Location: Functional Foods Research
2016 Annual Report
Objectives
Objective 1. Enable new methods using organogels and alternative oil structuring agents to generate commercial zero trans fat, low saturated fat margarines, shortenings, confectionary fats, and other lipid ingredients.
Sub-Objective 1.A. Investigate and optimize the physical, rheological, and sensory properties of edible organogels.
Sub-objective 1.B. Evaluate the effect of organogels on the properties of structured fats composed of either modified fatty acid composition vegetable oils or fully hydrogenated soybean or cottonseed oil with vegetable oils.
Objective 2. Enable new commercial delivery systems using natural antioxidant technologies to protect frying oils, polyunsaturated oils, and bioactive lipids.
Sub-Objective 2.A. Evaluate the activity of naturally occurring antioxidants and antioxidant combinations for protection of frying oils and fried foods.
Sub-objective 2.B. Evaluate antioxidants or natural antioxidant extracts for protection of polyunsaturated and omega-3 oils and bioactive lipids.
Sub-objective 2.C. Investigate new delivery systems for antioxidants, omega-3 oils, and bioactive ingredients.
Objective 3. Quantitate and evaluate bioactive ingredients including antioxidants and bioactive lipids in commodity and non-commodity crops as well as in food and agricultural waste processing streams.
Approach
In order to tackle health issues facing the nation including obesity, heart disease, and diabetes, nutritional experts are urging U.S. consumers to limit their consumption of both saturated fats and trans fats from hydrogenated oils, and to eat a diet high in fruits, vegetables, and whole grains, in order to obtain the added benefits of the bioactive food constituents found in these foods. Food manufacturers, restaurants and bakeries are looking for alternatives to hydrogenated vegetable oils or imported palm oil that have the stability necessary for frying, or the functionality needed for margarines and shortenings. U.S. commodity vegetable oils are low in saturated fats and high in healthy polyunsaturated and monounsaturated fats. However, without hydrogenation, the majority of these oils are not stable enough for frying and do not have the proper functionality for margarines and shortenings.
The first objective of this project plan is to develop alternative methods of structuring oils in order to solve the problem of functionality for margarine and shortening applications. Low concentrations of natural, inexpensive ingredients, will be used to form organogels with liquid oils. Physical and rheological characteristics of organogels will be fully investigated and test margarines and shortenings will be developed from organogels with desirable physical and rheological properties. These will be further tested in food applications for creaming, aerating, and structuring ability, as well as sensory quality.
The second objective of this plan is to develop natural antioxidant systems to protect polyunsaturated fats and bioactive lipids from oxidation and degradation in frying and in food systems, in order to extend the shelf-life and healthfulness of lipids and foods, and to replace synthetic antioxidants. Antioxidants will be tested for activity in commodity oils during frying, in order to extend the fry life and prevent oxidation products from forming. Potential antioxidants will also be tested for their ability to extend the oxidative stability and shelf life of model food systems, such as in oil-in-water emulsions, and in whole grain food products. The potential antioxidants will also be compared to synthetic antioxidants.
The third objective of this research is to analyze byproducts of food and agricultural processing for valuable bioactive lipids and/or antioxidants, in order to develop new ingredients from these products, and to reduce waste. Spent coffee grounds, blueberry pomace, and various pulse processing fractions will be extracted and analyzed for bioactive lipids and water soluble antioxidants.
Progress Report
The first Objective of this project plan is to develop alternative methods of structuring oils in order to solve the problem of functionality for margarine and shortening applications. As progress towards Objective 1.A., we obtained food-grade waxes and began to determine the minimum gelation concentrations and the melting and crystallization onset temperatures of these waxes alone and as binary mixtures. Additional mixtures will be screened, and these data as well as texture data will be used to narrow down the choice of organogelators and organogelator combinations to use for sensory analysis. In addition, in order to test the practical application of organogels as shortening or margarine substitutes, organogels were made using a combination of four different natural waxes (sunflower wax, candelilla wax, rice bran wax, and beeswax) and three different vegetable oils (olive oil, soybean oil, and flaxseed oil). The organogels were evaluated for firmness and melting behavior, and were tested as a replacement for margarine in cookies. We measured the hardness of the cookie dough as well as the spreading of the cookie dough during baking and the texture of the baked cookies. We found that organogels formed with these natural waxes and vegetable oils had high potential as alternatives to conventional margarines in cookie doughs. The waxes that were used for this study were not food-grade, but now that we have obtained some food-grade waxes, this data will guide studies incorporating sensory evaluation of baked goods. As progress towards Objective 1B, non-genetically modified organisms (GMO), high-stearic acid soybeans were obtained from an Agricultural Research Service (ARS) collaborator in Columbia, Missouri, and the oil was extracted by ARS scientists in Peoria, Illinois. Organogels were prepared with the high stearic oil and sunflower wax to examine organogel melting behavior and firmness. The second objective of this plan is to develop natural antioxidant systems to protect polyunsaturated fats and bioactive lipids from oxidation and degradation in frying and in food systems, in order to extend the shelf-life and healthfulness of lipids and foods, and to replace synthetic antioxidants. As progress towards this objective, amino acids were evaluated as natural antioxidants for frying. Twenty amino acids were added to soybean oil and heated at frying temperatures to compare their antioxidant activities. A new understanding of how the molecular structures of amino acids influence their antioxidant activities was obtained, and a database of amino acid antioxidant activity at frying temperatures was also developed. Several amino acids were found to be very effective antioxidants and showed high potential for practical use as antioxidants for frying. Amino acids were also shown to have synergistic antioxidant activity with tocopherols. In additional work towards the development of naturally occurring frying oil antioxidants, a number of frying studies were conducted to examine the antioxidant activity of phytosteryl ferulates and corn fiber extracts during frying, both alone and in combination with commercial antioxidants. In addition, the shelf-life of the resulting fried food, tortilla chips, was evaluated by analysis of headspace volatiles and by sensory analysis. Corn fiber extracts had excellent antioxidant activity during frying and also extended the shelf-life of the tortilla chips, and were superior to the commercial antioxidants. However, no synergism was found between corn fiber extracts and commercial antioxidants. We also examined sesamol, which naturally occurs in sesame oil, and gamma-oryzanol, which naturally occurs in rice bran oil, as natural antioxidants for protection of long-chain omega-3 fatty acid containing fish oils. In this case, sesamol had antioxidant activity that was comparable to a widely used commercial antioxidant, rosemary extract, and it was found to be a very effective antioxidant for protection of omega-3 oils during storage. Additionally, we investigated using differential scanning calorimetry (DSC) and steam jet-cooking for small-scale and large-scale, respectively, determination of the formation of amylose helical complexes between high amylose starch and phytosterols, ferulate phytosterol esters, and tocopherols. Preliminary evaluation by DSC as well as x-ray diffraction analysis indicated that these compounds formed amylose helical complexes. Analysis of the chemical and physical properties of complexes is ongoing. These complexes may have potential as delivery systems for lipophilic antioxidants or bioactive lipids in low-fat and other food systems. The third objective of this research is to analyze byproducts of food and agricultural processing for valuable bioactive lipids and/or antioxidants, in order to develop new ingredients from these products, and to reduce waste. We used solvents with varying polarities to extract and evaluate the antioxidants in corn wet fiber and corn dry fiber, which are byproducts of the corn wet processing industry that are normally sold for use in animal feed. Antioxidant activities and content of phytosteryl ferulates were determined in these extracts, and the extracts were then testing as frying oil antioxidants, as described in the research progress for the second objective. In addition, preliminary experiments were done to evaluate blueberry pomace (waste product from blueberry juice industry) and spent coffee grounds as sources for antioxidants. They were extracted with ethanol, acetone, and hexane and extracts were examined for their activity to reduce oxidation of soybean oil at frying temperatures. Negative effects were observed, thus, future experiments will include modifying the extraction method to optimize antioxidant components, characterization of antioxidants in the extracts, and evaluation in frying and other oil and/or food systems. Beyond the research described above that was conducted in order to meet our project milestones, we also conducted several collaborative studies where our research interests and skills complemented those of our collaborators. We collaborated with ARS scientists in Ames, Iowa, to characterize the oxidative state of oils that are typically used in pig, cattle, and dairy feedlots. The overall goal of the research is to evaluate the impact of oxidized oils and fat on animal performance, digestion, and gene expression. We also collaborated with ARS scientists in the Sunflower Research Laboratory in Fargo, North Dakota, to evaluate the tocopherol content and composition in new cultivars of sunflower that were selectively bred to have altered tocopherol profile, which should lead to improved oxidative stability of the resulting oil. Finally, we finished up a project with collaborators in Brazil to develop a method using tocopherol profiling as well as near infrared spectroscopy (NIR) to detect adulteration of roasted coffee with corn, a common adulterant. Both methods could detect adulteration at a level of 5%, but NIR has the advantage of being faster and non-destructive.
Accomplishments
1. Healthier margarines for cookies. Margarines and shortenings contain saturated fats and/or trans fats from partially hydrogenated oils. Consumption of saturated and trans fats increases the risk for heart disease, but baked goods such as cookies rely on these solid fats to provide proper texture and mouthfeel. Organogels made with natural waxes and three different vegetable oils were evaluated as margarine replacements in cookies by Agricultural Research Service researchers in Peoria, Illinois. The texture and shape of the cookies was similar to cookies made with a commercial margarine. This indicates that wax-vegetable oil organogels have high potential as replacements for conventional solid fats containing high contents of saturated fats and/or trans fats in baked goods such as cookies, which is essential for commercial development.
2. Sesamol for antioxidant protection of omega-3 oils. The use of omega-3 oil supplements and foods fortified with these oils has increased in recent years because long-chain omega-3 polyunsaturated fatty acids have beneficial health effects such as reducing the incidence of heart attacks, reducing inflammation, and in fetal brain development. However, omega-3 oils are easily broken down by oxidation and require antioxidants to protect them from degradation. Agricultural Research Service researchers in Peoria, Illinois, treated fish oil with sesamol, a natural compound found in sesame oil, to prevent oxidation in an accelerated storage study where the oils were subjected to heat and oxygen. Sesamol had stronger antioxidant activity than a commercial synthetic antioxidant, butylated hydroxytoluene (BHT), and a leading commercial natural antioxidant, rosemary extract. Sesamol offers an inexpensive, food label friendly alternative to synthetic antioxidants for protection of omega-3 oils, and may also offer some advantages over rosemary extracts, which typically has flavor, odor, color, and solubility issues associated with oil applications.
3. Egg yolk quality improved by dried distillers grains in feed. Dried distillers grains (DDGS) are a co-product from ethanol production from corn that are typically used as a feed component for cattle and pigs. Agricultural Research Service scientists in Peoria, Illinois, in collaboration with scientists at the National Corn to Ethanol Research Center, Edwardsville, Illinois, University of Georgia, Athens, Georgia, and Tufts University, Medford, Massachusetts, demonstrated that both regular and low-fat distillers grains could be incorporated into layer hen diets at levels up to 20% with no detrimental impacts on hen weight gain or on egg production. In addition, egg yolks from hens fed DDGS were more red and yellow in color, and contained higher levels of carotenoids and tocopherols. This research indicates that both regular and low-fat DDGS can safely be incorporated into laying hen diets and that these feed components actually improve the color and content of bioactive lipids in egg yolks.
4. Detecting coffee adulteration. Coffee is a highly valuable commodity, thus it is subject to adulteration with lower value materials, such as corn, wheat, and even sticks. Agricultural Research Service researchers in Peoria, Illinois, in collaboration with scientists in Brazil, have developed tocopherol profiling and near-infrared (NIR) technologies to detect adulteration of coffee with corn, a common adulterant. Levels of 5% adulteration could be accurately detected with both methodologies, and levels of 1% could also be detected, with less accuracy. This technology may be used for the detection of other common adulterants, and while NIR was faster and non-destructive than tocopherol profiling, the two methods may be complementary when a wide variety of adulterants need to be detected. Tocopherol profiling as well as NIR may also have application for the detection of adulteration of other high-value food or agricultural products. This is important to maintaining quality, safety, and consumer confidence in a product or brand, which ultimately affects profits.
None.
Review Publications
Fhaner, M., Hwang, H.-S., Winkler-Moser, J.K., Bakota, E.L., Liu, S.X. 2016. Protection of fish oil from oxidation with sesamol. European Journal of Lipid Science and Technology. 118(6):885-897.
Hwang, H.-S., Singh, M., Lee, S. 2016. Properties of cookies made with natural wax-vegetable oil organogels. Journal of Food Science. 81(5):C1045-C1054.
Hwang, H.-S., Winkler-Moser, J.K. 2016. Oxidative stability and shelf life of frying oils and fried foods. In: Hu, M., Jacobsen, C., editors. Oxidative Stability and Shelf Life of Foods Containing Oils and Fats. Amsterdam, The Netherlands: Elsevier. p. 251-285.
Hwang, H.-S. 2015. NMR spectroscopy for assessing lipid oxidation. Lipid Technology. 27(8):187-189.
Winkler-Moser, J.K., Singh, M., Rennick, K.A., Bakota, E.L., Jham, G., Liu, S.X., Vaughn, S.F. 2016. Detection of corn adulteration in Brazilian coffee (Coffea arabica) by tocopherol profiling and near-infrared (NIR) spectroscopy. Journal of Agricultural and Food Chemistry. 63(49):10662-10668.
Trupia, S., Winkler-Moser, J.K., Guney, A.C., Beckstead, R., Chen, C.-Y.O. 2016. Nutritional quality of eggs from hens fed distillers dried grains with solubles. Poultry Science. doi: 10.3382/ps/pew142.
Hwang, H.-S. 2016. Organogels of vegetable oil with plant wax – trans/saturated fat replacements. Inform. 27:708-711.
Hwang, H.-S., Bakota, E.L. 2016. NMR spectroscopy for evaluation of lipid oxidation. In: Rahman, A.U., Choudhary, M.I., editors. Applications of NMR Spectroscopy. Volume 4. Oak Park, IL: Bentham eBooks. p. 62-95.
