Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-27T08:25:54.359Z Has data issue: false hasContentIssue false

Identifying variation in the nutritional value of corn based on chemical kernel characteristics

Published online by Cambridge University Press:  28 June 2013

C.K. GEHRING
Affiliation:
Department of Poultry Science, Auburn University, AL 36849, USA
A.J. COWIESON
Affiliation:
Poultry Research Foundation, The Faculty of Veterinary Science, University of Sydney, Camden, NSW 2570, Australia
M.R. BEDFORD
Affiliation:
AB Vista Feed Ingredients, Marlborough, Wiltshire, SN8 4AN, United Kingdom
W.A. DOZIER III*
Affiliation:
Department of Poultry Science, Auburn University, AL 36849, USA
*
Corresponding author: bill.dozier@auburn.edu
Get access

Abstract

The metabolisable energy of corn can vary by more than 400 kcal/kg in poultry. Chemical, rather than physical kernel characteristics may be more accurate for predicting nutrient and energy availability. Factors that affect variability include genetics, agronomic conditions, proximate composition, pre- and post-harvest processing variables, and the presence of anti-nutritional factors. Variation in the nutritional value of corn may be better identified when the relationship between protein and starch are considered rather than by total content or predicted digestibility values alone. Recently, the use of near-infrared reflectance spectroscopy has made rapid valuation of corn based on chemical kernel characteristics a possibility. Prediction equations may be useful for formulating diets to more closely approximate actual metabolisable energy content for poultry.

Type
Review Article
Copyright
Copyright © World's Poultry Science Association 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

AFNOR (Association Française de Normalisation), (2008) Méthode Promatest d’évaluation de la dénaturation des proteins Thermosensibles. NF-V03-741. AFNOR, La Plaine Saint-Denis, France.Google Scholar
ALTAY, F. and GUNASEKARAN, S. (2006) Influence of drying temperature, water content, and heating rate on gelatinisation of corn starches. Journal of Agricultural and Food Chemistry 54: 4235-4245.CrossRefGoogle Scholar
ANGEL, R., TAMIM, N.M., APPLEGATE, T.J., DHANDU, A.S. and ELLESTAD, L.E. (2002) Phytic acid chemistry: influence on phytin-phosphorus availability and phytase efficacy. Journal of Applied Poultry Research 11: 471-480.CrossRefGoogle Scholar
ARRUDA, P., DA SILVA, W.J. and TEIXEIRA, J.P.F. (1978) Protein and free amino acids in a high lysine maize double mutant. Phytochemistry 17: 1217-1218.CrossRefGoogle Scholar
BARRIER-GUILLOT, B., ZUPRIZAL, , JONDREVILLE, C., CHAGNEAU, A.M., LARBIER, M. and LEUILLET, M. (1993) Effect of heat drying temperature on the nutritive value of corn in chickens and pigs. Animal Feed Science and Technology 41: 149-159.CrossRefGoogle Scholar
BENEDETTI, M.P., SARTORI, J.R., CARVALHO, F.B., PEREIRA, L.A., FASCINA, V.B., STRADIOTTI, A.C., PEZZATO, A.C., COSTA, C. and FERREIRA, J.G. (2011) Corn texture and particle size in broiler diets. Brazilian Journal of Poultry Science 13: 227-234.CrossRefGoogle Scholar
BHUIYAN, M.M., ISLAM, A.F. and IJI, P.A. (2010) Response of broiler chickens to diets containing artificially dried high-moisture maize supplemented with microbial enzymes. South African Journal of Animal Science 40: 348-362.Google Scholar
BOUNDY, J.A., WOYCHIK, J.H., DIMLER, R.J. and WALL, J.S. (1967) Protein composition of dent, waxy, and high-amylose corns. Cereal Chemistry 44: 160-169.Google Scholar
BRADFORD, M.M. (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 72: 248-254.CrossRefGoogle ScholarPubMed
BRAKE, J., FAUST, M. and STEIN, J. (2003) Evaluation of transgenic event Bt11 hybrid corn in broiler chickens. Poultry Science 82: 551-559.CrossRefGoogle ScholarPubMed
BRAKE, J. and VLACHOS, D. (1998) Evaluation of transgenic event 176 “Bt” corn in broiler chickens. Poultry Science 77: 648-653.CrossRefGoogle ScholarPubMed
BRESSANI, R. and CONDE, R. (1961) Changes in the chemical composition and in the distribution of nitrogen of maize at different stages of development. Cereal Chemistry 38: 76-84.Google Scholar
CARVALHO, D.C.O., ALBINO, L.F.T., JrDE VARGAS, J.G., TOLEDO, R.S., DE OLIVIERA, J.E. and DE SOUZA, R.M. (2009) True digestibility of amino acids and digestible amino acids values of corn samples submitted to different drying temperatures and storage periods. Revista Brasileira de Zootecnia 38: 850-856.CrossRefGoogle Scholar
CLASSEN, H.L., MAENZ, D.D. and CARUTHERS, C. (2010) Ingredient considerations, total phytate concentrations and susceptibility of phytate to hydrolysis. Proceedings of the 1st International Phytase Summit, pp. 173-177 (Washington D.C., U.S.)Google Scholar
COLLINS, N.E., JrMORAN, E.T. and STILBORN, H.L. (2001) Influence of yellow dent corn hybrids having different kernel characteristics yet similar nutrient composition on broiler production. Journal of Applied Poultry Research 10: 228-235.CrossRefGoogle Scholar
COWIESON, A.J. (2005) Factors that affect the nutritional value of maize for broilers. Animal Feed Science and Technology 119: 293-305.CrossRefGoogle Scholar
COWIESON, A.J. (2010) Corn nutritional value, composition analyzed. Feedstuffs 7: 30-32.Google Scholar
COWIESON, A.J., ACAMOVIC, T. and BEDFORD, M.R. (2004a) The effect of phytic acid and phytase on the digestibility of maize starch for growing chickens. International Poultry Scientific Forum, Atlanta, Georgia, USA, (Abst.): p. 31.Google Scholar
COWIESON, A.J., ACAMOVIC, T. and BEDFORD, M.R. (2004b) The effects of phytase and phytic acid on the loss of endogenous amino acids and minerals from broiler chickens. British Poultry Science 45: 101-108.CrossRefGoogle ScholarPubMed
COWIESON, A.J. and COWIESON, N.P. (2011) Phytate and the thermodynamics of water. Proceedings of the Australian Poultry Science Symposium, Sydney, New South Wales, February 14-16.Google Scholar
CROMWELL, G.L., BITZER, M.J., STAHLY, T.S. and JOHNSON, T.H. (1983) Effects of soil nitrogen fertility on the protein and lysine content and nutritional value of normal and opaque-2 corn. Journal of Animal Science 57: 1345-1351.CrossRefGoogle Scholar
DALE, N. (1994) Relationship between bushel weight, metabolizable energy, and protein content of corn from an adverse growing season. Journal of Applied Poultry Research 3: 83-86.CrossRefGoogle Scholar
DELCURTO, T., COCHRAN, R.C., HARMON, D.L., BEHARKA, A.A., JACQUES, K.A., TOWNE, G. and VANZANT, E.S. (1990) Supplementation of dormant tallgrass-prairie forage: I. Influence of varying supplemental protein and (or) energy levels on forage utilisation characteristics of beef steers in confinement. Journal of Animal Science 68: 515-531.CrossRefGoogle ScholarPubMed
DETURK, E.E., HOLBERT, J.R. and HOWK, B.W. (1933) Chemical transformations of phosphorus in the growing corn plant with results on two first generation crosses. Journal of Agricultural Research 46: 121-141.Google Scholar
DOMBRINK-KURTZMAN, M.A. and BIETZ, J.A. (1993) Zein composition in hard and soft endosperm of maize. Cereal Chemistry 70: 105-108.Google Scholar
DUVICK, D.N. (1961) Protein granules of maize endosperm cells. Cereal Chemistry 38: 374-385.Google Scholar
EARL, F.R., CURTIS, J.J. and HUBBARD, J.E. (1946) Composition of the component parts of the corn kernel. Cereal Chemistry 77: 721-723.Google Scholar
EARLY, E.B. and DETURK, E.E. (1944) Time and rate of synthesis of phytin in corn grain during the reproductive period. Journal of the American Society of Agronomy 36: 803-814.CrossRefGoogle Scholar
EVERTS, H., DEKKER, R.A., SMITS, B. and CONE, J.W. (1996) The digestion of maize and native pea starch in the small intestine of pigs. Proceedings of the Nutrition Society 55: 59A.Google Scholar
FRENCH, R.C. and KINGSOLVER, C.H. (1964) The effect of excessive heat during artificial drying of corn on reducing sugar content and diastatic activity. Cereal Chemistry 41: 47-58.Google Scholar
GEHRING, C.K., BEDFORD, M.R., COWIESON, A.J., DOZIER, W.A. and III., (2012) Effects of corn source on the relationship between in vitro assays and ileal nutrient digestibility. Poultry Science 91: 1908-1914.CrossRefGoogle ScholarPubMed
GILLIS, M.B., KEANE, K.W. and COLLINS, R.A. (1957) Comparative metababolism of phytate and inorganic P32 by chicks and poults. The Journal of Nutrition 62: 13-26.CrossRefGoogle ScholarPubMed
GOUGH, B.M. and PYBUS, J.N. (1971) Effect on the gelatinisation temperature of wheat starch granules of prolonged treatment with water at 50° C. Starch-Stärke 23: 210-212.CrossRefGoogle Scholar
GRBESA, , D, and KIŠ, G. (2005) Relation between endosperm and in vitro kinetic of starch digestibility in maize hybrids for broiler chickens. Italian Journal of Animal Science 4(Suppl. 3): 139-141.CrossRefGoogle Scholar
HAMILTON, T.S., HAMILTON, B.C., CONNOR JOHNSON, B. and MITCHELL, H.H. (1951) The dependence of the physical and chemical composition of the corn kernel on soil fertility and cropping system. Cereal Chemistry 28: 161-176.Google Scholar
HELDT, J.S., COCHRAN, R.C., MATHIS, C.P., WOODS, B.C., OLSON, K.C., TITGEMEYER, E.C., NAGARAJA, T.G., VANZANT, E.S. and JOHNSON, D.E. (1999) Effects of level and source of carbohydrate and level of degradable intake protein on intake and digestion of low quality tall grass-prairie hay by beef steers. Journal of Animal Science 77: 2846-2854.CrossRefGoogle Scholar
HOLM, J., LUNDQUIST, I., BJÖRCK, I., ELIASSON, A.-C. and ASP, N.-G. (1988) Degree of starch gelatinisation, digestion rate of starch in vitro, and metabolic response in rats. The American Journal of Clinical Nutrition 47: 1010-1016.CrossRefGoogle Scholar
JACOBS, C.M., UTTERBACK, P.L., PARSONS, C.M., RICE, D., SMITH, B., HINDS, M., LIEBERGESELL, M. and SAUBER, T. (2008) Performance of laying hens fed diets containing DAS-59122-7 maize grain compared with diets containing nontransgenic maize grain. Poultry Science 87: 475-479.CrossRefGoogle ScholarPubMed
JANG, D.A., FADEL, J.G., KLASING, K.C., Jr.MIRELES, A.J., ERNST, R.A., YOUNG, K.A., COOK, A. and RABOY, V. (2003) Evaluation of low-phytate corn and barley on broiler chick performance. Poultry Science 82: 1914-1924.CrossRefGoogle ScholarPubMed
KACZMAREK, S., COWIESON, A.J., JÓZEFIAK, D., BOCHENEK, M. and RUTKOWSKI, A. (2007) The effect of drying temperature and exogenous enzymes supplementation on the nutritional value of maize for broiler chickens. Proceedings of the 16th European Symposium on Poultry Nutrition, Strasbourg, France, pp. 555-558.Google Scholar
KATO, R.K., BERTECHINI, A.G., FASSANI, E.J., GONCALVES DE BRITO, J.A. and CASTRO, S.F. (2011) Metabolizable energy of corn hybrids for broiler chickens at different ages. Ciência e Agrotecnologia 35: 1218-1226.CrossRefGoogle Scholar
LASSERAN, J.C. (1973) Incidence of drying and storing conditions of corn (maize) on its quality for starch industry. Starch 25: 257-262.CrossRefGoogle Scholar
LEESON, S., YERSIN, A. and VOLKER, L. (1993) Nutritive value of the 1992 corn crop. Journal of Applied Poultry Research 2: 208-213.CrossRefGoogle Scholar
LI, T.-J., DAI, Q.-Z., LIN, Y.-L., ZHANG, J., HUANG, R.-L., RUAN, Z., DENG, Z. and XIE, M. (2008) Dietary starch sources affect net portal appearance of amino acids and glucose in growing pigs. Animal 2: 723-729.CrossRefGoogle ScholarPubMed
LI, Y.C., LEDOUX, D.R., VEUM, T.L., RABOY, V. and ERTL, D.S. (2000) Effects of low phytic acid corn on phosphorus utilisation, performance, and bone mineralization in broiler chicks. Poultry Science 79: 1444-1450.CrossRefGoogle ScholarPubMed
LIU, N., RU, Y.J., LI, F.D. and COWIESON, A.J. (2008) Effect of diet containing phytate and phytase on the activity and messenger ribonucleic acid expression of carbohydrase and transporter in chickens. Journal of Animal Science 86: 3432-3439.CrossRefGoogle ScholarPubMed
MAGA, J.A. (1982) Phytate: its chemistry, occurrence, food interactions, nutritional significance, and methods of analysis. Journal of Agricultural and Food Chemistry 30: 1-9.CrossRefGoogle Scholar
MALUMBA, P., JANAS, S., MASIMANGO, T., SINDIC, M., DEROANNE, C. and BÉRA, F. (2009) Influence of drying temperature on the wet-milling performance and the proteins solubility indexes of corn kernels. Journal of Food Engineering 95: 393-399.CrossRefGoogle Scholar
MÉTAYER, J.P., DEBICKI-GARNIER, A.-M. and SKIBA, F. (2009) Le Promatest: un bon indicateur de la qualite du sechage et de la valeur alimentaire du mäis grain chez les volailles. Huitièmes Journées de la Recherche Avicole, St Malo, March 25-26.Google Scholar
MITCHELL, H.H., HAMILTON, T.S. and BEADLES, J.R. (1952) The relationship between protein content of corn and the nutritional value of the protein. Journal of Nutrition 48: 461-476.CrossRefGoogle ScholarPubMed
MOORE, S.M., STALDER, K.J., BEITZ, D.C., STAHL, C.H., FITHIAN, W.A. and BREGENDAHL, K. (2008) The correlation of chemical and physical corn kernel traits with production performance in broiler chickens and laying hens. Poultry Science 87: 665-676.CrossRefGoogle ScholarPubMed
Jr.MORAN, E.T. (1982) Starch digestion in fowl. Poultry Science 61: 1257-1267.CrossRefGoogle ScholarPubMed
Jr.MORAN, E.T. (1985) Digestion and absorption of carbohydrates in fowl and events through perinatal development. Journal of Nutrition 115: 665-674.CrossRefGoogle ScholarPubMed
MORITZ, J.S., CRAMER, K.R., WILSON, K.J. and BEYER, R.S. (2003) Feed manufacture and feeding of rations with graded levels of added moisture formulated at different energy densities. Journal of Applied Poultry Research 12: 371-381.CrossRefGoogle Scholar
MOURAD, M., HEMATI, M. and LAGUERIE, C. (1996) Kinetic study and modeling of the degradation of the maize kernels quality during drying in fluidized bed. Drying Technology 14: 2307-2337.CrossRefGoogle Scholar
NAUCK, M.A., NIEDEREICHHOLZ, U., ETTLER, R., HOLST, J.J., ØRSKOV, C., RITZEL, R. and SCHMIEGEL, W.H. (1997) Glucagon-like peptide 1 inhibition of gastric emptying outweighs its insulinotropic effects in healthy humans. American Journal of Physiology – Endocrinology and Metabolism 273: E981-E988.CrossRefGoogle ScholarPubMed
NGONYAMO-MAJEE, D., SHAVER, R.D., COORS, J.G., SAPIENZA, D., CORREA, C.E.S., LAUER, J.G. and BERZAGHI, P. (2008) Relationships between kernel vitreousness and dry matter degradability for diverse corn germplasm I. Development of near-infrared reflectance spectroscopy calabrations. Animal Feed Science and Technology 142: 247-258.CrossRefGoogle Scholar
O'DELL, B.L., DE BOLAND, A.R. and KOIRTYOHANN, S.R. (1972) Distribution of phytate and nutritionally important elements among the morphological components of cereal grains. Journal of Agricultural and Food Chemistry 20: 718-721.CrossRefGoogle Scholar
ODJO, S., MALUMBA, P., DOSSOU, J., JANAS, S. and BÉRA, F. (2012) Influence of drying and hydrothermal treatment of corn on the denaturation of salt-soluble proteins and color parameters. Journal of Food Engineering 109: 561-570.CrossRefGoogle Scholar
O'NEILL, H.V.M., LIU, N., WANG, J.P., DIALLO, A. and HILL, S. (2012) Effect of xylanase on performance and apparent metabolisable energy in starter broilers fed diets containing one maize variety harvested in different regions of china. Asian-Australian Journal of Animal Science 25: 515-523.CrossRefGoogle Scholar
PAIVA, E., KRIZ, A.L., PEIXOTO, M.J., WALLACE, J.C. and LARKINS, B.A. (1991) Quantitation and distribution of γ-zein in the endosperm of maize kernels. Cereal Chemistry 68: 276-279.Google Scholar
PAULLAF, J. and RIMBACH, G. (1997) Nutritional significance of phytic acid and phytase. Archives of Animal Nutrition 50: 301-319.Google Scholar
PEPLINSKI, A.J., PAULIS, J.W., BIETZ, J.A. and PRATT, R.C. (1994) Drying of high-moisture corn: Changes in properties and physical quality. Cereal Chemistry 71: 129-133.Google Scholar
PHILIPPEAU, C., LE DESCHAULT DE MONREDON, F. and MICHALET-DOREAU, B. (1999) Relationship between ruminal starch degradation and the physical characteristics of corn grain. Journal of Animal Science 77: 238-243.CrossRefGoogle ScholarPubMed
PONTOPPIDAN, K., PETTERSSON, D. and SANDBERG, A.-S. (2007) The type of thermal feed treatment influences the inositol phosphate composition. Animal Feed Science and Technology 132: 137-147.CrossRefGoogle Scholar
RERAT, A.A. (1985) Intestinal absorption of end products of digestion of carbohydrates and proteins in the pig. Archiv für Tierernährung 35: 561-580.CrossRefGoogle ScholarPubMed
RIVERA, P.H., Jr.PEO, E.R., FLOWERDAY, D., CRENSHAW, T.D., MOSER, B.D. and CUNNINGHAM. P.J., (1978a) Effect of maturity and drying temperature on nutritional quality and amino acid availability of normal and opaque-2 corn for rats and swine. Journal of Animal Science 46: 1024-1036.CrossRefGoogle Scholar
RIVERA, P.H., Jr.PEO, E.R., MOSER, B.D., CRENSHAW, T. and CUNNINGHAM, P.J. (1978b) Effect of drying temperature on nutritional quality and availability of amino acids in normal and opaque-2 corn for rats. Journal of Animal Science 46: 1275-1286.CrossRefGoogle Scholar
ROONEY, L.W. and PFLUGFELDER, R.L. (1986) Factors affecting starch digestibility with special emphasis on sorghum and corn. Journal of Animal Science 63: 1607-1623.CrossRefGoogle ScholarPubMed
SKOCH, E.R., BEHNKE, K.C., DEYOE, C.W. and BINDER, S.F. (1981) The effect of steam-conditioning rate on the pelleting process. Animal Feed Science and Technology 6: 83-90.CrossRefGoogle Scholar
SUMMERS, J.D. (2001) Maize: Factors affecting its digestibility and variability in its feeding value, in: BEDFORD, M.R. & PARTRIDGE, G.G. (Eds) Enzymes in Farm Animal Nutrition, pp. 109-124 (CABI, New York, NY).Google Scholar
SUZUKI, T., NAKAYA, M., ITOH, Z., TATEMOTO, K. and MUTT, V. (1983) Inhibition of interdigestive contractile activity in the stomach by peptide YY in Heidenhain pouch dogs. Gastroenterology 85: 114-121.CrossRefGoogle ScholarPubMed
TATEMOTO, K., CARLQUIST, M. and MUTT, V. (1982) Neuropeptide Y–a novel brain peptide with structural similarities to peptide YY, and pancreatic polypeptide. Nature 296: 659-660.CrossRefGoogle ScholarPubMed
TAYLOR, M.L., HARTNELL, G.F., RIORDAN, S.G., NEMETH, M.A., KARUNANANDAA, K., GEORGE, B. and ASTWOOD, J.D. (2003a) Comparison of broiler performance when fed diets containing grain from Roundup Ready (NK603), YieldGard × Roundup Ready (MON810 × NK603), non-transgenic control, or commercial corn. Poultry Science 82: 443-453.CrossRefGoogle ScholarPubMed
TAYLOR, M.L., HYUN, Y., HARTNELL, G.F., RIORDAN, S.G., NEMETH, M.A., KARUNANANDAA, K., GEORGE, B. and ASTWOOD, J.D. (2003b) Comparison of broiler performance when fed diets containing grain from YieldGard Rootworm (MON863), YieldGard Plus (MON810 × MON863), nontransgenic control, or commercial reference corn hybrids. Poultry Science 82: 1948-1956.CrossRefGoogle ScholarPubMed
TESTER, R.F. and DEBON, S.J.J. (1999) Annealing of starch – a review. International Journal of Biological Macromolecules 27: 1-12.CrossRefGoogle Scholar
USDA (United States Department of Agriculture), (2004) Grain Inspection Handbook-Book II: Grain Grading Procedures. Federal Grain Inspection Service, USDA, Washington, DC.Google Scholar
VAN DER MEULEN, J., BAKKER, J.G.M., SMITS, B. and DE VISSER, H. (1997) Effect of source of starch on net portal flux of glucose, lactate, volatile fatty acids and amino acids in the pig. British Journal of Nutrition 78: 533-544.CrossRefGoogle ScholarPubMed
WALKER, G.J. and HOPE, P.M. (1963) The action of some alpha-amylases on starch granules. Biochemical Journal 86: 452-462.CrossRefGoogle ScholarPubMed
WALL, J.S., JAMES, C. and DONALDSON, G.L. (1975) Corn proteins: Chemical and physical changes during drying of grain. Cereal Chemistry 52: 779-790.Google Scholar
WANG, Z.-H., LI, S.-X. and MALHI, S. (2008) Effects of fertilization and other agronomic measures on nutritional quality of crops. Journal of the Science of Food and Agriculture 88: 7-23.CrossRefGoogle Scholar
WEURDING, R.E., VELDMAN, A., VEEN, W.A.G., VAN DER AAR, P.J. and VERSTEGEN, M.W.A. (2001) Starch digestion rate in the small intestine of broiler chickens differs among feedstuffs. Journal of Nutrition 131: 2329-2335.CrossRefGoogle ScholarPubMed
WEURDING, R.E., ENTING, H. and VERSTEGEN, M.A. (2003) The relation between starch digestion rate and amino acid level for broiler chickens. Poultry Science 82: 279-284.CrossRefGoogle ScholarPubMed
WHISTLER, R.L. and THORNBURG, W.L. (1957) Development of starch granules in corn endosperm. Journal of Agricultural and Food Chemistry 5: 203-207.CrossRefGoogle Scholar
WILSON, C.M. (1987) Proteins of the kernel, in: WATSON, S.A. & RAMSTEAD, P.E. (Eds) Corn Chemistry and Technology, pp. 273-277 (American Association of Cereal Chemists, St. Paul, MN).Google Scholar
WISEMAN, J., NICOL, N.T. and NORTON, G. (2000) Relationship between apparent metabolisable (ame) values and in vivo/in vitro starch digestibility of wheat for broilers. World's Poultry Science Journal 56: 1-14.CrossRefGoogle Scholar
WOLF, M.J., KHOO, U. and SECKINGER, H.L. (1967) Subcellular structure of endosperm protein in high-lysine and normal corn. Science 157: 556-557.CrossRefGoogle ScholarPubMed
WÜRSCH, P. (1986) Cell structure and starch nature as key determinants of the digestion rate of starch in legume. American Journal of Clinical Nutrition 43: 25-29.CrossRefGoogle ScholarPubMed
YOON, J.H., THOMPSON, L.U. and JENKINS, D.J.A. (1983) The effect of phytic acid on in vitro rate of starch digestibility and blood glucose response. American Journal of Clinical Nutrition 38: 835-852.CrossRefGoogle ScholarPubMed