Recipient Organization
TENNESSEE STATE UNIVERSITY
3500 JOHN A. MERRITT BLVD
NASHVILLE,TN 37209
Performing Department
College of Agriculture, Human and Natural Sciences
Non Technical Summary
Pigeon pea (Cajanus cajan (L.) Millsp.) has been used as a traditional remedy for various disease treatments including anti-cancer, anti-inflammation, and anti-diabetes etc. Pigeon pea is becoming an emerging crop in the United States. Currently, research is underway on Pigeon pea production at Tennessee State University, Alabama A & M University, and Virginia State University with funding support from the United States Department of Agriculture (USDA). However, very few studies are available on Pigeon pea's health-promoting effects through dietary consumption. It is becoming an urgent calling for food scientists to introduce this emerging crop to public consumers with the evidence that Pigeon pea acts an exceptional source of a healthy ingredient.In this project,the PD willexplore the application of Pigeon pea in food models. The hypotheses are: protein and non-starch polysaccharides in Pigeon pea exhibit anti-inflammation, anti-diabetes and intestinal benefit; food containing Pigeon pea will exhibit health benefit, and will meet consumer acceptance by sensory evaluation. The objectives of this project are: i). Characterize chemical, physical, and physiological properties of protein and non-starch polysaccharides; ii). Develop food products incorporated with Pigeon pea flour at various levels, and evaluate their health benefits on anti-inflammation, anti-diabetes, and gastrointestinal health; iii). Conduct sensory evaluations on the developed food model for customer acceptance. The successful delivery of this project will help build research capacity and competency for attracting external funding for their future research.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Goals / Objectives
Pigeon pea is becoming an emerging crop and a new marketable resource for small farms in the southeast states in the United States. Pigeon pea is tolerant to draught weather and can improve soil condition. Usage of Pigeon pea in food applications is becoming more important to integrate the goals in "sustainable agriculture." This proposal address the Priority: Food Safety, Nutrition and Health since Pigeon pea is a nutritive food that can also satisfy human food and fiber needs. Pigeon pea is an important, healthy ingredient of many people's diet in Asia, Africa, and South America (Martinez-Villaluenga et al., 2010). It contains 29% protein, 41% total starch, and 39% total dietary fiber (Torres et al., 2007). It has been used as a traditional remedy as it contains multiple bioactive components. In recent years, more research has been carried out to study health benefits of Pigeon pea and its components (e.g. Srijunthongsiri, Pradipasena and Tulyathan, 2016; Al-Saeedi and Hossain, 2015; Lee, B-H., Lai, Y-S. and Wu, S-C., 2015).This study will provide evidence on how the processing conditions and interactions among different components will affect the overall physiological roles on potential health promotion and disease prevention effects, and will help produce healthy food products to reduce costs for health risks and improve health conditions through community education. The outcome of this study will serve to add value to food products with exceptional health benefits to potentially promote the general health of consumers and to prevent chronic diseases.In this project, Pigeon pea will be used as a whole in three food models. Supporting objectives of the projects include: (i) Investigating phytochemical profile and antioxidant activity of Pigeon pea flour; (ii) Understanding physicochemical and physiological properties of protein and non-starch polysaccharides in Pigeon pea; (iii) Developing food products containing Pigeon pea and evaluate their health benefits, sensory quality, and consumer's willingness to accept the developed products.
Project Methods
Objective 1: Investigating phytochemical profile and antioxidant activity of Pigeon pea flour;Work 1.1. Phytochemical profileTask 1.1.1. Total phenolic content (TPC)Determination of TPC was based on Folin-Ciocalteu assay described by Singleton, Orthofer, and Lamuela-Raventos (1999) and Xu and Chang (2007) with little modification.TPC will be expressed as gallic acid equivalents (mg of GAE/g sample) through the calibration curve of gallic acid.Task 1.1.2. Total flavonoids content (TFC): Total flavonoid content was determined using a colorimetric method described by Heimler and others (2005).Task 1.1.3. Total phytic acids (TPA): Phytic acid in the Pigeon pea will be extracted according to the method of Gao et al (2007). TheTask 1.1.4. Total saponin content (TSC):Total saponin content will be determined following the method of Makkar and Becker (1997). The amount of condensed tannin is calculated and expressed as mg of catechin equivalents (mg of CAE/g sample) using the calibration curve of (+)-catechin.Work 1.2. Antioxidant activitiesTask 1.2.1. Reducing power: The reducing power will be determined according to the method of Oyaizu (1986) with little modification.A higher absorbance indicates higher reducing power. The assays will be carried out in triplicate and the results are expressed as mean values ± standard deviations. Ascorbic acid will be used as a standard.Task 1.2.2. DPPH-free radical scavenging capacity: DPPH-free radical scavenging capacity of Pigeon pea will be evaluated according to the method of Chen and Ho (1995).The percent of DPPH discoloration of the sample was calculated according to the equation percent discoloration: (A0 - (A - Ab))/ A0 X 100. The free radical scavenging activity of legume extracts is expressed as an equivalent of that of ascorbic acid. Every sample will be extracted in triplicate.Task 1.2.3. FRAP test: Determination of FRAP followed a previous study by Benzie and Strain (1996).Objective 2. Understanding physicochemical and physiological properties of protein and non-starch polysaccharides in Pigeon peaWork 2.1. Pigeon pea protein isolation and physicochemical propertiesTask 2.1.1. Protein isolation: will follow the method described by Mwasaru et al. (1999). Pigeon pea meal will be dispersed in 0.1 M NaOH (1:10 meal to solvent w/v) with pH adjusted to 12.5. The suspension will be homogenized followed by centrifugation. The protein in the supernatant will be precipitated by adjusting the pH to 4.5 followed by centrifugation to recover the protein.Task 2.1.2. Viscosity and viscoelasticity measurement: ARES-G2 Rheometer (TA Instruments USA) will be used to measure viscosity, storage and loss modulus (G' and G") as described in Dr. Wu's recent publication (Wu et al., 2015).Task 2.1.3. Emulsifying properties of protein and non-starch polysaccharides will follow Dr. Wu's protocols described in her recent publication (Wu et al., 2015).Work 2.2. Non-starch polysaccharides in Pigeon pea: physicochemical propertiesTask 2.2.1. Isolation of non-starch polysaccharides: follow the method described by Sasaki, Kohyama and Yasui (2004).Task 2.2.2. Monosaccharide composition of non-starch polysaccharides: Monosaccharide composition will be determined by dissolving the isolated non-starch polysaccharide sample into 12 M H2SO4 at 35 C for 0.5 h followed by diluting the solution to 1 M H2SO4 which will be kept at 100 C for 2 h. The hydrolyte will be diluted to appropriate concentration and analyzed by HPLC with ELSD detector for the monosaccharide composition.Task 2.2.3. Total, soluble and insoluble dietary fiber in Pigeon pea: will be determined by Megazyme Analysis Kits for total, soluble and insoluble dietary fiber. In this method proteinase, amylase, and amyloglucosidase will be used to hydrolyze protein and starch in samples. Filtration through a celite matrix will separate soluble and insoluble dietary fibersTask 2.2.4. Molecular weight of protein and polysaccharides: Size Exclusion Chromatography (SEC) equipped with a triple detector: a low angle laser light scattering detector (LALS), a differential viscometer (DP), and a refractive index detector (RI) (Viscotek 305 TDA, Malvern Instruments Ltd., Westborough, MA, USA).Work 2.3. Health benefits of whole Pigeon pea flour: Antidiabetic and intestinal health promoting effect.Task 2.3.1. Anti-diabetic effects: In vitro glycemic index: The study of in vitro glycemic index will follow the procedure described in one of Dr. Wu's publications (co-author) which has been well developed in Dr. Wu's lab for the soy polysaccharide study (Roberts, et al. 2012). In vitro inhibition of glucosidase and amylose effect: The in vitro inhibition of a-glucosydase and a-amylase will follow the method developed in Dr. Wu's lab as well (Wang et al., 2016, manuscript submitted to Food Chemistry).Task 2.3.2. Gastrointestinal health:Prebiotic effect of Pigeon pea and its fractions will be evaluated to estimate the benefit in gastrointestinal health by using the method described by Madhukumar and Muralikrishna (2010) with some modifications. Intestinal microflora (Salmonella typhimurium, Enterococcus cloacae, Escherichia coli 0157:H7, Bifidobacter longum, Lactobacillus planturum) will be used for the prebiotic activity determination studies. Turbidity will be monitored with an UV-Visible spectrophotometer at 600 nm. Resultant supernatant from Bifidobacter longum, Lactobacillus planturum will be analyzed for SCFA by a HPLC with an ELSD detector.Anti-colon cancer effects of whole Pigeon pea and its isolated fractions (protein and non-starch polysaccharides, developed food products) will be evaluated after in vitro digestion. The digesta at 4 h will be centrifuged and the supernatant will be passed through 0.2 μm sterile syringe filter. The filtrates will be evaluated for their cytotoxic activity in cancer Caco-2 cells by MTT assay (Rosa et al., 2013).Objective 3. Developing food products containing Pigeon pea and evaluate their health benefits, sensory quality, and consumer's willingness to accept the developed products.Three products, pan bread, flour tortillas, and fried noodle, will be developed using Pigeon pea as an ingredient to replace 5%, 10% and 20% of wheat flour.Work 3.1. Dough properties and product sensory evaluationTask 3.1.1. Dough propertiesDough pasting properties: Pasting properties will be studied by using Rapid-Visco-Analyzer (RVA) (RVA, Pertern) controlled by the Thermocline software (Pertern). Viscosity profiles of sample flours will be recorded using flour suspensions (20%, w/w; 28.5 g total weight) (Acevedo et al., 2013).Dough rheology: The effect of pigeon pea flour replacement of wheat flour on dough rheology during mixing will be determined by a Farinograph (Brabender Instruments Inc., Duisburg, Germany), following the AACC International Approved Method 54-21.Task 3.1.2. Sensory evaluation and consumer acceptance of flour tortillas, pan bread and instant fried noodleThe sensory evaluation will be carried out during selected community nutrition education events using the developed products. The scorecard (Chlopicka et al., 2012) will have 10-point category scale (disliked = 0; extremely liked = 10), each testers will be asked to assess the products for overall quality, based on the color, odor, consistency and taste.Experimental data will be collected and processed, then analyzed by SAS (SAS Version 9.1, SAS Institute Inc. Cary, NC). One way Analysis of Variance (ANOVA) will be used to test if treatments have different effects. If the treatment effects are significant, least significant difference (LSD) method will be used for multiple comparisons.Work 3.2. In vitro evaluation of health benefits of product supplemented with Pigeon peaTask 3.2.1. Anti-diabetes: follow the method described in Task 2.3.1.Task 3.2.2. Gastrointestinal health: follow the method described in Task 2.3.2.