Acids in chicory roots and malt 1. Identification in roasted products and method of determination

A determination method for non-volatile acids in roasted chicory roots and roasted barley malt is described. The clean-up was accomplished using preparative gel electrophoresis followed by gas chromatography (GC)/mass spectrometry of the methoximes (ketonic acids) or trimethylsilyl derivatives (all acids). Using these methods, 64 non-volatile acids have been identified in chicory (among those 48 for the first time). In barley malt 60 acids could be detected (47 for the first time). Ten commercially unavailable substances have been synthesized. Most of the acids have been quantified using the same clean-up and GC/selected ion monitoring or GC/flame ionisation detection (FID). The recoveries range from 41 to 105% (average 79%), the detection limits from 1 to 72g/kg being somewhat lower for the FID and considerably lower for malt, and the relative standard deviations from 1 to 10% for the main acids, from 2 to 89% for the minor acids and from 8 to 133% for the trace acids. In addition formic and acetic acids were determined by isotachophoresis.

---

Säuren in Zichorienwurzeln und Malz: 1. Identifizierung in Röstprodukten und Bestimmungsmethode

Zusammenfassung In Röstzichorie wurden 64 nichtflüchtige Säuren, davon 48 neu in Zichorie, in Röstmalz 60 Säuren, davon 47 neu in Malz, durch GC/MS nach Abtrennung durch präparative Gelelektrophorese, Überführung der Oxosäuren in ihre Methoxime und Trimethylsilylierung identifiziert. 10 im Handel nicht erhältliche Säuren wurden synthetisiert. Die meisten Säuren wurden quantitativ nach derselben Abtrennung mittels GC/SIM oder GC/FID bestimmt. Die Wiederfindungsraten liegen zwischen 41 und 105%, im Mittel bei 79%, die Nachweisgrenzen zwischen 1 und 72 g/kg (etwas niedriger bei GC/FID, erheblich niedriger bei Malz), die Variationskoeffizienten zwischen 1 und 10% bei den Hauptsäuren, zwischen 2 und 89% bei den Minorsäuren und zwischen 8 und 133% bei den Spurensäuren. Zusätzlich wurden Ameisen- und Essigsäure durch Isotachophorese bestimmt.

---

---

Excerpt from doctoral thesis: Säuren in Zichorie und Malz of H. Barlianto [13]     

Acids in chicory roots and malt

Acids known to be decomposition products of carbohydrates were quantified in raw, dried and roasted chicory roots and in dried and roasted barley malt by means of gas liquid chromatography/mass spectrometry and isotachophoresis. Acids derived from other educts will be dealt with in following papers. Of the acids found, eight are of the aldonic type, ten are deoxyaldonic, three are oxo acids, two are derivatives of furanoic acid, two are volatile acids and the others are methyl succinic and oxalic acid. Qualitatively, chicory and malt are composed of the same acids, but generally speaking the concentration of acids in chicory is higher. While in the dried educts only trace amounts can be detected, the concentration of acids increases upon roasting. In roasted chicory roots considerably high contents of acetic, formic, glycolic, pyruvic, lactic, metasaccharinic, oxalic, glyceric and 3-hydroxypropionic acids were quantified. 5-Hydroxymethyl-2-furanoic, 2,4-dihydroxybutyric, 3,4-dihydroxybutyric, arabonic, gluconic, ribonic, erythronic, threonic, 4-oxovaleric, methyl succinic, 2-furanoic, mannonic, 3-deoxypentonic, saccharinic, isosaccharinic, methyl glyceric and 2-oxovaleric acids are minor compounds. In malt samples only acetic, pyruvic, formic, oxalic and lactic acids were detected in relatively high concentrations. Gluconic, 3,4-dihydroxybutyric, 3-hydroxypropionic, metasaccharinic, mannonic, glyceric, glycolic, 2,4-dihydroxybutyric, ribonic, threonic, 5-hydroxymethyl-2-furanoic, erythronic, 4-oxovaleric, 2-furanoic, saccharinic, methyl succinic, arabonic, 3-deoxypentonic, methyl glyceric, 2-oxovaleric and isosaccharinic acids are minor compounds.     

Norharman and harman in instant coffee and coffee substitutes

Norharman and harman are two neuroactive β-carbolines present in several plants and thermally processed foods, including roasted coffee. The objective of this study was to evaluate their amounts in commercial instant coffee-based and coffee substitute beverages (n = 48), with variable amounts of coffee, chicory, barley, malt, and rye. All samples contained variable amounts of both β-carbolines, always with a higher proportion of norharman than harman. The highest levels (p < 0.01) were found in 100% instant coffees, with mean amounts of 3.8 μg/g and 1.5 μg/g for NH and H, respectively, followed by plain chicory. The lowest amounts were found in 100% barley, with 1.1 μg/g for NH and 0.3 μg/g for H. The NH and H content was statistically higher (p < 0.01) in all mixtures with coffee when compared to those without it. Nevertheless, and except for 100% barley, the amounts provided by beverages based on coffee substitutes are within those reported for standard coffee brews.     

Impact of Dark Specialty Malts on Extract Composition and Wort Fermentation

Dark specialty malts are important ingredients for the production of several beer styles. These malts not only impart colour, flavour and antioxidative activity to wort and beer, they also affect the course of wort fermentations and the production of flavour‐active yeast metabolites. The application of considerable levels of dark malt was found to lower the attenuation, mainly as a result of lower levels of fermentable sugars and amino acids in dark wort samples. In fact, from the darkest caramel malts and from roasted malts, practically no fermentable material can be hydrolysed by pilsner malt enzymes during mashing. Compared to wort brewed with 50% pilsner malt and 50% dark caramel malt or roasted malt, wort brewed with 100% pilsner malt contained nearly twice as much fermentable sugars and amino acids. Reduced levels of yeast nutrients also lowered the fermentation rate, ranging from 1.7°P/day for the reference pilsner wort of 9 EBC to 1.1°P/day for the darkest wort (890 EBC units), brewed with 50% roasted malt. This additionally indicates that lower attenuation values for dark wort are partially due to the inhibitory effects of Maillard compounds on yeast metabolism. The application of dark caramel or roasted malts further led to elevated levels of the vicinal diketones diacetyl and 2,3‐pentanedione. Only large levels of roasted malt gave rise to two significant diacetyl peaks during fermentation. The level of ethyl acetate in beer was inversely related to colour, whereas the level of isoamyl acetate appeared to be affected by the use of roasted malt. With large levels of this malt type, negligible isoamyl acetate was generated during fermentation.     

Chlorogens?nren in Kaffee-Ersatzstoffen

Zusammenfassung Mittels Umkehrphasen-HPLC auf RP-18 und Gradientenelution (2%ige Essigsäure/Methanol) wurde das Vorkommen von Chlorogensäureisomeren in Kaffee-Ersatzstoffen untersucht. Bei Grünmalz konnten keine Chlorogensduren nachgewiesen werden, bei Röstzichorie und zwei Handelsproben (eine Mischung, ein Extrakt) nur die n-Chlorogensäure (3-CQA) in Mengen von 0,08-0,33 g/kg í. Tr. Bei Darrzichorie wurden 1,93 g/kg i. Tr. Gesamtchlorogensäuren nachgewiesen, wobei neben den Monocaffeoylchinasduren (3-CQA, 4-CQA, 5-CQA) auch einige Dicaffeoylchinasduren (3,4-diCQA, 3,5diCQA, 4,5-diCQA) auftraten.

---

Chlorogenic acids in coffee substitutes

Summary Chlorogenic acids in coffee substitutes were determined by reversed phase HPLC with gradient elution (2% acetic acid/methanol) on RP-18. In green barley malt no chlorogenic acids could be detected. n-Chlorogenic acid could be detected in roasted chicory and in two commercial samples (one mixture of coffee substitutes, one instant product); the concentrations ranged from 0.08 to 0.33 g/kg dry weight. In dried chicory 1.93 g/kg d. m. total chlorogenic acids were determined and 6 isomers (3-CQA, 4-CQA, 5-CQA, 3,4-diCQA, 3,5-diCQA, 4,5-diCQA) were present.

---

---

Auszug aus der wissenschaftlichen Abschlußarbeit von H. Haffke     

固相萃取-高效液相色谱法测定啤酒原辅料中黄曲霉毒素B_1

以啤酒酿造中主要原辅料(大麦麦芽、大麦、大米、小麦麦芽)为样品,比较了几种不同净化柱净化黄曲霉毒素B1(AFB1)的回收率,最终选择了硅胶-硅藻土-中性氧化铝混合柱作为净化柱,建立了一种检测啤酒原辅料中AFB1的反相高效液相色谱(RP-HPLC)方法。结果表明,AFB1的检测线性范围为0.5～50μg/kg,线性相关系数r为0.999 7。方法检出限为0.15μg/kg,加标回收率80.1%～109.2%,相对标准偏差(RSD)为0.23%～4.29%。该方法简便、准确、成本低廉,可用于啤酒原辅料中的AFB1的质量控制。     

HPLC法测定啤酒原料中的脱氧雪腐镰刀菌烯醇毒素

建立了一种利用多功能净化柱-高效液相色谱检测啤酒大麦和麦芽中脱氧雪腐镰刀菌烯醇毒素（DON）含量的方法。把该方法和GC／ECD方法进行了对比,线形回归分析表明两种方法的检测结果接近。分析了10种国产、进口的大麦和麦芽,大麦和麦芽中DON最高污染水平分别为1．23μg／g、0．24μg／g。该方法可应用于啤酒酿造原料中DON污染情况的检测分析。     

Residue levels of malathion and fenitrothion and their metabolites in postharvest treated barley during storage and malting

In order to investigate residue levels of malathion and fenitrothion and their metabolites (malaoxon, isomalathion and fenitrooxon) during storage and malting, pesticide-free barley was treated with these insecticides. Barley was placed in a sealed plastic container and treated with a dust of malathion (2%). Fenitrothion emulsion (41.6% wettable powder) was applied onto the walls of a small-scale storage vessel. Residues were determined in barley at about 1-month intervals during storage and in malt produced from the barley stored at various times. The analysis of the residues was carried out by GC equipped with a nitrogen-phosphorus detector (NPD). Although the approved doses of insecticides for stored grain were used, the residue levels exceeded the maximum residue limits (MRLs) at the beginning of storage. While the degradation of malathion and isomalathion in barley was observed to be about 65–72% during the storage period, the malaoxon was degraded extensively (85%). A significant percentage of fenitrothion residues (80%) were dissipated from grains for the short-term storage probably because of hot weather conditions. In malt, rates of degradation and volatilisation of the residues increased by the heat involved in malting. The carryover of the residues from barley into malt was also found to be dependent on the log P_ow (partition coefficient between n-octanol and water) values of the insecticides.     

Acids in chicory roots and malt II. Determination of acids derived from carbohydrates

Acids known to be decomposition products of carbohydrates were quantified in raw, dried and roasted chicory roots and in dried and roasted barley malt by means of gas liquid chromatography/mass spectrometry and isotachophoresis. Acids derived from other educts will be dealt with in following papers. Of the acids found, eight are of the aldonic type, ten are deoxyaldonic, three are oxo acids, two are derivatives of furanoic acid, two are volatile acids and the others are methyl succinic and oxalic acid. Qualitatively, chicory and malt are composed of the same acids, but generally speaking the concentration of acids in chicory is higher. While in the dried educts only trace amounts can be detected, the concentration of acids increases upon roasting. In roasted chicory roots considerably high contents of acetic, formic, glycolic, pyruvic, lactic, metasaccharinic, oxalic, glyceric and 3-hydroxypropionic acids were quantified. 5-Hydroxymethyl-2-furanoic, 2,4-dihydroxybutyric, 3,4-dihydroxybutyric, arabonic, gluconic, ribonic, erythronic, threonic, 4-oxovaleric, methyl succinic, 2-furanoic, mannonic, 3-deoxypentonic, saccharinic, isosaccharinic, methyl glyceric and 2-oxovaleric acids are minor compounds. In malt samples only acetic, pyruvic, formic, oxalic and lactic acids were detected in relatively high concentrations. Gluconic, 3,4-dihydroxybutyric, 3-hydroxypropionic, metasaccharinic, mannonic, glyceric, glycolic, 2,4-dihydroxybutyric, ribonic, threonic, 5-hydroxymethyl-2-furanoic, erythronic, 4-oxovaleric, 2-furanoic, saccharinic, methyl succinic, arabonic, 3-deoxypentonic, methyl glyceric, 2-oxovaleric and isosaccharinic acids are minor compounds.

---

Säuren in Zichorienwurzeln und Malz. II. Bestimmung von Säuren, die aus Kohlenhydraten entstehen

Zusammenfassung Säuren, die als Abbauprodukte von Kohlenhydraten bekannt sind, wurden in rohen, getrockneten und gerösteten Zichorienwurzeln und in getrocknetem sowie geröstetem Gerstenmalz mit Hilfe der Gaschromatographie/Massenspektrometrie und Isotachophorese quantitativ bestimmt. Es handelt sich um 8 Aldon- und 10 Desoxyaldonsäuren. Ferner wurden drei Oxosäuren, zwei Derivate der Furancarbonsäure, zwei flüchtige Säuren, Methylbernsteinsäure und Oxalsäure bestimmt. Zichorie und Malz zeigen qualitativ die gleiche Säurezusammensetzung, doch weisen im allgemeinen die Zichorienwurzeln einen wesentlich höheren Gehalt an Säuren auf. Während sich in Darrprodukten die Säuren nur in Spuren nachweisen lassen, nehmen die Gehalte beim Rösten zu. Der Zichorienkaffee enthält Essig-, Ameisen-, 2-Hydroxyessig-, Brenztrauben-, Milch-, Metasaccharin-, Oxal-, Glycerin- und 3-Hydroxypropionsäure in relativ großen Mengen. 5-Hydroxymethyl-2-furancarbon-, 2,4-Dihydroxy- und 3,4-Dihydroxybutter-, Arabon-, Glucon-, Ribon-, Erythron-, Threon-, 4-Oxovalerian-, Methylbernstein-, 2-Furancarbon-, Mannon-, 3-Desoxypenton-, Saccharin-, Isosaccharin-, Methylglycerin- und 2-Oxovaleriansäure finden sich in Spuren. Im Malzkaffe wurden nur Essig-, Brenztrauben-, Ameisen-, Oxal- und Milchsäure in relativ großen Mengen gefunden. Glucon-, 3,4-Dihydroxybutter-, 3-Hydroxypropion-, Metasaccharin-, Mannon-, Glycerin-, 2-Hydroxyessig-, 2,4-Dihydroxybutter-, Ribon-, Threon-, 5-Hydroxymethyl-2-furancarbon-, Erythron-, 4-Oxovalerian-, 2-Furancarbon-, Saccharin-, Methylbernstein-, Arabon-, 3-Desoxypenton-, Methylglycerin-, 2-Oxovalerian- and Isosaccharinsäure fanden sich in Spuren.

---

---

Dedicated to Prof. Dr. Reinhard Schmutzler on the occasion of his 60th birthday     

The chlorogenic acids content of coffee substitutes

This paper reports the chlorogenic acids content of unroasted chicory root and eleven coffee substitutes which contain either chicory or dandelion. Unroasted chicory root contained CQA and diCQA but at a much lower level than green coffee beans. In the roasted products only 5-CQA was found consistently and 4-CQA occasionally at levels approximately two orders of magnitude lower than in the corresponding roasted coffee products. The roasted substitutes were characterised chromatographically by very large amounts (some 80 to 95% of total chromatogram area) of rapidly eluting material. The chromatograms of most substitutes were characterised by a peak provisionally identified as 5-hydroxymethyl furfural.     

Identification of a new flavanol glucoside from barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) and malt

(2R,3S)-Catechin-7-O-#-D-glucopyranoside is isolated from barley (Hordeum vulgare L.) and malt for the first time. For identification, the glucoside was isolated from acetone-water extracts of malt by polyamide clean-up and semi-preparative HPLC. The structure was elucidated by various NMR techniques, fast atom bombardment mass spectrometry and UV and circular dichroism spectroscopy. The investigation of 20 different barley varieties and the corresponding malts by HPLC with UV and coulometric electrode array detection revealed that the amount of the glucoside increases during malting. In contrast, the content of the monomeric (+)-catechin decreases and (-)-epicatechin was not detected.     

EXAMINATION OF SOME BREWING MATERIALS AND CARAMELS FOR THE POSSIBLE OCCURRENCE OF 4-METHYLIMIDAZOLE

An investigation was carried out to determine how much, if any, 4-methylimidazole is present in caramels and some other materials used in brewing. Existing analytical methods were modified to improve sensitivity. 4-Methylimidazole was not detectable in roasted barley, chocolate malt, crystal malt, Farbebier, wort and beer, when the limit of detection was 1 mg/kg. However, caramels manufactured by different processes contained amounts ranging from undetectable to 280 mg/kg.     

烘烤和发芽对大麦挥发性风味影响的分析研究

以发芽大麦为研究对象,采用电子鼻,电子舌与气相色谱串联质谱技术相结合分别对发芽前后大麦、烘烤发芽前后大麦进行了挥发性风味研究。结果表明烘烤发芽第一天的大麦茶风味有明显的变化,电子鼻能灵敏地检测到相较于烘烤未发芽大麦茶,烘烤发芽大麦茶在传感器PA/2、T70/2、P40/1、P10/2、P10/1、T30/1上的响应值有所增加。电子舌的苦味值、鲜味值在烘烤发芽第一天的时候最高。电子鼻主成分分析能够较好地区分烘烤发芽大麦茶和烘烤未发芽大麦茶,电子舌主成分分析显示发芽1 d大麦和未发芽大麦有部分重叠。在挥发性物质上,烘烤发芽第一天的大麦的挥发性组分醛类、酮类、酸类的相对含量有所下降,在第一天分别比未发芽下降了15.3%、0.44%、7.14%。香气组分杂环类有显著变化,相比未发芽大麦增加了46.87%,香气组分比未发芽大麦多出了8种。相较于烘烤未发芽大麦,烘烤发芽第一天大麦的风味具有明显变化。     

A Survey of Barley,Malt and Beer Contamination with Ochratoxin A in Turkey

The presence of ochratoxin A (OTA) was investigated in barley, malt and beer samples using an ELISA method (RIDASCREEN). The lower detection limit of this OTA test was 0.08 μg/L for beer and 0.4 μg/kg for barley and malt. In 26 out of 29 barley samples the OTA content was between 0.53–12 μg/kg. OTA was between 0.5–6.6 μg/kg in 23 out of 24 malt samples. Only one malt sample had no detectable OTA using RIDASCREEN. The OTA content was between 0.1–8.10 μg/L in 42 out of 150 beer samples (28%) and in 108 beer samples OTA was not found at detectable levels (72%). Only one beer sample contained more than 5 μg/L OTA.     

SPME/GC/MS analysis of headspace aroma compounds of the Cameroonian fruit Tetrapleura tetraptera (Thonn.) Taub.

The aroma components of fresh and dried fruit shell of Tetrapleura tetraptera (Thonn.) Taub. (Mimosaceae) from Cameroon were analyzed by GC/FID, GC/MS, SPME/GC/FID, SPME/GC/MS, and olfactometry. The headspace is characterized by a high percentage of lower acids and esters. The main compounds in the SPME-headspace samples are 2-methylbutanoic acid (8.1%-14.5%), 2-methylbutenoic acid (3.5%-5.4%), acetic acid (13.0%-48.2%), butanoic acid (1.9-9.5%), 2-methylbutanoic acid ethyl ester (1.4%-3.4%), and 2-methylbutenoic acid ethyl ester (0.9%-10.3%) as well as 3-methylbutanone (0.3%-3.9%), butanol (0.4%-4.6%), 2-hydroxy-3-butanone (8.1%-31.6%), and 2-methylbutanol (3.6%-6.1%). Additional information on volatiles of an oleo-resin and a headspace sample from dried T. tetraptera fruits has been given and the analytical data correlated with olfactoric impressions to provide information about the aroma compounds responsible for the characteristic odour impression of these fruit samples.     

Coffee mixtures—Spectrophotometric method for the determination of coffee content

The method described in this paper gives results which are good approximations of the actual coffee contents of roasted coffee/roasted chicory and roasted coffee/roasted fig mixtures.It has also been applied to coffee and chicory essence, cereal products and instant coffee/chicory, instant coffee/cereal/chicory mixtures.     

苣荬菜中脂肪酸的气相色谱-质谱分析

本文采用索氏提取法提取苣荬菜中脂肪酸，再进行甲酯化处理，以气相色谱-质谱联用仪分离和鉴定脂肪酸的组成和含量。结果表明：由苣荬菜中分离鉴定出12种脂肪酸，占脂肪酸总量的90．21％，不饱和脂肪酸占脂肪酸总量的52．09％，饱和脂肪酸占脂肪酸总每的38．12％。     

Changes in carbohydrates during the production of coffee substitute extracts,especially in the roasting process

The changes in the content of starch, dextrin and reducing sugars in rye and barley, and inulin and fructose in chicory roots, during the roasting process, were investigated. The analysis of carbohydrates was connected with the estimation of changes in extract content, colour of the roasted materials, pH and the sensoric evaluation of the brew. The changes in the content of the respective carbohydrates in the basic stages of the whole process of production of coffee substitute extract were also investigated.In the case of roasted rye and barley the high quality of the brew was connected with the highest content of dextrin and reducing sugars. In the case of roasted chicory the highest fructose content (～13%) and the relation between inulin and fructose may be recognised as parameters for ‘optimum’ quality.As a result of the specific technology of the enzymatic treatment of the extract, a very characteristic carbohydrate composition in the final product, with a high content of dextrins (above 30%) and of reducing sugars, could be observed.     

The influence of unmalted barley on the oxidative stability of wort and beer

The aim of this study was to investigate the influences of unmalted barley on the brewing process and the quality of the resulting beer‐like beverages, with the main focus on the oxidative stability, using traditional beer analyses, GC‐MS for the determination of aging compounds and electron paramagnetic resonance spectroscopy to determine free radical activity. For the investigation, brews with different barley proportions and 75% barley brews with a colour malt addition, to compensate for a lower colour using barley, were produced. In general, it can be said that beers with a proportion of up to 50% barley achieved a comparable or higher extract yield and final attenuation owing to the combined effectiveness of the malt and microbial enzymes. Although all analytical values were within the normal range according to Methodensammlung der Mitteleuropäischen Brautechnischen Analysenkommission (MEBAK), a slight decrease in total polyphenols and free amino nitrogen content was observed. Also in response to higher barley portions, an increase of higher molecular weight proteins and β‐glucan was detected. Barley is not exposed to heat and oxidative stress in the malting plant, which explains the lower values of the thiobarbituric acid index and colour as an indicator of Maillard reaction products in the resulting wort and beer. Additionally, the results demonstrate a slower increase of aging compounds during beer storage with increasing barley proportions. Furthermore, it was observed that higher barley proportions led to a better oxidative stability indicated by a lower radical generation (T₄₅₀‐value) in wort and an increasing beverage antioxidant index/endogenous antioxidative potential (BAX/EAP value) in the final beverage. The case of ‘barley beers’ showed that the positive effect of barley on the oxidative beer stability was greater than the negative effect of the addition of colour malt, to adjust the colour of a 100% malt beer. In sensory comparison with beer produced with 100% malt, the beers brewed with a barley proportion up to 50% showed a slight flavour preference and up to a 75% equivalent evaluation. Copyright © 2012 The Institute of Brewing & Distilling     

Effect of substrate composition and inoculum on the fermentation kinetics and flavour compound profiles of potentially non-dairy probiotic formulations

Most of the commercialized probiotic formulations are dairy-based, and the development of non-dairy probiotic products could be a key area for new functional products. It has been proved that probiotic microorganisms can grow on cereal-based substrates, but flavour development in these has not been studied. In this work nine prospective cereal-based probiotic beverages were produced by inoculating oats, barley and malt substrates with single cultures of Lactobacillus acidophilus (NCIMB 8821), Lactobacillus plantarum (NCIMB 8826), and Lactobacillus reuteri (NCIMB 11951). Volatile, and non-volatile flavour compounds, as well as cell growth, pH, free amino nitrogen (FAN), and total reducing sugars (TRS) profiles were monitored during fermentation. The malt beverage inoculated with L. plantarum had the highest amounts of acetaldehyde and diacetyl with concentrations of 6.21 mg/L and 0.38 mg/L respectively. The greatest amount of lactic acid (4.2 g/L) was measured in the malt beverage inoculated with L. acidophilus. In most of the beverages the maximum cell growth was reached after 8 h of fermentation (6.4–8.2 Log₁₀ CFU/mL). It is clear from this work that each microorganism develops different flavours in the three media tested, and the right combination of microorganisms and substrates could lead to palatable probiotic products.