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

More documents

Recommendations

Info

Abstract Microwave blanching of peanuts has been explored as an alternative to conventional oven methods based on its speed of operation, energy savings, and efficiency of process control. Although processing times can be greatly reduced, the occurrence of stale/floral and ashy off-flavors have been reported at high process temperatures. This study examined the chemical compounds responsible for this off-flavor using solvent extraction / solvent assisted flavor evaporation (SAFE), gas chromatography-olfactometry (GC/O), gas chromatography-mass spectrometry (GC/MS), and aroma extract dilution analysis (AEDA). Select compounds were quantified based on AEDA results using SAFE and GC/MS. Quantification, threshold testing, and analysis of model systems revealed increased formation of guaiacol and phenylacetaldehyde in the off-flavored peanuts which resulted in the burnt and stale/floral flavors noted by a trained panel. Key Words: microwave, peanut, off-flavor, gas chromatography-olfactometry, threshold 142
Introduction The most common use of world peanut production remains the crushing of peanuts for oil and meal. However, the proportion of peanuts used for other food products has steadily increased (Revoredo and Fletcher 2002). The unique flavor of roasted peanuts drives product marketing for products such as peanut butter and confections. This flavor is the result of genetics, production, handling, storage, and processing factors (Sanders and others 1995). The main sources of volatile flavor compounds in peanuts are non-enzymatic carbonyl-amine browning and lipid oxidation reactions, and include interactions between peanut components as well as thermal decomposition products and loss of volatiles (Hoffpauir 1953; Warner and others 1996). Maillard reactions are primarily responsible for browning reactions in roasted peanuts, and produce pyrazines, pyrroles, furans, and other low molecular weight compounds. In addition to Maillard products, carbonyls are produced by Strecker degradation and oxidation, but can then be lost by volatilization (Buckholz and others 1980). Pyrazines, which are volatile heterocyclic nitrogen-containing compounds, are thought to be the major flavor compounds impacting roasted peanut flavor (Warner and others 1996). The causes of off-flavors in peanuts include lipid oxidation, induction of anaerobic respiration, and external contamination with compounds such as limonene, antioxidants, or insecticides (Ory and others 1992). Lipid oxidation is one of the leading causes of off-flavors in raw and roasted peanuts, due to a high content of unsaturated fatty acids (Warner and others 1996; Lee and others 2002). Oxidation of the fatty acids in peanut oil can be caused by light, heat, air, metal 143
Page 1 and 2:
Abstract SCHIRACK, ANDRIANA VAIS. T
Page 3 and 4:
THE EFFEGT OF MICROWAVE BLANCHING O
Page 5 and 6:
BIOGRAPHY Andriana Schirack is orig
Page 7 and 8:
TABLE OF CONTENTS v Page List of Ta
Page 9 and 10:
Materials and Methods..............
Page 11 and 12:
Table 3 High Impact Aroma-Active Co
Page 13 and 14:
CHAPTER 1: INTRODUCTION 1
Page 15 and 16:
The processing parameters used duri
Page 17 and 18:
educed from 35-40% moisture to 8-10
Page 19 and 20:
REFERENCES Adelsberg GD, Sanders TH
Page 21 and 22:
Interdependency and underlying dime
Page 23 and 24:
Composition of Peanuts The structur
Page 25 and 26:
and Burma. The peanut prices in the
Page 27 and 28:
(w.b.) within 3 days, large quality
Page 29 and 30:
cdry = Specific heat of dry seeds (
Page 31 and 32:
there is no direct correlation publ
Page 33 and 34:
Peanuts are commonly stored in flat
Page 35 and 36:
lanching has been imitated using a
Page 37 and 38:
(1999), no detrimental effects of b
Page 39 and 40:
when the air is distributed from ab
Page 41 and 42:
y-product (Giese, 1992). Drying is
Page 43 and 44:
the material to absorb electromagne
Page 45 and 46:
ε' = Relative real permittivity (d
Page 47 and 48:
oils, both ε' and ε" are low and
Page 49 and 50:
1969). The flavor characteristics o
Page 51 and 52:
et al., 1980). Likewise, sugars pre
Page 53 and 54:
n-methylpyrrole. Walradt et al. (19
Page 55 and 56:
fact, Ory et al. (1992) suggested t
Page 57 and 58:
Flavor Research in Other Nuts Sever
Page 59 and 60:
changed with time of roasting and i
Page 61 and 62:
polyunsaturated acids that have a c
Page 63 and 64:
hexanal are intensified to the high
Page 65 and 66:
The results of temperature stress i
Page 67 and 68:
Brown et al. (1977) found that the
Page 69 and 70:
exhibited the fruity fermented off-
Page 71 and 72:
(Pawliszyn, 2000). Also, the elevat
Page 73 and 74:
compounds eluting from microwave-he
Page 75 and 76:
Table 1: Peanut Volatile Analysis b
Page 77 and 78:
the identification of volatile comp
Page 79 and 80:
the detector. The compounds can the
Page 81 and 82:
GC-O Applications High vacuum disti
Page 83 and 84:
each half was allocated into one of
Page 85 and 86:
Woody/Hulls/Skins Cardboard Table 2
Page 87 and 88:
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 and 140: Sensory Analysis RESULTS AND DISCUS
Page 141 and 142: significantly lower final moisture
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: CHAPTER 5: CHARACTERIZATION OF AROM
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
Page 191 and 192: Conclusions This research investiga
Page 193 and 194: microwave technology may provide ma
Page 195 and 196: protect against colon, prostate, an
Page 197 and 198: APPENDICES 185
Page 199 and 200: SAFE (3 SAFE's can be done in 1 day
Page 201 and 202: 2. Turn off waterbath. 3. Turn off
Page 203 and 204: 5. Filter through a third sodium su
Page 205 and 206:
contamination, and run a blank on t
Page 207 and 208:
AC nutty/burnt 975 1.5 NB cabbage/g
Page 209 and 210:
AC oxidized 1289 1.5 NB dusty/nutty
Page 211 and 212:
NB brothy 1612 3.5 NB honey/hay 161
Page 213 and 214:
Table 2: Aroma-Active Compounds in
Page 215 and 216:
AC cedar 1081 3.0 AC burnt sugar/nu
Page 217 and 218:
AC brothy 1350 2.0 NB garlic 1352 5
Page 219 and 220:
NB fruity/floral 1670 3.0 NB rosy 1
show all

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

Create successful ePaper yourself

Delete template?

Save as template?