Pigment Reduction in Corn Gluten Meal and Its Effects on Muscle ...

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from 160 to 250 °C. Addition of soy flour to CGM resulted <strong>in</strong> a slight <strong>in</strong>crease <strong>in</strong> prote<strong>in</strong> content<strong>and</strong> improv<strong>in</strong>g wet CGM am<strong>in</strong>o acid balance, ea. lys<strong>in</strong>e (Cha et al., 2000).2.10.2 Other enzymesA total reduction of β-carotene from bread dough (prepared with 100 g of wheat flour)was obta<strong>in</strong>ed with 3,000 <strong>and</strong> 815 U of peroxidase (from soybeans) <strong>and</strong> lipase <strong>in</strong> the presence ofl<strong>in</strong>oleic acid (Gel<strong>in</strong>as et al., 1998).2.10.3 Chemical reagents as pigment bleach<strong>in</strong>g agents2.10.3.1 Benzoyl peroxideBenzoyl peroxide is widely utilized <strong>in</strong> mill<strong>in</strong>g plants from Canada <strong>and</strong> the U.S. as ableach<strong>in</strong>g agent for the yellow pigment content <strong>in</strong> wheat flour (Mercier <strong>and</strong> Gel<strong>in</strong>as, 2001). Thisproduct is a free radical <strong>in</strong>itiator that <strong>in</strong>duces the oxidation of carotenoid molecules by a typicalfree radical reaction. Dur<strong>in</strong>g pigment bleach<strong>in</strong>g, part of the benzoyl peroxide is converted <strong>in</strong>tobenzoic acid (Saiz et al., 2001).2.10.3.2 Hydrogen peroxideHydrogen peroxide (HP) is widely utilized as a food additive. Alkal<strong>in</strong>e HP (pH 11.5)reduced more than half of the colour (expressed as colour difference) <strong>in</strong> wheat distillers’ gra<strong>in</strong>,when 60 g of this commodity was suspended <strong>in</strong> 300 ml of an aqueous HP solution (0.3 M) for 2hours (Abdel-Aal et al., 1996).27
2.11 ConclusionInclusion of <strong>in</strong>creas<strong>in</strong>g levels of cost-effective plant-orig<strong>in</strong> commodities <strong>in</strong>to formulated dietsfor salmonid fish is a common practice widely utilized <strong>in</strong> order to susta<strong>in</strong> <strong>in</strong>creas<strong>in</strong>g productionlevels.Colour <strong>in</strong> fillet from salmonid fish is determ<strong>in</strong>ed by the deposition of carotenoid pigments,ma<strong>in</strong>ly astaxanth<strong>in</strong>, with<strong>in</strong> fiber muscles. This colour attribute plays a key role on consumer’sperception as well as on will<strong>in</strong>gness to pay. Salmonid fish are unable to synthetize carotenoid denovo, hence formulated diets are supplemented with expensive pigment premix.Anecdotal evidence from fish farmers along with a few scientific studies support a reduction<strong>in</strong> astaxanth<strong>in</strong> deposition <strong>and</strong> reduction <strong>in</strong> color attributes <strong>in</strong> fillets from ra<strong>in</strong>bow trout fed dietsconta<strong>in</strong><strong>in</strong>g corn gluten meal. This commodity, a highly digestible high prote<strong>in</strong> (~60% on a drymatter basis) by-product of the corn wet mill<strong>in</strong>g conta<strong>in</strong><strong>in</strong>g substantial levels of yellowxanthophylls (200 – 550 mg kg -1 ), ma<strong>in</strong>ly lute<strong>in</strong> <strong>and</strong> zeaxanth<strong>in</strong>. The effects related to the<strong>in</strong>clusion of substantial levels of corn gluten meal on muscle pigmentation need to be addressed<strong>in</strong> order to avoid potential reduction <strong>in</strong> astaxanth<strong>in</strong> utilization <strong>and</strong> colour expression <strong>in</strong> muscleform ra<strong>in</strong>bow trout.The development of straight-forward/cost-effective process<strong>in</strong>g techniques, aim<strong>in</strong>g to reduceyellow xanthophylls content <strong>in</strong> corn gluten meal <strong>and</strong> to <strong>in</strong>crease this commodity’s nutritionalvalue for salmonid fish are highly necessary. The use of common bleach<strong>in</strong>g agents, eitherapplied directly to corn gluten meal or to corn kernels dur<strong>in</strong>g the corn wet mill<strong>in</strong>g process canbecome a practical tool <strong>in</strong> order to <strong>in</strong>crease the feed<strong>in</strong>g value of corn gluten meal.28
Page 1 and 2: Pigment Re
Page 3 and 4: ingredients. Furth
Page 5 and 6: Thanks to all my colleagues, friend
Page 7 and 8: 2.10.1 Enzymatic treatments .......
Page 9 and 10: LIST OF TABLESTable 3. 1 - Factors
Page 11 and 12: LIST OF FIGURESFigure 2. 1 - Molecu
Page 13 and 14: Ingredients commonly in</st
Page 15 and 16: CHAPTER - 2 LITERATURE REVIEW2.1 In
Page 17 and 18: leached when 5% of soy flour as LOX
Page 19 and 20: deep and fast glyc
Page 21 and 22: observed in ra<str
Page 23 and 24: Chylomicron constituents are remove
Page 25 and 26: Muscle growth in r
Page 27 and 28: 2.7.2 Corn gluten
Page 29 and 30: 2010). However, due to its imbalanc
Page 31 and 32: No differences in
Page 33 and 34: supplemented with 42% of a vegetabl
Page 35 and 36: Soybean seeds are the richest known
Page 37: 2.10.1.4 Bleaching
Page 41 and 42: 4.0%*68%* 5.6%* 12%* 3.5%* 6.5%*Fig
Page 43 and 44: Figure 2. 4 - Schematic representat
Page 45 and 46: 3.1 IntroductionThe characteristic
Page 47 and 48: many factors such as LOX source lev
Page 49 and 50: During the 12-week
Page 51 and 52: 3.2.3 Analytical methodsDry matter
Page 53 and 54: solution was generated by mix<stron
Page 55 and 56: 3.2.4 Statistical analysisData from
Page 57 and 58: Factors defined as
Page 59 and 60: chromatography). Relative amounts o
Page 61 and 62: After carotenoids are absorbed thro
Page 63 and 64: and ended up <stro
Page 65 and 66: Table 3. 2 - Experimental design us
Page 67 and 68: Table 3. 4 - Analysed proximate com
Page 69 and 70: Proximate composition (Analysed; dr
Page 71 and 72: Table 3. 7 - Lipoxygenase activity
Page 73 and 74: 18 1 0 -1 0 120 15 0 10 2519 -1 0 1
Page 75 and 76: Table 3. 10 - HPLC carotenoid profi
Page 77 and 78: Table 3. 12 - Retain</stron
Page 79 and 80: Table 3. 14 - Fillet carotenoid con
Page 81 and 82: Total yellow pigment(mg•kg -1 )25
Page 83 and 84: Figure 3. 4 - Growth curve of ra<st
Page 85 and 86: effects of dietary CGM and<
Page 87 and 88: soybean meal in a
Page 89 and 90:
were randomly samp
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An aliquot (1 ml) of chloroform low
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Retained nitrogen
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significant (p
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Values for all-trans astaxanth<stro
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previous reports where colour attri
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Proximate composition (analysed), d
Page 103 and 104:
Table 4. 2 - Growth performance of
Page 105 and 106:
Table 4. 3 - Carcass chemical proxi
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Table 4. 4 - Retain</strong
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Table 4. 5 - Pigment</stron
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Table 4. 6 - Colour attributes <str
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FiguresFigure 4. 1 - Growth curves
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Figure 4. 3 - Muscle colour attribu
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the effects of dietary reduced-caro
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astaxanthin deposi
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After steeping, ke
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0.9994 and 0.9999,
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under acidic and a
Page 127 and 128:
oxidation within t
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colour difference usin</str
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TablesTable 5. 1 - Analyzed proxima
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Effects of
Page 135 and 136:
Effects of
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Effects of
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Effects of
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Data are mean (n=2).a Steepwater pH
Page 143 and 144:
CHAPTER - 6 GENERAL DISCUSSIONCurre
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significant reduction in</s
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Reduction of pigme
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though wheat gluten meal conta<stro
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BibliographyAas, G.H., Storebakken,
Page 153 and 154:
Bjerkeng, B., Hatlen, B., Wathne, E
Page 155 and 156:
Choubert, G., Cravedi, J., Laurenti
Page 157 and 158:
Fauconneau, B., Andre, S., Chmaitil
Page 159 and 160:
Johnston, I., Li, X., Vieira, V., N
Page 161 and 162:
Li, M.H., Oberle, D.F., Lucas, P.M.
Page 163 and 164:
Peter, C.M., Han, Y., Bolin
Page 165 and 166:
Skonberg, D.I., Hardy, R.W., Barrow
Page 167:
Ytrestoyl, T., Struksnæs, G., Kopp
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