tel (1986),and Camireandothers viewed byBjorck andAsp(1983),Chef- ing extrusion-cookinghave beenre- chemical andnutritionalqualities dur- quality offood.Thechanges inthe detrimental effectsonthenutritional ers 1989). biotin, andfolicacid)(Adsuleoth- vitamins (suchasthiamine,riboflavin, um, magnesium,andpotassium) erals (forexample,phosphorus,calci- also anexcellentsourceofcertainmin- 1983).It is 35% linoleicacid(Woodroof contains 76to82%oleicacid,and30 (Adsule andothers1989).Peanutoil ids, suchasoleicacidandlinoleic source ofproteinandessentialfattyac- international market.Peanutisagood is desirableinsnacksproducedforthe Ackman 1995).Additionally, fishflavor and Weihrauch 1992; 1976;Erickson acid, anddocosahexaenoicacid(Exler such aslinoleicacid,eicosapentaenoic several polyunsaturatedfattyacids and Weihrauch 1976).Fishalsocontains vitamin AandD, (Exler found inliver such asvitaminE,foundinflesh,and is agoodsourceoffat-solublevitamins digestible (Haard 1995).Moreover, fish tains essentialaminoacidsandishighly excellent nutritivevaluebecauseitcon- prior toextrusion.Fishproteinhasan can beincludedinsnackformulations sources suchasfishorpeanutflour and nutritivevalue,variousprotein pet foods. To increase protein content vegetable protein,confectioneries,and snacks, ready-to-eatcereals,textured E K. S Retinyl PalmitateinSnackExtrudates Stability ofTocopherols and Extrusion hasbothadvantages and diates becauseofthehightocopherolcontentinfryingoilanditsuptake. during snackproduction was48%and27%, respectively. Final products containedmore tocopherol thaninterme- tocopherols andretinylpalmitateinbothproducts.Reductionoffishpeanutextrudates step ofsnackproductionusingadirectsolventextractionmethod.Extrusionsignificantlyreducedthecontent 60:40, wet basis). Half-products were puffedby deep-fatfrying. wereVitamins determinedsimultaneouslyateach retinyl palmitate-fortifiedmixturesoftapiocastarchandmincedfishorpartiallydefattedpeanutflour(PDPF ABSTRACT: Fish- andpeanut-containinghalf-products were obtainedby tocopherol- extrudinganddrying and duce awidevarietyoffoodssuchas XTRUSION UKNARK Keywords: extrusion,fish,peanut,,tocopherol , J. L , J. Introduction

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PRO , AND - Roberton 1993). functional properties(O’Brien and add oxidationstabilityand modify gredients asencapsulating agentsto components oracombination ofin- with gelatin,starch,gums, andother dlet formsofvitaminAare produced Eitenmiller andLanden1999).Thebea- used forfoodfortification(Olson1990; stable thanretinol;therefore,theyare tate The esterforms,suchasretinylpalmi- oxidation (Olson1990;Ottaway1993). of oxygen,light,heat,andcatalysts sensitive tooxidationinthepresence long chainalcohol(Ottaway1993).Itis ucts, thenexpandedbydeep-fatfrying. screw machinetoproducehalf-prod- or fishtissuethatisprocessedinatwin- starch mixedwitheitherpeanutflour ously uninvestigatedsystem:tapioca extend theseobservationstoaprevi- diameter. The present studyseeksto moisture content,throughput,anddie and screwspeedadecreasein with anincreaseinbarreltemperature of vitaminsdecreasedduringextrusion, Killeit (1994)reportedthattheretention light, moisture,pH,andexposuretime. storage, suchastemperature,oxygen, countered duringfoodprocessingand of vitaminsisdependentonfactorsen- cal structures(Killeit1994).Degradation erties becauseoftheirdifferentchemi- Vitamins havedifferentstabilityprop- retention, asreportedbyKilleit(1994). ported byPhillips(1989)andonvitamin quality ofplantproteins,werealsore- sion-cooking, especiallyonnutritional (1990). Reviewsontheeffectofextru- R.D. P Vitamin Eis an essentialnutrient Vitamin Acanbecharacterizedasa (RP) HILLIPS and retinylacetate,aremore activity of ton andIngold1986).Theantioxidant the chainreaction(Sherwin1978;Bur- radicals, andpreventingpropagationof pressing theformationoflipidperoxy (Nawar 1985;Counsell1993)bysup- rate ofoxidationautoxidativespecies acceptor. This reaction candelaythe as anelectrondonororafree-radical the chromanolringintocopherolsacts dants becausethehydroxylgroupof foods, tocopherolsareusedasantioxi- which isfunctionalasanantioxidant.In er thanthatof phy (LC). Recently, Leeand others on reversed-phase liquidchromatogra- chromatography priortoquantification rated byhigh-pressuregelpermeation thylene chloride. wereVitamins sepa- solvent mixtureofisopropanol andme- acetate ininfantformulas, usingthe determination ofRPand cessfully developedamethodforthe Landen 1995,1999).(1982)suc- food matrix(Ball1988;Eitenmillerand move vitamincomponentsfromthe destruction, inordertoefficientlyre- tein bonds,whileminimizingoxidative penetrate thetissueandbreaklipopro- min AandEextractionmusteffectively solvent mixturesappropriateforvita- traction methodofchoice.Asolventor chosen oversaponificationastheex- ties, directsolventextractionisoften of simplicity, costandtime-savingabili- miller andLanden1995,1999).Because prior toquantification(Ball1988;Eiten- vitamins AandEfromfoodmaterials vent extractioncanbeusedtoextract Pike 1993;Giese1996). most matrices(Nawar1985;Rankinand Both saponificationanddirectsol- ␥ - and ␣ - and ␦ -tocopherols ishigh- ␤ -tocopherols in ␣ -tocopherol

Sensory and Nutritive Qualities of Food C by cooling water. C by Њ C for 12 h. Each fish blend C for 12 h. Њ A co-rotating twin-screw extruder Approximately 8-kg batches of the 8-kg batches Approximately (Model MPF 1700-30, APV Baker Ltd., with a England) Newcastle-U-Lyne, length-to-diameter ratio of 25:1 was used. The length and diameter of the extruder barrel were 750 and 30 mm, The slit die had dimensions respectively. a of 1 mm × 20 mm. The extruder had clam-shell barrel consisting of 4 inde- pendent temperature zones controlled by electrical heating, and 1 controlled zone at the die. Cooling water was cir- culated through the extruder barrel jacket and the die holder to maintain temperature. The barrel at the feed hopper was not heated and was main- tained at 25 to 30 Dough temperature was measured by thermocouples which extended through the barrel and contacted the moving material at 3 locations. Pressure at the slit die and torque were record- ed. Material was fed into the extruder volumetric inlet port with a K-Tron™ Corp., K2VT20, K-Tron feeder (Model Pitman, N.J., U.S.A.). The feeder was calibrated to determine the set point to give a feed rate of 27 g/min total mate- rials for all experimental runs. A screw configuration with feed screws and for- ward paddles was set up to use for both formulations (as described in the previ- Extrusion processing Before processing, the mixtures were mixtures the processing, Before 7 thawed at was prepared in duplicate batches. was prepared by mixture were prepared peanut flour and 40% tapioca starch mixing 60% kg tapioca water (3.31 PDPF without Tocopherols kg PDPF). and 2.20 starch (as described above and RP were added Five-hundred for the fish product). were slowly grams of vitamin pre-mix and blended with and gradually added starch and PDPF the rest of the tapioca N-50G, Hobart in a mixer (Model U.S.A.) which was Ohio, Troy, Mfg.Co., operat- and beater, equipped with a flat 1) without water ed at low speed (Speed The moisture con- addition for 30 min. adjusted to 40% tent of this blend was directly in the extruder during the ex- trusion process with a calibrated, pro- & N-P31, Bran portioning pump (Type Lubbe, Buffalo Grove, Ill., U.S.A.). This approach was used because the tapioca starch/PDPF blend became sticky and difficult to feed, if adjusted to 40% wa- ter prior to extrusion. After blending, the mixture was packaged, stored, and thawed as described for the fish-based product. Each peanut blend was also prepared in duplicate. ® C. Њ -tocopherol ␤ -tocopherol on -tocopherol ␦ -tocopherol stan- ␦ -, and -, and ␥ -, -, and ␤ ␥ -, -, ␣ ␣ Approximately 8-kg batches of tapi- The dards, all-trans RP, and BHT were ob- and BHT were all-trans RP, dards, tained from Sigma Chemical Co. (St. Louis, Mo., U.S.A.). The oca and minced fish were prepared by blending 60% tapioca starch and 40% minced fish (4.8 kg tapioca starch and 3.2 kg minced fish). The tocopherols and RP were manually and thoroughly mixed with 20 g of tapioca starch. Then, the vitamin pre-mix was blended with additional tapioca starch until a final vi- tamin pre-mix of 500 g was prepared. The 500 g of vitamin pre-mix were slowly and gradually added and blend- ed with the rest of the tapioca starch in a mixer (Model N-50G, Hobart This mixer U.S.A.). Ohio, Mfg.Co.,Troy, was equipped with a flat beater and op- erated at low speed (Speed 1) for 15 min. Then, minced fish was added and mixed for 15 min. At this time, the mix- ture contained approximately 36% wa- content was adjusted The moisture ter. Af- adding water. to 40% (wet basis) by ter blending, the ingredient mixture was packed in 3.25-mil plastic bags (Curlon was obtained from Henkel Corporation (La Grange, Ill., U.S.A.). All the chemi- cals and solvents were of high-perfor- mance liquid chromatography (HPLC) grade. Hexane, isopropanol, ethyl ace- tate, and anhydrous magnesium sulfate (Phil- Co. Baker J.T. from obtained were lipsburg, N.J., U.S.A.). natural natural a gum acacia carrier. Dry A vitamin carrier. a gum acacia form 250-SD in beadlet Type palmitate, by Hoff- IU/g) was provided (250,000 N.J., (Nutley, Inc. Roche mann-La palmitate dry U.S.A.). The sucrose, modified starch, RP, contained oil, butylated hy- fractionated coconut (BHT),droxytoluene sodium benzoate, add- were Tocopherols and sorbic acid. of the fat content ed at 0.02% by weight (Nawar 1985), of the finished products experiments based on preliminary in final products to showing fat content addition as- Tocopherol be 37 to 41%. content of 41%. RP sumed a final fat mixture to was added to the ingredient 250 retinol provide approximately (28 g) in the fin- equivalents per serving ished products. This concentration of vitamin A provides approximately 25% of the Required Daily Allowance (RDA) 1996). for adults (FAO Grade 863, Curwood, Oshkosh, Wis., Oshkosh, 863, Curwood, Grade U.S.A.) and these were stored at –18 Sample preparation Reagents and standards C until Њ -tocopheryl ␣ C for 12 h, prior Њ bags, stored at – ® -tocopheryl acetate -tocopheryl ␣ ) Materials and Methods C and thawed at 7 Tocopherols were added to the ex- were Tocopherols Partially defatted peanut flour Catfish were purchased live and fil- Tapioca starch was obtained from starch Tapioca Suknark and others (1999) previously Suknark and others Њ trusion mixtures to act as antioxidants during the production of half-products. Mixed natural tocopherols in powder form were provided by Henkel Corpo- ration (Kankakee, Ill., U.S.A.). The pow- der contained at least 30% by weight of (PDPF), obtained from Pert Laborato- ries, Edenton, N.C., U.S.A., was further ground in a hammer mill (Model 6×14, Champion Products, Inc., Eden Prairie, Minn., U.S.A.) which was equipped with a 1.6 mm screen. The PDPF was sealed in plastic bags and stored at 7 used. leted at the DeKalb Farmer Market in Market Farmer leted at the DeKalb Atlanta, Georgia. Belly flaps and fillets a prepared from catfish were minced in belt-and-drum mechanical meat sepa- Ltd., Work Machinery (Yasagiya rator The mince Japan). PREF., Yamaguchi was sealed in Ziploc National Starch and Chemical Co., N.J., U.S.A. Bridgewater, Tocopherols and RP Tocopherols Partially defatted peanut flour (PDPF Minced fish Tapioca starch Tapioca (1999) analyzed all-rac- analyzed (1999) acetate, tocopherols, and RP in extrud- and RP acetate, tocopherols, foods, using isopropanol ed weaning an extract- acetate as and hexane/ethyl followed by quantification ing solvent, recoveries LC. The with normal-phase all-rac- for RP and for extruded were 98.6% and 103.2% Like- respectively. products, soybean (1998) successfully wise, Lee and others extraction to the applied direct solvent E in peanuts and analysis of vitamin tree nuts. production of reported the successful snacks using fish- and peanut-based These foods were twin-screw extrusion. by consumers found to be acceptable 1998). Since such (Suknark and others extruded foods can be used to deliver micronutrients, the objective of this study was to determine the stability of RP and tocopherols in both fish- and peanut-based foods during extrusion and frying. 18 to use. Tocopherol and Retinyl Palmitate in Snacks . . . . Snacks in Palmitate Retinyl and Tocopherol

Sensory and Nutritive Qualities of Food before andafter fryingwereplacedin and cooledatambienttemperature. products weredrainedonpapertowels fried for1.5min.Afterfrying,the each (26to30pieces)weredeep-fat 2.0 trudates werecutintoapproximately stored at–18 sealed inZiploc prevent sticking.Theextrudateswere min toremovesurfacemoistureand Fort Wayne, Ind., U.S.A.)at90 Lincoln FoodserviceProducts,Inc., Experimental design Deep-fat frying 12% moisturecontent. 5 htoobtainhalf-productswith10 Co., BlueIsland,Ill.,U.S.A.)at50 in aforcedairoven(BlueMElectric Lincoln Impinger cut into15-cmlengthsanddriedina twice inseparateruns. Each duplicatedbatchwasextruded moisture contentforthePDPFmixture. termine thesetpointtogivea40% The waterpumpwascalibratedtode- ous studybySuknarkandothers,1999). Tocopherol andRetinylPalmitateinSnacks. stored at–18 placed inair-tightglasscontainers, and bags, flushedwithnitrogen gas,then sampled andsealedinZiploc 50 the half-products(extrudates driedat extrudates immediatelyafter extrusion, rate was27g/min. adjusted to40%(wetbasis)andthefeed Moisture contentofthemixtureswas set at60,90,and120 hopper), second,andthirdzoneswere temperatures ofthefirst(nearfeed 100 zones, nearthedieandatdie,of truded attemperatureinthelasttwo rpm. ThePDPFformulationwasex- at thedie,of97 in thelasttwozones,neardieand mulation wasextrudedattemperature to duplicateformulations.Thefishfor- 1998). Tocopherols andRPwere added previous study)(Suknarkandothers from theconsumeracceptancetestina and screwspeed(whichwereselected the optimumconditionoftemperature a PDPFmixture,wereextruded,using 200 obtain equilibriumtemperatureof Eau Claire, Wis., U.S.A.)for30minto 06000, NationalPrestoIndustries,Inc., in aKitchenKettle™fryer(Model Upon exitingthedie, extrudateswere The mixturesofrawmaterials,the Two formulations,afishmixture and One literofsoybeanoilwasheated ϫ Њ Ϯ Њ C), andthefriedproducts were C atscrewspeedof250rpm.The 0.1cm 5 Њ C. Half-productsweighing20g 2 Њ Њ piecesbeforebeingdried C. Samplesofsoybean oil C priortodrying.Theex- Њ C atscrewspeedof285 ® ® freezerbagsand oven(Model1450, Њ C, respectively. ® Њ C for10 freezer Њ C for BHT inhexane. by dilutingstocksolutionwith0.01% dard solutionwaspreparedseparately bined tocopherols.TheRPworkingstan- ane-BHT solutioncontaining4com- stock standardsolutiondilutedwithhex- tion oftocopherolswaspreparedfroma separately. The working standard solu- BHT. Eachstockstandard wasprepared dard anddissolvedinhexanewith0.01% pared byanaccuratelyweighedstan- (Scott 1978). nm, and91.2at298respectively 71 at294nm,86.429792.8298 ␦ on samplesfromeachextrusionrun. analyses wereconductedinduplicate trogen gas,thenstoredat–18 screw-cap testtubes,flushedwithni- son, 1990).TheE absorption,is960at326nm(Ol- (UV) which exhibitsthemaximumultraviolet all-trans RPstandardinisopropanol, Tocopherols andRPanalysis Water activity products Proximate analysisofextruded Extraction the amountof 15mLtothesample, ed tonear-boiling point,thenaddedin Isopropanol with0.01%BHT washeat- on thetocopherolsandRP.materials with aspatulatodissolvethe coating water ratioof1:4andthenit wasmixed ed tothesamplewithdrysample-to- extinction coefficient(E (Fullerton, Calif.,U.S.A.).Thespecific Beckman DU-64Spectrophotometer® of thestandardsweremeasuredbya dards preparation,purityandstability was usedtocalibratetheequipment. chloride andsodiumsolution magnesium SaturatedAquaLab Water fried productswasdeterminedusingan Procedure 30.25oftheAACC(1976). Kansas City, Mo., U.S.A.),according to 35001, LaboratoryConstructionCo., using aGoldfischextractor(Model tracted withpetroleumetherfor18h, of theAOAC (1995).Fat contentwasex- mined accordingtoProcedure925.09 position. Moisturecontentwasdeter- ucts wereanalyzedforproximatecom- ized water(80 125 mL-roundglassbottle.Hotdeion- trudate wereaccuratelyweighedina -tocopherols’ standardinethanolare Stock standardsolutionswerepre- In thetocopherols’ andRP’s stan- Water activityinhalf-productsand The half-productsandfriedprod- Samples of2to2.5ggroundex- Њ C, about8mL)wasadd- 1% 1cm of ␣ 1% -, 1cm ␤ -, ) ofthe ␥ Њ -, and C. All with aPolytron then added.Themixturewasblended water inthemixture,plus1gram,was and others1999). tion processtoobtaintherecovery(Lee was assayedateachstepoftheextrac- performed intriplicate.Aspikedsample tion. Theextractionofeachsamplewas with hexane-BHTsolutionbeforeinjec- propriate concentrationofthesample trogen gas,andthenmadetotheap- bined filtratewasevaporatedwithni- accurately determinedvolumeofcom- volume withextractionsolution.The 100-mL volumetricflaskanddilutedto which tocollectthecombinedfiltrate. the original125-mLErlenmeyerflaskin homogenization andfiltration,using were addedtothemixture,followedby point) and20mLofextractingsolution isopropanol (heatedtonear-boiling the secondextraction.Fivemillilitersof 125 mL-roundglassbottletoprocess cake wasthentransferredtothesame 10 mLofextractionsolution.Thefilter broken withaspatula,andwashed was releasedandthefiltercake 125-mL Erlenmeyerflask.Thevacuum tus (Kontes, Vineland, N.J.,U.S.A.)toa and avacuumbelljarfiltrationappara- through amedium-porosityglassfilter solution. Themixturewasfiltered nizer wasrinsedwith10mLextraction um speedfor1minandthehomoge- HPLC quantification fate (MgSO amount ofanhydrousmagnesiumsul- sample wasmixedbyspatula.An thenthe 85:15, v/vwith0.1%BHT), tion (hexane:ethylacetateinaratioof followed by30mLofextractionsolu- sium sulfatewasaddedtoabsorbwater, for 5min.Approximately9gofmagne- cating withanFS-30FisherScientific™ and mixedwithaspatulabeforesoni- mm, 5µm ucts Inc.,Calif.,U.S.A.),anda25cm Separation Prod- autosampler (Thermo Md., U.S.A.),andaSpectraSeriesAS100 detector (ShimadzuCorp.,Columbia, with anRF-10Aspectrofluorometric consisted ofanLC-6Apumpequipped ing a0.22µm nylonmembranefilter min. Themobile phasewasfilteredus- N.J., U.S.A..Theflowratewas 1.0mL/ J.T. BakerChemicalCo., Phillipsburg, isopropanol in isocratic mobilephasecontained 0.9% F.R.40 µm(Darmstadt, Germany). The pre-column packedwithPerisorb A30- Germany) whichwasequippedwitha (Hibar Fertigsaule RT., F.R. Darmstadt, The filtratewasthentransferredtoa The normal-phaseHPLCsystem 4 ) equivalenttotheweightof

Lichrosorb Si60column n ® -hexane, obtainedfrom homogenizeratmedi- ϫ 4

Sensory and Nutritive Qualities of Food - C ␤ Њ -toco- ␣ (0.08) - and Retinyl ␣ -tocopherol ␣ 0.05). -tocotrienol were C and 14.6% mois- Ͻ (0.28) Њ

␤ p tocopherol palmitate* -tocotrienol in the mild ␣ (0.07) -tocotrienol. The loss of ␣ Erickson (1992) reported that the Hakansson and others (1987) studied -tocopherol and pherol and and severe conditions were about 85 to The losses of 87% and 94%, respectively. ␤ ture content). These two extrusions were conducted at a screw speed of 200 rpm and feed rate of 318 g/min. They found that the losses of both about 63 to 67% in the mild condition and 78% in the severe condition, which were lower than in the and tocopherols in that study was higher than those in the fish and peanut extru- dates of this study. and 24.6% moisture content), and se- vere condition (197 of tocopherol in peanut extrudate com- of tocopherol in peanut during extrusion pared to fish extrudate was probably due to the difference in fatty acid composition in the different raw materials. The most predominant fatty acids occurring in fin-fish were re- ported to be (C16:0), oleic acid (C18:1), and the highly polyunsatu- such fatty acid in the n-3 family, rated as eicosapentaenoic acid (C20:5) and (C22:6) (Exler 1976). and Weihrauch predominant fatty acid in the total lipid fraction for three catfish strains was oleic acid, and the predominant poly- unsaturated fatty acids were linoleic acid (C18:2) and docosahexaenoic acid. Fish oil contains more highly polyun- saturated fatty acids that are more sus- ceptible to oxidation, which results in reduction of tocopherol (Machlin 1990; Li and others 1996). The susceptibility to rancidity and the rate of autoxidation increase as the number of double bonds increases in the fatty acid (Mach- lin 1990; Erickson 1992). the effect of extrusion-cooking on vita- min E in white flour from wheat with two conditions: mild condition (148 (0.15) (0.31) (0.12) (0.46) (0.11) -, -, ␥ ␣ -, ␣ -toco- Tocopherol Total ␤ ␣␤␥␦ - and ␣ (0.04) (0.01)(0.08) (0.24) (0.07) (0.13) (0.14) (0.26) (0.42) (0.43) (0.08) (0.04) C and 250 rpm. 1.22 c 0.15 c 4.12 c 2.17 c 7.66 cb 1.34 Њ -tocopherols de- -tocopherols -tocopherol was ␦ ␥ C. A lower reduction Њ - and ␥ 0.05) during extrusion. -tocopherol in the lowest -tocopherols in peanut ex- ␤ ␦ Ͻ

p -tocopherols were reduced signifi- -, and ␦ C at screw speed of 285 rpm, where- ␥ The fish mixture was extruded at a During extrusion, the fish and pea- Њ -, as the peanut mixture was extruded un- der conditions of 100 These conditions were chosen based on observations made during preliminary the exiting product However, studies. temperature from the extruder of both formulations was observed to be in the range of 91 to 93 temperature in the last two zones of 97 nut mixtures were extruded under slightly different conditions. creased more than the pherols (which was similar to the find- the ings in the fish extrudate). However, reduction of tocopherols in the peanut extrudate was lower than the reduction of tocopherols in the fish extrudate during extrusion. The reduction of ␤ trudate during extrusion was 18, 11, 28, of The reduction and 30%, respectively. total tocopherol in the peanut product during extrusion was 27%. The varying stability of the various forms of toco- pherol is a complex function of the ma- trix and processing conditions. An insig- nificant loss of all tocopherol forms was found in the peanut half-products dur- ing drying (similar to the results noted for the fish half-products). Fried peanut snacks contained the highest amount of tocopherols within the series, as was true with the fish snacks. * Mean values in fat-free dry basis * Mean values in fat-free Sample materialRaw mixture 1.67 b 0.25 b 7.02 b represent the standard deviations. Numbers in parentheses (0.23) ( with different letters are significantly different Means within the same column b 3.75 (0.02) b 12.79 2.65 a Table 1—Tocopherols (mg/100 g) and retinyl palmitate (mg/100 g) of fish snack g) of fish (mg/100 palmitate retinyl g) and (mg/100 1—Tocopherols Table of extrusion process in different steps products Half-product Fried product 2.70 a 0.57 a 25.61 a 13.54 a 42.30 a 1.38 b Extrudate immediatelyExtrudate after extrusion 1.28 c c 0.18 4.17 c (0.03) 2.24 c (0.03) 7.75 cb 1.44 found in the highest amount (8.6 mg/ 100 g) and and the Moreover, amount (0.27 mg/100 g) in the PDPF- and-tapioca starch mixture. The cantly ( tocopherol and total tocopherol con- tocopherol and total peanut snack are tents (dry basis) of the the significant shows 2. It Table in given difference of the vitamin content during snack production. - -, ␦ OF ␤

-, - and ␣ ␣ - and ␥ -tocopherol, ␤ EXTRACTION

(DJMRT). Signifi- © 8.02%. Recovery of Ϯ C for 1.5 min, the fish 4.28%. SOLVENT Њ

Ϯ -tocopherol was found in ␤ -tocopherol) and total toco- ␦ DIRECT

Results and Discussion 0.05) from the extrudates. After 0.05. HE tocopherols and RP in extruded

In the fish snack, the content (dry The data were subjected to analysis The data were subjected Recovery of tocopherols in the sam- In the peanut snack, the individual With the exception of Ͼ Յ -tocopherols, respectively. The reduc- respectively. -tocopherols, -, and p basis) of individual tocopherols (

Effect of extrusion and frying on vitamin E T cant difference was established at cant difference was p Tocopherol and Retinyl Palmitate in Snacks . . . Snacks in Palmitate Retinyl and Tocopherol U.S.A.) and Mass., Westboro, Inc., (MSI The by stirring under vacuum. degassed in the of tocopherols concentrations the av- calculated, using samples were between areas compared erage peak and 330 and samples at 290 standards wave- and emission nm for excitation injections. The lengths after duplicate changed to 325 and wavelengths were and emission for 470 nm for excitation RP. the determination of differ- The mean of variance (ANOVA). using Duncan’s ence was determined test multiple range samples, using hot isopropanol and hexane/ethyl acetate at the ratio of 85:15, proved to be reliable method of sample extraction. This method elimi- nated saponification which hydrolyzes the ester linkage and produces some in- terfering compounds in the extract and others 1989), and emulsion. (Tuan ples was 100.43 RP was 95.85 ␥ the lowest amount (0.25 mg/100 g). A significant decrease in tocopherols oc- 1). De- during extrusion (Table curred creases were about 40% for pherol are shown in Table 1. All toco- Table in shown pherol are pherol forms were found in the mixture of fish-and-tapioca starch raw material, which was fortified with mixed natural tocopherols. Gamma-tocopherol was found in the highest amount (7.02 mg/ 100 g) and snacks contained all tocopherols at a significantly higher level than samples at other points of the process, because samples absorbed the soybean oil. the loss of tocopherols during drying was in the range of 1 to 5%. The con- tents of all tocopherols in half-products were not significantly different ( frying at 200 tocopherols and 23 and 28 % for ␤ tion of total tocopherol in fish extru- date during extrusion was 39%.

Sensory and Nutritive Qualities of Food and friedproducts Table 4—Moisture content,fatandwateractivity( ihfidpout .7(.2 74 22)0.16(0.02) 0.15(0.01) 37.41 (2.28) 37.35 (0.33) 1.17(0.12) 1.03(0.07) 1 Numbers inparenthesesrepresentthestandarddeviations. 10.40 (0.08) Peanut fried products Fish friedproducts Peanut half-products Fish half-products vitamin A Effect ofextrusionandfrying on soybean oil Effect offryingonvitaminEin 96.75b 94.09 30.74a 99.58a 29.81 b 59.04b c 57.09 a 1.25 31.38a 1.18 b 60.75 a b 5.83 Means withinthesamecolumnwithdifferentlettersaresignificantly( Numbers inparenthesesrepresentthestandarddeviations. 5.77 b a 1.29 peanut snack frying after Oil a 6.16 fish snack Oil afterfrying c 2.00 frying before Oil 43.18a Sample 13.20a and peanutsnackproducts 26.26a 2.19 b Table 3—Tocopherols fish (mg/100g)ofsoybeanoilbefore andafterfrying a 0.65 a 3.07 2.74a 10.55 c Means withinthesamecolumnwithdifferentlettersaresignificantly( 14.44 b Numbers inparenthesesrepresentthestandarddeviations. 2.86 4.11b product Fried 6.15c 8.58b 0.24 bc Half-product 1.32c 0.27b after extrusion 1.60b Extrudate immediately mixture material Raw Sample snack productsindifferentstepsofextrusionprocess Table 2—Tocopherols (mg/100g)andretinyl palmitate(mg/100g)ofpeanut Tocopherol andRetinylPalmitateinSnacks. ture, whichwas fortifiedwithdryvita- free drybasis. RPintherawfishmix- samples werecalculatedbased onafat- detected insoybeanoilwas predominant tocopherolhomologue sample ispresented in Table 3. The oil (beforeandafterfrying)ofthe * Meanvaluesinfat-freedrybasis soybean oilwasheatedat200 and pherol whichwasfollowedby to 9%. duction oftocopherolsrangedfrom2 curred duringuse (Table 3). The re- tocopherol contentinsoybeanoiloc- 1.5 min.Asignificantreductionoftotal ture, thehalf-productswerefriedfor min toobtainequilibriumtempera- Values calculatedfromcompositionofingredients In thefishsnack,RPcontents inthe The tocopherolcontentofsoybean Sample ␤ -tocopherols, respectively. After 01)(.3 09)(.0 (1.66) (0.66) (0.70) (0.94) (0.45) (0.03) (0.36) (0.12) (0.04) (0.03) (0.07) ␤ ␦ ␣␤␥ 1.92c 10.36 c 2.84c 6.03c 0.20c 1.26 c 02)(.7 14)(.7 21)(0.10) (0.03) (2.16) (0.05) (0.48) (0.67) (0.12) (1.40) (0.41) (0.13) (0.07) (0.33) (1.02) (0.15) (0.21) (0.01) (0.21) (0.54) (0.02) (0.02) (0.47) (0.08) (0.04) (0.11) osue(b a d)a (db) Fat Moisture (wb) ␣␤␥␦ 11 00)3.84 11.15 (0.09) Њ C for30 ␥ 00)(.0 03)(0.91) (0.37) (0.70) (0.03) oohrlTotal Tocopherol Total Tocopherol -toco- ␦ -, ␣ - 200 1.44 mg/100g,asshown in Table 1). was about46%(areductionof2.65to during extrusion.ThereductionofRP min Apalmitate,decreasedsignificantly ples (Table 2). The reduction ofRPin content (fat-free drybasis)inthesam- drying didsignificantlyaffect theRP linkage ofRP. extrusion didnothydrolyze theester absence inchromatograms. Therefore, snack production,asindicated byits in thesamplesatanypointfish raw material.Retinolwasnotdetected duction fromtheinitialamountin 1.38 mg/100gRP, whichwasa48% re- fat-free basis,theproductscontained raw materialmixture.Measuredona nificantly lowerRPcontentthanthe uct, andfriedproductcontainedasig- immediately afterextrusion,half-prod- affect thecontentsofRP. Extrudate Drying at50 In thepeanutsnack,extrusion and Њ C for1.5mindidnotsignificantly 4.69 1 1 Њ oohrlpalmitate* tocopherol C for5handfryingat p p a a a a a

w w w w w Յ Յ ) ofhalf-products 0.05). 0.05). tocopherol 0.60 (0.01) 0.66 (0.01) Retinyl w

c I of extrudedproducts Chemical andnutritionalqualities higher concentrations ofpolyunsaturat- nut extrudates, probablybecauseof fish extrudateswashigherthan inpea- reduction oftotaltocopherol andRPin dation ofbothtocopherolsand RP. The trusion significantlyaffected thedegra- tocopherols andRPusingextrusion. Ex- RDA, respectively. to 28g)wereabout16,and2022%of min Ainpeanutsnacksperserving(25 RDA, respectively. Tocopherol andvita- were about15,and14to15%ofthe A infishsnacksperserving(25to28g) content (37%). Tocopherol andvitamin and peanutfriedproductshadhighfat than friedproducts(0.15to0.16).Fish half-products (0.60to0.66)werehigher 4.69%, respectively. Water activityof tained lowfatcontentof3.84and fish andpeanuthalf-productscon- products are presented in Table 4.Both water activityofhalf-productsandfried 130 increased vitaminAdestructionat ed longextrusionresidencetimeand respectively. Low screw speedsprovid- palmitate were90to100and5291%, of vitaminAacetateand source beforeextrusion.Theretention it uneconomicaltoaddaprovitaminA about 75%afterextrusion,whichmade ed that speed of700to1,000rpm.Theyreport- temperature of130 tenoid) duringextrusionatacooking ity ofvitaminAandprovitamin(caro- Lee andothers(1978)studiedthestabil- its degradation(AryaandThakur1990). velopment ofoff-flavorsaccompanies in thepresenceofoxygen,andde- production. also notfoundinanysamplesofpeanut amount intherawmaterial.Retinolwas about a27%reductionfromtheinitial 2.00 mg/100gRP(drybasis)whichwas The fat-freefriedproductcontained was20and12%,respectively.drying peanut extrudatesduringextrusionand from shortresidencetime. struction duetothesignificanteffect content mightdecreasethevitaminde- crease inscrewspeedathighmoisture creased temperature. However, anin- struction, becauseshearforcein- content probablyincreasedvitaminde- crease inscrewspeedatlowmoisture fish andpeanutsnacksfortified with T Fat content,moisture content,and Vitamin Aissusceptibletooxidation

IS Њ C. Cheftel(1986)notedthatanin-

POSSIBLE ␤ - destructionwas Conclusions

TO

PRODUCE Њ C andascrew

NUTRITIOUS

Sensory and Nutritive Qualities of Food ed. Westport, ed. rd inquiries to author inquiries to ed. New York: Marcel York: ed. New nd Conn.: AVI. p 165-179. AVI. Conn.: Handbook of Vitamins. 2 Vitamins. of Handbook Dekker, Inc. p 1-57. Inc. Dekker, in Vitamins of Technology The editor. PB, Ottaway & Professional Blackie Academic York: New Foods. Hall. p 90-113. Chapman & Phillips RD, of plant proteins. In: tional quality of and the Effect Quality Protein editors. JW, Finley p 219- Inc. Dekker, Marcel York: New Processing. 246. several natural antioxi- inhibition varies among system. J Food Sci dants in an aqueous model 58(3):653-655, 687. Plenum York: 2. New Vol book of Lipid Research. Press. p 133-210. Chem Soc 55: 809-814. and oil processing. J Am Oil consumers of extrud- tance by American and Asian products. J Food Sci ed fish and peanut snack 63(4):721-725. snacks by twin-screw ex- fish and tapioca-peanut trusion and deep-fat frying. J Food Sci 64(2):303- 308. tion of vitamin E homologues in infant formulas by HPLC using fluorometric determination. J Mi- cronutr Anal 6(1):35-45. Pro- Peanuts: JG, editor. Woodroof In: of peanuts. 3 Products. duction, Processing, MS 20000601 This research was partially supported by a grant from the is Georgia Commodity Commission for Peanuts. Gratitude also expressed to the Anantamahidol Foundation under the Thailand, for The King of Majesty, of His Patronage Royal support of Dr. Jangchud (nee Suknark) during her doctoral studies. Dept. University’s is with Kasetsart Suknark Author of Product Development and is on the Agro-Indus- try faculty in Bangkok, Thailand. Author Lee is with at Science and Technology of Food the Dept. Au- of Korea. Republic Univ., Chingbuk National of thors Eitenmiller and Phillips are with the Dept. of Georgia, at Univ. Science and Technology Food Athens, GA 30602, and Griffin, GA 30223-1797, Aaddress U.S.A., respectively. Phillips ([email protected]). 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Ingold GW, Burton Bjorck I, Asp NG. 1983. The effects of extrusion-cook- Ball GFM. 1988. Fat-Soluble Vitamin in Food Assays GFM. 1988. Fat-Soluble Ball Arya SS, Thakur BR. 1990. Effect of water activity on Arya SS, Thakur BR. 1990. AOAC. 1995. Procedure 925.09. In: Official Methods AOAC. 1995. Procedure 925.09. Adsule RN, Kadam SS, Salunkle DK. 1989. Peanut. In: Adsule RN, Kadam SS, Salunkle Ackman RG. 1995. Composition and nutritive value Ackman RG. 1995. Composition AACC. 1976. Procedure 30.25. In: Approved Methods AACC. 1976. Procedure 30.25. Tocopherol and Retinyl Palmitate in Snacks . . . Snacks in Palmitate Retinyl and Tocopherol direct solvent in fish. A acids ed fatty and hex- using isopropanol extraction, sol- acetate as an extracting ane/ethyl toco- extracted both vent, efficiently simultaneously. and RP pherols

Sensory and Nutritive Qualities of Food