Sains Malaysiana 46(5)(2017): 713–718

http://dx.doi.org/10.17576/jsm-2017-4605-05

 

Molecular Weight, Solubility and Viscosity of Β-Glucan Preparations from Barley Pearling Byproducts

(Berat Molekul, Keterlarutan dan Kelikatan Persediaan Β-Glukan daripada Hasil Sampingan Hampas Barli)

 

YOUNG-TACK LEE^1*, PRADEEP PULIGUNDLA¹ & PAUL B. SCHWARZ²

 

¹Department of Food Science and Biotechnology, Gachon University, Seongnam 13120

Korea

 

²Department of Plant Sciences, North Dakota State University, Fargo, ND 58108-6050 USA

 

Received: 29 October 2015/Accepted: 17 October 2016

 

ABSTRACT

β-Glucan, the representative dietary fibre component of barley, has received much attention, primarily due to its nutritional significance. In this study, β-glucans prepared from barley pearling byproducts were characterized with respect to their molecular weight, solubility and viscosity. Following the initial alkaline extraction, the crude β-glucan extract (45% purity) was further purified to approximately 90%. The isolated β-glucans exhibited a wide molecular weight range with peak molecular weight of less than 1 × 106 daltons. Solubilities of crude and purified β-glucans in water were lower than that of β-glucan in the native barley pearling byproducts. However, the aqueous solubility of purified β-glucan from pearlings was substantially higher than that of commercial β-glucan. Compared to the latter, purified β-glucan exhibited low apparent viscosity in aqueous solutions.

 

Keywords: Barley; β-glucan; molecular weight distribution; pearling byproduct; solubility; viscosity

 

ABSTRAK

β-Glukan, komponen wakil serabut diet barli telah mendapat banyak perhatian, terutamanya disebabkan oleh kepentingan pemakanan. Dalam kajian ini, β-glukan yang disediakan daripada hasil sampingan hampas barli telah dicirikan dengan berat molekul, keterlarutan dan kelikatan. Mengikut pengekstrakan beralkali asal, ekstrak mentah β-glukan (45% ketulenan) telah dimurnikan lagi sehingga 90%. β-glukan yang dipencilkan mempamerkan pelbagai julat berat molekul dengan puncak berat molekul kurang daripada 1 × 106 dalton. Keterlarutan β-glukan mentah dan tulen dalam air adalah lebih rendah daripada β-glukan dalam bahan sampingan hampas barli asli. Walau bagaimanapun, kebolehlarutan akueus β-glukan tulen daripada hampas adalah tinggi daripada β-glukan komersial. Berbanding dengan kedua, β-glukan tulen menunjukkan kelikatan yang rendah dalam larutan akueus.

 

Kata kunci: Barli; β-glukan; hasil sampingan hampas barli; kelikatan; keterlarutan; pengagihan berat molekul

 

REFERENCES

AACC. 2000. Approved Methods of the AACC. 10th ed. St. Paul, MN: American Association of Cereal Chemists.

Aman, P. & Graham, H. 1987. Mixed-linked β-(1→3), (1→4)-D-glucans in the cell walls of barley and oats-chemistry and nutrition. Scandinavian Journal of Gastroenterology 22: 47-51.

Bacic, A. & Stone, B.A. 1981. Chemistry and organization of aleurone cell wall components from wheat and barley. Australian Journal of Plant Physiology 8: 475-495.

Beer, M.U., Wood, P.J., Weisz, J. & Fillion, N. 1997. Effect of cooking and storage on the amount and molecular weight of (1→3), (1→4)-β-D-glucan extracted from oat products by an in vitro digestion system. Cereal Chemistry 74: 705-709.

Bhatty, R.S. 1997. Milling of regular and waxy starch hull-less barley for the production of bran and flour. Cereal Chemistry 74: 693-699.

Bhatty, R.S. 1993. Extraction and enrichment of (1→3), (1→4)-β-D-glucan from barley and oat brans. Cereal Chemistry 70: 73-77.

Forrest, I.S. & Wainwright, T. 1977. The mode of binding of β-glucans and pentosans in barley endosperm cell walls. Journal of the Institute of Brewing 83: 279-286.

Gaosong, J. & Vasanthan, T. 2000. Effect of extrusion cooking on the primary structure and water solubility of beta-glucans from regular and waxy barley. Cereal Chemistry 77: 396-400.

Izydorczyk, M.S. & Dexter, J.E. 2008. Barley β-glucans and arabinoxylans: Molecular structure, physicochemical properties, and uses in food products-a Review. Food Research International 41: 850-868.

Izydorczyk, M.S., Storsley, J., Labossiere, D., MacGregor, A.W. & Rossnagel, B.G. 2000. Variation in total and soluble β-glucan content in hulless barley: Effects of thermal, physical, and enzymatic treatments. Journal of Agricultural and Food Chemistry 48: 982-989.

Kahlon, T.S. & Chow, F.I. 1997. Hypocholesterolemic effects of oat, rice, and barley dietary fibers and fractions. Cereal Food World 42: 86-92.

Lazaridou, A., Biliaderis, C.G. & Izydorczyk, M.S. 2007. Cereal β-glucans: Structures, physical properties, and physiological functions. In Functional Food Carbohydrates, edited by Biliaderis, C.G. & Izydorczyk, M.S. Boca Raton: CRC Press, Taylor & Francis Group. pp. 1-72.

Lee, Y.T. 1992. β-Glucans from hull-less barley: Isolation, chemical and rheological characterization and utilization as a food gum. PhD. dissertation, North Dakota State Univ., USA (Unpublished).

Li, J., Kaneko, T., Qin, L.Q., Wang, J. & Wang, Y. 2003. Effects of barley intake on glucose tolerance, lipid metabolism, and bowel function in women. Nutrition 19: 11-12.

McCleary, B.V. 1988. Purification of (1→3), (1→4)-β-D-glucan from barley flour. In Methods in Enzymology, edited by Wood, W.A. & Kellogg, S.T. San Diego: Academic Press. 160: 511-514.

McCleary, B.V. & Glennie-Holmes, M. 1985. Enzymatic quantification of (1→3), (1→4)-β-D-glucan in barley and malt. Journal of the Institute of Brewing 91: 285-295.

Miller, S.S. & Fulcher, R.G. 1994. Distribution of (1→3), (1→4)-β-D-glucan in kernels of oat and barley using microspectroflourometry. Cereal Chemistry 71: 64-68.

Newman, R.K., Newman, C.W., Fadel, J. & Graham, H. 1987. Nutritional implications of beta-glucans in barley. Barley Genetics V: 773-780.

Oscarsson, M., Parkkonen, T., Autio, K. & Aman, P. 1997. Composition and microstructure of normal, waxy and high-amylose barley samples. Journal of Cereal Science 26: 259-264.

Panfili, G., Fratianni, A., Criscio, T.D. & Marconi, E. 2008. Tocol and β-glucan levels in barley varieties and in pearling by-products. Food Chemistry 107: 84-91.

Prosky, L., Asp, N., Sweizer, T.F., Devries, J. & Furda, I. 1988. Determination of insoluble, soluble, and total dietary fiber in foods and food products: Interlaboratory study. Journal of the Association of Official Analytical Chemists 71: 1017-1023.

Rimsten, L., Haraldsson, A.K., Andersson, R., Alminger, M., Sandberg, A.S. & Aman, P. 2003. Effects of malting on β-glucanase and phytase activity in barley grain. Journal of the Science of Food and Agriculture 82: 904-912.

Seog, H.M., Seo, M.S., Kim, Y.S. & Lee, Y.T. 2002. Physicochemical properties of barley bran, germ and broken kernel as pearling by-products. Food Science and Biotechnology 11: 623-627.

Tamagawa, K., Iizuka, S., Fukushima, S., Endo, Y. & Komiyama, Y. 1997. Antioxidative activity of polyphenol extracts from barley bran. Nippon Shokuhin Kagaku Kogaku Kaishi 44: 512-515.

Vaikousi, H., Biliaderis, C.G. & Izydorczyk, M.S. 2004. Solution flow behavior and gelling properties of water-soluble barley (1→3, 1→4)-β-glucans varying in molecular size. Journal of Cereal Science 39: 119-137.

Wang, L., Xue, Q., Newman, R.K. & Newman, C.W. 1993. Enrichment of tocopherols, tocotrienols, and oil in barley fractions by milling and pearling. Cereal Chemistry 70: 499-501.

Wood, P.J., Braaten, J.T., Scott, F.W., Riedel, D. & Poste, L.M. 1990. Comparisons of viscous properties of oat and guar gum and the effects of these and oat bran on glycemic index. Journal of Agricultural and Food Chemistry 38: 753-757.

Wood, P.J., Braaten, J.T., Scott, F.W., Riedel, K.D., Wolynetz, M.S. & Collins, M.W. 1994. Effect of dose and modification of viscous properties of oat gum on blood glucose and insulin following an oral glucose load. British Journal of Nutrition 72: 731-743.

Wood, P.J., Weisz, J. & Blackwell, B.A. 1991. Molecular characterization of cereal β-D-glucans. Structural analysis of oat β-D-glucan and rapid structural evaluation of β-D-glucans from different sources by high performance liquid chromatography of oligosaccharides released by lichenase. Cereal Chemistry 68: 31-39.

Woodward, J.R., Phillips, D.R. & Fincher, G.B. 1988. Water-soluble (1→3, 1→4)-β-D-glucans from barley (Hordeum vulgare) endosperm. IV. Comparison of 40 and 65°C soluble fractions. Carbohydrate Polymers 8: 85-97.

Woodward, J.R., Fincher, G.B. & Stone, B.A. 1983. Water-soluble (l→3), (1→4)-β-D-glucans from barley (Hordeum vulgare) endosperm. II. Fine structure. Carbohydrate Polymers 3: 207-225.

Wood, P.J., Paton, D. & Siddiqui, I.R. 1977. Determination of β-glucan in oats and barley. Cereal Chemistry 54: 524-533.

York, W.S., Darvill, A.G., McNell, M., Stevenson, T. & Albersheim, P. 1986. Isolation and characterization of plant cell walls and cell wall components. In Methods in Enzymology, edited by Weissbach, A. & Weissbach, H. New York: Academic Press, Inc. 118: 3-41.

Zheng, G.H., Rossnagel, B.G., Tyler, R.T. & Bhatty, R.S. 2000. Distribution of β-glucans in the grain of hull-less barley. Cereal Chemistry 77: 140-144.

 

 

*Corresponding author; email: ytlee@gachon.ac.kr