Roasting barley and other cereal grains

Transcription

1 A. Abrh 1 Norwegin University of Life Sciences, Ås, Norwy, nd Mekelle University, College of Drylnd Agriculture nd Nturl Resources, Mekelle, Ethiopi A. K. Uhlen Norwegin University of Life Sciences, Ås, Norwy F. Aby Mekelle University, College of Drylnd Agriculture nd Nturl Resources, Mekelle, Ethiopi S. Shlstrøm Nofim The Norwegin Institute of Food, Fisheries nd Aquculture Reserch, Ås, Norwy Å. Bjørnstd Norwegin University of Life Sciences, Ås, Norwy Rosting brley nd other cerel grins is n ncient trdition documented in ncient texts nd rcheologicl records, nd these foods re still commonly consumed in the highlnds of Ethiopi. Brley is primrily cultivted for feed nd mlt production but is lso stple food in number of countries in ddition to Ethiopi (13,31), such s zenbou flour in Morocco (4) nd rosted tsngp nd yue in Tibet (37). Brley my be consumed whole or s milled flour in cold nd hot dishes. In Western countries, smll but incresing quntities of perled whole grin brley, flked or milled, re used in brekfst cerels, soups, nd porridges or blended with whet to mke breds (9,21). The recent increse in consumption of brley products is due to the prtilly soluble (1 3)(1 4)- -d-glucn contined in brley tht hve beneficil helth effects such s lowering plsm cholesterol, regulting glycemic response, nd reducing the risk of hert diseses (12,27,32,38). In the midlnds nd highlnds of Ethiopi, brley contributes significntly to food security (7,13,41). Different trditionl dishes such s injer (thin, levened flt bred), kitt (unfermented, thin flt bred), kolo, tihlo, besso, nd kinkn re commonly prepred from brley. Kolo nd tihni cn be prepred from ny brley vriety, but white seeded brley cultivrs re preferred. Kolo is dehulled, well-rosted brley whole grin tht is eten s snck, lone or mixed with rosted seeds such s groundnut, chickpe, sunflower, or sfflower seeds (7,13). Whole grin kolo is commonly consumed both t home nd t vrious socil gtherings, such s fter funerls, during coffee ceremonies, fter joint trditionl workdy, or when trveling. Kolo is lso stple in monsteries (7,13). Loclly those who hve gstritis problems re dvised to et kolo nd tihni (18). Some hulless (nked) brley vrieties re cultivted for kolo production in the centrl, southern, nd northwestern res of Ethiopi (7), becuse the husk is more esily removed from these vrieties during threshing. Kolo nd tihni most commonly re mde from hulled brley vrieties, requiring lborious dehulling 1 Corresponding uthor. E-mil: ddis.hindey@umb.no or ddisbr@yhoo.com AACC Interntionl, Inc. CEREAL FOODS WORLD / 71

2 process tht trditionlly involves soking in hot wter, sun-drying, nd pounding. Tihni is milled, fine flour prepred from lightly rosted brley grins nd is used to prepre number of trditionl foods such s tihlo (tihni flour kneded into thick dough served with spicy met suce), porridge, besso (tihni flour eten fter being moistened with wrm wter nd oil), kinkn (tihni flour diluted in wter nd sugr consumed s beverge). Tihlo is brley food commonly consumed in estern Tigry nd lso in Eritre; it is served during culturl ceremonies s specil brley dish (1). Kolo nd tihni pckged in plstic bgs re now being sold t better prices in supermrkets nd locl open mrkets nd t bus stops long min rods. This expnded mrket is creting new opportunities for kolo nd tihni producers nd sellers. At the sme time, improving the qulity of kolo nd tihni products through better processing would benefit both producers nd consumers. Unprocessed brley costs 6 8 Ethiopin birr/kg, wheres well-processed nd -pckged kolo my cost up to 50 Ethiopin birr/kg in locl supermrkets (personl observtion). Although kolo nd tihni re not well-known outside Ethiopi, producers hve recently begun exporting smll quntities to communities of Ethiopins living brod, which is creting new opportunities to introduce kolo, especilly, s helthy snck in new mrkets. The effects of kolo nd tihni processing (soking, dehulling, rosting, nd milling) on the qulity of the finl product depends on properties linked to the rw mteril, such s grin color, texture, kernel hrdness, nd chemicl composition nd the pretretment of grins before milling. For exmple, rosting cuses the strch endosperm to prtilly extrude nd the strch grnules to geltinize. The prtilly cooked strch becomes more susceptible to enzymtic brekdown nd hydrolysis, which in turn ffects wter bsorption cpcity (WAC), wter solubility index (WSI), nd doughmixing properties (24,35). Generlly less highly rosted grins re preferred for kolo products becuse greter rosting produces n undesirble flvor (due to Millrd effects). These processing effects hve importnt implictions for the enduse qulities of rosted, whole grin kolo nd tihni products. However, the impct of kolo nd tihni processing on nutritionl vlue hs not been investigted. This rticle discusses 1) the impct of processing brley grins for kolo nd tihni preprtion on functionl properties nd color; 2) vrietl differences ffecting tihni nd kolo processing qulity trits; nd 3) fctors impcting the potentil sles of such trditionl foods in locl, ntionl, nd interntionl mrkets. Brley Smples Vrieties. Eight brley vrieties (Tble I) commonly grown nd utilized in brley-growing res of Tigry in northern Ethiopi (2) were brodcst in 4 m 5 m plots in rndomized complete block design with two replictions during the 2008 summer seson in Tigry: t Korem (164 km south of Mekelle; ltitude 2,500 m; rinfll 643 mm) nd t Mekelle University (ltitude 2,215 m; rinfll 348 mm). Among the brley vrieties studied, only Demhy ws hulless (nked) nd only Himblil hd purple glume; the remining vrieties hd n off-white glume. Regionlly recommended seed rtes (100 kg/h) nd fertilizer rtes Tble I. Required time (minutes) for soking, dehulling, nd rosting brley for tihni nd kolo processing Brley Tihni Kolo Vriety Soking Dehulling Rosting Soking Dehulling Rosting Ats Burgud Demhy Hftusene Himblil Rie Ses Sihumy Averge LSD (0.05) CV (%) Only tihni dehulling nd soking times were significnt t P < Vriety Demhy ws hulless nd not included in the dehulling comprison. (50 kg of ure nd 100 kg of dimmonium phosphte per hectre) were pplied, nd locl gronomic mngement prctices were followed. The grins were threshed, nd 360 g seed smples from ech plot were clened for kolo nd tihni processing nd nlyses of nonrosted kernels. The dt from the Korem nd Mekelle University sites were considered replictions (rndom effects), nd vrieties nd tretments (nonrosted, lightly rosted, nd well rosted) were considered fixed during ll dt nlyses. For ll prmeters studied, nlyses of vrince were performed both seprtely for nonrosted, lightly rosted (tihni), nd well-rosted (kolo) smples nd s fctoril nlyses using Genstt Discovery Edition 3 softwre for bioscience (VSN Interntionl). Fisher s LSD tests were used to detect differences mong tretment mens (P < 0.05 level of significnce). Simple correltions were nlyzed using Minitb, version 16, softwre (Minitb Inc.). The verge dt from the two loctions for different prmeters were stndrdized nd used in principl component nlysis (PCA) to study the reltionships mong chemicl nd physicl components using Unscrmbler X, version 10.1, softwre (CAMO Softwre AS). The results re presented s scores nd lodings in biplots. Physicl Properties. All smples of rosted nd nonrosted whole grins from ech brley vriety were nlyzed t the Norwegin University of Life Sciences, Deprtment of Plnt nd Environmentl Sciences, Ås, Norwy. Kernel hrdness ws determined for nonrosted brley grins using singlekernel chrcteriztion system (SKCS 4100, Perten Instruments NA) to nlyze 200 kernels from ech smple. Thousnd kernel weight (TKW) ws mesured (in grms) by counting smple of 1,000 kernels using numericl seed counter. All smples were milled using lbortory mill (model 3100, Perten Instruments AB) with 0.5 mm sieve. The moisture content of the flour smples ws determined by oven-drying duplicte smples of 800 mg of flour t 105 C overnight. Flour smples were stored in irtight plstic bgs before chemicl nlyses. For kolo nd tihni preprtion, lrge seeds tht re esily dehulled re preferred; the impct of hrdness depends on the milling technology used. Significnt differences (P < 0.05; Tble II) were ob- 72 / MARCH APRIL 2013, VOL. 58, NO. 2

3 served for kernel hrdness nd TKW mong the brley vrieties tested. On verge, TKW vried from 36.8 to 49.5 g mong vrieties, with men of 42.5 g. As expected the two-row vrieties Ats, Burgud, nd Ses hd higher TKW vlues compred with the six-row vrieties. The hulless vriety Demhy hd higher kernel hrdness thn the hulled vrieties. Of the hulled vrieties, the six-row Hftusene, Himblil, nd Sihumy hd the highest hrdness vlues. Men kernel dimeter, s mesured by the SKCS system, did not significntly differ mong the vrieties. This is n importnt point becuse Ethiopin brley vrieties tend to hve longer nd nrrower seed shpe thn the plump seeds commonly found in modern vrieties. Plump kernels with higher kernel weight nd lower hrdness re preferred for esier processing nd chewing of whole grin kolo. For this reson, the two-row vrieties Ats, Burgud, nd Ses would be preferred becuse of their lrge grin size. The hulless vriety Demhy would lso be preferred, but it hd the highest kernel hrdness index in this study. Aby et l. (1) reported, however, tht Demhy hd good popping qulity suitble for use in kolo, indicting there my not be simple reltionship between the physicl hrdness of nonrosted nd rosted kernels. Ngmine et l. (29) used SCKS (initilly designed for whet) to select from mong mlting brley lines nd found tht kernel hrdness ws effective for identifying the mlt qulity of lines. Using SKCS Nir et l. (30) obtined higher hrdness index for hulless thn for hulled brley. Their findings support those of the current study tht hulled brley vrieties hd lower kernel hrdness indices thn the hulless vrieties; however, wider kernel hrdness rnge (30 92) mong 959 breeding lines ws reported by Nir et l. (30). Kernel hrdness is n importnt qulity trit in whet, ctegorizing grin endosperm texture s soft versus hrd, nd hs mjor impct on dmged strch nd flour wter bsorption (16,39). Kernel hrdness hs lso been shown to ffect perling bility in brley (17). In whet, kernel hrdness is controlled by three closely linked genes locted on chromosome 5D, identified s Pin-D1, Pinb-D1, nd Gsp-1, tht code for puroindoline nd b nd grin softness proteins, respectively (28). In study of brley hordoindolines, Beecher et l. (11) found three HinA nd two HinB sequences mong eight brley cultivrs tht contined mny differences from the puroindoline sequences of whet. Their finding indictes tht vrition in hrdness mong brley cultivrs is much less thn the vrition found mong hrd nd soft whets. Bsed on this study, physicl kernel hrdness, s nlyzed by SKCS, my not be n importnt chrcter to consider when selecting rw mterils for tihni nd kolo processing. Further study is needed, involving lrger set of vrieties with wider vrition, to explore the impct of kernel hrdness on brley processing qulity. Impct of Kolo nd Tihni Preprtion Processing. Processing brley grins for food products such s kolo nd tihni is common in the highlnds of Tigry. In tihni nd kolo preprtion, brley vrieties with short soking, dehulling, nd rosting times re preferble. The soking, dehulling, nd rosting times required for tihni nd kolo processing for the eight vrieties tested re given in Tble I. The verge rosting time ws 1.4 nd 1.8 min for tihni nd kolo smples, respectively. Aprt from slight difference (P < 0.05) in the dehulling time required for tihni preprtion mong the hulled brley Fig. 1. Procedures for preprtion of lightly rosted brley flour (tihni) nd well-rosted brley grin (kolo). CEREAL FOODS WORLD / 73

4 vrieties, there were no significnt vrietl differences in processing prmeters. Vrieties Himblil nd Burgud required longer dehulling time thn did vrieties Ats, Rie, Ses, nd Sihumy (Tble I). There ws slight vrition (P = 0.079) in soking time durtion, nd gin, Burgud nd Himblil required longer soking times, while Ats nd Ses required shorter times. Soking, dehulling, nd rosting were done in three replictions by n experienced womn using trditionl processing methods for preprtion of kolo nd tihni (Fig. 1). For both processes, clened grin smples were soked in wrm wter (60 C) for n verge of 25 min, the smples were drined, nd the grins were pounded in wooden mortr nd pestle to remove the husks nd then sun-dried for 2 hr. Trditionlly, grins used for kolo re pounded more thoroughly before rosting thn re grins used for tihni. All smples were rosted (verge of 1 min, 24 sec for tihni nd 1 min, 50 sec for kolo) in circulr cly oven clled moklo with fine snd cover nd stirred to obtin uniform rosting het verge of 140 C (mesured with digitl thermometer). The rosted grins were llowed to cool t room temperture for 5 min nd were lightly pounded nd clened by ir-blowing. The soking, dehulling, nd rosting times used were optimized for ech smple bsed on locl experience nd were recorded. Smples tht were not subjected to dehulling were rosted using het tretment similr to tht described bove for processing tihni nd kolo. Soking grins in wrm wter for 25 min conditions the grins to become plump nd mkes dehulling esier (Fig. 1), lthough it is still tedious nd lborintensive. As result, hulless vrieties such s Demhy re preferble. However, nked nd seminked vrieties re still rre in Tigry. Most vilble vrieties re hulled, possibly due to other gronomic considertions. Genetic vrition does exist in hull dherence, however, nd cn be utilized. The hulled or nked chrcter of brley is geneticlly controlled by single gene locted on the long rm of chromosome 7H (36), nd the covered cryopsis llele (Nud) is dominnt over the nked gene (nud). Thus, breeding nked vrieties for cultivtion in northern Ethiopi utilizing the nud gene is techniclly simple, lthough it my be chllenge to void pleiotropic effects tht hve negtive impct on other gronomic trits. For exmple, in study to investigte the effect of the hulless Hiproly high-lysine lys gene, Blsrswthi et l. (10) found tht high-lysine lys nd norml lines segregted with respect to seeds tht were covered versus seminked in 1:1 rtio, indicting n llele effect for the prtil dherence of the hull to the seed. The report indicted tht n unknown modifier gene cused seminkedness nd lso hd negtive effect on grin yield nd kernel weight. In Ethiopi, seminked brley vrieties re being cultivted specificlly for preprtion s kolo becuse they re esily dehulled in processing (7). None of the selected vrieties in this study were seminked, but the gene for seminkedness should be investigted in further studies nd utilized in breeding brley vrieties for the Tigry re to reduce dehulling time in the processing of kolo nd tihni. Flour Color. The mjor purpose of brley rosting is to degrde digestion inhibitors nd confer crispness to products, but it hs to be blnced ginst overheting nd to minimize formtion of unwnted compounds such s crylmide. A white color is generlly preferred for tihni nd kolo products. The color of flour smples ws mesured using spectrophotometer (LbScn XE, Hunter Assocites Lb) nd color vlue system indicting the degree of whiteness (L*), redness (*), nd yellowness (b*). Test results showed vrietl differences in the color of unprocessed flour relted to differences in glume nd leurone color. Chnges in flour color vlues were due to browning nd Millrd effects (33,35). Flour color redings reveled significnt (P < 0.05) vrition mong the eight brley vrieties nd mong the nonrosted nd rosted smples. As expected, rosting significntly reduced whiteness (L*) from the nonrosted men (83.0) to the lightly rosted tihni men (78.5) nd well-rosted kolo men (71.8). Conversely, men flour redness (*) nd yellowness (b*) incresed by 64.0 nd 41.6%, respectively, from the nonrosted smples to rosted kolo smples (Tble II). Rosting ffected the flour color of ll eight vrieties tested (Tble II). The nked vriety Demhy hd lighter color fter rosting, which my be prtilly explined by the shorter rosting time used for this vriety. When rosted for kolo processing, the vriety Ats hd whiter color compred with the other vrieties, wheres Himblil, which hs purple glume, hd the lowest L* vlues for unprocessed, lightly rosted, nd wellrosted flours. Vrieties Hftusene, Himblil, Ses, nd Sihumy hd higher reductions in whiteness nd higher increses in redness nd yellowness when rosted. Procedures for Anlyzing Brley Flours Totl strch content ws nlyzed using totl strch ssy procedure (myloglucosidse/ -mylse method) (Megzyme Interntionl Irelnd Ltd.) for AACCI Approved Method nd AOACI Method s described by McClery et l. (26). Apprent mylose content ws determined using n iodine test s described by Knutson (23) nd is expressed s percentge of totl strch. Dmged strch ws nlyzed using n enzymtic tretment of fungl -mylse nd myloglucosidse s prt of strch dmge ssy (Megzyme Interntionl) procedure for AACCI Approved Method nd is expressed s percentge of flour weight. Totl -glucn content ws nlyzed using mixed-linkge ssy kit (Megzyme Interntionl) bsed on the McClery nd Codd method (25). The rosted smples were pre-extrcted with 50% ethnol to remove free sugrs, fts, nd oils s recommended. Insoluble -glucn content ws determined ccording to Anker-Nilssen (6) with some modifictions. A 200 mg smple of flour ws treted with 10 ml of 50% ethnol in boiling wter bth for 10 min, centrifuged t 1,000 g for 10 min, nd the superntnt ws removed. Distilled wter (10 ml) ws dded nd vigorously vortexed nd incubted in wter bth t 37 C for 2 hr nd vigorously vortexed for 20 sec every 15 min. The smples were centrifuged t 3,000 rpm for 10 min, nd the superntnt ws removed. The sme procedure ws repeted twice but with n incubtion time of 1 hr ech. The finl pellet contining insoluble -glucn ws nlyzed using the mixed-linkge ssy kit (Megzyme Interntionl) s described bove. Soluble -glucn content ws clculted s the difference between totl nd insoluble -glucns. Totl nitrogen content ws determined using the method described by Bremner nd Mulvney (14) nd n elementl nlyzer (model CHN-1000, LECO Corportion). Protein content ws clculted s %N 6.25, nd the results re expressed s percentge of dry weight. 74 / MARCH APRIL 2013, VOL. 58, NO. 2

5 WAC nd WSI of flour smples (nonrosted, lightly rosted, nd well rosted) were mesured using the centrifugtion method (5). Brley flour (3 g smple) ws dispersed in 30 ml of distilled wter t 30 C in preweighted centrifuge tube nd stirred constntly for 30 min in vortex mixer. The slurry ws centrifuged t 3,000 g for 15 min (model 5810, Eppendorf). The superntnt ws crefully poured into preweighted evporting dish nd dried t 135 C for 3 hr in drier (Hereus, Kendro Lbortory Products GmbH). The sme smple ws used to clculte WAC nd WSI: WAC = weight of sediment (g)/weight of dry smple (g), nd WSI (%) = dry weight of wter soluble mtter (g) 100/dry smple (g). Psting properties of strch were mesured using rpid visco nlyzer (model RVA-4, Newport Scientific Pty. Ltd.) ccording to the procedures described by Crosbie nd Ross (15). Flour smples (3.5 g bsed on 14% moisture) were mixed with 25 ml of distilled wter in cnister, nd using plstic stirring pddle, the suspension ws mixed continuously during the progrmmed heting nd cooling process of the RVA. The stndrd profile (RVA STD1) ws followed with Thermocline for Windows, version 3.0, softwre (Newport Scientific). The smple suspension ws heted to n initil temperture of 50 C, incresed to 95 C over 6 min, held t 95 C for 3 min, nd cooled to finl temperture of 50 C over 4 min. Pek viscosity (mximum hot pste viscosity), trough (lowest viscosity fter pek), brekdown viscosity (difference between pek nd trough), setbck (viscosity chnge from trough to finl viscosity), finl viscosity (viscosity t end of RVA run fter heting nd cooling phses), pek time, nd psting temperture were determined. Flour Properties Strch nd Protein Contents. The totl strch content of nonrosted brley smples vried from 49.0 to 60.1% (P < 0.05; Tble III). As expected, the hulless vriety Demhy hd the highest strch content. The strch content of the hulled vrieties rnged from 49.0 to 56.9%; the lowest totl strch contents were observed in Himblil, Hftusene, nd Ses (Tble III). The mylose content of nonrosted smples rnged from 17 to 21%. No vrietl differences were found in either mylose or protein content. The chemicl composition chnged to some extent with processing. Strch nd protein contents incresed slightly in lightly rosted (tihni) smples nd incresed further in well-rosted (kolo) smples (Tble IV). These chnges reflect the removl of the hull from rosted smples, which were removed more extensively from kolo smples. -Glucn Content. The -glucn contents of the eight commercil vrieties selected for this study were within the norml vrition reported for brley (40). Becuse the intke of -glucns my be relted to humn helth (12,38), there is n incresing interest in the documenttion of -glucn content in rw mterils, Tble II. Chrcteristics of different brley vrieties nd effects of rosting on tihni nd kolo flour color Brley Row Aleurone Nonrosted Grin Flour Color Tihni Flour Color Kolo Flour Color Vriety Type Color L* * b* L* * b* L* * b* Ats 2 White Burgud 2 White Demhy 6 White Hftusene 6 White Himblil 6 White Rie 6 White Ses 2 Blue Sihumy 6 White Men LSD (0.05) CV (%) Flour color of ll nonrosted nd rosted brley smples ws significnt t P < Tble III. Chemicl composition nd physicl properties of nonrosted brley smples Brley TKW Strch Amylose Protein β-glucn (%) DS WAC WSI PV Trough BDV FV Vriety KH (g) (%) (% of Strch) (%) Totl Soluble Insoluble (%) (g/g) (%) (cp) (cp) (cp) (cp) Ats ,392 1, ,166 Burgud ,363 1,241 1,122 2,871 Demhy ,426 1,360 1,066 2,972 Hftusene ,065 1, ,483 Himblil ,654 1,577 1,076 3,084 Rie ,002 1, ,443 Ses ,598 1,396 1,201 3,244 Sihumy ,031 1, ,664 LSD (0.05) P vlue NS NS NS NS <0.001 < < CV (%) NS = not significnt t P = KH = kernel hrdness; DS = dmged strch; WAC = wter bsorption cpcity; WSI = wter solubility index; PV = pek viscosity; BDV = brekdown viscosity; nd FV = finl viscosity. CEREAL FOODS WORLD / 75

6 s well s in finl products. In ddition, -glucn content my influence flour wter bsorption nd sensory properties. This study documented chnges in -glucn content, s well s in the rtio of soluble to insoluble -glucns with rosting. The verge -glucn content of nonrosted brley smples ws 3.8%, with rnge of 3.2 to 4.5% (Tble III). Hulless vriety Demhy hd the highest -glucn content followed by Himblil; Sihumy hd the lowest content. Rosting ffected totl, soluble, nd insoluble -glucn contents (Fig. 2). Totl -glucn content ws slightly reduced in rosted smples compred with nonrosted smples. Insoluble -glucn showed liner decrese with incresed rosting time for ll smples, with men decrese of 21.5 nd 36.7% for tihni nd kolo processed smples, respectively. Soluble -glucn content incresed (men increse of 11.7%) from lightly rosted tihni to well-rosted kolo smples. Although the chnges observed were modest, the pprent incresed solubility of insoluble -glucn in wellrosted kolo smples indictes kolo my hve nutritionl dvntge over nonrosted brley grin. To determine whether the dehulling process, which my hve removed some outer prts of the kernel contining -glucn, could cuse chnges in soluble nd insoluble -glucn contents, the rosting processes for tihni nd kolo were repeted with smples tht hd not been dehulled. The rosted smples were then nlyzed for soluble nd insoluble -glucns. Similr decreses in insoluble -glucn nd increses in soluble -glucn with rosting were chieved, indicting soking in wrm wter nd dehulling were not responsible for the observed chnges in -glucns. Consequently, these chnges my be linked to the rosting process. There is very little literture on how rosting ffects -glucn content. In study on extrction of soluble -glucn with wter, Åmn nd Grhm (3) reported tht the yield of insoluble -glucn decresed s temperture incresed from 80 to 100 C. They suggested tht the decrese in insoluble -glucn ws due to combintion of incresed solubility t incresed tempertures nd dectivtion of endogenous -glucnses. Knuckles nd Chiu (22) reported tht incresing the heting temperture from 120 to 140 C for 45 min significntly reduced -glucnse ctivity nd decresed the moleculr weight of -glucns in different brley cultivrs. Although the current Tble IV. Effects of tihni nd kolo processing (rosting) on the chemicl contents nd wter bsorption properties (verge vlues) of eight brley vrieties Dmged Totl Strch Amylose Strch Protein β-glucn WAC WSI Tretment (%, wt/wt) (%) (%, wt/wt) (%, wt/wt) (%, wt/wt) (g/g) (%) Nonrosted 53.8 b 19.3 b 3.0 c 10.8 b c 8.2 b Tihni 55.3 b b b c Kolo b 3.9 b 8.4 LSD (0.05) SED CV (%) All prmeters were significnt t P < Vlues in column followed by different letters re significntly different. WAC = wter bsorption cpcity nd WSI = wter solubility index. study did not investigte the ltter prmeters, the results my be in ccordnce with these findings. Dmged Strch, WAC, nd WSI Properties. The percentge of dmged strch in nonrosted smples vried significntly mong brley vrieties, rnging from 2.2 to 3.6% (P < 0.001; Tble III). The percentge of dmged strch in rosted smples ws four times higher thn in nonrosted smples (Tble IV), which hs importnt implictions for the digestibility of whole grin kolo nd tihni products. Significnt vrietl differences were found in the WAC nd WSI of nonrosted smples. WAC incresed from nonrosted to kolo smples by 53%, reflecting increses in dmged strch due to the combined effects of rosting nd mechnicl milling. WSI vried differently with rosting, nd the lowest vlues were found for lightly rosted tihni smples (Tble IV). In line with our results, incresed dmged strch nd WAC due to het tretment were reported by Shrm et l. (35) for brley nd Mriotti et l. (24) for different cerel grins. Holm et l. (20) lso reported incresed WSI nd WAC in extruded nd popped whet smples. In nonrosted smples, vrieties with higher kernel hrdness (excluding hulless vriety Demhy) were ssocited with higher WAC, nd both of these trits were negtively ssocited with dmged strch. Thus, n ssocition between endosperm hrdness nd n increse in dmged strch, which is common in whet, ws not found in this study. However, dmged strch vlues were low, nd vritions mong the eight vrieties were limited. Strch Psting Properties. Strch psting properties lso vried significntly mong the eight brley vrieties tested Tble V. Men strch psting properties (cp) of nonrosted nd tihni nd kolo processed grin smples from eight brley vrieties Pek Brekdown Finl Setbck Pek Psting Tretment Viscosity Trough Viscosity Viscosity Viscosity Time Temperture Nonrosted 2,316 1, ,116 1, c 84.4 b Tihni 1,592 b 1,121 b 472 b 2,172 b 1,043 b 6.36 b 77.9 c Kolo 590 c 515 c 65 c 1,406 c 881 c LSD (0.05) SED CV (%) All prmeters were highly significnt t P < Vlues in column followed by different letters re significntly different. Fig. 2. Averge of totl, soluble, nd insoluble -glucn contents of nonrosted, tihni, nd kolo smples. 76 / MARCH APRIL 2013, VOL. 58, NO. 2

7 (Tble V). Himblil, Ses, nd Demhy hd high pek viscosity, wheres Hftusene nd Rie hd high finl viscosity. Significnt chnges in strch psting properties were observed s result of tihni nd kolo processing. Mjor decreses in most st rch psting properties were observed (P < 0.01; Tble III) from nonrosted smples to tihni nd kolo smples. The mgnitude of the effects ws more thn 10-fold for brekdown viscosity. The exceptions were pek time nd psting temperture, which incresed slightly (dt not shown). Tests confirmed prtil geltiniztion of strch due to processing. For well-rosted kolo smples, degree of geltiniztion of 75% in the finl product ws clculted. These tihni nd kolo pro-cessing effects greed with effects re-ported in other studies (24,35). Correltions. The ssocitions between different qulity trits of nonrosted brley smples re presented in PCA biplot (Fig. 3); PC-1 ccounted for 34% nd PC-2 for 24% of the totl vrition. PC-1 differentited the eight brley vrieties bsed on kernel hrdness, TKW, protein content, dmged strch, nd WAC. Vrition in strch content nd WSI were ssocited with PC-2 (Fig. 3). Kernel hrdness negtively correlted with TKW (r = 0.83; P = 0.01), nd WAC negtively correlted with protein (r = 0.78; P = 0.02) nd TKW (r = 0.80; P = 0.016). Vrieties Ats nd Burgud were positively correlted with higher TKW, protein, nd dmged strch, wheres Demhy, Hftusene, nd Himblil were positively correlted with higher kernel hrdness. Sihumy nd Demhy plotted on the top of PC-2 correspond to high strch content nd WSI. Kernel dimeter positively correlted (r = 0.740; P = 0.036) with TKW, indicting tht vrieties with plump kernels nd greter TKW my be suitble for tihni nd kolo products. Commercil Considertions Kolo hs recently become more commonly vilble in locl supermrkets, nd smll quntities re being exported to communities of Ethiopins living brod. As result, the potentil for consumption of kolo s helthy snck hs grown substntilly. However, the mixing of kolo with rosted groundnuts nd the ddition of some cooking oils my ffect its shelf life nd increse contmintion with toxic compounds. Contmintion of both brley nd groundnuts used in kolo with mycotoxins is of gret concern for consumer helth nd product mrketbility. Mycotoxins do occur in brley grown in Ethiopi. Aylew et l. (8) found fltoxin B1 t μg kg 1 (verge 3.8 μg kg 1 ), deoxynivlenol (DON) t μg kg 1 (verge 70 μg kg 1 ), nd ochrtoxin t μg kg 1 (verge 17.2 μg kg 1 ) in Ethiopin brley. Storge fungi, in generl, were more importnt thn field infections. In brley from Tigry, Semunigus (34) found high levels of some fungi, but neither DON nor nivlenol were detected in ny smples from tht prticulr yer. However, very high levels of fltoxins (men μg kg 1 ), rnging from 14.1 to 55.3 μg kg 1, were found in freshly hrvested groundnut smples collected from different sites in Tigry (Assef et l., unpublished report). The fltoxin nd ochrtoxin levels detected were fr bove the limit of 0 20 μg kg 1 estblished by FAO (19) nd pose high risk for fltoxin contmintion of commercil kolo. Close monitoring of mycotoxins, nd possibly crylmides, is necessry. For kolo to be mrketed s helthy snck food, informtion on its nutritionl composition nd shelf life should be included on product pckging. Currently, no system for providing expirtion dte informtion on product lbeling is in plce in Ethiopi. Conclusions The results of this study show significnt chnges in the chemicl nd physicl properties of rw mterils during kolo nd tihni processing. The most obvious re chnges in psting properties (indicting high degree of strch geltiniztion), dmged strch, nd wter bsorption properties, s well s color. Furthermore, the results show slight decreses in totl -glucn with rosting nd incresed -glucn solubility in well-rosted kolo. Further investigtions re needed to identify optiml rosting tempertures nd times to increse soluble -glucn content without dversely ffecting the overll nutritionl vlue. Modest vritions were found mong the eight brley vrieties tested for most chemicl nd physicl trits, s well s dehulling properties of hulled brley types. The results confirm tht vrietl trits such s lrge grin size nd white seed color re importnt in the selection of rw mterils for kolo nd tihni processing. Further study of the prtilly hulless (seminked) trit should be considered for more efficient kolo nd tihni processing. Further investigtions, including genotypes of wider vritions in chemicl nd physicl trits, re lso needed to identify more precisely the breeding gols for qulity chrcteristics of brley used for kolo nd tihni processing. Fig. 3. Principl component nlysis (PCA) biplot of the first two PCs of nonrosted brley vrieties (Ats, Burgud, Demhy, Hftusene, Himblil, Rie, Ses, nd Sihumy) nd mesured trits, which explin 34% (PC-1) nd 24% (PC-2) of totl vrince. TKW = thousnd kernel weight; WSI = wter solubility index; nd WAC = wter bsorption cpcity. Acknowledgments This work ws finnced by the NUFU Seed Sfety Through Diversity Project coordinted jointly by the Norwegin University of Life Sciences (UMB) from Norwy nd by Mekelle University from Ethiopi. We thnk the Deprtment of Plnt nd Environmentl Sciences CEREAL FOODS WORLD / 77

8 of UMB for providing ll lbortory fcilities nd Mekelle University, Deprtment of Drylnd Crops nd Horticulturl Sciences, for providing vehicles for the field work. References 1. Aby, F., B yer, A. W., nd Bjørnstd, Å. Frmers seed mngement nd innovtion in vrietl selection: Impliction for brley breeding in Tigry, northern Ethiopi. Ambio 37:312, Aby, F. A. Div ersity, dpttion nd G E interction of brley (Hordeum vulgre L.) vrieties in northern Ethiopi. Ph.D. thesis. Norwegin University of Life Sciences, Ås, Norwy, Åmn, P., nd Grhm, H. Anlysis of totl nd insoluble mixed-linked (1-3), (1-4)- -d-glucns in brley nd ots. J. Agric. Food Chem. 35:704, Amri, A., Oummou, L., nd Nssif, F. Brley-bsed food in southern Morocco. Pge 22 in: Food Brley: Importnce, Uses nd Locl Knowledge. Proceedings of the Interntionl Workshop on Food Brley Improvement. S. Grndo nd H. G. Mcpherson, eds. ICARDA, Aleppo, Syri, Anderson, R. A., C onwy, H. F., Pfeifer, V. F., nd Griffin, E. L. Roll nd extrusioncooking of grin sorghum grits. Cerel Sci. Tody 14:372, Anker-Nilssen, K. In vitro strch degrdtion in brley (Hordeum vulgre L.) Effect of growth temperture nd strch genotype. Ph.D. thesis. Norwegin University of Life Sciences, Ås, Norwy, Asfw, Z. The brle ys of Ethiopi. Pge 77 in: Genes in the Field: On-Frm Conservtion of Crop Diversity. S. B. Brush, ed. Lewis Publishers, Boc Rton, FL, Aylew, A., Fehrmn n, H., Lepschy, J., Beck, R., nd Abte, D. Nturl occurrence of mycotoxins in stple cerels from Ethiopi. Mycopthologi 162:57, Bik, B.-K., nd Ul lrich, S. E. Brley for food: Chrcteristics, improvement, nd renewed interest. J. Cerel Sci. 48:233, Blsrswthi, R., Køire, B., nd Doll, H. The concentrtion nd yield of hordein nd some lysine-rich proteins s influenced by the lys gene of Hiproly brley. Heredits 100:225, Beecher, B., Smidns ky, E. D., See, D., Blke, T. K., nd Giroux, M. J. Mpping nd sequence nlysis of brley hordoindolines. Theor. Appl. Genet. 102:833, Behll, K. M., Schol field, D. J., nd Hllfrisch, J. Diets contining brley significntly reduce lipids in mildly hypercholesterolemic men nd women. Am. J. Clin. Nutr. 80:1185, Bekele, B., Alemyeh u, F., nd Lkew, B. Food brley in Ethiopi. Pge 53 in: Food Brley: Importnce, Uses nd Locl Knowledge. Proceedings of the Interntionl Workshop on Food Brley Improvement. S. Grndo nd H. G. Mcpherson, eds. ICARDA, Aleppo, Syri, Bremner, J. M., nd Mulvney, C. S. Nitrogen Totl. Pge 595 in: Methods of Soil Anlysis. Prt 2. 2nd ed. Agron. Monogr. 9. A. L. Pge nd R. H. Miller, eds. Americn Society of Agronomy nd Soil Science Society of Americ, Mdison, WI, Crosbie, G. B., nd Ross, A. S. The RVA Hndbook. AACC interntionl, St. Pul, MN, Drlington, H. Strc h grnule ssocited proteins in brley nd whet. J. Cerel Sci. 32:21, Edney, M. J., Rossn gel, B. G., Endo, Y., Ozw, S., nd Brophy, M. Perling qulity of Cndin brley vrieties nd their potentil use s rice extenders. J. Cerel Sci. 36:295, Etich, E., Berghofe r, E., nd Grusgruber, H. Utiliztion of brley (Hordeum vulgre L.) lndrces in the highlnds of West Shew, Ethiopi. Plnt Genet. Resour. 7:154, FAO. Worldwide regul tions for mycotoxins in food nd feed in Food Nutr. Pp. 81. Food nd Agriculture Orgniztion of the United Ntions, Rome, Holm, J., Bjorck, I., nd Elisson, A. Effects of therml processing of whet on strch: I. Physico-chemicl nd functionl properties. J. Cerel Sci. 8:249, Jdhv, S. J., Lutz, S. E., Ghorpde, V. M., nd Slunkhe, D. K. Brley: Chemistry nd vlue-dded processing. Crit. Rev. Food Sci. Nutr. 38:123, Knuckles, B. E., nd Chiu, M.-C. M. -Glucnse ctivity nd moleculr weight of -glucns in brley fter vrious tretments. Cerel Chem. 76:92, Knutson, C. A. A sim plified colorimetric procedure for determintion of mylose in mize strches. Cerel Chem. 63:89, Mriotti, M., Almpr ese, C., Pgni, M. A., nd Lucisno, M. Effect of puffing on ultrstructure nd physicl chrcteristics of cerel grins nd flours. J. Cerel Sci. 43:47, McClery, B. V., nd Codd, R. Mesurement of (1-3),(1-4)- -d-glucn in brley nd ots A stremlined enzymtic procedure. J. Sci. Food Agric. 55:303, McClery, B. V., Gib son, T. S., Solh, V., nd Mugford, D. C. Totl strch mesurement in cerel products Interlbortory evlution of rpid enzymtic test procedure. Cerel Chem. 71:501, McIntosh, G. H., Why te, J., McArthur, R., nd Nestel, P. J. Brley nd whet foods Influence on plsm-cholesterol concentrtions in hypercholesterolemic men. Am. J. Clin. Nutr. 53:1205, Morris, C. F. Puroin dolines: The moleculr genetic bsis of whet grin hrdness. Plnt Mol. Biol. 48:633, Ngmine, T., Sekiw, T., Ymguchi, E., Oozeki, M., nd Kto, T. Reltionship between qulity prmeters nd SKCS hrdness index in mlting brley. Inst. Brew. Distill. 115:92, Nir, S., Ullrich, S. E., Blke, T. K., Cooper, B., Griffey C. A., et l. Vrition in kernel hrdness nd ssocited trits in U.S. brley breeding lines. Cerel Chem. 87:461, Newmn, C. W., nd N ewmn, R. K. A brief history of brley foods. Cerel Foods World 51:4, Newmn, R. K., Newm n, C. W., Hofer, P. J., nd Brnes, A. E. Growth nd lipid metbolism s ffected by feeding of hullless brleys with nd without supplementl -glucnse. Plnt Foods Humn Nutr. 41:371, Rufián-Henres, J. A., Delgdo-Andrde, C., nd Morles, F. J. Assessing the Millrd rection development during the tosting process of common flours employed by the cerel products industry. Food Chem. 114:93, Semunigus, L. Occurre nce of fungi gener nd DON in brley grins collected from mjor brley growing res of Tigry, northern Ethiopi. M.S. thesis. Mekelle University, Mekelle, Ethiopi, Shrm, P., Gujrl, H. S., nd Rosell, C. M. Effects of rosting on brley -glucn, therml, texturl nd psting properties. J. Cerel Sci. 53:25, Tket, S., Amno, S., Tsujino, Y., Sto, T., Sisho, D., et l. Brley grin with dhering hulls is controlled by n ERF fmily trnscription fctor gene regulting lipid biosynthesis pthwy. Proc. Ntl. Acd. Sci. USA 105:4062, Tshi, N. Food prepr tion from hull-less brley in Tibet. Pge 115 in: Food Brley: Importnce, Uses nd Locl Knowledge. Proceedings of the Interntionl Workshop on Food Brley Improvement. S. Grndo nd H. G. Mcpherson, eds. ICARDA, Aleppo, Syri, Tiwri, U., nd Cummi ns, E. Met-nlysis of the effect of -glucn intke on blood cholesterol nd glucose levels. Nutrition 27:1008, Turnbull, K.-M., nd Rhmn, S. Endosperm texture in whet. J. Cerel Sci. 36:327, Ullrich, S. E., Clnc y, J. A., Eslick, R. F., nd Lnce, R. C. M. -Glucn content nd viscosity of extrcts from wxy brley. J. Cerel Sci. 4:279, Yirg, C., Alemyehu, F., nd Sinebo, W. Brley-bsed frming systems in the highlnds of Ethiopi. Ethiopin Agriculturl Reserch Orgniztion (EARO), Addis Abb, Ethiopi, / MARCH APRIL 2013, VOL. 58, NO. 2

9 Addis Abrh ws born in 1976 in Chercher town, Tigry, Ethiopi. He grduted with B.S. degree in drylnd crop sciences in 1999 from Mekelle University, Deprtment of Drylnd Crops nd Horticulturl Sciences. He pursued n M.S. degree in plnt breeding nd grduted in 2003 from Alemy University, Ethiopi. Addis worked s n ssistnt resercher in the Field Crops Improvement Division of the Mekelle Agriculturl Reserch Center from 2000 to He ws employed in 2006 t Mekelle University s lecturer in the Deprtment of Drylnd Crops nd Horticulturl Sciences. Addis joined the Norwegin University of Life Sciences, Deprtment of Plnt nd Environmentl Sciences, in Norwy in 2008, where he performed his Ph.D. study in plnt breeding nd genetics, grduting in He is currently working s n ssistnt professor t Mekelle University, Ethiopi. Addis cn be reched t ddis.hindey@umb.no or ddisbr@yhoo.com. Anne K. Uhlen holds degree in crop science (1983) nd Ph.D. degree in whet qulity (1989). She hs gined experience in whet breeding ( ) nd conducted reserch on the qulity of cerels nd other seed crops grown in Norwy. Her reserch ctivities hve been focused on gluten proteins nd bredmking qulity the effects of genetic vrition in gluten protein composition nd environmentl effects on gluten qulity, s well s on polyscchrides, in brley nd ots importnt for food nd feed. Anne hs been n ssocite professor t the Norwegin University of Life Science since 1994 nd professor since 2009, teching courses on plnt production in cerels nd seed crops, s well s cerel food science. Fetien Aby is n ssocite professor in plnt breeding nd seed bsed t Mekelle University, Ethiopi. She hs mster s degree in rurl resource mngement from the University of Wles, Bngor, U.K. She crried out her Ph.D. work t the Norwegin University of Life Sciences in G E interction nd focused her reserch on decentrlized (breeding for specific dpttion) nd prticiptory plnt breeding. Fetien is coordintor of the NUFU-supported SSD (Seed Sfety through Diversity) project. Her interest is in promoting nd recognizing smllholders innovtion in plnt breeding, use vlue, nd locl food production through joint experimenttion nd promotion of their locl cretivity. Fetien cn be reched t fetien.by@yhoo.com. Senior Reserch Scientist Stefn Shlstrøm performed M.S. nd Ph.D. theses work t the University of Umeå, Sweden, with focus on the enzymes involved in photorespirtion in plnts. After his Ph.D. studies he worked s postdoc t the University of Life Science, Ås, Norwy, where he studied proteolytic enzymes in propionic nd lctic cid bcteri. In 1990 he ccepted position s reserch scientist t Nofim AS, Ås, Norwy. His reserch interests includes purifiction nd chrcteriztion of cerel strches, dietry fiber, nd pssenger molecules, e.g., phenolic cids. An importnt tsk is to study their biologicl ctivities using both in vitro nd in vivo models. Recently Stefn hs been involved in different reserch projects finnced by the Europen Union, Nordic Industril Fund, nd Norwegin Reserch Council nd projects finnced by the industry relted to brley nd ots. He hs lso been leder in the Dietry Fibre nd Helth strtegic reserch progrm t Nofim AS. Stefn is n AACC Interntionl member. Åsmund Bjørnstd (born in 1951) hs been professor of plnt breeding in the Agriculturl University of Norwy since 2001 (since 2004, the Norwegin University of Life Sciences). Åsmund s min current interests re genetic diversity nd mpping of Fusrium resistnce in ots nd whet nd breeding of brley vrieties for Tigry (Ethiopi) using prticiptory methods. He hs recently (2012) published populr science book titled Our Dily Bred A History of Cerels. CEREAL FOODS WORLD / 79