Location: Healthy Processed Foods Research2011 Annual Report
1a. Objectives (from AD-416)
Objective 1. Fractionate fiber, water-soluble, alcohol-soluble and lipid-soluble fractions from the increasingly large amounts of fruit and vegetable byproducts including pomace of olives, grapes, and pomegranates and the bran of cereal grains in order to identify, condense, and test bioactive compounds in animal models of obesity related diseases. Sub-Objective 1.1. Separate different fruit tissues (skin, pulp, juice) and cereal brans (germ, aleurone, fat) using physical processes, and fractionate followed by extraction with food approved solvent methods. Sub-Objective 1.2. Assess bioactivity of extracts and residues of 1.1 by feeding mice or hamsters hypercholesterolemic diets and determining physiologic characteristics of obesity related metabolic syndrome. Objective 2. Develop processing methods that disrupt food matrices or cell barriers in order to increase accessibility to cellular contents and increase the bioavailability of phytonutrients from fractions of fruit and vegetable based byproducts including pomace of olives, grapes, and pomegranates, as well as grain byproducts from Obj. 1.1 that contain complex mixtures of phenolic compounds that may help to prevent obesity related diseases and add value. Sub-Objective 2.1. Evaluate processes such as enzymatic treatment (cellulase, esterase, phytase), sonication, ethanol extraction, and high pressure to increase bioavailability of phytochemicals and fiber, and to improve consistency of composition and bioavailability of samples for in vivo studies. Subobjective 2.2. Test samples identified as bioactive in 1.2 as well as those further processed in 2.1 for their bioavailability. Also characterize phytochemical composition of bioavailable fractions by HPLC. Objective 3. Evaluate a variety of viscous and gelling soluble dietary fibers to produce breads and other cereal products that are high in fiber and micronutrients. Sub-Objective 3.1. Breads and other baked products will be developed from non-gluten whole grains and bran such as corn, rice, oat, barley, rye, quinoa, amaranth in order to increase the diversity of whole grain products available to consumers. Viscous soluble dietary fibers are necessary to replace gluten, but also reduce postprandial glycemic response and plasma cholesterol. Sub-Objective 3.2. Preliminary studies indicate difference in hepatic nutrient metabolism between wheat and barley flours was not accounted for by soluble fiber content. We propose to evaluate a variety of cereal grains and seeds for bioactivity by analyzing expression of hepatic genes representative of metabolism of sterols, bile acids, and fat, and indicators of inflamation.
1b. Approach (from AD-416)
Food processing technologies will be applied to release the high concentration of polyphenolic components from the matrices of the skin and bran byproducts of juice, wine, oil and flour production. Polyphenolics will be extracted from these processed matrices by systematic application of food grade solvents into broad classes and a fiber fraction. Mice and hamster models of obesity related diseases will be used to determine the potential of the polyphenolic or fiber fractions to reduce or prevent the characteristics of metabolic diseases. Mechanisms will be investigated through gene expression pathway analysis. Of particular interest is the ability of polyphenolics or fiber to reduce the absorption of lipopolysaccharides that trigger adopose inflammatory responses. Viscous soluble fibers will be used to develop breads from nontraditional whole grains and seeds to determine if they have potential to reduce metabolic syndrome in animal models.
3. Progress Report
In collaboration with other ARS scientists we evaluated the ability of tomato processing byproducts: tomato pomace, tomato oil, and tomato fiber, in a hyper-cholesterolemic hamster model. Some tomato fractions reduced plasma lipids. Olive pomace was also evaluated in the same animal model but there were no differences in plasma lipids with control. In collaboration with an industry cooperator we produced and evaluated the protein hydrolysates of brown rice, white rice, and soy isolate in a obese, hyperlipidemic animal model. Some hydrolysates reduced weight gain and liver lipids. Expression of genes in the liver for fat burning were increased while genes for fat storage were decreased in diets that reduced weight gain. We developed and evaluated the acceptability to consumers of whole grain flat breads from corn, millet, brown rice and sorghum flour. Taste panels of 35-46 volunteers resulted in high acceptance ratings of several formulations. The results suggest alternative whole grains are acceptable to consumers and may increase whole grain consumption.
1. Development of bioactive products from processing byproducts. Tomato and olive pomace are byproducts currently used as low value feed or have no use and are buried in landfills at a cost to the manufacturer. Researchers with ARS, Albany, CA and the University of California, Davis evaluated the potential of tomato and olive oil processing byproducts and fractions in an animal model of obesity related diseases. Tomato processing byproducts and some of their fractions reduced undesirable plasma and liver lipids. The research may result in products that will improve health and increase profits to growers and food processors.
2. Bioactive peptides from plant proteins. Many cereal brans are high in protein, fiber and oil. Cereal brans are abundant but have few food applications. Bran proteins may contain amino acid sequences with potential bioactivity when released in the form of peptides. Researchers at ARS, Albany, CA and Jiangnan University, China found that rice protein hydrolysates decreased weight gain in mice on a high fat diet and also reduced undesirable liver lipids. These results suggest that bran proteins contain peptide fragments that may be useful in combating obesity and obesity related metabolic diseases. The development of peptide products from brans may increase the value of this underutilized byproduct.
Rosell, C., Shoemaker, C.F., Yokoyama, W.H. 2011. Rheology of different hydrocolloids–rice starch blends. Effect of successive heating–cooling cycles. Carbohydrate Polymers. 84(1): 373-382.