THESIS

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(O’Dea et al. 1981, Jenkins et al. 1982, Bornet et al. 1989, Granfeldt et al. 1992 and Englyst et al. 2003). The rate and extent of starch digestion is influenced by many intrinsic food factors. Starch consists of two glucose polymers; amylose amylopectin. The physical arrangement of amylose and amylopectin in food and their interaction and/or interconnection with other food component (protein, lipids and fibre) determine the physicochemical and functional properties of starch and is susceptibility to amylolytic enzymes, and thus its bioavailability. Hydroyhermic food processing has a major impact on starch availability (Bjorck, 2000). The arrangement of starch components changes continuously under the influence of hydrothermic parameters during both food processing and storage. 6.3.2 The role of starch sources and starch granule on low GI food Common food starch is derived from seed (wheat, maize rice, barley), roots (potatoes, cassava) and legumes (pea, lentils, mungbeen). Native starch in granule form is insoluble in cold water. Its microcrystalline structure gives rise to a characteristic polarization cross under polarized light. Under dry heat conditions, starch granules are not disrupted and the polarization cross remains unchanged. Native starch granules are slowly attacked by salivary and pancreatic amylases. Mechanical processes cause fissures to appear on the surface increase the susceptibility of starch to α- amylase (Bjorck and Asp, 1984). 6.3.3 The role of gelatinized starch on low GI food Starch is usually eaten after an initial gelatinization step. Dramatic changes occur in the structure of the starch granule when it is heated in the presence of water are descried in above topic (2.4). Amylose content is not a discriminate indicator of α- amylase susceptibility when starch is native (Bornet et al. 1989). Tuber starches are highly resistant to amylase despite their low amylose content. However, after gelatinization, amylose content becomes an important factor in determining α- amylase susceptibility. It is explained by the marked tendency of high amylose content starch to produce hard gels, retrograded amylose and amylose lipid 65
complexes. In the meantime, and inverse relationship appears between amylose content and the degree of glycemic response to processed starchy food (Bornet et al. 1989, Granfeldt et al. 1995). 6.3.4 The role of starch gel and retrograded starch on low GI food As temperature decreases, a gel forms progressively under the action of the system and consists of the remaining wrapping of the starch granules (ghost systems) enriched in amylopectin, following immersion in high amylose content; this is called the gelification step. A rearrangement between starches occurs and a threedimensional network is rapidly constituted. The higher the amylose content of starch had a harder the starch gel. The starch gel structure has lower α- amylase susceptibility than a paste (Eliasson, 1980). As starch chain rearranges, hydrogen bonds between chains reappear and a novel crystalline structure is created; this is referred to as the retrograded phenomenon. Over time, starch gel retrogradation increases. It is the more marked if the gelatinization of the starch has been conducted well, such as at high temperature, with high moisture and under prolonged and effective stirring. The other factors that promote retrogradation are high amylose content, low starch gel moisture and low storage temperature (4°C). Retrogradation is delayed when mono-or glycerides are added, whereas all the preventing dehydration of starch gel encourages its retrogradation. The crystalline structure of retrograded amylose is acid and heat- resistant. Its melting-point is above 120°C. In vitro, the retrograded starch and retrograded amylose fraction are highly resistant to α- amylase. This resistant starch fraction is resistant to amylase digestion in the human digestive tract and exhibits digestive behavior similar to that of the non-starchy polysaccharide fraction (NSP) or indigestible oligosaccharides (Fan and Marks, 1999). 66
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THESIS ENZYME-RESISTANT STARCH TYPE
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ACKNOWLEDGEMENTS I wish to express
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LIST OF TABLES Table Page 1 Classif
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LIST OF TABLES (Continued) Table Pa
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LIST OF FIGURES (Continued) Figure
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LIST OF FIGURES (Continued) Appendi
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LIST OF ABBREVIATIONS (Continued) R
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een used to produce a sample with l
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Overall objectives: OBJECTIVES 1. T
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However, it was discovered that a r
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Cassidy et al. (1994), in an intern
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fed both the 45 and 63g/100g rice s
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only about 3 g. The physiological b
Page 29 and 30: (Brown et al. 1995). This product,
Page 31 and 32: Figure 1 A detailed structure of th
Page 33 and 34: 2.3 Chemical composition of rice st
Page 35 and 36: helix with only the ring oxygen poi
Page 37 and 38: Figure 5 Idealized diagram of the c
Page 39 and 40: 2.5 Rice starch gelatinization Gela
Page 41 and 42: in excess water. The loss of birefr
Page 43 and 44: morphological changes occurring at
Page 45 and 46: amylose is the linear fraction of s
Page 47 and 48: units are known to inhibit retrogra
Page 49 and 50: (-1 to 43 o C) on concentrated star
Page 51 and 52: Figure 10 Schematic diagram showing
Page 53 and 54: ice due to the various cooking and
Page 55 and 56: Recently, there has been a flurry o
Page 57 and 58: 3.1 Processing condition on improve
Page 59 and 60: of RS overall, 60%, among the three
Page 61 and 62: chains but liberates longer chains
Page 63 and 64: 4.1 Amylolytic enzymes Three groups
Page 65 and 66: Structure and properties of β- amy
Page 67 and 68: Structure and properties: The pullu
Page 69 and 70: Action pattern: The amyloglucosidas
Page 71 and 72: methods, for instance in scanning e
Page 73 and 74: 6. Low glycemic butter cake product
Page 75 and 76: Sugar increases cake volume by decr
Page 77 and 78: cereals, and baked potatoes. Low gl
Page 79: way to achieve a healthy food produ
Page 83 and 84: would be only 2. In comparison, the
Page 85 and 86: ecause of an absolute decrease in t
Page 87 and 88: enhanced fat oxidation at the expen
Page 89 and 90: 1. Raw Materials MATERIALS AND METH
Page 91 and 92: Methods 1. Production of resistant
Page 93 and 94: 1.2.3 Degree of syneresis Degree of
Page 95 and 96: 1.2.9 Starch hydrolysis rate and es
Page 97 and 98: 1.3.3 Resistant starch content, sta
Page 99 and 100: 2.1.1 Cake sample preparation Cake
Page 101 and 102: Nevertheless, the former refers to
Page 103 and 104: 3. Experimental Design and Statisti
Page 105 and 106: essentially linear polymer of α-(1
Page 107 and 108: hydrolysis of the rice starch prehe
Page 109 and 110: a) b) Figure 15 Scanning electron m
Page 111 and 112: amylose content of starch had a har
Page 113 and 114: Degree of syneresis (%) 70.0 60.0 5
Page 115 and 116: 1.2.7 Physicochemical properties of
Page 117 and 118: 1.2.8 In vitro starch digestibility
Page 119 and 120: 1.2.9 Hydrolysis index and glycemic
Page 121 and 122: Table 16 Effect of preheated treatm
Page 123 and 124: 1.2.10 Crystallinity of RS III 108
Page 125 and 126: Figure 22 X-ray diffraction pattern
Page 127 and 128: content. The high correlation facto
Page 129 and 130: 1.3.2 β-amylolysis (%) 114 β-amyl
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1.3.4 In vitro starch digestibility
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118 Non significant differences (P
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1.4.2 Degree of hydrolysis 120 The
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2 An application of resistant starc
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sucrose or maltose are reducing suc
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126 The different effect of HFCS on
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2.1.2 Sensory evaluation of HFCS re
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and objective percent moisture gene
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132 In the dietetic cake mix of Cor
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3) In vitro starch digestibility 13
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Table 23 Percentage (dwb) of starch
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al. (2006) reported that when gluco
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140 volume, crust and crumb color o
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(P
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2.2.2 Sensory evaluation of RS III
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3) Flavor score 146 Flavor is the m
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2.2.3 Chemical composition of RS II
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Table 27 Mean values for chemical c
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Table 28 Percentage (dwb) of starch
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cake is lower in these samples than
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CONCLUSIONS AND RECOMMENDATIONS 156
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158 syneresis of retrograded starch
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LITERATURE CITED Abe, J.I., K. Naka
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Biliaderis, C.G. and J. Zawastowski
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Cheng, H.H. and M.H. Lai. 2000. Fer
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Elgun, A. Z. Ertugay, M. Certel, an
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Fitt L.E. and E.M. Snyder. 1984. Ph
Page 185 and 186:
Grandfeldt, A., C. Eliasson and I.
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Hoseney, R.C. 1990. Principles of C
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Juliano, B.O. and M.S. Goddard. 198
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Lavin, M., E. Eshbaugh, J.-M. Hu, S
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Ludwig, D.S. and R.H. Eckel. 2002.
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Meilgaard, M., Civille, O.V., and C
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Nakazawa, F., S. Noguchi, J.Takahas
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Piyarat, N. 2003. The assessment of
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Schoch, T. J. 1969. Non-carbohydrat
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Srinivasa Rao, P. 1970. Studies on
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Towar, J., C. Melito, E. Herrera, A
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Yuan, R.C. and D.B. Thompson. 1998.
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Appendix A Chemical analysis proced
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2.2 Method determination 196 Total
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source and detach the extractor and
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5.3 Procedure for Preparation for S
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1) Standard curve procedure 202 Usi
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7. Reducing sugar determination by
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8. Resistant starch determination b
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8.2.3 Measurement of resistant star
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lank. starch. 210 3. Measure the ab
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Appendix B Physical analysis proced
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2. X Ray Diffraction Measurement 2.
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Appendix C Picture of some experime
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Heated debranched samples Cooled de
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Appendix Figure C4 Visuals appearan
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1. Introduction 222 There are sever
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Appendix E Experimental data 224
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Appendix Table E3 X-ray diffraction
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Appendix F List of publications 228
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NAME : Miss Jirapa Pongjanta BIRTH
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