Optimization of the protein concentration process from residual peanut oil-cake

Transcription

1 grss y eites, 64 (5), otubre-diiembre, , 2013, issn: doi: /gy Optimiztion of the protein onentrtion proess from residul penut oil-ke By M.F. Gyol 1, *, M.C. Prmpro 1, V. Nepote 2, H. Fernndez 3 nd N.R. Grosso 4 1 Fultd de Ingenierí, UNRC, Río Curto, Córdob, Argentin 2 ICTA, Fultd de Cienis Exts, Físis y Nturles (UNC), IMBIV-CONICET, Córdob, Argentin 3 Fultd de Cienis Exts, UNRC, Río Curto, Córdob, Argentin 4 Quími Biológi, Fultd de Cienis Agropeuris (UNC), IMBIV-CONICET, Córdob, Argentin * Corresponding uthor: mgyol@ing.unr.edu.r RESUMEN Optimizión del proeso de preprión de onentrdo de proteín de l tort residul de mní El objetivo de este trbjo fue enontrr ls mejores ondiiones pr obtener un onentrdo de proteíns prtir de l tort residul de mní (POC). El estudio se llevó bo en POC provenientes de l extrión industril de eite de mní. Se utilizron distints ondiiones pr l extrión y preipitión de proteíns: relión gu / hrin (10:1, 20:1 y 30:1), ph de extrión (8, 9 y 10), onentrión de NCl (0 y 0,5 M), tiempo de extrión (30, 60 y 120 min), tempertur (25, 40 y 60 C), número de etps de extrión (1, 2 y 3), y el ph de preipitión (4, 4,5 y 5). Ls ondiiones de extrión y de preipitión que mostrron myor rendimiento de proteín fueron: relión de 10:1 en gu / hrin, ph de extrión de 9, en useni de NCl, 2 etps de extrión de 30 min d un 40 C y el ph de preipitión de 4,5. En ests ondiiones, el onentrdo de proteín de mní (PC) fue de 86,22%, mientrs que el porentje de proteíns de l POC iniil fue de 38,04%. Ls POC son un fuente lterntiv de proteíns que pueden ser utilizds pr el onsumo humno o l limentión niml. De est mner, se le puede dr un vlor gregdo extr un residuo de l industri del eite del mní. PALABRAS CLAVE: Conentrdo Mní Proteín Tort Residul. SUMMARY Optimiztion of the protein onentrtion proess from residul penut oil-ke The objetive of this study ws to find the best proess onditions for prepring protein onentrte from residul penut oil-ke (POC). The study ws rried out on POC from industril penut oil extrtion. Different protein extrtion nd preipittion onditions were used: wter/ flour rtio (10:1, 20:1 nd 30:1), ph (8, 9 nd 10), NCl onentrtion (0 nd 0.5 M), extrtion time (30, 60 nd 120 min), temperture (25, 40 nd 60 C), extrtion stges (1, 2 nd 3), nd preipittion ph (4, 4.5 nd 5). The extrtion nd preipittion onditions whih showed the highest protein yield were 10:1 wter/flour rtio, extrtion t ph 9, no NCl, 2 extrtion stges of 30 min t 40 C nd preipittion t ph 4.5. Under these onditions, the penut protein onentrte (PC) ontined 86.22% protein, while the initil POC hd 38.04%. POC is n lterntive soure of protein tht n be used for humn onsumption or niml nutrition. Therefore, it dds vlue to n industry residue. KEY-WORDS: Conentrte Oil-ke Penut Protein. 1. INTRODUCTION Penuts re hrterized by high oil nd protein ontent nd by low perentges of rbohydrtes nd sh. Penut seed ontins pproximtely 47-52% oil nd 25-30% protein (Grosso nd Guzmán, 1995). Previous reserh hs shown tht penut seeds re potentil soure of food-grde protein for the fortifition of food produts. Suh protein ould be onentrted from residul kes nd flours through industrilly pplible tehniques (Rhee et l., 1972, 1973; Quinn nd Beuht, 1975; Kim et l., 1992; Yu et l., 2007). The mino id profile of penut residul flours showed tht it ould be n ingredient for protein fortifition (Yu et l., 2007). Penut protein onentrtes were obtined using rw nd rosted, fermented nd unfermented penut flours (Yu et l., 2007). These uthors obtined penut protein onentrtes with 85% protein versus 50% protein in the deftted penut flour. Prtilly deftted penut flour is n inexpensive nd underutilized by-produt from the penut oil industry whih is rih in protein nd offers the sme helth nd dietry benefits of penuts but with less ft. Thus, in ountries like Argentin, where penut protein is vilble in bundne, it ould reple niml proteins for produt formultion. In Argentin, the nnul penut prodution is bout 900,000 Tns, nd nerly 30% of the totl penut prodution is used for oil extrtion, leving lrge mount of residue in the form of penut oil ke (Fint et l., 2012). There is limited informtion vilble in the literture on the penut protein onentrtion proess from residul oil-ke. The extrtion nd preipittion ph, extrtion temperture, time nd 489

2 M.F. GAYOL, M.C. PRAMPARO, V. NEPOTE, H. FERNANDEZ AND N.R. GROSSO number of extrtion stges, nd onentrtion of NCl re importnt ftors to be onsidered in the protein extrtion proess (Kim et l., 1992; Johnson nd Kikuhi, 2004; Lopes Brbos et l., 2006; Yu et l., 2007). Penut oil-ke is by-produt from the oil extrtion industry. The proess onsists of the following steps: ) lmintion, b) ooking t 110 C, ) pressing, d) solvent extrtion (hexne), nd e) solvent elimintion proess (Cheftel nd Cheftel, 2000). This rw mteril is very hrd to be treted nd hs never been used to study different extrtion onditions for produing high qulity protein onentrte. The onentrtion of proteins from this mteril ould inrese its vlue; nd it ould beome soure of new protein with pplitions in different industries nd proesses. Therefore, the objetive of this study ws to find the best proessing onditions for the preprtion of protein onentrte from residul penut oilke. 2. MATERIALS AND METHODS 2.1. Mterils Penut oil-ke (POC) is residue obtined from industril penut oil prodution fter pressing nd solvent extrtion of penut kernels. POC ws provided by the ompny Lorenzti- Ruesht y Ci from Tiino, Córdob, Argentin in Methods Penut oil-ke pre-tretment POC ws ground to flour until homogenous prtile size ws obtined (sieve Mesh 0,75 mm). The flour ws divided into two smples: penut oilke flour (P) nd penut oil-ke flour extrted with 70% ethnol (EP). The EP smple ws obtined by two stges of solid-liquid extrtion of 50 g P with 150 ml 70% ethnol (in wter, v/v) in order to eliminte soluble rbohydrtes (Conkerton nd Ory, 1976). This smple ws dried in the oven t 60 C for 2 h Protein extrtion nd preipittion Proteins from P nd EP smples (5 g) were extrted t different onditions with distilled queous solutions t different ph using mgneti shker. The different extrtion onditions were: wter/flour rtio (10:1, 20:1 nd 30:1, v/w respetively), extrtion ph (8, 9 nd 10, djusted with 1 M NOH), NCl onentrtion (0 nd 0.5 M), extrtion time (30, 60 nd 120 min), temperture (25, 40 nd 60 C) nd number of extrtion stges (1, 2 nd 3). The obtined slurries were entrifuged t 12,000 g for 20 min t 25 C in Bekmn Coulter Allegr TM 25R entrifuge (Germny) in order to eliminte residul flour. Proteins were preipitted from the obtined suspensions t different ph: 4, 4.5, nd 5 nd djusted with 1 M HCl. Then, the extrt ws entrifuged t 12,000 g for 20 min (25 C). The preipitte ws nlyzed for onentrte yield (g dry weight of the onentrte per 100 g flour), protein ontent in the onentrte (g protein per 100 g onentrte) nd protein yield (g protein in the onentrte per 100 g flour) Chemil omposition of penut oil-ke nd protein isoltes Moisture, lipids, shes nd protein ontents in POC nd PC were determined by the AOAC methods (AOAC, 1995). The nitrogen ontent ws onverted to protein perentge using the onversion ftor The rbohydrte ontent ws estimted by the differene of the other omponents using the following formul: rbohydrte ontent = 100% - (% protein + % oil + % sh) (Gyol et l., 2010) Amino id profile The mino id omposition ws determined by high performne liquid hromtogrphy (Alonso et l., 1994) using hromtogrph Perkin Elmer (Wlthm, Msshusetts, USA), series 200, equipped with UV-visible detetor nd Mirosorb-mv C18 ( mm) olumn Sttistil nlyses The experiment ws rried out in three repetitions. Dt were nlyzed using the InfoStt softwre, version 2011p (Fultd de Cienis Agropeuris, Universidd Nionl de Córdob). Mens nd stndrd devitions were lulted. Simple nd ftoril nlysis of vrine nd the LSD test were used to detet signifint differenes (α = 0.05). 3. RESULTS AND DISCUSSION 3.1. Protein extrtion nd preipittion onditions Wter/flour rtio Three wter/flour rtios (10:1, 20:1 nd 30:1, v/w) were tested for protein extrtion from P nd EP under the following onditions: ph = 9, 25 C, shking for 60 min. There were no signifint differenes in protein yields mong the wter/ flour rtios tested. Under these onditions, protein yields were between g protein 100g 1 penut flour. Therefore, the lower wter/flour rtio (10:1) ws hosen in suessive tests. The sme wter/ flour rtio ws used by Kim et l. (1992) to obtin protein isoltes from nine penut ultivrs. Yu et 490 grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

3 OPTIMIZATION OF THE PROTEIN CONCENTRATION PROCESS FROM RESIDUAL PEANUT OIL-CAKE l. (2007) working on fermented nd unfermented penut flour nd using 10:1 100:1 wter/flour rtio rnge (ph = 10, shking for 60 min t room temperture), found wter/flour rtio of 20:1 for the optimum penut protein reovery. The wter/ flour rtio of 50:1 yielded bout the sme mount of protein s the rtio 20:1; however, to remove exess wter the 20:1 rtio is more ost effetive ph nd NCl onentrtion for protein extrtion The onentrte nd protein yield results fter protein extrtion from flour smples (P nd EP) t different ph nd NCl onditions re presented in Tble 1. Smples were proessed in one extrtion stge with 10 wter/flour rtio by shking for 60 min t 25 C. After extrtion, the protein ws preipitted t ph 4.5. Dt were nlyzed by ftoril ANOVA (ftors: smple, extrtion ph, nd NCl onentrtion). Signifint effets on the onentrtion yield vrible fter protein extrtion were found for ll of these ftors nd in the intertions smple ph, smple NCl, nd ph NCl. The mximum onentrte yields (between %) were observed when P nd EP where extrted t either ph 9 or 10, in the bsene of NCl. Another vrible inluded in Tble 1 ws the protein ontent in the onentrtes. Smple nd NCl were the only ftors with signifint effets on this vrible. In generl, the verge protein ontents were higher in the onentrtes from EP with 0.5 M NCl thn from P with no NCl. The ph ftor did not show signifint effet on the protein ontent in the onentrte. The onentrte with the highest protein ontent (88.38%) ws obtined from EP t ph 9 nd 0.5 M NCl. However, signifint differenes were not found for the protein ontent with respet to the onentrte obtined from P under the sme onditions (ph 9 nd 0.5 M NCl). The lst vrible studied (Tble 1) ws the protein yield fter the flour smple extrtions. The smple ftors, ph, nd NCl nd the intertions smple NCl, nd ph NCl showed signifint effets on the protein yield vrible. The mximum protein yield were obtined when the P nd EP smples were extrted t ph 9 or 10, in the bsene of NCl, with no signifint differenes between them. Considering the obtined results, wshing in the penut flour with 70% ethnol my not be neessry sine no signifint inrese hs been obtined in the finl protein yield. In ddition, the extrtion yield of P with 70% ethnol ws 7.31%. P nd EP hd 38.04% nd 36.26%, respetively, nd the ethnoli extrt hd 10.57% proteins, whih indites tht wshing penut flour smples with 70% ethnol not only extrted soluble ompounds suh s rbohydrtes but lso ould hve extrted some soluble proteins. The extrtion of P t ph 9 nd 10 showed higher onentrtions nd protein yields thn t ph 8. The perentges of proteins reovered from POC were 35.12% nd 32.75% (g of protein in the Tble 1 Conentrte nd protein yields of protein extrts obtined from penut flour smples (P nd EP) extrted t different ph nd NCl onentrtions. Protein extrtion onditions: 10:1 wter/flour rtio, one extrtion stge, shking for 60 min, 25 C, nd ph 4.5 for protein preipittion Flour smple Extrtion ph NCl (M) Conentrte yield b * Protein ontent in the onentrte * Protein yield d * P ± 0.44 d ± 6.03 b 6.48 ± 0.98 d P ± ± 5.77 b 9.16 ± 1.43 b P ± 0.43 d ± 4.10 b 7.01 ± 0.35 d P ± ± 3.81 b ± 1.83 P ± 0.48 d ± 5.63 b 7.57 ± 0.38 bd P ± ± ± 1.28 EP ± 0.15 f ± 3.13 b 2.52 ± 0.13 f EP ± 0.05 b ± 5.03 b 9.44 ± 0.52 b EP ± 0.20 f ± ± 0.18 ef EP ± ± 4.02 b ± 0.90 EP ± 0.37 e ± 4.20 b 5.32 ± 0.31 de EP ± ± 4.05 b ± 1.71 Penut flour smples: P = penut oil-ke flour nd EP = penut oil ke flour extrted with 70% ethnol solution. b Conentrte yield: g isolte 100 g 1 flour. Protein ontent in the onentrte: g proteins 100 g 1 onentrte. d Protein yield: g proteins 100 g 1 flour. * Mens nd stndrd devitions followed by different letters in eh olumn indite signifint differenes (ANOVA, LSD test, α = 0.05). grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

4 M.F. GAYOL, M.C. PRAMPARO, V. NEPOTE, H. FERNANDEZ AND N.R. GROSSO onentrte per 100 g of protein in the flour) for different ph extrtion (ph 9 nd 10, respetively). The ddition of 0.5 M NCl hd slightly positive effet on the protein purity of onentrtes, but negtively ffeted protein yield. Rhee et l. (1973) nd Bsh nd Cherry (1976) reported tht the lrgest mounts of soluble proteins extrted in wter nd sodium phosphte buffer were t ph 9 nd 10. At ph vlues bove 10, protein levels in different extrtion medi deresed slightly s result of lkline denturtion. Ntrjn et l. (1975) reported tht penut proteins re known to be soluble t ph < 2 nd ph > 7, nd re very stble to het tretment. Yu et l. (2007) found tht the optimum penut protein reovery ws hieved t ph 10. The use of ph higher thn 10 ws not dvisble beuse of undesirble hnges suh s protein denturtion nd disolortion, whih ould ffet the funtionlity nd sensory qulity of penut protein onentrte. Liu et l (2012) obtined onentrte (89% protein) from deftted penut flour t ph 8 extrtion. In this study, the extrtion nd protein yields did not differ signifintly t either ph 9 or 10. The onditions hosen for prepring protein onentrtes from penut oil- ke were those using penut flour without wshing with 70% ethnol, nd extrting the protein t ph 9 with no NCl ph of protein preipittion The onentrte nd protein yields fter the penut oil-ke flour (P) extrtion nd preipittion t different ph (4.0, 4.5 nd 5.0) re shown in Tble 2. The protein extrtion onditions were 10:1 wter/flour rtio, one extrtion stge, shking for 60 min, ph 9, nd 25 C. The preipitte obtined t ph 4.5 showed the highest vlues in onentrte nd protein yields in omprison with the other ph onditions. The onentrtes t ph 4.5 nd 5.0 hd higher protein ontents thn tht obtined t ph 4.0. The perentges of protein reovered from POC were 23.34%, 35.12%, nd 28.55% (g of protein in the onentrte per 100 g of protein in POC) for different protein preipittion ph (ph 4, 4.5, nd 5, respetively). Yu et l. (2007) worked t ph 4.0 to seprte the penut protein from the superntnt by isoeletri preipittion beuse the penut proteins pper to be less soluble t this ph. Wu et l. (2009) found tht 4.5 ws the isoeletri ph for preipittion of penut protein for prepring protein onentrtes Extrtion time nd number of extrtion stges of proteins Protein ontent in the onentrte nd protein yield fter the extrtion of penut oil-ke flour (P) using different extrtion stges nd shking during different times re shown in Figure 1. The protein extrtion onditions were: 10:1 wter/flour rtio, ph 9, with no NCl, 25 C, nd ph 4.5 for protein preipittion. The dt were nlyzed by two-wy ANOVA (ftors: number of extrtion stges nd extrtion time). The number of stges ftor ws the only one tht showed signifint effet on the vribles studied, protein ontent in the onentrte nd protein yield. The protein yield ws higher in the first stge (between nd 11.66%) thn in the other stges. About 90% of totl proteins were extrted in the first nd seond stges. The extrtion time did not show signifint effet on the vribles studied. As onsequene of these results, the extrtion proess hosen onsisted of two extrtion stges of 30 min eh. Lopes Brbos et l. (2006) reported tht n inrese in extrtion time (1 nd 3 h) in deftted soy flour did not result in higher protein yield Extrtion temperture of proteins from penut oil-ke flour The results of the onentrte nd protein yields fter penut oil-ke flour (P) extrtion obtined t different tempertures (25, 40 nd 60 C) re shown in Tble 3. Proteins were extrted nd preipitted t the following onditions: 10:1 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, with no NCl, 25 C, nd ph 4.5 for protein preipittion. The perentges of proteins reovered from POC were 37.57%, 45.37%, nd 45.61% (g of protein Tble 2 Conentrte nd protein yields of protein extrts obtined from penut oil-ke flour (P) extrted nd preipitted t different ph. Protein extrtion onditions: 10:1 wter/flour rtio, one extrtion stge, shking for 60 min, ph 9, nd 25 C Preipittion ph Conentrte yield * Protein ontent in the onentrte b * Protein yield * ± 0.20 b ± ± ± ± 3.81 b ± ± 0.44 b ± ± 0.36 b Conentrte yield: g isolte 100g 1 flour. b Protein ontent in the onentrte: g proteins100g 1 onentrte. Protein yield: g proteins100g 1 flour. * Mens nd stndrd devitions followed by different letters in eh olumn indite signifint differenes (ANOVA, LSD test, α = 0.05). 492 grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

5 OPTIMIZATION OF THE PROTEIN CONCENTRATION PROCESS FROM RESIDUAL PEANUT OIL-CAKE % protein yield % protein in the onentrte () (b) 1 b b b Figure 1 () Protein ontent in the onentrte nd (b) protein yield of the protein extrts obtined from penut oil-ke flour (P) using different extrtion stges nd shking during different times. Protein extrtion onditions: 10:1 wter/flour rtio, ph 9, 25 C, nd ph 4.5 for protein preipittion. in the onentrte per 100 g of protein in POC) for different extrtion tempertures (25, 40 nd 60 C, respetively). The highest onentrte nd protein yields were obtined t 40 nd 60 C without signifint differenes between them. The protein ontent in the onentrte ws higher t 40 C. Lopes Brbos et l. (2006) reported n inrese in the effiieny of protein extrtion in deftted soy flour, mesuring 64 nd 88% protein extrted t 4 nd 50 C, respetively. Johnson nd b 2 b Extrtion stge b b Extrtion stge d 3 30 min 60 min 120 min 30 min 60 min 120 min Kikuhi (2004) worked on tempertures between 27 nd 66 C for the protein extrtion of soy flour observing tht the proteins beme progressively less soluble t tempertures higher thn 70 C. In the present study, 40 C ws the best extrtion temperture for prepring penut protein isoltes from penut oil-ke flour. M et l. (2010), using response surfe methodology, found the optiml prmeter for the proess of protein extrtion from deftted penut flour for primry nd seondry extrtion. They reported tht the optiml vlues re 11.79:1 liquid/ solid rtio (v/w), C extrtion temperture, nd 85% ethnol onentrtion for the primry protein extrtion; nd 8:1 liquid/solid rtio (v/w), C extrtion temperture, nd 97.5% ethnol onentrtion for the seondry protein extrtion Chemil omposition of penut oil-ke nd protein onentrte The hemil omposition of penut oil-ke (POC) nd protein onentrte (PC) from penut oil-ke flour (P) obtined t the optimum extrtion nd preipittion onditions (10 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, in the bsene of NCl, 40 C, nd ph 4.5 for protein preipittion) re shown in Tble 4. PC hd 86.22% protein ontent nd POC showed 38.04% protein ontent. Lower shes, rbohydrtes, nd moisture nd higher lipids were observed in PC thn in POC. Yu et l. (2007) reported tht the proximte omposition of penut protein onentrtes is influened by the type of penut flour used. The penut protein onentrte obtined from rosted penut flour exhibits higher protein (85.67%) nd lower ft ontents (2.9%), moisture (2.73%), nd other omponents (0.55%) thn the onentrte obtined from rw penut flour (77.8 % protein, 13% ft, 4.6% moisture, nd 1.86% other omponents). The lower protein ontent (77%) of the protein onentrte prepred from rw penut flour ws probbly due to higher ft ontent exhibiting 17% ft in rw penut flour nd 12% ft in rosted penut Tble 3 Conentrte nd protein yields of protein extrts obtined from penut oil-ke flour (P) extrted t different tempertures. Protein extrtion onditions: 10:1 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, 25 C, nd ph 4.5 for protein preipittion Extrtion temperture ( C) Conentrte yield * Protein ontent in the onentrte b * Protein yield * ± 0.47b ± 0.91 b ± 0.21 b ± ± ± 0, ± ± 0.31b ± 0.30 Conentrte yield: g isolte 100 g 1 flour. b Protein ontent in the onentrte: g proteins/100g onentrte. Protein yield: g proteins 100 g 1 flour. * Mens nd stndrd devitions followed by different letters in eh olumn indite signifint differenes (ANOVA, LSD test, α = 0.05). grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

6 M.F. GAYOL, M.C. PRAMPARO, V. NEPOTE, H. FERNANDEZ AND N.R. GROSSO flour. The ft mtter in rw penut flour ould hve redued the effiieny of protein extrtion due to the formtion of emulsion in onjuntion with protein during extrtion, resulting in higher ft nd lower protein ontents in the finl produt. The sh ontents in both protein onentrtes were bout the sme but muh lower thn those found in flours. Deresing sh ontent is expeted sine most minerls should be disrded in the superntnt fter protein preipittion (Yu et l., 2007). Wu et l. (2009) obtined penut protein onentrtes through different preprtion proesses preipitting the penut proteins t isoeletri ph of 4.5. The penut protein onentrtes were lled s follows: isoeletri preipittion penut protein onentrte, lohol preipittion penut protein onentrte, isoeletri preipittion with lohol preipittion penut protein onentrte, nd lkli solution with isoeletri preipittion, nd showed different protein ontents (72.35%, 69.54%, 71.49%, nd 96.65%, respetively). Jnghud nd Chinnn (1999) reported 81.37% protein in penut protein onentrted from deftted penut flour with hexne (oil 2%). Liu et l. (2012) reported onentrte with 89% protein from deftted penut flour. Johnson nd Kikuhi (2004) reported % protein, 4.9-7% moisture nd % sh in soyben protein isoltes. Tble 4 Chemil omposition (% w/w on dry bsis) of penut oil ke (POC) nd protein onentrtes (PC) from penut oil-ke (P) obtined t the optimum extrtion nd preipittion onditions (10:1 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, with no NCl, 40 C, nd ph 4.5 for protein preipittion) Component (%) POC* PC* Proteins ± 0.32 b ± 0.92 Moisture 5.99 ± ± 0.18 b Lipids 2.54 ± 0.23 b 7.76 ± 0.03 Ashes 8.32 ± ± 0.01 b Crbohydrtes ± ± 0.22 b * Mens nd stndrd devitions followed by different letters in eh olumn indite signifint differenes (ANOVA, LSD test, α = 0.05). Tble 5 Amino id omposition expressed s reltive perentges (g 100g 1 mino ids) of penut oil-ke (POC) nd protein onentrte (PC) prepred t optimum extrtion nd preipittion onditions (10:1 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, with no NCl, 40 C, nd ph 4.5 for protein preipittion) Amino id POC* PC* Al (Alnine) 0.97 ± ± 0.16 Arg (Arginine) 0.91 ± ± 0.19 Asx (Asprgine or sprti id) ± 0.36 b ± 0.41 Glx (Glutmine or glutmi id) ± 0.18 b ± 0.22 Gly (Glyine) 1.84 ± ± 0.09 b His (Histidine) 8.78 ± ± 0.06 IIe + Leu (Isoleuine + Leuine) 6.46 ± ± 0.15 b Lys (Lysine) 7.74 ± ± 0.05 b Phe (Phenyllnine) 5.96 ± ± 0.07 b Pro (Proline) 0.46 ± 0.06 b 2.58 ± 0.08 Ser (Serine) 2.04 ± ± 0.11 b Thr (Threonine) 0.20 ± 0.03 b 0.90 ± 0.06 Tyr (Tyrosine) 5.24 ± ± 0.07 b Cys + Vl + Met (Cysteine + Vline + Methionine) ± ± 0.13 b Essentil mino ids * Mens nd stndrd devitions followed by different letters in eh row indite signifint differenes (ANOVA, LSD test, α = 0.05). 494 grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

7 OPTIMIZATION OF THE PROTEIN CONCENTRATION PROCESS FROM RESIDUAL PEANUT OIL-CAKE 3.3. Amino id omposition in penut oil-ke nd protein onentrte Amino id omposition in penut oil ke (POC) nd in protein onentrte (PC) obtined t the optimum extrtion nd preipittion onditions (10:1 wter/flour rtio, two extrtion stges, shking for 30 min, ph 9, 40 C extrtion temperture, nd ph 4.5 for protein preipittion) re shown in Tble 5. Asprti id - sprrgine (Asx), glutmi id - glutmine (Glx), nd ysteine, vline nd metionine (Cys + Vl + Met) were the mjor mino ids in both smples (PCO nd PC). PC hd higher perentge of Asx (34.41%), Glx (24.13%), proline (2.58%) nd threonine (0.90%) with respet to POC. On the ontrry, POC hd higher ontent of glyine (1.84%), isoleuine + leuine (6.46%), lysine (7.74%), phenyllnine (5.96%), serine (2.04%), tyrosine (5.24%) nd Cys + Vl + Met (21.92%) thn PC. Ferreyr et l. (2007) nd Kim et l. (1992) lso reported higher proportions in the ontents of glutmi id nd mino ids in the penut flour nd penut protein isoltes, respetively. Other uthors (Neuere, 1969; Dwson, 1971; Bsh nd Cherry, 1976; Kim et l., 1992) reported penut seed proteins with high perentges of sprti id, glutmi id, rginine nd glyine nd low perentges of ysteine nd methionine. The ontents of id nd bsi mino ids orrespond to g nd g per 100 g penut protein, respetively (Neuere, 1969; Dwson, 1971; Bsh nd Cherry, 1976; Kim et l., 1992). 4. CONCLUSION The preprtion of penut protein onentrtes ws ffeted by hnges in the extrtion nd preipittion onditions suh s temperture, extrtion ph, ioni strength, nd number of extrtion stges, nd the preipittion ph. The extrtion onditions whih resulted in higher protein yield from penut oil-ke were 10:1 wter/ flour rtio, ph 9 for extrtion solution, with no NCl, 2 extrtion stges, shking for 30 min, 40 C, nd ph 4.5 for protein preipittion. The residul penut oil-ke is sub produt of the oil extrtion industry, nd it ould be extrted effiiently under the onditions desribed in this study in order to obtin penut protein onentrte with protein ontent higher thn 85%. This kind of protein onentrte ould be potentil soure of vegetl proteins with pplitions in different industries nd proesses. ACKNOWLEDGEMENTS We wish to thnk CONICET (Consejo Nionl de Investigiones Científis y Ténis) nd SECyT-UNC (Seretri de Cieni y Tenologí, Universidd Nionl de Córdob) for finnil support nd Lorenzti- Ruesht y Ci SA for the provision of the penut oil-ke smples. REFERENCES Alonso ML, Alvrez AI, Zpio,J Rpid nlysis of free mino ids in infnt foods. J. Liq. Chromtogr. R T 17, AOAC. (1995). Ofiil methods of nlysis of the Assoition of Ofiil nlytil hemist. Editor: Horwitz W. 13 th Ed. Wshington, DC. Bsh SM, Cherry, JP Composition, solubility, nd gel eletrophoreti properties of proteins isolted from Florunner (Arhis hypoge L.) penut seeds. J. Agri. Food Chem. 24, Cheftel JC, Cheftel, H Introduion l bioquimi y tenologí de los limentos, Vol. I, Editoril Aribi S.A., Zrgoz, Espñ. Conkerton EJ, Ory, RL Penut proteins s food supplements: A ompositionl study of seleted Virgini nd Spnish penuts. J. Am. Oil Chem. So. 53, Dwson R Comprison of frtiontion of groundnut proteins by two different methods. Anl. Biohem. 41, Ferreyr, JC, Kuskoski, EM, Bordignon Luiz, MT, Brrer Arellno, D, Fett, R Propieddes emulsifintes y espumntes de ls proteíns de hrin de hute (Arhis hypoge Lineu). Grss Aeites 58, Fint S, Alonso C, Fontn T, Spinzzé C, Costero D, Bonvehi L, Moroni A Crterizión de l Produión de Mní (Arhis hipoge)- Cmpñ 2011/2012. XXVII Jornd Nionl de Mní. 20 de setiembre de Generl Cbrer, Córdob (AR): INTA CIA. p ISBN/ISSN Gyol MF, Riveros C, Juregui P, Quirog PR, Grosso NR, Nepote V Elbortion proess, hemil nd sensory nlyses of fried-slted soyben. Grss Aeites 61, Grosso NR, Guzmán CA Chemil Composition of boriginl penut (A. hypoge) seeds from Perú. J. Agri. Food Chem. 43, Jnghud, A, Chinnn, MS Penut Protein Film s Affeted by Drying Temperture nd ph of Film Forming Solution. J. Food Si. 64, Johnson, DW, Kikuhi, S Proesmiento pr l obtenión de isldos de proteín de soj. A&G 55, Kim, N, Kim, YJ, Nm, YJ. (1992). Chrteristis nd Funtionl Properties of Protein Isoltes from Vrious Penut (Arhis hypoge L.) Cultivrs. J. Food Si. 57, Liu Y, Zho G, Zho M, Ren J, Yng B Improvement of funtionl properties of penut protein isolte by onjugtion with dextrn through Millrd retion. Food Chem. 131, Lopes Brbos AC, Ljolo MF, Genovese MI Influene of temperture, ph nd ioni strength on the prodution of isoflvone-rih soy protein isolte. Food Chem. 98, M T, Wng Q, Wu H Optimiztion of extrtion onditions for improving solubility of penut protein onentrtes by response surfe methodology. Food S. Te. 43, Ntrjn KR, Rhee KC, Cter CM, Mttil KF Destrution of fltoxins in penut protein isoltes by sodium hypohlorite. J. Am. Oil Chem. So. 52, grss y eites, 64 (5), otubre-diiembre, , 2013, issn: , doi: /gy

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