Recipient Organization
NORTH DAKOTA STATE UNIV
1310 BOLLEY DR
FARGO,ND 58105-5750
Performing Department
Plant Sciences
Non Technical Summary
The USDA estimates that approximately 4.2 million acres of pulses were harvested across 40 U.S. states in 2016. The primary stakeholders include pulse growers, pulse grower associations, and food manufactures such as seed cleaners, millers, and ingredient suppliers. For growers, favorable economic impact of replacing existing cropland with pulses currently exists due to favorable crop value and reduce nitrogen fertilization. Ingredient companies have capitalized on nutrient composition and functionality of pulses. However, a limiting factor in continued expansion of pulse ingredients in the food industry is the intense distasteful flavor associated with some of the pulses. Stakeholders identified flavor issues as one of the top concerns regarding increased pulse utilization at a recent pulse milling workshop hosted by the pulse and milling industries.Fortification of cereal-based products is an ideal application of deodorized pulse ingredients because pulses are rich in folate, minerals, and lysine, an amino acid that is limiting in cereals. Furthermore, the cereal amino acids complement the amino acids in pulses and when used in the correct proportion, produce a complete protein. However, the intense flavors associated with dry pulse flours and ingredients deters food companies from utilizing nutrient dense pulse flours.The focus of this project is to understand pulse flavor chemistry and methods to mitigate the intense pulse flavor through deodorization. Furthermore, defining processing methods to create pre-cooked flours will aid the industry overall since no true standard method exists for pre-cooking and the effects of varying pre-cooking processing parameters on chemical composition, physical properties, and functional attributes has not been reported. The improved shelf life and sensory attributes of the pulse flour will facility the wider use of nutrient dense pulses as ingredients in the food industry. Consumers benefit by having available to them products that are nutrient dense and for some individuals this would include gluten free products.
Animal Health Component
50%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Goals / Objectives
This Pulse Crop Utilization projectmeets the goals addressed in the Improving Food Quality research area of the National Institute of Food and Agriculture. More specifically to improve our knowledge and understanding of the physical, chemical, and biological properties of foods and food ingredients.The interest in pulses relates to the nutritional composition, functionality and their non-GMO status. The focus of this project, however, includes the understanding of peaflavor chemistry and methods to mitigate the intense pea flavor through processing. Furthermore, the fundamental processing parameters to create pre-cooked pea flour will be defined and their applications in non-traditional products demonstrated. To address the utilization of dry pea as an ingredient, the following objectives will be investigated:1. Assess the degree of volatile reduction (i.e. deororization) in pea flours subjected to solvent and supercritical fluid extraction protocols.2.To evaaluatethe effects of pre-cooking processes on the chemical composition, physical properties, and functional attributes of pea flours.3. To assess the sensory and shelf life stability of milled, deodorized, and pre-cooked pea flours and products made with these flours.
Project Methods
Objective 1. To assess the degree of volatile reduction (i.e. deodorization) in pea flours subjected to solvent and supercritical fluid extraction protocols.Phase 1. Parameter identification: Two separate evaluations will be completed based on the processing approach. The pressure enhanced solvent extraction will be completed using combinations of ethanol (%), pressure cycles, and extraction time. Ninety runs will be completed using combinations of the three variables. Supercritical carbon dioxide extraction will follow the same basic approach as in the pressure-enhanced solvent extraction except that samples will be subjected to different conditions that include ethanol modifier concentration, pressure, and temperature. Sixty runs will be completed using combinations of the three variables.The degree of deodorization will be measured using a trained sensory panel and measurement of the chemical compounds (i.e., volatiles) that contribute pea flavor. A trained sensory panel will assess the intensity of the pea flavor while the volatile analysis will be measured on an Agilent GC-MS system. The conditions that reduce the flavor and measured volatiles the most and the least will be moved forward to Objective 2. Phase 2. Parameter validation: Response surface methodology (RSM) will be used to predict the optimum conditions for the flavor reductions in pea flour. In the pressure-enhanced solvent extraction and supercritical carbon dioxide research, ethanol %, pressure cycle and time, and ethanol %, pressure, and temperature, respectively, will be used to estimate the level of pea flavor reduction by a sensory panel and the concentration of specific volatiles. The minimum and maximum processing parameters identified in Phase 1 will be incorporated into the RSM model. The optimal conditions identified in the RSM will be run and the flavor reduction and concentration of specific volatiles measured.The predicted processing conditions will be used as the processing conditions in Phase 3.Phase 3. Particle size evaluation: Peas flour of various particle sizes will be obtained by hammer milling peas into flour followed by sieving with openings of 600, 425, 250 and 150 µm. Flours of different particles sizes will be subjected to the optimal extraction conditions obtained in Phase 2. Volatile analysis using GC-MS will be conducted to confirm the presence or absence of key volatiles. The particles that a trained sensory panel deemed to be void of pea flavor will be moved into product formulations (Objective 3).Objective 2. Assess the effects of pre-cooking processes on the chemical composition, physical properties, and functional attributes of pea flours.Phase 1. Parameter identification: The pre-cooking of pea flour will be conducting using various combinations of hydrothermal treatments.The approach will target the use of the whole and split pulses and flours. The pre-cooking will target hydrating pulses at temperatures of 22 to 100 °C and times ranging from 30 min to 16 hrs. Based on the preliminary investigation, 16 hrs was required to achieve complete hydration. However, most treatments will be concentrated on short time (<4 hrs) and higher temperature for hydration. Furthermore, flours will be prepared by hammer milling and then gelatinized using hydrothermal conditions. In addition to the hydrothermal conditions, drying time and temperature will be evaluated. After drying, samples will be milled using the hammer mill with a screen of 0.5 mm. All analytical and functional tests will be run using this flour.Phase 2. Chemical, Physical and Functional Characterization: Methods used to determine the composition and physicochemical properties have been used in our laboratory previously. We do not anticipate any issues with applying these methods to the pre-cooked pea flours. The flour obtained from precooking will be subjected to chemical analyses (e.g., protein, starch), and evaluation of physicochemical properties (e.g., viscosity, emulsion and foam capacities). Comparison of the original flour and pre-cooked flours will be completed.Objective 3. To assess the sensory and shelf life stability of milled, deodorized, and pre-cooked pulse flours and products made with these flours.Food production and functionality experiments: The flours obtained from Objectives 1 and 2 will be incorporated into cereal-based food products such as crackers, cakes, and cookies. Cookie and cracker quality such as weight, diameter,height, and firmness will be determined. Gluten-free cakes will be made following previously published methods, except that dry pea flour will substitute for the other forms of flour. The height and symmetry of the cakes and firmness will be measured within one day of preparation.Sensory Evaluation: Pea flavor intensity will be used as the criteria for processing optimization in Objective 1. A panel of 10 trained individuals will complete the sensory evaluation of the flours. They will be trained to assess the intensity or strength of the pea flavor using various pea products, including dry peas and fresh peas. They will also be asked to identify any off-flavors that are present in the flour. A similar trained panel will evaluate pea flavor in pre-cooked flours and in the shelf-life evaluation. Food products developed with deodorized and pre-cooked flours will be subjected to acceptability sensory tests. An untrained panel of 50 individuals, both male and female, will complete the test using a nine-point hedonic scale to evaluate the overall acceptability. The panelists will score the products on the hedonic scale from 1 (dislike extremely) to 9 (like extremely) for appearance, flavor, texture, and overall acceptability.Shelf-life Properties: Shelf-life testing is an indicator of how well quality factors of a product withstand change as the product sits on a shelf. Shelf-life determination will include general quality tests conducted on products deemed acceptable by consumer panelists. Oxidative or rancidity assessments will be completed using peroxide values and volatile analysis. Shelf life at 23 and 50°C and 50% relative humidity will be used as storage conditions.The change in knowledge will be the significant output of this research. The research will provide pulse processors with an approach to eliminate pea flavor. Furthermore, the contribution of particle size to flavor reduction will be characterized and incorporated into processing recommendations to the pulse industry. The number of pulse ingredient manufacturers that adopt the flavor reducing strategies in this project will be quantified and provided as an indicator of impact. The research will provide ingredient suppliers with information regarding the processing of pre-cooked pea flour. The chemical and functional characteristics of the flour will be associated with the processing approach. Thus, allowing ingredient supplier the opportunity to provide a portfolio of pre-cooked flour to food manufacturers. The number of pulse ingredient manufacturers that adopt the pre-cooking approaches in this project will be quantified and provided as an indicator of impact. The application of the flours will also be demonstrated and may cause bakers and other food manufacturers to adopt these processed flours as ingredients in food items. Technology transfer is an important emphasis on creating food ingredients. The data and interpretation of the results will be made available to Extension agents and the Northern Crops Institute (NCI) to provide stakeholders (both nationally and internationally) with information regarding the production and utilization of deodorized pea flour. Results of these experiments will be presented at professional meetings and published in peer-reviewed journals. Major findings will be communicated to the various pulse grower associations and be included in the NCI pulse short courses and pulse milling workshops.