Cytochemical study of intact and processed barley grain

Transcription

1 Cychemical study tact processed barley gra Gallant D.J., Monredon F. de, Bouchet B., Tacon P., Delort-Laval J. Mola-Cano J.L. (ed.), Brufau J. (ed.). New trends barley quality for maltg feedg Zaragoza : CIHEAM Options Méditerranéennes : Série A. Sémaires Méditerranéens; n pages Article available on le / Article dponible en ligne à l adresse : To cite th article / Pour citer cet article Gallant D.J., Monredon F. de, Bouchet B., Tacon P., Delort-Laval J. Cychemical study tact processed barley gra. In : Mola-Cano J.L. (ed.), Brufau J. (ed.). New trends barley quality for maltg feedg. Zaragoza : CIHEAM, p (Options Méditerranéennes : Série A. Sémaires Méditerranéens; n. 20)

2 Cychemicalstudy tactprocessed barleygra D.J. GALLANT F. de MONREDON B. BOUCHET P. TACON J. DELORT-LAVAL INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE LABORATOIRE DE TECHNOLOGIE APPLIQUEE A LA NUTRITION BP 527, NANTES CEDEX FRANCE - - d'orge tacts et traités". L'analyse microscopique par fluorescénce est un outil précieux d'étude de l'orge soum à divers traitements technologiques. met en évidence le rôle origal des produits du broyage de la grae (péricarpe, couches à aleurone, endosperme) sur les caractértiques physiques des agglomérés. montre aussi comment se modifient, sous l'effet de la chaleur, les prcipaux composants du gm d'orge : selon l'tensité du traitement, les protées s'étirent en lames mces et les gras d'amidon gorflent ou se gélatent progressivement. Introduction wheat, husk attached seed. When on a section, shows a outle a As a consequence, husk which closely attached tegument may not be at level without elimatg a a mosaic dull When on a longitudal section, small with whole attached by an tsue, scutellum, whose essential Methods Cychemical studies (Fig. la lh) useful knowledge composition as well as The most usual easiest technique (Fig. la) consts a chemical fixation by a acetic acid alcohol (10:5:85), sections beg ( iode ( dyed blue As one most wayswhich can be used study 1982; et al., 1989). may specific sensitive et al., 1959), though not commonly used, because it close well known acid-schiff) fitted techniques. consts a mild oxidation some a-glycols ( lked C2 C3 cellulose) which dye excitation staed sections at n.o : 31-34

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4 Fig. 1. (a) (al) a elongated (b) at nm, A (al: (c) hulled b) showg that husk also (al: e: (d) as b) shows that hull has been sal: (e) flaked (al: e: ss: (f) a e: (g) a - a (h) a pellet obtaed a (al: e: sal: a wall th elongated sheets. nm sample emsion at 515 nm. Oxidized emit yellow Th mode such as cell walls (which. tense deepyellow) at expense wavelengths (excitation W light at 350 nm emsion at 400 nm), pellet samples sample pellet samples cluded fixg embeddg be sectioned. gel keeps n itial position but, sectiong, it cannot be gel takes also a emsion. As a a shiftg wavelength emsion thus specific tensity dye. cells whole, elongated. homy but, on light samples by technique, (type A small polygonal (type lipids yellow; cell walls which stas shows some emsion wavelengths tsues, tsue. cells, type also vible than when staed with iode. Treatments barley gra Microstructure barley gra cells, stead one wheat cells show dense content as a staed bodies, nucleus cells light tsue, still small outside side used technologies. some dietetic foods humans animal feedg. much less used than wheat human Some dietetic foods use a sized than millg, by which husk millg vually by technologt as as showg glossy aspect obtaed. that husk has been cleaned (Fig. lc)

5 also locally by at side it show hull millg n not an about 70%. mechanical used all Such hulled much completely cleaned called equivalent polhed as small it can be tsues seem even when can be seen at that even when 90% level. Flaked (Fig. le) good quality hulled Long steamg time (45 m.) applied a steam followed by flakg between two heated Flaked flat, show place place deeply cuttg up tsues. such as elimation These with Gallant (1976) who also noticed swellg obtaed hulled milled which fed a puffg-gun, a few mutes cookg time until steam builds up which suddenly show alveolated At do not seem modified by such although th tsue many places, but a shift emsion wavelength shows that chemical between meal give samples facg each (Fig. lg). th meal beg high size between m, especially when show th case, fal a homogeneous constituted by husk divided mute small olated a cohesion between but flat husk which by which pellet ax, it somewhat give a spongy made a multiphasic gel with gas bubbles, as shown on Fig. gel shows an composition with (yellow components, which some solid elements such as cell wall (husk, mostly as th elongated sheets emsion), less seen tsue puffed gives two wavelength emsions (a yellow emsion a a still unexplaed phenomenon. shows that, when yellow emsion tact swell (solid phase), emsion, have gel gelatized sheets. modified show quite animal feedg, used whithout dehullg; millg, it can be submitted cookg. quality depends a on how milled. stance, two pellets made beg milled by two millg shown Fig. lg lh. References GALLANT, Etudes hlogiques du maïs et d'expansion et de floconnage. Ann. Zootechn. 25: et a mill give a mill. th husk easily only size specific USA. polyaldehyde moieties food analys L., ed.). J. Wiley Sons, V. (1959):