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Ferulic Acid and its Position Among the PhenolicCompounds of WheatJoanna Klepacka a & Łucja Fornal b

a Institute of Commodities Science and Food Quality Evaluation, University of Warmia andMazury in Olsztyn, Polandb Chair of Food Plants Chemistry and Processing, University of Warmia and Mazury inOlsztyn, Poland

Available online: 18 Jan 2007

To cite this article: Joanna Klepacka & Łucja Fornal (2006): Ferulic Acid and its Position Among the Phenolic Compounds ofWheat, Critical Reviews in Food Science and Nutrition, 46:8, 639-647

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Critical Reviews in Food Science and Nutrition, 46:639–647 (2006)Copyright C©© Taylor and Francis Group, LLCISSN: 1040-8398DOI: 10.1080/10408390500511821

Ferulic Acid and its Position Amongthe Phenolic Compounds of Wheat

JOANNA KLEPACKAInstitute of Commodities Science and Food Quality Evaluation, University of Warmia and Mazury in Olsztyn, Poland

�LUCJA FORNALChair of Food Plants Chemistry and Processing, University of Warmia and Mazury in Olsztyn, Poland

Ferulic acid (3-methoxy-4-hydroxycinnamic acid) is the main phenolic acid occurring in cell walls of monocotyledones. Dueto its blue-and-white fluorescence it is easily identified and is located in the cereal grain morphological parts. Its 40-foldgreater concentration was found in the cells walls of the seed coat and aleuronic layer than in the cells walls of endosperm.Most often, it is linked by ester bonds with hemicellulose chains, mainly with arabinose residues and it also polymerizes withlignin through ether bonds. However, ferulic acid in the pentosane molecules forms specific complexes with proteins throughchemical bonds with amino acids. It is interesting to mention the theory of the pentosane gel formation in which a great roleis assigned to ferulic acid. An oxidized form of ferulic acid—diferulic acid—produces gel formation by linking two pentosaneor protein molecules.

The blue-and-white fluorescence of ferulic acid can be applied to determine flour contamination with grain coat particlesand its ability to form complexes with pentosanes and proteins is important in the formation of dough texture with itssemi-elastic properties.

Keywords ferulic acid, phenolic compounds, wheat, cereal grains

INTRODUCTION

Interest in phenolic compounds originates mainly from theirwell-known antioxidant features(Onyeneho and Hettiarachchy,1992; Sikorski, 1994; Buchwald and Czapska, 1995; Amiotet al., 1996; Maillard et al., 1996; Bourne and Rice-Evans,1998; Deighton et al., 2000; Zielinski and Koz�lowska, 2000).Particular attention has been paid to their role as “free radicalscavengers” and has provoked numerous studies into phenoliccompounds in many plants, including cereals.

The antioxidant activity of extracts from cereal products hasbeen found to correlate with the content of plant phenols oc-curring in these cereals (Zielinski and Koz�lowska, 2000; Burdaet al., 2001). Cereals contain a wide range of phenolic com-pounds, of different chemical structures, of which phenolic acidsare of great significance (Kahkonen et al., 1999). In wheat grains,ferulic acid occurs in the highest amounts (McKeehen, 1999).Due to the valuable functions and content of phenolic com-pounds, including ferulic acid, cereal products may constitute avaluable source of phenolic compounds in the human diet (Parr

Address correspondence to Joanna Klepacka, Institute of Commodities Sci-ence and Food Quality Evaluation, University of Warmia and Mazury, PLACCIES2YWSKI 1, Olsztyn, 10-718. Poland. E-mail: klepak@uwm.edu.pl

and Bolwell, 2000). The phenolic compounds, especially ferulicacid, occurring in cereals also exhibit technological functions.

What, therefore, is current the stage of knowledge of thechemical structure and properties of phenolic compounds, par-ticularly the role of the ferulic acid in wheat grain?

CLASSIFICATION AND PROPERTIES OFPOLYPHENOLS

Phenolic compounds appear only in plants and are their ma-jor secondary metabolites. Phenylalanine and tyrosine are theirprecursors. Phenolic compounds are characterized by a high di-versity of chemical structure. They occur in a free as well as abound form with such compounds as saccharides and organicacids. Over 800 aglycones have been identified and ca. 4000 ofthese compounds occur in the form of glycosides, esters as wellas in other combinations (Oszmianski, 1988; Lachman et al.,1991; Ashraf et al., 1994; Rozes and Peres, 1998; Scalbert andWilliamson, 2000).

Due to the structure of the basic carbon skeleton, polypheno-lic compounds can be divided into three subgroups:

− C6 − C1 − phenyl-carboxyl acids—derivatives of benzoicacid, e.g. protocatechuic acid and gallic acid;

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640 J. KLEPACKA AND �L. FORNAL

Figure 1 Benzoic acid and its derivatives (Borkowski, 1993).

− C6 − C3 − phenyl-propene acids—derivatives of cinnamicacid, e.g. ferulic acid or caffeic acid;

− C6 − C3 − C6 − flavonoids which include:• flavones and flavonols, e.g. quercetin and rutin;• flavanones, e.g. hesperidin and naringin;• flavanols: catechins, leuco- and proanthocyanins;• anthocyanins, e.g. cyanin and malvidin;• chalcones, e.g. phlorizidin;• isoflavones and aurones—rarely occurring in food.

The most important groups of polyphenols which affect thesensory properties of food include: anthocyanins—responsiblefor the red color of many fruit and flower species; and phenolicacids, catechins, and proanthocyanidins which as the precursorsof tannins and substrates of enzymatic browning are responsiblefor the color, flavor and odor of many food products (Sikorski,1994).

To date, no toxic effect of plant- originated polyphenols hasbeen found in human diet, although their role and metabolism inthe human organism has not yet been fully studied. Flavonoidsare the most known and described for their protective role againstcardiovascular diseases resulting mainly from their stabilizingactivity on the walls of capillary vessels (Feng and McDonald,1989; Chu et al., 2000; Parr and Bolwell, 2000; Kris-Ethertonet al., 2002).

CLASSIFICATION, PROPERTIES AND OCCURRENCEOF PHENOLIC ACIDS IN CEREAL GRAINS

Two sequences of phenolic acids are of significantimportance—derivatives of benzoic and cinnamic acids which

Figure 2 Cinnamic acid and its derivatives (Borkowski, 1993).

have been the subject of research since at least the 1970s(Koz�lowska et al., 1977; Salomonsson et al., 1978; S�lominski,1980; Krygier et al., 1982; D↪abrowski and Sosulski, 1984; Nord-kvist et al., 1984; Rotkiewicz et al., 1984; Collins et al., 1991;Szajdak and Zyczynska-Ba�loniak, 1994; Bocchi et al., 1996;Dimberg et al., 1996; Stefanowska et al., 1996; Opoku et al.,1997; Phelps and Young, 1997; Sharma et al., 1998; Watanabeet al., 1998; Andreasen et al., 1999; Kennedy et al., 1999; Mc-Keehen et al., 1999; Amakura et al., 2000; Parr and Bolwell,2000; Silva et al., 2000).

The chemical structures of benzoic and cinnamic acids aswell as their derivatives are presented in Figures 1 and 2.

The results of studies on the quality and content of phenolicacids in wheat grains are not equivocal. They are different interms of the range of the acid contents as well as the form inwhich they occur in. Sosulski et al. (1982) analyzed the phenolicacids occurring in rice, oat, maize, and wheat. They found cis-ferulic and vanillic acids among the acids released from esterbonds while in insoluble fraction trans-ferulic acid which oc-curs in the highest amounts in maize (Table 1). Among the freephenolic acids in triticale, Maga and Lorenz (1974) also foundvanillic, ferulic, and p-coumaric acids.

Hatcher and Kruger (1997) also characterized three fractionsof phenolic acids in wheat grain: free acids, acids in soluble esterbonds and acids occurring in insoluble complexes. In the latter,only ferulic acid was found. Depending on the wheat variety,its content ranged from 274.8 to 337.6 ppm. Free phenolic acidsconstituted 2–3.5% of the total phenolic acids. Of all free pheno-lic acids, ferulic acid was found to dominate. Its content rangedfrom 0.2 to 6.3 ppm, depending on the wheat variety. In esterbonds, sinapic, ferulic, vanillic and syringic acids were found inthe highest amounts reaching: 16.9 – 30.5 ppm, 8.6 – 17.6 ppm,

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Table 1 Content of phenolic acids released from ester bonds and frominsoluble fraction (Sosulski et al., 1982)

Grain [ppm]

Phenolic acids Rice Oat Maize Wheat

Phenolic acids released from ester bondscis-ferulic 1,6 1,9 5,1 tracetrans-ferulic 9,6 6,7 44,9 3,8Vanillic 0,8 3,5 2,7 3,0

Phenolic acids released from insoluble fractioncis-ferulic trace 0,7 0,8 tracetrans-ferulic 63,1 54,6 208,6 58,6

4 – 7.2 ppm, and 1.7–6.5 ppm, respectively. Therefore, the re-sults of the studies by Hatcher and Kruger (1997), support thethesis that the content of ferulic acid is a variety-dependent trait.

Weidner et al. (1999) analyzed the content of phenolic acidsin kernels of Polish varieties of wheat, rye, and triticale. Thecharacteristics covered three fractions: free phenolic acids, acidsreleased from soluble ester bonds, and acids released from sol-uble glycosides. The results of these studies clearly indicate ahigher content of ferulic acid in grain depending on the vari-ety (Elena, Alba variety), especially when determined in esteror glycoside bonds. Besides ferulic acid, sinapic, p-coumaric,and caffeic acids were present in all the analyzed phenolic frac-tions in wheat, rye, and triticale. Papers by Boskov-Hansen et al.(2002) also support the thesis that the following acids occur inthe highest amounts in rye: ferulic (1079 µg/g d.m.), sinapic (76µg/g d.m.) and p-coumaric (35 µg/g d.m.). Ciska et al. (2003)analyzed the content of phenolic acids in five cereal varieties:wheat, barley, rye, oat and buckwheat. The following acids oc-curring in a free or ester-bonded form were identified in the ana-lyzed grains: vanillic, syringic, ferulic, and coumaric. Rye, oat,and buckwheat grain also contained sinapic and caffeic acids.Ferulic acid predominated among the phenolic acids found inthe analyzed varieties of wheat and barley while syringic acidpredominated in the grain of oat, rye, and buckwheat. The to-tal amount of phenolic acids occurring in both forms was thehighest in rye and oat.

FERULIC ACID IN WHEAT GRAIN—ITS PROPERTIESAND OCCURRENCE

Studies into the occurrence of phenolic acids in cereal grainssupport the thesis of the distinguished content of ferulic acidamong the phenolic compounds of wheat grain. This resultsfrom, among others, the fact that ferulic acid (3-methoxy-4-hydroxycinnamic acid) is the major phenolic acid occurring inthe cell walls of monocotyledones (Smith and Hartley, 1983;Micard et al., 1994; Cabrera et al., 1995; Bartolome et al., 1997;Kroon et al., 1997; Lempereur et al., 1997; Madhavi et al., 1997;Wakabayashi et al., 1997; Rousseau and Rosazza, 1998; Zupferet al., 1998; Muheim and Lerch, 1999). The following acids

are its precursors: p-coumaric (p-hydroxycinnamic) and caffeic(3,4-dihydroxycinnamic). They are synthesized in plants fromphenylalanine and L-tyrosine on the shikimic pathway (Bourneand Rice-Evans, 1998). Ferulic acid appears in the form ofcis- and trans-isomers (Sosulski et al., 1982). Molecules of fer-ulic acid may bind oxygen atoms forming dimers (Ishii, 1997;Oosterveld et al., 1997; Saulnier and Thibault, 1999). Numer-ous dehydrodimers of ferulic acid, including 5-5′-diferulic acid[(E,E)-4,4′-dihydroxy-5,5′-dimethoxy-3,3′-bicinnamic] occur-ring in the largest amounts in cereal grain were found in thepentosane fraction of wheat (Ng et al., 1997; Andreasen et al.,2000a,b; Bunzel et al., 2000; Renger and Steinhart, 2000). Theblue autofluorescence of ferulic acid confirms its presence in thecell walls of the wheat kernel aleurone layer (Smart and O’Brien,1979; Seitz, 1989; Morales et al., 1996; Regnier and Macheix,1996). Ferulic acid esters reveal blue fluorescence at pH 5.8 andchange their color into green at pH 10 (Ishii, 1997 after Harrisand Hartley, 1976).

Fulcher et al. (1972) noted that the blue-white autofluores-cence of wheat kernel cell walls is exactly the same as thatrevealed by pure crystals of ferulic acid. It indicates that ferulicacid, whose concentration in the aleurone layer is very high,may be responsible for the fluorescence of cell walls. It wassupported by the studies of Smart and O’Brien (1979).

Rotkiewicz et al. (1984) found that the ferulic acid contentin wheat kernels in all its forms amounts to 31.0 µg/g. On theother hand, Pussnawin and Wetzel (1987) determined the totalferulic acid content at the level of 500 µg/g. Rybka et al. (1993)confirmed the predominating character of this acid among freephenolic acids and those in ester bonds. Lempereur et al. (1997)showed a high genetic (variety-dependent) diversity of the fer-ulic acid content in durum wheat grains (from 0.693 to 2.443mg/g d.m.). The mean content of that acid was higher comparedto that reported for Triticum aestivum.

Hatcher and Kruger (1997) analyzed the content of phenolicacids, including ferulic acid, in grains and flour of different purityobtained from five quality classes of Canadian wheat: CWSWS(Canadian Western Soft White Spring), CPSR (Canadian PrairieSpring Red), CWRW (Canadian Western Red Winter), CWRS(Canadian Western Red Spring), and CWES (Canadian West-ern Extra Strong). They isolated three fractions of phenolicacids: free phenolic acids, acids bound into insoluble complexes,and acids occurring in soluble ester linkages. The highest share(80%) in the total sum of phenolic acids was reported for acidsoccurring in insoluble complexes. Of all the acids in this frac-tion, only ferulic acid could be determined quantitatively; itscontent in the whole kernels ranged from 274.8 to 337.6 µg/g,depending on the quality class of wheat. The lowest content wasfound in CWRW and CWES class grain. These classes repre-sent the highest quality. This suggests a relation between hightechnological quality of wheat kernels and low content of ferulicacid in insoluble linkages. The content of ferulic acid determinedin the soluble ester linkages of wheat grains reached 8.6–17.6µg/g, while in the fraction of free phenolic acids—from 0.2 to6.3 µg/g, depending on the wheat variety.

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The results obtained by other authors also confirm the the-sis of the predominating character of ferulic acid, however, itscontent found in wheat kernels indicates great discrepancieswhich result from the varied properties of the analyzed varieties(Hatcher and Kruger, 1997; Weidner et al., 1999).

CONTENT OF FERULIC ACID IN BRAN

Quoting the studies of Munck et al. (1979), Symons and Dex-ter (1993) claimed that determination of components revealingfluorescence, e.g. ferulic acid, and occurring in high concentra-tions in selected layers of the kernel may indicate the purity offlour. Jensen et al. (1982) used fluorescence to determine thecontamination of flour with particles of aleurone layer and seedcoat. Pussayanawin and Wetzel (1987) showed that ferulic acidmay indicate the degree of flour purity, which may then be help-ful in determining its milling quality. Kelfkens (1995) verifiedwhether the determination of the ferulic acid content in flouris more efficient for estimating the presence of seed coat parti-cles in the flour, compared to determination of the ash content.The thesis of his studies was based on the assumption that thecontent of ferulic acid in the seed coat is about 40-fold higherthan that determined in the endosperm. However, further stud-ies indicated that the above correlations are characterized by anunexpectedly large variability.

In the bran of durum and soft wheat, ferulic acid can oc-cur in bonds with polisaccharides and proteins (Regnier andMacheix, 1996; Saulnier et al., 1999; Bartolome et al., 2000). Itcan be linked by ester bonds with hemicellulose chains, mainlywith arabinose residues (Jung and Shalita-Jones, 1990; Hosnyand Rosazza 1997; Andreasen et al. 2000a,b). Moreover, it maypolymerize with lignin forming bonds resistant to the activity

of alkaline compounds (Rybka et al., 1993; Lozovaya et al.,1999).

Ester linkages of ferulic acid with arabinoxylans and their rolein the formation of arabinoxylanic structures have been widelydescribed (Ciacco and D’Appolonia, 1982; Michniewicz et al.,1990; Izydorczyk et al., 1991; Izydorczyk and Biliaderis, 1993;Rybka et al., 1993; Raczynska- Bojanowska and Rybka, 1994;Ralet et al., 1994; Rattan et al., 1994; Ishii, 1997; Figueroa-Espinoza and Rouau, 1998; Figueroa- Espinoza et al., 1999;Andreasen et al., 2000a,b; Lu et al., 2000). Ferulic acid and itsdimers play an important role in the formation and functionalproperties of dietary fiber (Ishii, 1997; Ng et al., 1997; Bunzelet al., 2000; Renger and Steihart, 2000). This acid binds withpolysaccharides by ester linkages, while its binding with ligninalso proceeds with ether linkages (Andreasen et al., 2000a,b;Lozovaya et al., 1999 and 2000; Renger and Steinhart, 2000;Weidner et al., 2000). Renger and Steinhart (2000) reported thatover 60% of ferulic acid contained in dietary fiber occurred inether bonds. It is possible that ether linkages of ferulic acid bindtogether molecules of arabinoxylans and lignin.

Klepacka et al. (2000) found that the total content of phenoliccompounds in bran is greater than in flour and their relationshipis variety dependent (Figure 3). On the other hand, ferulic acid inthe analyzed bran varieties occurs mainly in ester linkages (Fig-ure 4). These results also indicate a varied content of ferulic acidin bran of low and high technological quality varieties (Elena,Begra). Similar correlations were observed by Hatcher andKruger (1997) who indicated the highest content of ferulic acidoccurring in insoluble linkages in Canadian wheat kernels ofhigh technological quality.

Few studies indicate a correlation between the contentof ferulic acid and kernel size. Lempereur et al. (1997) re-ported that in small kernels of Primadur Durum wheat the

Figure 3 Content of total phenolic compounds in flour and brans of wheat varieties (Klepacka et al., 2000).

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FERULIC ACID 643

Figure 4 Content of ferulic acid in brans of wheat varieties (Klepacka et al., 2000).

content of arabinoxylans and ferulic acid is higher than in va-rieties characterized by larger kernels. Based on the studies byKlepacka et al. (2002), the content of ferulic acid in wheat branvaries between the studied varieties and is kernel-size depen-dent (Table 2). The differences were found to be statisticallysignificant within certain sized kernels.

CONTENT OF FERULIC ACID IN FLOUR

The results of studies on the ferulic acid content in particularlayers of wheat kernel as well as in milling fractions are notclear.

Sosulski et al. (1982) found that in flour directly after milling,the trans-ferulic acid content reaches 63.6 µg/g, while in flourstored for 6 months it drops to 23.3 µg/g. These results refer tothe content of total ferulic acid, i.e. the total sum of its contentsin the fraction of free phenolic acids, soluble esters and insolublefraction.

Hatcher and Kruger (1997) reported that a high correlation(r>0.93, α <0.05) was found between the ferulic acid content ininsoluble fraction and the ash content in the flour of all analyzedwheat varieties, which may be explained by the presence of thisfraction of phenolic acids in the bran.

Lempereur et al. (1997) reported that ferulic acid determinedin the fraction of medium flour makes up 55.6 % of the ferulicacid content in the whole kernel (ca. 429 µg/g). Symons andDexter (1993) determined the ferulic acid content in particu-lar milling fractions of wheat. In the medium flour, its contentranged from 25 to 177.5 µg/g, depending on the break-sievingstage. Lempereur et al. (1997) characterized the content of fer-ulic acid in particular milling fractions of the French wheat va-riety Ardente. The content of ferulic acid determined by theseauthors in the whole kernels of wheat durum ranged from 780to 1980 µg/g, depending on the variety, while that determinedin semolina was substantially lower. The lower the flour yield,the lower was the content of ferulic acid occurring in that flour.Nishizawa et al. (1998) obtained similar results in the ferulicacid content in milling fractions of wheat.

The differences in the ferulic acid contents reported by dif-ferent authors may have causes, the most significant of whichinclude genetic and environmental conditions as well as differentanalytical techniques applied (Hatcher ad Kruger, 1997). Prepa-ration of grain for analyses involves its disintegration, whichmay proceed under different conditions, thus resulting in differ-ent sizes of the particles obtained, which in turn affects the re-sults of the determinations. The application of different mills forthe preparation of selected milling fractions, as well as different

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644 J. KLEPACKA AND �L. FORNAL

Table 2 Statistical analysis of ferulic acid content in the bran depending on variety and grain size of wheat (Klepacka et al., 2002)

Wheat variety Quality grade(∗) Fraction Content of ferulic acid[mg/100g dry matter]

Zyta winter A F>1,7 × 25mm 36,41b

Elena C 29,62a

Torka spring A 42,81d

Henika B 40,46c

Zyta winter A 32,66a

Elena C 2,5<F3<2,8 × 25mm 32,06a

Torka spring A 42,44c

Henika B 34,78b

Zyta A 49,80b,e

Elena C 52,29a

Begra winter A 2,8<F2<3,2 × 25mm 65,25c

Almari C 50,59b

Torka A 47,94d

Jasna A 49,02e

Ismena spring A(E) 43,44f

Nawra A(E) 39,99g

There are no statistically significant differences between the values marked with same letters in the column.(∗)—grade of technological value in accordance with multiple evaluation method applied in the evaluation of varieties in Poland:E—elite wheat, A—quality wheat, B—bread wheat, C—other wheat (feed).The brackets indicate proximity of other group (Kaczynski, 1999).

milling conditions, may contribute to obtaining not homogenousexperimental material. Various methods applied in the determi-nation of the ferulic acid content and different interpretation ofthe results obtained may have caused the discrepancies in itscontent quoted in different papers.

FERULIC ACID AND DOUGH RHEOLOGICALPROPERTIES

Ferulic acid is a component of glycoproteins of wheat flour(Smart and O’Brien, 1979). Arabinoxylans belong to pen-tosanes, substances of a non-starch fraction of polysaccharides,and their presence in the flour of bread cereal affects, among oth-ers, rheological properties of dough and bread quality (Ciaccoand D’Appolonia, 1982; Michniewicz et al., 1990; Izydorczyket al., 1991; Graybosch et al., 1993; Andreasen et al., 2000b).Chemical bonds have been found in pentosane molecules be-tween groups of ferulic acid and amino acids, e.g. tyrosine orcysteine. Such linkages create the formation of very strong bondsbetween peptide substances and pentosane molecules or cellu-lose. Many authors claim that pentosane gel is formed by phe-nolic acids, especially ferulic acid which occurs in the highestquantities. In the presence of oxygen, it oxidizes into diferulicacid by binding two or more neighboring pentosane moleculesor peptide subunits (Smart and O’Brien, 1979; Michniewicz,1995 after Geissman and Neukom, 1973; Hoseney, 1984;Jacksonem and Hoseney, 1986; Markwalder and Neukom,1976). In their studies, scientists have tended to ignore water-insoluble pentosanes as they are thought to have too high of anesterification degree of ferulic acid groups to actively participatein the formation of pentosane gel (Michniewicz, 1995). Ferulicacid makes up from 0.09 to 0.30% of water-soluble pentosane

substances (Ciacco and D’Appolonia, 1982), and ca. 0.11% ofwater-insoluble pentosanes (Michniewicz et al., 1990).

Huang and Hoseney (1999) carried out studies on the wheatflour components responsible for the formation of dough viscos-ity. They stated that compounds which produced such defect ofdough are water-soluble, have a carbohydrate-like structure, andabsorb UV light. They suggested that the most crucial compo-nent creating a dough viscosity is the molecule of trans-ferulicacid bound to β- glucan chain at ≈71 anhydrous glucose.

The production of food from whole grain flours, due to in-creased content of ferulic acid, might face such problems as theoccurrence of undesirable properties of dough and changes inits color, most probably caused by the reactions of enzymaticbrowning. When considered in terms of wheat grain milling,the quality of flour depends to a high extent on the contentof polyphenol oxidase. The milling fraction characterized bya flour yield higher than 70% makes its content substantiallyhigher. Phenolic acids, especially ferulic acid, occurring in highquantities may be potential substrates of this enzyme. Oxidativeprocesses, involving the participation of polyphenol oxidase,lead to the formation of labile chinones, which in turn causechromatosis of products through polymerization with othercomponents, e.g. amines or thiols (Hatcher and Kruger, 1997;Koh and Hoseney, 1994).

CONCLUSION

Present knowledge of phenolic compounds in cereal grain,particularly wheat grain, indicates a series of correlations. Themost important is the variety-dependence of phenolic compoundcontent, however, the variability of this trait for different varietiesaffected by biotic and abiotic factors has not yet been explained.

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On the other hand, it was found that the content of ferulic acid ismany times greater in the seed coat of wheat and its content inester linkages is many times greater than in insoluble complexes.These findings may be a starting point for further studies intothe application of ferulic acid content as a discriminate of ashcontent in flour. Moreover, provided quick methods based onfluorescence measurement can be developed, they can serve asanother milling quality technique to be applied in mills.

REFERENCES

Amakura, Y., Okada, M., Tsuji, S., and Tonogai, Y. 2000. Determination ofphenolic acids in fruit juices by isocratic column liquid chromatography. J.Chromatogr. A, 891:183–188.

Amiot, M. J., Forget- Richard, F., and Goupy, P. 1996. Polyphenols, oxidationand color: Progress in the chemistry of enzymatic and non- enzymatic derivedproducts. Herba Pol., XLII (4):237–242.

Andreasen, M. F., Christensen, L. P., Meyer A. S., and Hansen, A. 2000. Contentof phenolic acids and ferulic acid dehydrodimers in 17 rye (Secale cerealeL.) varieties. J. Agric. Food Chem., 48:2837–2842.

Andreasen, M. F., Christensen, L. P., Meyer, A. S., and Hansen, A. 1999. Releaseof hydroxycinnamic and hydroxybenzoic acids in rye by commercial plantcell wall degrading enzyme preparations. J. Sci. Food Agric., 79:411–413.

Andreasen, M. F., Christensen, L. P., Meyer, A. S., and Hansen, A. 2000b. Ferulicacid dehydrodimers in rye (Secale cereale L.). J. Cereal Sci., 31:303–307.

Ashraf, M. Y., Azmi, A. R., Khan, A. H., and Ala, S. A. 1994. Effect of waterstress on total phenols, peroxidase activity and chlorophyll content in wheat(Triticum aestivum L) Acta Physiol. Plant., 16(3):185–191.

Bartolome, B., Estrella, I., and Hernandez, M. T. 2000. Interaction of low molec-ular weight phenolics with proteins (BSA). J. Food Sci., 65(4):617–621.

Bartolome, B., Faulds, C. B., and Williamson, G. 1997. Enzymic release offerulic acid from barley spent grain. J. Cereal Sci., 25:285–288.

Baublis, A., Decker, E. A., and Clydesdale, F. M. 2000. Antioxidant effect ofaqueos extracts from wheat based ready-to-eat breakfast cereals. Food Chem.,68:1–6.

Bocchi, C., Careri, M., Groppi, F., Mangia, A., Manini, P., and Mori, G. 1996.Comparative investigation of UV, electrochemical and particle beam massspectrometric detecion for the high- performance liquid chromatographic de-termination of benzoic and cinnamic acids and of their corresponding phenolicacids. J. Chromatogr. A, 753:157–170.

Borkowski, B. 1993. Phenolic acids and their esters (Part I). Herba Polonica,XXXIX, 1-2:71–84 (in Polish).

Boskov-Hansen, B., Andreasen, M. F., Nielsen, M. M., Larsen, L. M., Bach-Knudsen, K. E., Meyer, A. S., Christensen, L. P., and Hansen, A. 2002.Changes in dietary fibre, phenolic acids and activity of endogenous enzymesduring rye bread-making. Eur. Food Res. Technol., 214(1):33–42.

Bourne, L. C., and Rice- Evans, C. 1998. Bioavailability of ferulic acid. Biochem.Biophys. Res. Commun., 253:222–227.

Buchwald, W., and Czapska, A. 1995. Tannins and phenolic acids in herbsof domestic species of Betonica L. i Stachys L genera. Herba Polonica,XLI(4):198–202.

Bunzel, M., Ralph, J., Marita, J., and Steinhart, H. 2000. Identification of 4-0-5′- coupled diferulic acid from insoluble cereal fiber. J. Agric. Food Chem.,48:3166–3169.

Burns, J., Gardner, P. T., O’Neil, J., Crawford, S., Morecroft, I., McPhail, D.B., Lister, C., Matthews, D., MacLean, M. R., Lean, M. E. J., Duthie, G.G., and Crozier, A. 2000. Relationship among antioxidant activity, vasodila-tion capacity, and phenolic content of red wines. J. Agric. Food Chem., 48:220–230.

Cabrera, H.M., Munoz, O., Zuniga, G.E., Corcuera, L.J., and Argandona, V.H.1995. Changes in ferulic acid and lipid content in aphid- infested barley.Phytochemistry, 39(5):1023–1026.

Chu, Y. H., Chang, Ch. L., and Hsu, H. F. 2000. Flavonoid content of severalvegetables and their antioxidant activity. J. Sci. Food Agric., 80:561–566.

Ciacco, C. F., and D’Appolonia, B. L. 1982. Characterization of pentosans fromdifferent wheat flour classes and of their gelling capacity. Cereal Chem.,59(2):96–99.

Collins, F. W., McLachlan, D. C., and Blackwell, B. A. 1991. Oat phenolics:Avenalumic acids, a new group of bound phenolic acids from oat groats andhulls. Cereal Chem., 68(2):184–189.

Da↪browski, K. J., and Sosulski, F. W. 1984. Composition of free and hydrolyz-able phenolic acids in defatted flours of ten oilseeds. J. Agric. Food Chem.,32:128–130.

Deighton, N., Brennan, R., Finn, Ch., and Davies, H. V. 2000. Antioxidant prop-erties of domesticated and wild Rubus species. J. Sci. Food Agric., 80:1307–1313.

Dervilly, G., Leclercq, C., Zimmermann, D., Roue, C., Thibault, J. F., andSaulnier, L. 2002. Isolation and characterization of high molar mass water-soluble arabinoxylans from barley and barley malt. Carbohyd. Polym.,47:143–149.

Dimberg, L. H., Molteberg, E. L., Solheim, R., and Frølich, W. 1996. Variation inoat groats due to variety, storage and heat treatment. I: Phenolic compounds.J. Cereal Sci., 24:263–272.

Feng, Y., and McDonald, C. E. 1989. Comparison of flavonoids in bran of fourclasses of wheat. Cereal Chem., 66(6):516–518.

Ferguson, L. R. 2001. Role of plant polyphenols in genomic stability. Mutat.Res., 475:89–111.

Figueroa- Espinoza, M. C., and Rouau, Z. 1998. Oxidative cross- linkingof pentosans by a fungal laccase and horseradish peroxidase: mechanismof linkage between feruloylated arabinoxylans. Cereal Chem., 75(2):259–265.

Figueroa- Espinoza, M. C., Morel, M. H., Surget, A., and Rouau, X. 1999.Oxidative cross - linking of wheat arabinoxylans by manganese peroxidase.Comparison with laccase and horseradish peroxidase. Effect of cysteine andtyrosine on gelation. J. Sci. Food Agric., 79:460–463.

Fulcher, R. G., O’Brien, T. P., and Lee, J. W. 1972. Studies on the aleuronelayer. I. Conventional and fluorescence microscopy of the cell wall withemphasis on phenol—carbohydrate complexes in wheat. Aust. J. Biol. Sci.,23–25.

Gimeno, E., Castellote, A. I., Lamuela-Raventos, R. M., De la Torre, M. C., andLopez-Sabater, M. C. 2002. The effects of harvest and extraction methods onthe antioxidant content (phenolics, α-tocopherol, and β-carotene) in virginolive oil. Food Chem., 78: 207–211.

Gokmen, V., Artik, N., Acar, J., Kahraman, N., and Poyrazoglu, E. 2001. Effectsof various clarification treatments on patulin, phenolic compound and organicacid compositions of apple juice. Eur. Food Res. Technol., 213:194–199.

Graybosch, R., Peterson, C. J., Moore, K. J., Stearns, M., and Grant, D. L. 1993.Comparative effects of wheat flour protein, lipid, and pentosan compositionin relation to baking and milling quality. Cereal Chem., 70(1):95–101.

Harborne, J. B., and Williams, Ch. A. 2000. Advances in flavonoid researchsince 1992. Phytochemistry, 55:481–504.

Hatcher, D. W., and Kruger, J. E. 1997. Simple phenolic acids in flours preparedfrom canadian wheat: Relationship to ash content, color, and polyphenol ox-idase activity. Cereal. Chem., 74(3):337–343.

Hatcher, D. W., Symons, S. J., and Kruger, J. E. 1999. Measurement of thetime dependent appearance of discolored spots in alkaline noodles by imageanalysis. Cereal Chem., 76(2):189–194.

Hosny, M., and Rosazza, J. P. N. 1997. Structures of ferulic acid glycoside estersin corn hulls. J. Nat. Prod., 60(3):219–222.

Hotta, H., Sakamoto, H., Nagano, S., Osakai, T., and Tsujino, Y. 2001. Unusuallylarge numbers of electrons for the oxidation of polyphenolic antioxidants.Biochim. Biophys. Acta, 1526:159–167.

Huang, W. N., and Hoseney, R. C. 1999. Isolation and identification of a wheatflour compound causing sticky dough. Cereal. Chem., 76(2):276–281.

Ishii T. 1997. Structure and functions of feruloylated polysaccharides. Plant Sci.,127:111–127.

Izydorczyk, M. S., and Biliaderis, C.G. 1993. Structural heterogeneity of wheatendosperm arabinoxylans. Cereal Chem., 70(6):641–646.

Izydorczyk, M. S., Biliaderis, C.G., and Bushuk, W. 1991. Comparison of thestructure and composition of water- soluble pentosans from different wheatvarieties. Cereal Chem., 68(2):139–144.

Dow

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ded

by [

Uni

vers

ity o

f Sa

skat

chew

an L

ibra

ry]

at 0

3:19

03

June

201

2

646 J. KLEPACKA AND �L. FORNAL

Jensen, S. V. A., Munck, L., and Martens, H. 1982. The botanical constituentsof wheat and wheat milling fractions. I - Quantification by autofluorescence.Cereal Chem., 59:477–484.

Jung, H. J. G., and Shalita- Jones, S. C. 1990. Variation in the extractability ofesterified p−coumaric and ferulic acids from forage cell walls. J. Agric. FoodChem., 38:397–402.

Jung, M. Y., Jeon, B. S., and Bock, J. Y. 2002. Free, esterified, and insoluble-bound phenolic acids in white and red Korean ginsengs (Panax ginseng C. A.Meyer). Food Chem., 79:105–111.

Kanner, J., Frankel, E., Granit, R., German, B., and Kinsella, J. E. 1994. Naturalantioxidants in grapes and wines. J. Agric. Food Chem., 42:64–69.

Kelfkens, M. 1995. Vorausbestimmung der Daulfahigkeit von Weizen. DieMuhle Mischfuttertechnik, 1322 (51/52):871–875.

Kennedy, J. F., Methacanon, P., and Lloyd, L. 1999. The identification andquantitation of the hydroxycinnamic acid substituents of a polysaccharideextracted from maize bran. J. Sci. Food Agric., 79:464–470.

Klepacka, J., Fornal, �L., Borejszo, Z., and Wrobel, E. 2000. The content of ferulicacid and the seed coat color of wheat of different technological quality. Natur.Sc., 6:55–65.

Klepacka, J., Fornal, �L., Konopka, S., and Choszcz, D. 2002. Relation betweenferulic acid content in wheat coat, and milling quality and color of grain.Electronic Journal of Polish Agricultural Universities, 5(2):1–11 (availableonline: http://www.ejpau.media.pl/series/volume5/issue2/food/art-15.html).

Koh, B. K., and Hoseney, R. C. 1994. Methoxyhydroquinone in wheat flour.Cereal Chem., 71(4):311–314.

Koz�lowska, H., Rotkiewicz, D., and Borejszo, Z. 1977. Identification of phenolicacids in rapeseed, variety K-20-40 using gas chromatography method. Zesz.Nauk. ART. Olszt., 11:123–131 (in Polish).

Kraushofer, T., and Sontag, G. 2002. Determination of some phenolic com-pounds in flax seed and nettle roots by HPLC with coulometric electrodearray detection. Eur. Food Res. Technol., 215:529–533.

Kris-Etherton, P. M., Hecker, K. D., Bonanome, A., Coval, S. M., Binkoski, A.E., Hilpert, K. F., Griel, A. E., and Etherton, T. D. 2002. Bioactive compoundsin foods: Their role in the prevention of cardiovascular disease and cancer.Amer. J. Med., 113(9B):71S–88S.

Kroon, P. A., Faulds, C. B., Ryden, P., Robertson, J. A, and Williamson, G.1997. Release of covalently bound ferulic acid from fiber in the human colon.J. Agric. Food Chem., 45:661–667.

Krygier, K., Sosulski, F., and Hogge, L. 1982. Free, esterified, and insoluble-bound phenolic acids. 1. Extraction and purification procedure. J. Agric. FoodChem., 30:300–334.

Lachman, J., Pivec, V., Rehakova, V., and Hubacek, J. 1991. Dominant polyphe-nolic compounds of the triticale grains. Rostl. Vyroba, 37(1):39–46.

Lempereur, I., Rouau, X., and Abecassis, J. 1997. Genetic and agro-nomic variation in arabinoxylan and ferulic acid contents of durum wheat(Triticum durum L.) grain and its milling fractions. J. Cereal Sci., 25:103–110.

Lozovaya, V.V., Gorshkova, T. A., Rumyantseva, N. I., Ulanov, A. V., Valieva, A.I., Yablokova, E. V., Mei, Ch., and Widholm, J. M. 2000. Cell wall- bound phe-nolics in cells of maize (Zea mays, Gramineae) and buckwheat (Fagopyrumtataricum, Polygonaceae) with different plant regeneration abilities. PlantSci., 152:79–85.

Lozovaya, V.V., Gorshkova, T. A., Yablokova, E. V., Rumyantseva, N. I., Valieva,A., Ulanov, A., and Widholm, J. M. 1999. Cold alkali can extract phenolicacids that are ether linked to cell wall components in dicotyledonous plants(buckwheat, soybean and flax). Phytochemistry, 50:395–400.

Lu, Z. X., Gibson, P. R., Muir, J. G., Fielding, M., and O’Dea, K. 2000. Arabi-noxylan fiber from a by- product of wheat flour processing behaves physio-logically like a soluble, fermentable fiber in the large bowel of rats. Am. Soc.Nut. Sci., 1984–1990.

Madhavi, D. L., Smith, M. A. L., Linas, A. C., and Mitiku, G. 1997. Accumu-lation of ferulic acid in cell cultures of Ajuga pyramidalis Metallica Crispa.J. Agric. Food Chem., 45:1506–1508.

Maga, J. A., and Lorenz, K. 1974. Phenolic acid composition and distribution inwheat flours and various triticale milling fractions. Lebensm. Wiss. Technol.,7(5):273–278.

Maillard, M. N., and Berset, C. 1995. Evolution of antioxidant activity duringkilning: Role of insoluble bound phenolic acids of barley malt. J. Agric. FoodChem., 43:1789–1793.

Maillard, M. N., Soum, M. H., Boivin, P., and Berset, C. 1996. Antioxidantactivity of barley and malt: Relationship with phenolic content. Lebensm.Wiss. Technol., 29:238–244.

Maniak, B., and Targonski, Z. 1996. Natural antioxidants in food. Scientific–Technical Magazine For Fermentation and Fruit & Vegetable Industry,40(4):7–10 (in Polish).

McKeehen, J. D., Busch, R. H., and Fulcher, R. G. 1999. Evaluation ofwheat (Triticum aestivum L.) phenolic acids during grain development andtheir contribution to Fusarium resistance. J. Agric. Food Chem., 47:1476–1482.

Micard, V., Renard, C. M. G. C., and Thibault, J. F. 1994. Studies on enzymicrelease of ferulic acid from sugar- beet pulp. Lebensm. Wiss. Technol., 27:59–66.

Michniewicz, J. 1995. Pentosans in cereal technology . Rocz. AR Pozn. 261 (inPolish).

Michniewicz, J., Biliaderis, C. G., and Bushuk, W. 1990. Water- insoluble pen-tosans of wheat: Composition and some physical properties. Cereal Chem.,67(5):434–439.

Modafar, C. E., Tantaoui, A., and Boustani, E. E. 2000. Changes in cell wall-bound phenolic compounds and lignin in roots of date palm cultivars differingin susceptibility to Fusarium oxysporum f. sp. albedinis. J. Phytopathology,148:405–411.

Morales, F., Cerovic, Z.G., and Moya, I. 1996. Time- resolved blue- green fluo-rescence of sugar beet (Beta vulgaris L.) leaves. Spectroscopic evidence forthe presence of ferulic acid as the main fluorophore of the epidermis. Biochim.Biophys. Acta, 1273:251–262.

Muheim, A., and Lerch, K. 1999. Towards a high- yield bioconversion of ferulicacid to vanillin. Appl. Microbiol. Biotechnol., 51:456–461.

Nandini, Ch. D., and Salimath, P. V. 2001. Carbohydrate composition of wheat,wheat bran, sorghum and bajra with good chapati/roti (Indian flat bread)making quality. Food Chem., 73:197–203.

Nardini, M., Cirillo, E., Natella, F., Mencarelli, D., Comisso, A., and Scaccini,C. 2002. Detection of bound phenolic acids: Prevention by ascorbic acidand ethylenediaminetetraacetic acid of degradation of phenolic acids duringalkaline hydrolysis. Food Chem., 79:119–124.

Ng, A., Greenshields, R.N., and Waldron, K.W. 1997. Oxidative cross-linking ofcorn bran hemicellulose: Formation of ferulic acid dehydrodimers. Carbohyd.Res., 303:459–462.

Nishizawa, Ch., Ohta, T., Egashira, Y., and Sanada, H. 1998. Ferulic acid contentsin typical cereals. Nippon Shokuhin Kagaku Kaishi, 45(8):499–503.

Nordkvist, E., Salomonsson, A. C., and Aman, P. 1984. Distribution of in-soluble bound phenolic acids in barley grain. J. Sci. Food Agric., 35:657–661.

O’Connell, J. E., and Fox, P. F. 2001. Significance and applications of phenoliccompounds in the production and quality of milk and dairy products: A review.Int. Dairy J., 11:103–120.

Obel, N., Porchia, A. C., and Scheller, H. V. 2002. Dynamic changes in cellwall polysaccharides during wheat seedling development. Phytochemistry,60:603–610.

Onyeneho, S. N., and Hettiarachchy, N. S. 1992. Antioxidant activity of durumwheat bran. J. Agric. Food Chem., 40:1496–1500.

Oosterveld, A., Grabber, J. H., Beldman, G., Ralph, J., and Voragen, A. G.J. 1997. Formation of ferulic acid dehydrodimers through oxidative cross-linking of sugar beet pectin. Carbohydr. Res., 300:179–181.

Opoku, G., Vyn, T. J., and Voroney, R. P. 1997. Wheat straw placement effectson total phenolic compounds in soil and corn seedling growth. Can. J. PlantSci., 77:301–305.

Oszmianski, J. 1988. Enzymatic changes of phenolic compounds in model sys-tems and fruits extracts. Zesz. Nauk. AR Wroc., 74 (in Polish).

Oszmianski, J. 1995. Polyphenols as natural food antioxidants. Food Industry,3:94–96 (in Polish).

Oszmianski, J., Lamer-Zarawska, E. 1992. Antimutagenic activities of plantpolyphenolic. Food Industry, 10:253–255 (in Polish).

Dow

nloa

ded

by [

Uni

vers

ity o

f Sa

skat

chew

an L

ibra

ry]

at 0

3:19

03

June

201

2

FERULIC ACID 647

Parr, A. J., Bolwell, G. P. 2000. Review: Phenols in the plant and in man. Thepotential for possible nutritional enhancement of the diet by modifying thephenols content or profile. J. Sci. Food Agric., 80:985–1012.

Phelps, C. D., and Young, L. Y. 1997. Microbial metabolism of the plant phe-nolic compounds ferulic and syringic acids under three anaerobic conditions.Microb. Ecol., 33:206–215.

Pussayanawin, V., and Wetzel, D. 1987. High- performance liquid chromato-graphic determination of ferulic acid in wheat milling fractions as a measureof bran contamination. J. Chromatogr., 391:243–255.

Raczynska- Bojanowska, K., and Rybka, K. 1994. Arabinoxylan structure andproperties. Hod. Roúl. Aklim., 38(5):85–90.

Ralet, M. C., Faulds, C. B., Williamson, G., and Thibault, J. F. 1994. Degradationof feruloylated oligosaccharides from sugar- beet pulp and wheat bran byferulic acid esterases from Aspergillus niger. Carbohydr. Res., 263:257–269.

Ramarathnan, N., and Osawa, T. 1989. Chemical studies on novel rice hullantioxidants. J. Agric. Food Chem., 37(2):316–319.

Rattan, O., Izydorczyk, M. S., and Biliaderis, C. G. 1994. Structure and rheolog-ical behaviour of arabinoxylans from canadian wheat flours. Lebensm. Wiss.Technol., 27:550–555.

Regnier, T., and Macheix, J. J. 1996. Changes in wall- bound phenolic acids,phenylalanine and tyrosine ammonia- lyases, and peroxidases in developingdurum wheat grains (Triticum turgidum L. Var. Durum). J. Agric. Food Chem.,44:1727–1730.

Renger, A., and Steinhart, H. 2000. Ferulic acid dehydrodimers as structuralelements in cereal dietary fibre. Eur. Food Res. Technol., 211:422–428.

Ribereau-Gayon, P. 1972. Plant phenolics. Hafner Publishing Company, NewYork.

Rotkiewicz, D., Zadernowski, R., and Koz�lowska, H. 1984. Phenolic acids ofgrain crops. Zesz. Nauk ART. Olszt., 19:135–143 (in Polish).

Rousseau, B., and Rosazza, J. P. N. 1998. Reaction of ferulic acid with nitrite:Formation of 7- hydroxy-6- methoxy- 1,2 (4H)- benzoxazin-4- one. J. Agric.Food Chem., 46(8):3314–3317.

Rozes, N., and Peres, C. 1998. Effects of phenolic compounds on the growthand the fatty acid composition of Lactobacillus plantarum. Appl. Microbiol.Biotechnol., 49:108–111.

Rybka, K., Sitarski, J., and Raczynska- Bojanowska, K. 1993. Ferulic acidin rye and wheat grain and grain dietary fiber. Cereal Chem., 70(1):55–59.

Salomonsson, A. C., Theander, O., and Aman, P. 1978. Quantitative determina-tion by GLC of phenolic acids as ethyl derivatives in cereal straws. J. Agric.Food Chem., 26(4):830–835.

Saulnier, L., and Thibault, J. F. 1999. Review: Ferulic acid and diferulic acids ascomponents of sugar- beet pectins and maize bran heteroxylans. J. Sci. FoodAgric., 79:396–402.

Saulnier, L., Crepeau, M. J., Lahaye, M., Thibault, J. F., Garcia- Conesa, M. T.,Kroon, P. A., and Williamson, G. 1999. Isolation and structural determinationof two 5,5′- diferuloyl oligosaccharides indicate that maize heteroxylans arecovalently cross- linked by oxidatively coupled ferulates. Carbohyd. Res.,320:82–92.

Scalbert, A., and Williamson, G. 2000. Dietary intake and bioavailability ofpolyphenols. J. Nutr., 130(8S):207–220.

Seitz, L. M. 1989. Stanol and sterol esters of ferulic and p− coumaric acids inwheat, corn, rye and triticale. J. Agric. Food Chem., 37:662–667.

Sharma, O. P., Bhat, T. K., and Singh, B. 1998. Thin- layer chromatography ofgallic acid, methyl gallate, pyrogallol, phloroglucinol, catechol, resorcinol,hydroquinone, catechin, epicatechin, cinnamic acid, p- coumaric acid, ferulicacid and tannic acid. J. Chromatogr. A, 822:167–171.

Shui, G., and Leong, L. P. 2002. Separation and determination of organic acidsand phenolic comounds in fruit juices and drinks by high—performance liquidchromatography. J. Chromatogr. A, 977:89–96.

Sieliwanowicz, B. 1998. The antioxidizing properties of the beer phenols and itspotential nutritient consistency. Scientific-Technical Magazine For Fermenta-tion and Fruit & Vegetable Industry, 4:9–11 (in Polish).

Sikorski, Z. E. 1994. Chemiczne i funkcjonalne w�laúciwoúci sk�ladnikowywnoúci. WNT, Warszawa (in Polish).

Silva, F. A. M., Borges, F., Guimaraes, C., Lima, J. L. F. C., Matos, C., andReis, S. 2000. Phenolic acids and derivatives: Studies on the relationshipamong structure, radical scavenging activity, and physicochemical parame-ters. J. Agric. Food Chem., 48:2122–2126.

Siranidou, E., Kang, Z., and Buchenauer, H. 2002. Studies on symptom devel-opment, phenolic compounds and morphological defence responses in wheatcultivars differing in resistance to Fusarium head blight. J. Phytopathology,150(4/5):200–209.

S�lominski, B. A. 1980. Phenolic acids in the meal of developing and storedbarley seeds. J. Sci. Food Agric., 31:1007–1010.

Smart, M. G., and O’Brien, T. P. 1979. Observations on the Scutellum. III*Ferulic acid as a component of the cell wall in wheat and barley. Aust. J. PlantPhysiol., 6:485–491.

Smith, M. M., and Hartley, R. D. 1983. Occurence and nature of ferulic acidsubstitution of cell- wall polysaccharides in graminaceous plants. Carbohyd.Res., 118:65–80.

Sosulski, F., Krygier, K., and Hogge, L. 1982. Free, esterified, and insoluble-bound phenolic acids. 3. Composition of phenolic acids in cereal and potatoflours. J. Agric. Food Chem., 30:337–340.

Stefanowska, M., Amarowicz, R., Koz�lowska, H., Kuraú, M., Tykarska, T.,and Zobel, A. 1996. Biochemical and ultrastructural analysis of phenoliccompounds in maturing rape (Brassica Napus L.) seeds. Herba Pol., XLII(4):273–277 (in Polish).

Symons, S. J., and Dexter, J. E. 1993. Relationship of flour aleurone fluorescenceto flour refinement for some canadian hard common wheat classes. CerealChem., 70(1):90–95.

Szajdak, L., and Zyczynska- Ba�loniak, I. 1994. Phenolic acids in brown soilsunder continuous cropping of rye and crop rotation. Pol. J. Soil Sci., XXVII(2):113–121.

Truswell, A. S. 2002. Cereal grains and coronary heart disease. Eur. J. Clin.Nutr., 56(1):1–14.

Tura, D., and Robards, K. 2002. Sample handling strategies for the determinationof biophenols in food and plants. J. Chromatogr. A, 975:71–93.

Wakabayashi, K., Hoson, T., and Kamisaka, S. 1997. Osmotic stress suppressescell wall stiffening and the increase in cell wall bound ferulic and diferulicacids in wheat coleoptiles. Plant Physiol., 113:967–973.

Wang, M., Hamer, R. J., van Vliet, T., and Oudgenoeg, G. 2002. Interaction ofwater extractable pentosans with gluten protein: Effect on dough propertiesand gluten quality. J. Cereal Sci., 36(1):25–38.

Watanabe, T., Yamamoto, A., Nagai, S., and Terabe, S. 1998. Micellar electroki-netic chromatography as an alternative to high-performance liquid chromatog-raphy for separation and determination of phenolic compounds in Japanesespirituous liquor. J. Chromatogr. A, 793:409–413.

Weidner, S., Amarowicz, R., Karamac, M., and Da↪browski, G. 1999. Pheno-lic acids in caryopses of two cultivars of wheat, rye and triticale that dis-play different resistance to pre- harvest sprouting. Eur. Food Res. Technol.,210:109–113.

Weidner, S., Amarowicz, R., Karamac, M., and Fra↪czek, E. 2000. Changes inendogenous phenolic acids during development of Secale cereale caryopsesand after dehydration treatment of unripe rye grains. Plant Physiol. Biochem.,38:595–602.

Weidner, S., Paprocka, J., and �Lukaszewicz, D. 1995. The role of phenoliccompounds in prevention of pre- harvest sprouting in cereal caryopses. Fragm.Agron., 2(46):100–101.

Wu, K., Zhang, W., Addis, P. B., Epley, R. J., Salih, A. M., and Lehrfeld, J. 1994.Antioxidant properties of wild rice. J. Agric. Food Chem., 42:34–37.

Zielinski, H., and Koz�lowska, H. 2000. Antioxidant activity and total phenolicsin selected cereal grains and their different morphological fractions. J. Agric.Food Chem., 48:2008–2016.

Zielinski, H., Koz�lowska, H., and Lewczuk, B. 2001. Bioactive compounds inthe cereal grains before and after hydrothermal processing. Food Sci. Emer.Technol., 2:159–169.

Zupfer, J. M., Churchill, K. E., Rasmusson, D. C., and Fulcher, R. G. 1998. Vari-ation in ferulic acid concentration among diverse barley cultivars measuredby HPLC and microspectrophotometry. J. Agric. Food Chem., 46:1350–1354.

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