Location: Small Grain and Food Crops Quality Research
Project Number: 3060-21650-002-046-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2023
End Date: Dec 31, 2025
Objective:
(1) To determine the effects of processing on composition (lipid, phenolic antioxidants, flavonoids, proteins, peptides and fiber) of raw or cooked pulses (pinto beans, black beans, green peas, chickpeas, and lentils); (2) To evaluate the impact of analytical methodologies, sample preparation, processing, and post-harvest storage and cooking process on determining the fiber content in pulses; and (3) To optimize, identify and determine the role of lactic acid fermentation of pinto beans, black beans, green peas, chickpeas, and lentils on the biological mechanisms and impact on markers of type-2 diabetes prevention.
Approach:
For Objective 1, the influence of storage conditions (ambient vs. freezing) after cooking on retrogradation of starches will be studied. The influence of particle size on fiber content, along with different fractions from whole grain will also be analyzed. Samples will be ground and extracted with solvents of varying polarity to maximize the extraction of different metabolites including lipids, phenolic antioxidants, and flavonoids. Metabolite fingerprints will be acquired for aqueous methanol extracts of raw and processed pulses using ultra-high-performance liquid chromatography-high resolution high accuracy/tandem mass spectrometry (UHPLC-HRAM/MS). Secondary metabolites will be isolated and identified using LC-HRMS coupled with a variety of diode-array and mass detectors. Results will be linked to changes in the nutrient profile in raw and processed pulses. For Objective 2, we will analyze dietary fiber using a semi-automated Ankom fiber analyzer to increase the analysis rate. This allows the separation of three fractions: insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and soluble dietary fiber solubles (SDFS). We plan to perform several modifications for the digestion to investigate the influence of temperature and enzyme content to evaluate the ruggedness of the optimized method. To understand the limitation associated with resistant starch analysis, we plan to determine the resistant starch analysis with AOAC 2002.02 methods for the limited number containing a higher quantity of resistant starch. For dietary fiber analysis, we will do a linkage analysis of IDF and SDF fractions using a modified permethylation procedure. The structures of different fractions will be assayed by different spectroscopic or microscopic techniques to see if spectral fingerprints can distinguished between different processed samples. For Objective 3, a response surface methodology will be used to determine the optimal conditions to ferment pulses. As response variables, dipeptidyl peptidase-IV and alpha-glucosidase will be used for the optimization process. The enzymatic activities for the optimization will be evaluated using luminescence or UV spectrophotometry based methods in microplates. In vitro antidiabetic potential of processed pulses will be assessed using simulated absorption in a cell culture system. Protein and gene expression levels of markers of insulin-related pathways and glucose transporter GLUT4, membrane translocation, and glucose uptake in cultured cells will be evaluated.
