EVALUATION OF FOUR SORGHUM HYBRIDS THROUGH THE ...

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Resting Once the dough is mixed, it will rest for about 5 minutes and then placed in a divider to create dough balls varying in size from 25 to 60g (Anonymous 1991). These dough balls are transferred to a proofing cabinet with a temperature of 30-36 o C and relative humidity between 65 and 75% (Serna-Saldivar and others 1988). This is a short resting period and is important for dough relaxation and prevention of skin formation or excess moisture (Qarooni 1993). Sheeting/Pressing After resting, there are differences between the three methods. For the hot press operation, the proofed dough pieces are placed on a heated conveyer and a hydraulic press sheets each piece into a flat disc. The temperature and pressure of the press ranges from 177 to 237 o C and 278 to 758 N/cm 2 respectively (Janson 1990). This process creates a skin that essentially seals the tortilla restricting the amount of steam and carbon dioxide released during baking. Therefore, the tortilla will puff. The hand stretched method passes the relaxed dough pieces through two sheet rollers creating a round disc. These discs are then further stretched by hand (Janson 1990). With such intense labor and sanitation issues, the hand stretch method is rare (Serna-Saldivar and others 1988). Finally, in the die-cut process, the dough is extruded and then gradually sheeted. This dough sheet is passed under a die-cut cylinder to create uniform discs (Janson 1990). Stronger doughs must be used in order to pass through such harsh processing conditions. Therefore, die-cut tortillas tend to be less elastic, have low moisture content, and crack 29
easily. These tortillas are best for frying to create hard taco shells, chimichangas, and other products. (Serna-Saldivar and others 1988). Baking A three-tier gas oven is typically used for baking flour tortillas. The conveyor belt moves at an opposite direction at each level. At the end of each level, the tortilla flips ensuring even baking. The temperature and bake time can very between 191-260 o C and 17 to 40 seconds, respectively (Janson 1990; Anonymous 1991). Bello and others (1991) produced hot press tortillas using a total bake time of 40 seconds and oven temperatures of 232 o C for the top and bottom tiers and 273 o C for the middle tier. Cooling and Packaging Tortillas are cooled on a similar type of conveyor used in the oven. There can be 3 to 11 tiers and the dwell time ranges from 5 to 9 minutes (Serna-Saldivar and others 1988; Qarooni 1993). Once the tortillas cool, they are packaged utilizing paddle bagging or horizontal form-fill-seal systems (Qarooni 1993). Twist ties and clip sealing have been common in the past, but resealable type packaging is becoming more familiar. Ingredients Flour The most important ingredient in flour tortillas is of course the flour. The flour is typically enriched, bleached hard-wheat flour. However, all purpose flours and soft- wheat flours have been used (Serna-Saldivar and others 1988). Waniska and others (2004) studied the effects of flour properties on tortilla quality by studying sixty-one commercial tortilla flours. They found that a protein content between 10.0 and 12.0%, 30
Page 1 and 2: EVALUATION OF FOUR SORGHUM HYBRIDS
Page 3 and 4: compared to a gluten-free wrap alre
Page 5 and 6: Flour Characterization Starch Isola
Page 7 and 8: Chapter 1 LIST OF FIGURES 1. Mechan
Page 9 and 10: 4. Comparison of color, pH, water a
Page 11 and 12: ACKNOWLEDGMENTS I cannot begin to t
Page 13 and 14: most important. As a continent, Afr
Page 15 and 16: Before this act, ingredients in foo
Page 17 and 18: Mechanism of Actions According to B
Page 19 and 20: symptoms similar to allergic reacti
Page 21 and 22: Table 1. Symptoms of Celiac Disease
Page 23 and 24: Treatment If an individual is diagn
Page 25 and 26: MARKET FOR GLUTEN-FREE PRODUCTS In
Page 27 and 28: This exported sorghum may be used f
Page 29 and 30: sorghum, White sorghum, and Mixed s
Page 31 and 32: The actual proportion of the three
Page 33 and 34: fiber (Bach-Knudsen and Munck 1985)
Page 35 and 36: preference towards white sorghums w
Page 37 and 38: cassava starch, and raw cassava sta
Page 39: (about 5 min.). Waniska and others
Page 43 and 44: starch, and leavening acids, is a c
Page 45 and 46: Gliadin, which is a prolamin charac
Page 47 and 48: gluten matrix can hold some of the
Page 49 and 50: LITERATURE CITED Aboubacar A, Hamak
Page 51 and 52: Federal Register. 2007. Food Labeli
Page 53 and 54: Murty DS, Singh U, Suryaprakash S,
Page 55 and 56: Subramanian V, Jambunathan R, Suury
Page 57 and 58: Chapter 2: Grain and Flour Characte
Page 59 and 60: Introduction: An estimated 1-2 perc
Page 61 and 62: The cleaned grain was then analyzed
Page 63 and 64: Starch Particle Size Distribution:
Page 65 and 66: Moisture Content: The moisture cont
Page 67 and 68: products. Grain hardness can also b
Page 69 and 70: Flour Characterization Flour Partic
Page 71 and 72: Starch Particle Size Distribution:
Page 73 and 74: Total Starch: The total starch cont
Page 75 and 76: Table 4. Comparison of total starch
Page 77 and 78: 66 Table 5. Comparison of starch pa
Page 79 and 80: create a flour of a specific ash co
Page 81 and 82: Conclusions: This study has shown t
Page 83 and 84: Evers AD, Stevens DJ. 1985. Starch
Page 85 and 86: Schober TJ, Bean SR, Boyle DL. 2007
Page 87 and 88: Abstract Gluten-free flour tortilla
Page 89 and 90: following five states in ranking or
Page 91 and 92:
increased. This is probably due to
Page 93 and 94:
than a typical tortilla process. Ov
Page 95 and 96:
Table 1. Formulation for sorghum fl
Page 97 and 98:
of 1.00 mm/s, test speed of 1.00 mm
Page 99 and 100:
values. Calibration was performed b
Page 101 and 102:
flour to use was determined by memb
Page 103 and 104:
Table 2. Comparison of weight, diam
Page 105 and 106:
Also, starch damage was found to be
Page 107 and 108:
Color: Significant differences were
Page 109 and 110:
98 Table 4. Comparison of color, pH
Page 111 and 112:
3.83 (TVM) to 8.00 (F-625). Grittin
Page 113 and 114:
102 Table 6. Comparison of texture
Page 115 and 116:
104 Table 8. Comparison of texture
Page 117 and 118:
Table 9. Comparison of scores from
Page 119 and 120:
REFERENCES Bejosano FP, Joseph S, L
Page 121 and 122:
Appendices 110
Page 123 and 124:
Appendix 2. Average starch particle
Page 125 and 126:
Appendix 4. RVA curve for F-1000. 1
Page 127 and 128:
Appendix 6. RVA curve for 5040C. 11
Page 129 and 130:
118 Appendix 8. RVA curve for TVM.
Page 131 and 132:
TEXTURE (in the hand) Roughness: Th
Page 133 and 134:
Hardness: The relative resistance t
Page 135 and 136:
Appendix 11: CONSUMER PRE-SCREENING
Page 137 and 138:
SAMPLE: 571 Please check only one b
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