May 23, Germinated Grains. Germination Phases. Germination Benefits. Starch Hydrolysates from Germinated Brown Rice

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1 Fresh weight (g)/1 seeds May 3, 18 Hydrolyzed Starch Products and Applications Starch Hydrolysates from Germinated Brown Rice Ana Gonzalez, Emily Wong, and Ya-Jane Wang Commercial Production of Starch Hydrolysates α-amylase Heat Liquefaction α-glucosidase or β-amylase Saccharifaction Germinated Grains Definition (AACCI 8) Malted or sprouted grains containing all of the original bran, germ, and endosperm shall be considered whole grains as long as sprout growth does not exceed kernel length and nutrient values have not diminished. These grains should be labeled as malted or sprouted whole grain. Fructose Sugar alcohols Isomerization Hydrogenation Glucose Maltose Maltodextrin Onset of starch degradation Germination Phases Rapid water uptake Phase I Starch hydrolysis Metabolism reactivation Phase II Amino acid biosynthesis Radicle protrusion Phase III respiration Coleoptile emergency Imbibition time (h) Germination Benefits Biotransformation from α-amylase, protease, and lipase Nutrient content Free amino acids Reducing sugars Soluble fibers Phytic acid gamma-aminobutyric acid (GABA) Sweetness Softer texture 1

2 May 3, 18 Importance of Internal Enzyme Activation Endogenous Enzymes and Hydrolyzed products α-amylase Hydrolyzed starch Amylase activated from germination can replace external enzymes to produce hydrolyzed starch products Starch β-amylase α-glucosidase Glucose Glucose syrup Maltose syrups Maltodextrins Maltose Objective Rice Samples Compare the activity of amylolytic enzymes and the composition of starch hydrolysate in germinated brown rices of varying amylose contents under aerobic and anaerobic conditions (% amylose) -grain ( 8.3% amylose) -grain (8.5% amylose) -grain (1.% amylose) Germination Conditions Incubation Mashing Germinated brown rice Ground Flour Incubation 3 C 85% RH 1,, 3 and days Moistened sponges Complete submersion Hydrolysate analysis 55 C and 75 C for h 33% (w/v) slurry Drying 3 C/ h Time (h)

3 Alpha amylase (U/g) Beta amylase (U/g) May 3, 18 Alpha-amylase Activity Starch Hydrolysates Characterization Starch hydrolysate Amount Phenol-sulfuric Acid Method Starch hydrolysate composition High-Performance Anion- Exchange Chromatography (HPAC-PAD) Radicle Development Rice -grain Rice Results -grain Rice -grain Rice Alpha-Amylase Activity Beta-Amylase Activity

4 Concentration (%) Alpha glucosidase (U/g) Concentration (%) Soluble Carbohydrate (%) -grain -grain -grain May 3, 18 Alpha-glucosidase Activity Soluble Carbohydrate (%) in the Mashes of Four Days Germinated Brown Rice 55 C 75 C Hydrolysates Composition of Four Days Germinated Brown Rice 55 C 75 C 55 C 75 C Conclusions Enzyme activity was greatly affected by cultivars with different amylose contents. Glucose and maltose were the predominant sugars, and the hydrolysate composition in mashes varied with cultivars and germination and mashing conditions. Enzyme activities were dependent on rice cultivar, but the extent of starch hydrolysis was not correlated with enzyme activities. Hydrolyzed starch composition in germinated rice was primarily affected by starch composition. Acknowledgements We thank Dr. Karen Moldenhauer for providing shortgrain rice and Bumpers College Undergraduate Research Grant for financial support.

5 May 3, 18 References Han, A., Jinn, J., Mauromoustakos, A., & Wang, Y. Effect of parboiling on milling, physicochemical, and textural properties of medium and Grain germinated brown rice. Cereal Chemistry 1;15, 93(1), 7-5. Palmiano, E.; Juliano, B. Biochemical changes in the rice grain during germination. Plant Physiology 197, 9, Moongngarm, A., & Saetung, N. Comparison of chemical compositions and bioactive compounds of germinated rough rice and brown rice. Food Chemistry 1, 1, Thank you 5