction yield is happening because excess oil in the pomace results in loss of product and reduced profits. NIR spectroscopy has been used for monitoring these parameters to optimize the yield of oil from the raw materials.
Storage and Oxidation
Once edible oil is produced, oxidation is a deterrent to product quality. Oils that are rich in polyunsaturated fatty acids are susceptible to the formation of peroxides and hydroperoxides after exposure to light, heat, and oxygen. Oils higher in oleic acid, such as linoleic and linolenic acids, are less susceptible to oxygen. Therefore, determination of fatty acid profiles is an essential quality control measurement in edible oils. Parameters to measure oxidation that has occurred are peroxide value for primary oxidation and anisidine value for secondary oxidation. NIR spectroscopy is a proven method for measuring fatty acids to determine the potential for oxidation and parameters that determine if oxidation has occurred in edible oil.
Adulteration and Food Fraud
Adulteration and food fraud are major problems for edible oil producers and many other companies in the global food industry. Food fraud is defined as the intentional act of substituting, adding, tampering of food products as well as misrepresentation of food, food ingredients, and food packaging. It is often done for economic purposes, and in the case of edible oils, it usually consists of adulterating higher quality oil with cheaper components. This is especially true in the case of extra virgin olive oil, which is strictly regulated for quality parameters and is much more expensive than other classes of olive oil. Palm oil is another expensive edible oil and demand for it is projected to grow in coming years, increasing the likelihood of adulteration. Another form of adulteration is a misrepresentation of geographical origin, again very prevalent in the case of olive oil. Genetic engineering has become a big part of the food industry, but there is some resistance in certain countries to consuming these food products. Representing a product as non-transgenic when it is transgenic can be another form of adulteration. Using such a technique like NIR spectroscopy to measure adulterants presents new and evolving challenges as the types and amounts of adulterants are constantly being changed by those adding them. To make NIR spectroscopy a feasible long-term tool for detecting food fraud, models must be kept up to date by adding data including new types of adulterants.
Process Analytical Technology (PAT) & Online Measurements
Process Analytical Technology is a framework for innovative process manufacturing and quality assurance. Critical points and parameters during manufacturing of a product are defined, and the process is designed in a way that such points and parameters can be measured using analytical tools and instruments for real-time process feedback and control. Such instruments must be able to measure online and in a non-invasive manner. Many vendors have developed instruments that can measure multiple points in a process with a single instrument, usually using optical fibers and probes. PAT has become an important part of pharmaceutical manufacturing and is beginning to acquire a hold in the food industry. One such analytical tool with great potential for use in PAT is NIR Spectroscopy.
There are significant challenges to implementing PAT in an edible oils manufacturing environment. NIR spectroscopy has been proven as a useful tool for measuring parameters of interest in edible oils measurement. Vendors are coming up with new and innovative ways to make online measurements a feasible solution for companies. Advances such as improved fiber-optics, in-situ sampling, a transition to integrated automation, improved data management systems, and communication systems in the Internet and Cloud age have all contributed to implementing PAT. The edible oil and food industries also present particular challenges due to natural product variability. In the case of pharmaceuticals and chemicals, the manufacturing process is usually conducted in a controlled environment with constituents that rarely show variability in spectral data over time. For foods and particularly agricultural products, there can be marked differences in products due to many factors, such as temperature variability, seasonal variation, differences in soil and nutrients, and different breeds of the same product. Such differences can create variability in spectral data that must be incorporated into calibration models for when calibrating NIR spectrometers and other analytical PAT tools. This is known as making models “robust” and often requires a larger and more incorporative sample set to achieve the desired results.
Feasibility studies have been conducted for measuring edible oil parameters online as well as in the laboratory. Results have been good and show that online measurements are a feasible tool for edible oils analysis using PAT. Full adoption of PAT in the food industry will require a collaborative effort from process engineers, food scientists, and other contributors to provide the industry with a manufacturing framework for the 21st century.
Manufacturing Process of Edible Oil – KMEC Engineering
Making Olive Oil – Olive Oil Source
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Determination of In-Shell Peanut Oil and Fatty Acid Composition Using Near-Infrared Reflectance Spectroscopy – Sundaram, Kandala, Holser, et al., J Am Oil Chem Soc (2010) 87:1103-1114 https://link.springer.com/article/10.1007%2Fs11746-010-1589-7
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Nontargeted, Rapid Screening of Extra Virgin Olive Oil Products for Authenticity Using Near-Infrared Spectroscopy in Combination with Conformity Index and Multivariate Statistical Analysis – Karunathilaka, Fardin Kia, Srigley, Chung, Mossoba, Journal of Food Science, Vol. 81, Nr. 10, 2016
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