Barley for Food and Health: Science, Technology, and Products

More documents

Recommendations

Info

OBJECTIVE EVALUATION 135 finished product. Rasper and Walker (2000) divided the methodology into three phases relevant to different stages of the baking process: dough mixing, dough transformation, and gelatinization (see Figure 6.1). In the first phase, recording mixers measure and record changes in mixing resistance during the dough development time. The Brabender farinograph (C.W. Brabender Instruments Co., South Hackensack, New Jersey) is widely used, following approved Method 54-21 (AACC 2000). Two Z-shaped blades in a mixing chamber rotate at constant but different speeds and subject the dough to gentle mixing at constant temperature. An inscribed record, the farinograph curve, shows the resistance of the dough to mixing as it is formed, developed, and softened. The maximum resistance or consistency of the dough is adjusted by altering the amount of water added, also termed water absorption, which is a guide to determining the “strength” of a flour. Water absorption is defined as the amount of water required for a flour dough to reach a definite consistency at the point of optimum development. Flours from strong wheat (higher protein content) and from hard wheat require more water than do flours from weak (lower protein) or soft wheats to make a dough of standard consistency. Consistency is indicated by the maximum height of the Brabender curve, the beginning of maximum height is termed the arrival time, andthestability time is the period between arrival time and departure time when the curve begins to fall (see Figure 6.2). Another type of recording mixer, FIGURE 6.1 Three-phase system of physical flour testing. (Courtesy of C. W. Brabender Instruments, Inc., South Hackensack, New Jersey.)
136 EVALUATION OF FOOD PRODUCT QUALITY 600 FU 500 400 300 200 Stability = 2.5 min FQN = 30 Development time = 1.8 min Degree of softening = 135 FU 12 min 100 0 5 10 Min 15 FIGURE 6.2 Representative farinogram showing some commonly measured indices. FU, farinograph units; FQN, farinograph quality number. (Courtesy of C.W. Brabender Instruments, Inc., South Hackensack, New Jersey.) the mixograph (TMCO, Lincoln, Nebraska), originally called the Swanson mixer, provides a planetary-type action and is more suited to testing dough made from hard wheat. The second phase of bread baking, structural transformation of dough by fermentation and maturation, employs stress–strain instruments that measure resistance of dough to extension. The extensiograph, also a Brabender instrument, records the resistance of dough to stretching and the distance a dough stretches before breaking, according to Approved Method 54-10 (AACC 2000). Another texture analyzer, the TA-XTZ (Stable Micro Systems, Surrey, England), is also effective for measuring resistance to extension. The third phase of bread baking, gelatinization, is measured by the Brabender amylograph by Approved Method 22-10 (AACC 2000). This instrument records relative viscosity, or the resistance of stirring a suspension of flour in water while temperature is increased. Starch granules swell when they approach a certain temperature, and amylose molecules seep into the liquid medium, increasing solubles concentration and therefore increasing viscosity. In its late phases, this gelatinization is also known as pasting. Whenα-amylase is present, this enzyme’s action on starch results in paste thinning. Part of the starch is hydrolyzed and liquefied, with reduced viscosity, and these viscosity changes are recorded by the amylograph. Izydorczyk et al. (2001) performed dynamic oscillatory testing using a Bohlin VOR rheometer (Bohlin Reologi, Edison, New Jersey). This system provides simultaneous measurements of elastic and viscous properties of dough. The Rapid Visco Analyzer (Newport Scientific Pt. Ltd., Warriewood, Australia) is used to measure the relative viscosity of a mixture according to Approved
Page 2:
BARLEY FOR FOOD AND HEALTH Science,
Page 5 and 6:
On a Seed “This was the goal of t
Page 7 and 8:
Cover design by Jean Rose Johnston.
Page 10 and 11:
CONTENTS Preface xiii 1 Barley Hist
Page 12 and 13:
CONTENTS ix Infrared Processing, 12
Page 14:
CONTENTS xi Asia, 221 Barley Mixed-
Page 17 and 18:
xiv PREFACE In the concluding two c
Page 19 and 20:
2 RELATIONSHIP OF HUMANS AND BARLEY
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
10 RELATIONSHIP OF HUMANS AND BARLE
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
2 Barley: Taxonomy, Morphology, and
Page 37 and 38:
20 BARLEY: TAXONOMY, MORPHOLOGY, AN
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
3 Barley Biotechnology: Breeding an
Page 51 and 52:
34 BARLEY BIOTECHNOLOGY: BREEDING A
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
4 Barley: Genetics and Nutrient Com
Page 75 and 76:
58 BARLEY: GENETICS AND NUTRIENT CO
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102: 84 BARLEY: GENETICS AND NUTRIENT CO
Page 113 and 114: 96 BARLEY PROCESSING: METHODS AND P
Page 115 and 116: 98 BARLEY PROCESSING: METHODS AND P
Page 117 and 118: 100 BARLEY PROCESSING: METHODS AND
Page 151: 134 EVALUATION OF FOOD PRODUCT QUAL
Page 155 and 156: 138 EVALUATION OF FOOD PRODUCT QUAL
Page 161 and 162: 7 Barley Food Product Research and
Page 163 and 164: 146 BARLEY FOOD PRODUCT RESEARCH AN
Page 195 and 196: 8 Health Benefits of Barley Foods I
Page 197 and 198: 180 HEALTH BENEFITS OF BARLEY FOODS
Page 203 and 204:
186 HEALTH BENEFITS OF BARLEY FOODS
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
9 Current Status of Global Barley P
Page 223 and 224:
206 CURRENT STATUS OF GLOBAL BARLEY
Page 225 and 226:
208 CURRENT STATUS OF GLOBAL BARLEY
Page 227 and 228:
10 Barley Foods: Selected Tradition
Page 229 and 230:
212 BARLEY FOODS: SELECTED TRADITIO
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 242 and 243:
APPENDIX 1 Glossary: Botany and Pla
Page 244 and 245:
APPENDIX 2 Glossary: Food and Nutri
Page 246 and 247:
APPENDIX 3 Glossary: Barley Terms T
Page 248 and 249:
APPENDIX 4 Equivalent Weights and M
Page 250 and 251:
SOURCES OF BARLEY AND BARLEY PRODUC
Page 252 and 253:
Rancho Cucamonga, CA 91730 Ph: 888-
Page 254 and 255:
SOURCES OF BARLEY AND BARLEY PRODUC
Page 256 and 257:
E-mail:Tony.Steeper@csiro.au Web: h
Page 258 and 259:
BARLEY RESOURCE ORGANIZATIONS 241 P
Page 260 and 261:
INDEX Air classification, 102, 122-
Page 262:
INDEX 245 Meat and barley casserole
show all

Barley for Food and Health: Science, Technology, and Products

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?