A pilot study on the effects of cultivation conditions of chicory (Cichorium intybus L.) roots on the levels of sesquiterpene lactones in chicons

 One of the quality parameters of chicory (Cichorium intybus L.) is its slightly bitter taste which is caused by sesquiterpene lactones. As the quality of chicons is highly dependent on the quality of the roots, the effects of the cultivation conditions of the roots on the levels of sesquiterpene lactones in chicons were investigated. Roots from a collection of 11 commercially available and 2 experimental chicory cultivars were grown at five different locations with two nitrogen manuring levels to evaluate the differences in sesquiterpene lactone levels as measured with enzyme-linked immunosorbent assays (ELISAs). There were significant differences (P<0.001) between cultivars in both lactucopicrin and lactucin-like (lactucin, 8-deoxylactucin and their 11β,13-dihydro derivatives) sesquiterpene lactone levels. In addition, a significant (P=0.006 and P=0.019, respectively) effect of additional nitrogen manuring was observed on the levels of lactucopicrin and lactucin-like sesquiterpene lactones. The interaction of cultivar with nitrogen manuring had a significant (P=0.013) effect on the level of lactucin-like sesquiterpene lactones. Furthermore, the lactucopicrin level was significantly influenced by the interactions of the cultivar with the nitrogen manuring level (P<0.001), with the location (P=0.001) and with both the nitrogen manuring level and location (P<0.001). The results indicate that it may be possible to influence the level of the bitter sesquiterpene lactones and, consequently, to influence the taste of chicons by cultivar choice and/or cultivation location and conditions. Received: 17 December 1996     

An update procedure for an effective and simultaneous extraction of sesquiterpene lactones and phenolics from chicory

A new method for recovering and purifying sesquiterpene lactones (SLs) and optimise the solvent system for their extraction from freeze-dried chicory leaves was studied. Catalogna (leafy chicory) and Head Radicchio types were used as test samples. Solid phase extraction (SPE) employing silica-based cartridges allowed a fast and straightforward purification of SL from interfering phenolics, before HPLC determination. Under these conditions, SL were eluted during loading and washing steps whereas polar phenolic compounds were retained on silica stationary phase. Hydrophilic mixtures methanol/water acidified by small percentages of formic acid led to consistently higher SL recoveries in comparison to organic solvents and enabled the simultaneous extraction of phenolics. Phenolic recovery in crude extracts was assessed at levels higher than 95% for both Catalogna and Head Radicchio. Total, free and bound SL amounts detected in extract obtained by 2% (v/v) formic acid in methanol/water 4/1 (v/v) were 2223.4, 778.5 and 1444.9 mg/kg of dried product in Catalogna, and 401.2, 105.1 and 296.0 in Head Radicchio. In both cases, recoveries were consistently higher than those obtained with methanol alone.     

Quantification of chicory root bitterness by an ELISA for 11β,13-dihydrolactucin

Chicory root (Cichorium intybus L. var. sativum) is an important foodstuff appreciated for its bitter taste, which is caused by sesquiterpene lactones. These compounds represent a quality parameter for monitoring the raw material. Using polyclonal antibodies, an enzyme-linked immunosorbent assay (ELISA) was developed to quantify the bitter compound 11β,13-dihydrolactucin in chicory root. Assay linearity ranged from 4.6 to 300 ng/ml, with intra- and inter-assay variations of 4.9% and 7.2%, respectively. An IC₅₀ of 2 ng/ml and a detection limit of 0.16 ng/ml were obtained. No or little cross-reactions with other sesquiterpene lactones occurred. Roots of three different chicory varieties were evaluated for their bitter taste and were investigated by the ELISA. Distinct concentrations of 11β,13-dihydrolactucin ranging from 485 to 1720 mg/kg dry matter were correlated with the bitterness degree (r = 0.9). The ELISA appeared sensitive, selective, accurate and may serve as screening tool in breeding of chicory roots for bitterness.     

Effect of light, solvents and commercial enzymes on the solubility and stability of sesquiterpene lactones from chicory roots

Summary The solubility of lactucin, 8-deoxylactucin and lactucopicrin, all sesquiterpene lactones of chicory roots, was determined as a function of pH (pH 1–10) in the presence and absence of polysaccharides. The stability of the sesquiterpene lactones, when dissolved in water, decreased under influence of daylight as a function of pH. Enzymatic hydrolysis of lactucopicrin by commercial enzyme preparations, used for liquefaction of chicory roots into lactucin and p-hydroxyphenylacetic acid, was not found.

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Einfluß von Licht, Lösungsmittel und Handelsenzymen auf die Löslichkeit und Stabilität der Sesquiterpen-Lactone von Zichorienwurzeln

Zusammenfassung Die Stabilität von LaCA Bussurnctucin, 8-Deoxylactucin und Lactucopicrin (alles SesquiterpenLactone der Zichorienwurzel) wurde in Abhängigkeit vom pH-Wert beim Aufbewahren im Licht studiert. Es konnte ein Abbau dieser Verbindungen nachgewiesen werden. Die Löslichkeit dieser drei Verbindungen wurde in Abhängigkeit vom pH-Wert mit und ohne Polysaccharide bestimmt. Es wurde keine Hydrolyse des Lactucopicrins unter der Einwirkung von kommerziellen Enzymen, die bei der Verflüssigung von Zichorienwurzeln verwendet werden, gefunden.

     

Influence of light exposure during storage on the content of sesquiterpene lactones and photosynthetic pigments in witloof chicory (Cichorium intybus L. var. foliosum Hegi)

Greening of witloof chicory is a major quality defect being commonly associated with increased bitterness. The aim of this study was to assess the effect of light exposure during storage on levels of bitter sesquiterpene lactones (SLs) and photosynthetic pigments in leaves and central axes of two cultivars of witloof chicory. For this purpose, witloof chicory packaged in consumer-sized polyamide bags was stored in the dark (8 °C) and under light exposure (8 °C, 4500 lux), respectively, over a period of 11 days. Throughout storage, O₂ and CO₂ levels in the modified atmosphere were monitored. Levels of six individual SLs, chlorophyll derivatives and β-carotene in leaves and central axes were assessed by HPLC-DAD-MSⁿ and color measurements were carried out applying the CIE L*a*b* system.     

Identification of cytotoxic sesquiterpenes from Laurus nobilis L.

A new sesquiterpene, lauroxepine and six known sesquiterpene lactones, were obtained through bioactivity-directed isolation from a methanol extract of the fruits of Laurus nobilis. The hexane-soluble part of the methanol extract yielded lauroxepine, costunolide and gazaniolide, while the dichloromethane-soluble part of the methanol extract afforded costunolide and four other sesquiterpene lactones including santamarine, reynosin, 11,13-dehydrosantonin and spirafolide. The new sesquiterpene lauroxepine and spirafolide have a rare molecular structure carrying an oxepine ring. Structures of the compounds were determined through 1D and 2D NMR and mass (EI-MS) techniques. The extracts were investigated for both ovarian cytotoxic activity and DNA damaging properties against three yeasts. Among the three tested extracts prepared from flowers, leaves and fruits of L. nobilis, the most cytotoxic active extract against ovarian cancer cell line was found to be the fruit extract with 98% inhibition. Among all tested extracts, only the fruit extract showed marginal inhibition (63.2%) against one DNA repair-deficient yeast strain (pRAD52 Gal). Six known sesquiterpene lactones were found to be highly cytotoxic against the A2780 ovarian cancer cell line, however, lauroxepine was not found to be active in A2780.     

Effects of cold storage on aroma compounds of white- and yellow-fleshed peaches

The stir bar sorptive extraction (SBSE) technique was used to determine volatile constituents in two peach cultivars, one yellow-fleshed (cv. Spring Lady) and one white-fleshed (cv. Regina Bianca). For both cultivars four distinct experimental samples were considered, each formed by fruits obtained with four different cultivation practices. In order to investigate the effects of cold storage on the volatile profile, on all peach experimental samples changes in aroma compounds after 1 and 2 weeks of storage at 1°C, plus 1 day at ambient temperature, were monitored; moreover, only on the four experimental samples from cv. Regina Bianca, the effect of a prestorage hot water treatment (46°C for 25 min) was also evaluated. On the isolate obtained by SBSE, 24 compounds were identified and quantified by GC-MS: saturated and unsaturated lactones, aldehydes, C₁₃ norisoprenoids, monoterpenes, alcohols and esters. The profile of the white-fleshed cultivar was characterised by a higher level of C₁₃ norisoprenoids, and, in particular, of 8,9-dehydrotheaspirone. In all experimental samples after 1 week of storage, plus 1 day at ambient temperature, a marked increase (on average by 89%) in total lactones was observed. This increase was due to a noticeable accumulation of saturated lactones with longer side chains (γ- and δ-decalactone) and unsaturated lactones ((Z)-dec-7-en-5-olide and γ-jasmolactone). Peaches analysed after 2 weeks of storage showed total lactone levels close to those detected in the samples at harvest, suggesting that increasing storage times reduced fruit ability to accumulate these character impact compounds of peach aroma. A similar effect of cold storage, although less marked, was also observed on C₁₃ norisoprenoid fraction, but only on cv. Regina Bianca. On the other hand, we did not find univocal effects of cold storage on C₆ aldehydes, whereas linalool, detected only in samples of cv. Spring Lady at harvest, disappeared quickly during the first days of storage. In samples of cv. Regina Bianca peaches subjected to hot water treatment, after 1 week of storage, lactone level was significantly reduced in comparison with untreated fruits, denoting a possible inhibition effect on lactone accumulation and on aroma development.     

Changes in volatile composition during fruit development and ripening of ‘Alphonso’ mango

BACKGROUND: Volatile blends of five developing and five ripening stages of mango (Mangifera indica L. cv. Alphonso) were investigated along with those of flowers and leaves. Raw and ripe fruits of cv. Sabja were also used for comparison. RESULTS: A total of 55 volatiles belonging to various chemical classes such as aldehydes, alcohols, mono‐ and sesquiterpene hydrocarbons, lactones and furanones were identified. In all Alphonso tissues monoterpenes quantitatively dominated, with 57–99% contribution; in particular, (Z)‐ocimene was found in the highest amount. Ripeness was characterized by the de novo appearance of lactones and furanones in the blend of monoterpenes. Sabja was distinguished by the abundance of monoterpene hydrocarbons in the raw fruit, and that of sesquiterpene hydrocarbons and their derivatives in the ripe stage. CONCLUSION: Various stages of the Alphonso fruit during transition from flower to ripe fruit are characterized by unique volatile signatures that are distinguished from each other by the qualitative and quantitative appearance of different volatile compounds. Thus volatiles can be highly informative markers while studying the development and ripening of mango. Copyright © 2009 Society of Chemical Industry     

Endogenous formaldehyde level of foods and its biological significance

 Formaldehyde was measured in different food samples based on its reaction with hydralazine to form s-triazolo-(3,4-α)-phthalazine(Tri-P). Formaldehyde reacts with hydralazine under mild acidic conditions to form Tri-P. The reaction products were separated by reversed-phase, high-performance liquid chromatography. The method of sample preparation and chromatography are reviewed and the analytical method validated. Using the discussed methods we measured formaldehyde levels in 23 animals and 22 vegetable and fruit samples. Formaldehyde levels were one and a half times higher in vegetable samples compared to meat samples. Received: 23 December 1996 / Revised version: 17 March 1997     

芽球菊苣根粗多糖提取工艺优化及其体外抗氧化活性和相对分子量分析

目的:以印度芽球菊苣根为原料优化粗多糖的提取工艺,测定其抗氧化性及相对分子量。方法:考察料液比、水浴温度和水浴时间对菊苣根粗多糖得率的影响;采用Box-Behnken结合Matlab分析法优化粗多糖热水浸提法提取工艺;测定所提菊苣根粗多糖体外羟自由基清除能力和还原力;纯化后分析中性糖和酸性糖的平均相对分子量。结果:经过单因素和Box-Behnken设计优化试验,得到最佳提取工艺为:料液比2.74:100 g/mL,水浴温度72 ℃和水浴时间165 min,此时菊苣根粗多糖得率的理论预测值为40.32%,经验证实际值为39.99%±0.43%,与预测值差异不显著（P>0.05）;经Matlab分析,当提取时间取较高值（C=165 min）,料液比2.4:100～3.1:100 mL/g,水浴温度70～74 ℃,粗多糖得率可以取得较大值。按照上述最优工艺所提菊苣根粗多糖具备羟自由基清除能力（IC₅₀值为1.36 mg/mL）和Fe3+还原力（3 mg/mL对应吸光值0.21）,且与浓度呈现正相关。此外,采用高效液相色谱（High Performance Liquid Chromatography,HPLC）测得菊苣中性糖和酸性糖峰型良好,酸性糖峰高且窄表现出较高的纯度,中性糖和酸性糖平均相对分子量分别为10072.07和2388.13 Da。结论:Box-Behnken优化法结合Matlab分析法优化菊苣根粗多糖提取工艺切实可行,所提粗多糖不仅高得率,也兼具良好的体外抗氧化能力,其中,酸性糖纯度较高,中性糖分子量较大。     

In vitro degradation of forage chicory (Cichorium intybus L.) by endopoly‐ galacturonase

BACKGROUND: Leaves of forage chicory break down rapidly in the rumen despite little or no rumination. Because chicory cell walls contain high concentrations of pectin, degradation of leaf midrib and leaf lamina tissues by pectinolytic enzymes was investigated. RESULTS: Treatment with endopolygalacturonase (endo‐PG) degraded fresh intact chicory leaves to particles of less than 1 mm in length and solubilised more than 70% of the dry matter within 16 h. Uronic acids were released more extensively than neutral monosaccharides. In similar treatments, 77% of white clover leaflets and 12% of perennial ryegrass leaf blades were solubilised or broken down to particles with a size of less than 1 mm. The degradation of pectic polysaccharides in chicory midribs was monitored by immunofluorescence labelling with monoclonal antibodies JIM5 and JIM7 which target partially methyl‐esterified epitopes of the homogalacturonan (HG) domain of pectin. Examination by fluorescence microscopy revealed that cell separation in the cortical parenchyma of chicory midrib following endo‐PG treatment was associated with loss of HG from the middle lamella, the corners of intercellular spaces and from the tricellular junctions. CONCLUSION: The results of the current study suggest that one of the main contributions to chicory breakdown in the rumen may be cell separation caused by degradation of HG by pectinolytic enzymes from rumen bacteria. Copyright © 2007 Society of Chemical Industry     

The effect of pretreatment on the fermentation of honeybush tea (Cyclopia maculata)

Different pretreatments (bruising, hot and cold water) were used to study their effect on fermentation as measured by the quality parameters of honeybush tea (Cyclopia maculata). Bruising and pretreatment with water (hot and cold) were investigated as means to increase the fermentation rate and to improve product quality. The development of the desired dark-brown colour and honey-like flavour during fermentation was faster in hot and cold water treated material and gave a more uniform coloured product than with the bruising pretreatment. Liquor characteristics also improved with water pretreatment. A red–brown extract, compared with the light yellow–brown of untreated samples, was obtained with the water pretreatment. Hot water pretreatment inactivated the enzymes polyphenol oxidase (PPO) and peroxidase (POD), but did not terminate or impair fermentation. The inactivation of the enzymes, together with high temperature (>60°C) fermentation, indicated a chemical oxidation process rather than an enzymatic reaction in honeybush tea fermentation. © 1998 SCI.     

Aqueous Extraction of Coconut Oil by an Enzyme-Assisted Process

A pre-extraction enzyme treatment of copra meal was incorporated into a rural wet copra oil extraction process to investigate the possibility of improving the traditional process by the enzyme treatment. The enzymes used in the study were combinations of a protease from Aspergillus niger, a cellulase/hemicellulase preparation from Trichoderma reseei, and α-amylase from A oryzae and a pectinase from A niger (all were crude preparations). Finely milled copra meal samples were mixed with water and the enzymes and incubated at 37°C for 6 h or more. After the treatment, the meal was extracted using a water flotation technique. Yield increases of about 50%, relative to experimental controls, were observed, suggesting the possibility of using the enzyme-assisted oil extraction methods to improve upon traditional copra processing. © 1997 SCI.     

Functionality of enzymes that hydrolyse starch and non-starch polysaccharide in breadmaking

 Nine commercial enzyme preparations and two laboratory-designed mixes with amylase and/or pentosanase/xylanase activity were used to prepare bread samples, and the effects on bread quality and keeping properties were determined. With the doses added, enzymes significantly shortened fermentation time without affecting the pH or the machinability of the doughs. Bread with an improved volume, a greater intensity of aroma and a softer texture was obtained. Loaves had a less intense and characteristic taste and, in some cases, an uneven grain. All enzymes delayed bread firming, but rates varied with each preparation. Factor analysis classified bread samples according to their composition and source. Received:7 November 1996/Revised version: 21 January 1997     

Functionality of enzymes that hydrolyse starch and non-starch polysaccharide in breadmaking

 Nine commercial enzyme preparations and two laboratory-designed mixes with amylase and/or pentosanase/xylanase activity were used to prepare bread samples, and the effects on bread quality and keeping properties were determined. With the doses added, enzymes significantly shortened fermentation time without affecting the pH or the machinability of the doughs. Bread with an improved volume, a greater intensity of aroma and a softer texture was obtained. Loaves had a less intense and characteristic taste and, in some cases, an uneven grain. All enzymes delayed bread firming, but rates varied with each preparation. Factor analysis classified bread samples according to their composition and source. Received:7 November 1996/Revised version: 21 January 1997     

Fish Protein Concentrate (FPC) from Bombay Duck Isolated by Radiation-Heat Combination Procedure: Functional and Nutritional Properties

A process involving gamma-irradiation (200 Krad) and heat treatment (60°C, 10 min), for the preparation of fish protein concentrate (FPC) from a tropical fish Bombay duck (Harpodon nehereus) is described. The procedure enabled the precipitation of 75% of proteins from Bombay duck muscle which accounted for 80% of myofibrillar proteins. The solubility of FPC was 3% in water and 15% in 5% NaCl. However, the preparation could be solubilized by treatments with alkali (0.2N NaOH) or proteolytic enzymes. Among the enzymes tested for FPC solubilization, pronase was Pound to be the most effective both with respect to the extent and the rate of hydrolysis. The FPC displayed good functional properties in terms of emulsifying capacity and wettability. The PER was better than that obtained for casein when fed to rats at 11% protein level.     

Extraction of capsaicinoids from chillies (Capsicum frutescens L.) and paprika (Capsicum annuum L.) using supercritical fluids and organic solvents

 Supercritical fluid extraction (SFE) with subsequent HPLC analysis was performed in order to determine the amount of capsaicinoids in paprika and chillie powder samples. The extraction yields obtained by SFE were compared to those obtained by organic solvent extraction and were found to be comparable or slightly lower. The advantages of SFE are shorter extraction times, less sample preparation needed prior to HPLC analysis and fewer interfering peaks in the chromatograms. In addition, the SFE method developed (extraction temperature=80 ^°C, density= 0.75 g/ml, modifier=20 μl water) was shown to be suitable for analysis of capsaicinoids (capsaicin, dihydrocapsaicin, nordihydrocapsaicin) that are present over a wide range of concentrations (10–1400 μg/g) in the samples. Received: 12 July 1996/Revised version: 26 August 1996     

Biogenic amines in dry sausages during shelf-life storage

 Supercritical fluid extraction (SFE) with subsequent HPLC analysis was performed in order to determine the amount of capsaicinoids in paprika and chillie powder samples. The extraction yields obtained by SFE were compared to those obtained by organic solvent extraction and were found to be comparable or slightly lower. The advantages of SFE are shorter extraction times, less sample preparation needed prior to HPLC analysis and fewer interfering peaks in the chromatograms. In addition, the SFE method developed (extraction temperature=80 ^°C, density= 0.75 g/ml, modifier=20 μl water) was shown to be suitable for analysis of capsaicinoids (capsaicin, dihydrocapsaicin, nordihydrocapsaicin) that are present over a wide range of concentrations (10–1400 μg/g) in the samples. Received: 12 July 1996/Revised version: 26 August 1996     

Effectiveness of a natural Rosemary (Rosmarinus officinalis) extract on the stability of filleted and minced fish during frozen storage

 The objective of this study was to evaluate the effect of adding a natural Rosemary (Rosmarinus officinalis L.) extract to filleted and minced frozen fish and to compare the fat stability of the samples with that of the controls. Horse mackerel (Trachurus trachurus), a relatively fatty fish, and Mediterranean hake (Merluccius mediterraneus), a low-fat fish, were used. Fat stability evaluation was done by comparing the changes of the malondialdehyde (MDA) content and the percentage of polyunsaturated fatty acid (PUFAs) degradation that occurred during frozen storage at –18°C for 120 days. Total volatile bases-N (TVB-N) were also measured to assess for quality. The results showed that the natural antioxidant extract retarded the oxidation process throughout storage. The control samples of both filleted and minced frozen fish of both species showed a significant reduction (^* P <0.05) of PUFAs until day 50 of storage, while the oxidation was gradual but slower in the treated samples. Fillets and minced samples of both species treated with antioxidant contained significantly (^* P <0.05) less MDA compared with the controls during storage. Received: 2 December 1996