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United States Department of Agriculture

Agricultural Research Service

Research Project: Optimization of the Nutritional, Functional, and Sensory Properties of Raw and Processed Legumes, Grains, and Specialty Crops

Location: Healthy Processed Foods Research

2013 Annual Report


1a.Objectives (from AD-416):
Objective 1: Characterize the physical, chemical, functional properties and biological activity of raw materials and food products from legumes, almonds, grapes, olives, and wild rice.

• Sub-objective 1.1. Pinpoint and identify impact aroma compounds of raw materials and food products from legumes, almonds, grapes, olives, and wild rice using GC-Olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Study flavor variation in different varieties. • Sub-objective 1.2. Isolate and characterize phytonutrients in raw materials and food products from legumes, almonds, grapes, olives, and wild rice. Determine the effects of processing on the levels of these constituents and also monitor changes in biological activity (i.e., antioxidant activity).

Objective 2: Add value to legumes, barley, rice, and potatoes and their fractions using extrusion, concentration and size reduction technologies to modify, control or enhance their nutritional, functional and sensory properties for the development of convenient and desirable gluten containing and gluten-free products with higher quality, shelf life and health benefits.

• Sub-objective 2.1. Develop healthy, nutritious, and convenient snack foods from legumes, barley, rice, wheat, apple, and potatoes, and their fractions using extrusion processing and forming technologies. • Sub-objective 2.2. Develop legume-based beverages formulated with conventional and non-conventional food ingredients, flours and protein powders from rice, wheat, and barley cooked by extrusion processing, drum drying, open kettle, pressure cooking, microwave cooking, and infrared cooking. The resulting cooked legume-based products in the form of powders will be used directly or pretreated by high pressure, microfluidizer processing, and high shear technology, as the base component for beverages with functional properties.

This project involves the production of novel snack foods and beverages from legumes, barley, rice, potatoes and other agricultural products. The development of nutritious and tasty foods requires knowledge about the phytonutrients and flavor precursors present in the raw materials. The effects of processing on phytonutrient and flavor concentrations will be studied and processing parameters will be optimized to preserve these constituents. The scientists on this project have expertise in their respective areas and will work closely to achieve the objectives.


1b.Approach (from AD-416):
Extrusion processing will be used to produce new value-added foods with enhanced nutritional and sensory properties. Extrusion operational parameters such as moisture content, temperature, feed rate, screw speed and screw element configuration will be optimized. Ingredients from barley, rice, and potato will be added to legume flours to enhance the physicochemical properties of the extruded products including both snacks and beverages. To understand the influence of processing on flavor, phytonutrients and antioxidant activity, qualitative and quantitative studies will be performed on the agricultural products before and after processing. Impact flavor constituents will be localized, characterized and quantified using aroma extract dilution analysis (AEDA), gas chromatography-mass spectrometry (GC-MS), calculation of odor units, and preparation of aroma models. Aroma compounds responsible for desirable and undesirable flavor characteristics will be identified and formation pathways will be elucidated. Phytonutrients will be separated, characterized and quantified using HPLC-DAD, HPLC-MS and 1H and 13C NMR spectroscopy. Antioxidant activity will be measured by the DPPH and ABTS assays.


3.Progress Report:
We assessed the effect of different food ingredients such as pea protein, rice, natural gums, honey, brown sugar, low-caloric sweeteners and different flavors for the development of value-added beverages. Water absorption index, water solubility index, water hydration capacity, viscosity, visual stability index, and sensory evaluation were used to characterize the different formulations. The viscosity of the beverages was in the range of 160-190 cP, which is considered acceptable for beverage-type products. Additionally, the developed beverages were stable after 10 days of storage at refrigeration temperature. Different flavors (chocolate, vanilla and coconut) were tested acceptable in a sensory evaluation.


4.Accomplishments
1. Lentil-based extruded snacks. One percent of the world’s population is allergic to gluten (Celiac disease) and the market for gluten-free foods is projected to reach over $90 billion by 2017. Currently, the gluten-free products available in the market are considered to have poor texture and flavor by consumers underscoring the need for improved products. The new gluten-free extruded snacks and pasta products developed from lentil and other legume sources have superior flavor and texture compared with current commercial products. Additionally, the lentil-based products are low in glycemic index and have unique nutraceuticals/healthy properties that reduced cholesterol levels and obesity in animal models. The commercialization of the value-added lentil and other legume-based products presents a way to gain a share of the global gluten-free market, significantly reduce the $950 billion in annual U.S. healthcare expenditures for diet-related health conditions and increase demand for this commodity in benefit of U.S. growers and processors. This accomplishment has generated a series of agreements, Cooperative Research and Development Agreement, and Material Transfer's Research Agreement’s with national and international organizations.

2. Cooked carrot flavor. Carrots, a member of the parley (Umbelliferae) family, are an important U.S. crop with a value (fresh and processed) of $642.8 million in 2012. We identified and quantified the aroma constituents in cooked carrots. We characterized two volatiles, linden ether and B-damascenone, which were identified for the first time in carrots. These volatiles were found to be major contributors to carrot aroma. We also identified 15 additional constituents that contribute to carrot aroma. This information will be useful to breeders and growers for the development and production of carrot varieties that are well-liked and highly accepted by consumers.

3. Domestic and imported black-ripe olives. The U.S. purchased imported table olives valued at $400 million in 2012 to meet consumer demands. We identified and quantified aroma constituents of various samples of domestic and imported (Spain, Egypt and Morocco) black-ripe olives. Domestic olives contained a fairly homogenous composition of volatiles while the imported olives had a much more diverse and complex mixture of volatiles. In addition to the same volatiles present in domestic samples, imported samples had volatiles typically associated with fermentation. We believe that the fermentation products produced off-flavors such as alcohol, artificial fruity, gassy, vinegary and rancid in some imported olives. With the knowledge gained from this study we will be able to develop standards for a testing protocol to be used by USDA to evaluate black-ripe olive quality which will help to prevent poor-quality products from being sold in the U.S.


Review Publications
Takeoka, G.R., Dao, L.T., Harden, L.A., Pantoja, A., Kuhl, J.C. 2012. Antioxidant activity, phenolic and anthocyanin contents of various rhubarb (Rheum-spp.) varieties. Journal of Food Chemistry. DOI: 10.1111/j.1365-2621.2012.03174.x.

Yang, J., Pan, Z., Takeoka, G.R., Mackey, B.E., Bingol, G., Brandl, M., Garcin, K., Mchugh, T.H., Wang, H. 2012. Shelf-life of infrared dry-roasted almonds. Journal of Food Chemistry. 138(1):671-678. DOI: 10.1016/j.foodchem.2012.09.142.

Felker, P., Takeoka, G.R., Dao, L.T. 2012. Pod mesocarp flour of North and South American species of Leguminous tree (mesquite): Composition and food applications. Food Reviews International. 29(1):49-66. DOI: 10.1080/87559129.2012.692139.

Berrios, J.D. 2011. Extrusion processing of main commercial legume pulses. In: Maskan, M. and Altan, A., editors. Advances in Food Extrusion Technology. Boca Raton, FL: CRC Press, Taylor & Francis Group. p. 209-236

Vargas, A., Berrios, J.D., Chiou, B., Wood, D.F., Glenn, G.M., Bello, L., Imam, S.H. 2012. Extruded/injection-molded composites containing unripe plantain flour, ethylene vinyl-alcohol and glycerol: Evaluation of color, mechanical property and biodegradability. Journal of Applied Polymer Science. 124(3):2632-2639.

Last Modified: 12/29/2014
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