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1.2.3 Resistant starch and metabolic responses Resistant starch is not absorbed and therefore causes minimal increase in post-prandial glucose potential (hence has low glycemic index, GI), and insulin. This is the case with most legume starches which have higher amylose content than cereal starches and are easily retrograded to produce higher levels of resistant starch (Crosby, 2003). Legumes and other complex carbohydrate-based foods constitute a large part of the diet in many non-Western societies, and the protective role of resistant starch may be more obvious. This is significant in the management and control of glucose-metabolism related diseases such as type II diabetes and obesity. 1.2.4 Resistant starch and insulin and glucose metabolism Insulin is a hormone that enables glucose uptake by muscle and adipose cells, thereby lowering blood glucose levels (Bornet et al. 1989). It also inhibits the use of stored body fat and together with an array of other physiological signals can modulate appetite and satiety signals. RS-rich foods release glucose slowly and therefore one would expect this to result in a lowered insulin response, greater access and used of stored fat and potential, a muted generation of hunger signals. Not only would these conditions help in the management of clinical conditions, such as diabetes and impaired glucose tolerance, but also possibly in the treatment of obesity and in weight management (Goddard et al. 1984). 1.2.5 Resistant starch and lipid metabolism Cheng and Lai (2000) investigated the effects of different proportion of rice starch and cornstarch on lipid metabolism in rats fed high dietary cholesterol. They found that the rice starch was aggregation (n= 20 - 60) of smaller granules (3 - 8 micron in diameter), whereas the cornstarch was composed of larger (5 - 15 micron), single granules. The compound rice starch (0.99 kg/L) was larger in size and denser in structure than cornstarch (0.63 kg/L). Serum total cholesterol concentrations in rats 9
fed both the 45 and 63g/100g rice starch diets were significantly lower than in all other groups. The serum propionate concentration in the rats fed 63 g/100g rice starch diets was significantly higher than that of other groups. Hepatic triglyceride and total cholesterol concentration in rat fed 63 g/100g rice starch diets were significantly lower than the control group. These results suggest that, because the compound rice starch was an aggregation of smaller granules, larger in size and denser in structure than cornstarch, it was digested more slowly and altered lipid metabolism. Resistant rice starch is fermented to produce propionate, which reduces serum and hepatic cholesterol. 1.3 Processing and resistant starch formation Food processing techniques, particularly those that utilize heat, moisture or chemicals influence the formation and levels of resistant starch. This is attributed to structural changes induced in the amylose in starch. Dehulling legumes by steam treatment and cooking for instance result in higher levels of resistant starch (Tovar et al. 2002). The high levels of amylose in legumes are converted to resistant starch with processing. Resistant starch most commonly found in processed foods is largely retrograded starch. Autoclaving, a moist-heat technique commonly employed in the food industry, involves somewhat extensive processing of the food product, as well as heating and cooling phases. Multi-cycle autoclaving of starch-based products results in retrogradation, and consequently increased levels of resistant starch (RS III), particularly in high amylose foods (Skrabanja et al. 2001). Processing techniques such as canning, extrusion and microwave heating however, are reported to result in lower levels of resistant starch (Mèance et al. 1999). These processes utilize moist heat thereby facilitating gelatinization of starch, and with no subsequent retrogradation phase, starch susceptibility to digestion is greatly enhanced. Baking for prolonged periods meanwhile, was shown to increase resistant starch content of wheat bread and rye bread (Rabe and Seivert, 1992). 10
Page 1: THESIS ENZYME-RESISTANT STARCH TYPE
Page 5 and 6: ACKNOWLEDGEMENTS I wish to express
Page 7 and 8: LIST OF TABLES Table Page 1 Classif
Page 9 and 10: LIST OF TABLES (Continued) Table Pa
Page 11 and 12: LIST OF FIGURES (Continued) Figure
Page 13 and 14: LIST OF FIGURES (Continued) Appendi
Page 15 and 16: LIST OF ABBREVIATIONS (Continued) R
Page 17 and 18: een used to produce a sample with l
Page 19 and 20: Overall objectives: OBJECTIVES 1. T
Page 21 and 22: However, it was discovered that a r
Page 23: Cassidy et al. (1994), in an intern
Page 27 and 28: 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
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Sugar increases cake volume by decr
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cereals, and baked potatoes. Low gl
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way to achieve a healthy food produ
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complexes. In the meantime, and inv
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would be only 2. In comparison, the
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ecause of an absolute decrease in t
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enhanced fat oxidation at the expen
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1. Raw Materials MATERIALS AND METH
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Methods 1. Production of resistant
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1.2.3 Degree of syneresis Degree of
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1.2.9 Starch hydrolysis rate and es
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1.3.3 Resistant starch content, sta
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2.1.1 Cake sample preparation Cake
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Nevertheless, the former refers to
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3. Experimental Design and Statisti
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essentially linear polymer of α-(1
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hydrolysis of the rice starch prehe
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a) b) Figure 15 Scanning electron m
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amylose content of starch had a har
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Degree of syneresis (%) 70.0 60.0 5
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1.2.7 Physicochemical properties of
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1.2.8 In vitro starch digestibility
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1.2.9 Hydrolysis index and glycemic
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Table 16 Effect of preheated treatm
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1.2.10 Crystallinity of RS III 108
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Figure 22 X-ray diffraction pattern
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content. The high correlation facto
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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
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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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THESIS

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