Abstract SCHIRACK, ANDRIANA VAIS. The Effect of Microwave ...

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total offnote. Also, dark roast was correlated positively with bitter, woody/hulls/skins, ashy, and total offnote, and negatively correlated with raw beany and sweet taste. Total offnote, which was the attribute primarily used to differentiate the processing treatments, was correlated to dark roast, woody/hulls/skins, cardboardy/stale, bitter, and ashy and was related inversely to the positive attributes of roasted peanutty, sweet aromatic, and sweet (p < 0.05). It is notable that although total offnote was correlated to attributes commonly linked to over-roasting, all treatments were roasted to the same endpoint based on color, implying that this off-flavor was not related to actual roasting differences. A progression of changes in sensory attributes can be observed with longer microwave exposure times during blanching. As exposure times increased to 11 minutes and air was not circulated in the conveyor, the treatments were characterized by high intensities of total offnote attribute. The use of increased airflow during processing affected off-flavor formation, as 11F was more similar to treatments with shorter exposure times in the microwave. Temperature profiles and change in moisture content The maximum internal temperature reached in these treatments was compared (Table 5), and treatments were significantly different (p < 0.0001). As the amount of energy absorbed and internal temperatures increased, peanuts lost more moisture during heating. The final moisture content of the peanuts was affected significantly by treatment (p < 0.0001), and the treatments of 8NF and 11NF had 128
significantly lower final moisture content (Table 6) than the other treatments. The peanuts which lost the most moisture also exhibited the highest total off-flavor. Moisture content has been shown to have a significant effect in peanut flavor development and quality, both by affecting the concentrations of precursors available for flavor formation, and by changing the susceptibility to quality loss due to the environment. For example, hydrolysis can occur during roasting in peanuts with higher moisture contents, which increases the amounts of free amino acids and monosaccharides that serve as precursors for flavor development (Chiou et al., 1991). This indicates that the changes in moisture content during blanching may affect final peanut flavor. In past studies, lower moisture content after blanching appeared more conducive to higher blanching efficiency. However, this loss in moisture also may lead to the creation of off-flavors. Ongoing volatile analysis may help identify the causes of microwave- associated off-flavor. Specific compounds identified by GC-MS have been linked to sensory attributes in peanuts (Young and Hovis, 1990; Vercellotti et al., 1992; Didzbalis et al., 2004). By identifying the compounds responsible for the total offnote perception, a chemical anchor for clarification of this flavor can be identified. As a result, the metabolic cause may be determined and the off-flavor itself possibly can be prevented if microwave blanching is adopted as an industry practice. 129
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Abstract SCHIRACK, ANDRIANA VAIS. T
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THE EFFEGT OF MICROWAVE BLANCHING O
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BIOGRAPHY Andriana Schirack is orig
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TABLE OF CONTENTS v Page List of Ta
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Materials and Methods..............
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Table 3 High Impact Aroma-Active Co
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CHAPTER 1: INTRODUCTION 1
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The processing parameters used duri
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educed from 35-40% moisture to 8-10
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REFERENCES Adelsberg GD, Sanders TH
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Interdependency and underlying dime
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Composition of Peanuts The structur
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and Burma. The peanut prices in the
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(w.b.) within 3 days, large quality
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cdry = Specific heat of dry seeds (
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there is no direct correlation publ
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Peanuts are commonly stored in flat
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lanching has been imitated using a
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(1999), no detrimental effects of b
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when the air is distributed from ab
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y-product (Giese, 1992). Drying is
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the material to absorb electromagne
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ε' = Relative real permittivity (d
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oils, both ε' and ε" are low and
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1969). The flavor characteristics o
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et al., 1980). Likewise, sugars pre
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n-methylpyrrole. Walradt et al. (19
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fact, Ory et al. (1992) suggested t
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Flavor Research in Other Nuts Sever
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changed with time of roasting and i
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polyunsaturated acids that have a c
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hexanal are intensified to the high
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The results of temperature stress i
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Brown et al. (1977) found that the
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exhibited the fruity fermented off-
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(Pawliszyn, 2000). Also, the elevat
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compounds eluting from microwave-he
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Table 1: Peanut Volatile Analysis b
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the identification of volatile comp
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the detector. The compounds can the
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GC-O Applications High vacuum disti
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each half was allocated into one of
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Woody/Hulls/Skins Cardboard Table 2
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Givaudan-Roure developed Quantitati
Page 89 and 90: during high temperature microwave b
Page 91 and 92: OVM Organic volatiles meter Pa Pasc
Page 93 and 94: References Abegaz EG, Kerr WL, Koeh
Page 95 and 96: odorants in high temperature cured
Page 97 and 98: 17(4): 728-732. Mason ME, Waller GR
Page 99 and 100: partitioning constants and release
Page 101 and 102: Vercellotti JR, Crippen KL, Lovegre
Page 103 and 104: ABSTRACT Peanut blanching consists
Page 105 and 106: peanut moisture content from 5.5 to
Page 107 and 108: The computer monitored power output
Page 109 and 110: RESULTS AND DISCUSSION Energy Absor
Page 111 and 112: All treatments using the fan (F) ha
Page 113 and 114: Treatments 11NF, 8NF, and 5NF also
Page 115 and 116: lanchabilities as well as a longer
Page 117 and 118: microwave attain much higher temper
Page 119 and 120: REFERENCES ADELSBERG, G.D. and SAND
Page 121 and 122: TABLES AND FIGURES Table 1: Process
Page 123 and 124: Energy absorbed (kJ) 3000 2500 2000
Page 125 and 126: Temperature of peanuts (°C) 160 14
Page 127 and 128: Percent blanchability 100 90 80 70
Page 129 and 130: Maximum internal temperature (°C)
Page 131 and 132: ABSTRACT Microwave blanching of pea
Page 133 and 134: Several methods are used for blanch
Page 135 and 136: Peanuts MATERIALS AND METHODS Mediu
Page 137 and 138: Canada) on a laptop computer (Dell
Page 139: Sensory Analysis RESULTS AND DISCUS
Page 143 and 144: ACKNOWLEDGMENTS Funded in part by t
Page 145 and 146: Foods and Beverages, Vol. 29, (G. C
Page 147 and 148: TABLE LEGENDS Table 1. Microwave ap
Page 149 and 150: TABLE 2. LEXICON OF PEANUT FLAVOR D
Page 151 and 152: Sweet Aromatic TABLE 4. CORRELATION
Page 153 and 154: CHAPTER 5: CHARACTERIZATION OF AROM
Page 155 and 156: Introduction The most common use of
Page 157 and 158: The objective of this study was to
Page 159 and 160: attributes which were different fro
Page 161 and 162: Volatile compounds from the solvent
Page 163 and 164: 0.25 μm df; J & W Scientific, Fols
Page 165 and 166: adjusted with the same concentratio
Page 167 and 168: characterized by the attributes of
Page 169 and 170: (E,E)-2,4-decadienal (fried/oxidize
Page 171 and 172: flavor dilution factors, nor did th
Page 173 and 174: that of the control, but only in th
Page 175 and 176: e high enough for pyrazine formatio
Page 177 and 178: sensory panelists analyzing process
Page 179 and 180: References (ASTM) American Society
Page 181 and 182: Megahed MG. 2001. Microwave roastin
Page 183 and 184: Vercellotti JR, Mills OE, Bett KL,
Page 185 and 186: Table 2- Model system concentration
Page 187 and 188: 28 4-acetoxy-2,5-dimethyl- 3(2H)-fu
Page 189 and 190: Table 5 - Quantification, sensory o
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Conclusions This research investiga
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microwave technology may provide ma
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protect against colon, prostate, an
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APPENDICES 185
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SAFE (3 SAFE's can be done in 1 day
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2. Turn off waterbath. 3. Turn off
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5. Filter through a third sodium su
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contamination, and run a blank on t
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AC nutty/burnt 975 1.5 NB cabbage/g
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AC oxidized 1289 1.5 NB dusty/nutty
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NB brothy 1612 3.5 NB honey/hay 161
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Table 2: Aroma-Active Compounds in
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AC cedar 1081 3.0 AC burnt sugar/nu
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AC brothy 1350 2.0 NB garlic 1352 5
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NB fruity/floral 1670 3.0 NB rosy 1
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