Analysis of leaf surface sesquiterpenes in potato varieties

A comparative study of potato leaf sesquiterpenes was carried out. GC, GC-MS, and NMR analyses were used to identify and quantify the sesquiterpenes in the leaf surfaces of 10 potato (Solanum tuberosum) varieties. Two sesquiterpene alcohols and 17 sesquiterpene hydrocarbons were identified and quantitatively determined. The distribution of the sesquiterpenes was found to be variety-specific. The sesquiterpene contents of the different potato varieties were subjected to cluster and principal component analyses. The eight potato varieties of the main chemotype cluster were dominated by beta-caryophyllene (9-148 ng/cm2), germacrene D (2-46 ng/cm2), germacrene D-4-ol (0.4-31 ng/cm2), beta-sesquiphellandrene (1-34 ng/cm2), and an unknown sesquiterpene alcohol III (0.2-37 ng/cm2). Chemometric classification distinguished two varieties, Mila and Vistula, from a major cluster. The Vistula variety was distinguished from the others by its high contents of beta-caryophyllene, alpha-humulene, germacrene D, and germacrene D-4-ol and the Mila variety by beta-elemene, trans-alpha-bergamotene, (Z)-beta-farnesene, (E)-beta-farnesene, trans-beta-bergamotene, beta-sesquiphellandrene, and unknown sesquiterpene alcohols I, II, III.     

Potential chemopreventive properties of extract from baked sweet potato (Ipomoea batatas Lam. Cv. Koganesengan)

The extract from baked sweet potato (Ipomoea batatas Lam. cv. Koganesengan) showed potential cancer-preventing effects. The extract was partially fractionated to four fractions (I, II-a II-b, and III) by Sephadex G-25 gel chromatography. The cytotoxicity against human myelocytic leukemia HL-60 cells, the suppression of TPA-induced transformation in mouse skin JB6 C141 cells, the apoptosis inducing activity in HL-60 cells, and the scavenging capacity against DPPH radical were tested on the four fractions. Fractions II-a and III showed markedly strong radical scavenging effects on the DPPH radical, coinciding with the high content of total phenolic compounds in the fractions. Both of these fractions suppressed strongly the proliferation of HL-60 cells with apoptosis induction in a dose-dependent manner. Moreover, the two fractions markedly blocked TPA-induced cell transformation in the JB6 cell line. Taken together, these data suggest that the water extract from baked sweet potato had potential chemopreventive properties.     

Monosaccharide composition of sweetpotato fiber and cell wall polysaccharides from sweetpotato, cassava, and potato analyzed by the high-performance anion exchange chromatography with pulsed amperometric detection method

The cell wall materials (CWMs) from sweetpotato (Ipomoea batatas cv. Kokei 14), cassava (Manihot esculenta), and potato (Solanum tuberosum cv. Danshaku) and commercial sweetpotato fiber as well as their polysaccharide fractions were analyzed for sugar composition by the high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method. The separation of arabinose and rhamnose, and xylose and mannose, by this method has been improved using a CarboPac PA 10 column. Pretreatment of the CWMs and cellulose fractions with 12 M H(2)SO(4) was required for complete hydrolysis to occur. Commercial sweetpotato fiber was found to be mainly composed of glucose (88.4%), but small amounts of other sugars were also detected. Among the root crops, sweetpotato CWM had the highest amount of pectin and galacturonic acid. Fucose was detected only in cassava CWM and its hemicellulose fraction, while galactose was present in the highest amount in potato CWM. Among the polysaccharide fractions, it was only in the hemicellulose fraction where significant differences in the sugar composition, especially in the galactose content, were observed among the root crops.     

Antioxidant activity and phenolic compositions of lentil (Lens culinaris var. Morton) extract and its fractions

Phenolic compounds were extracted from Morton lentils using acidified aqueous acetone. The crude Morton extract (CME) was applied onto a macroresin column and desorbed by aqueous methanol to obtain a semipurified Morton extract (SPME). The SPME was further fractionated over a Sephadex LH-20 column into five main fractions (I-V). The phytochemical contents such as total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the CME, SPME, and its fractions were examined by colorimetric methods. Antioxidant activity of extracts and fractions were screened by DPPH scavenging activity, Trolox equivalent antioxidant capacity (TEAC), ferric reduced antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC) methods. In addition, the compositions of active fractions were determined by HPLC-DAD and HPLC-MS methods. Results showed that the fraction enriched in condensed tannins (fraction V) exhibited significantly higher values of TPC, CTC, and antioxidant activity as compared to the crude extract, SPME, and low molecular weight fractions (I-IV). Eighteen compounds existed in those fractions, and 17 were tentatively identified by UV and MS spectra. HPLC-MS analysis revealed fraction II contained mainly kaempferol glycoside, fractions III and IV mainly contained flavonoid glycosides, and fraction V was composed of condensed tannins. The results suggested that the extract of Morton lentils is a promising source of antioxidant phenolics and may be used as a dietary supplement for health promotion.     

Flavor composition of cashew (Anacardium occidentale) and marmeleiro (Croton species) honeys

The aim of this work was to characterize the volatile fractions of two Brazilian honeys known as caju and marmeleiro. The volatile components were isolated by a column extraction technique using acetone as the extraction solvent. Totals of 59 and 36 volatile compounds were definitely or tentatively identified in the caju and marmeleiro honeys, respectively, using reference substances, mass spectral libraries, and the odor qualities of the compounds eluted from the GC column. Aroma extraction dilution analysis allowed the tentative identification of furfuryl mercaptan, benzyl alcohol, delta-octalactone, gamma-decalactone, eugenol, benzoic acid, isovaleric acid, phenylethyl alcohol, and 2-methoxyphenol as impact volatile compounds in the caju honey. In the marmeleiro honey, only isovaleric acid, gamma-decalactone, benzoic acid, and vanillin were considered to be potent odorants. This study showed that the medium- to high-boiling volatile compounds are important contributors to the characteristic aroma of these honeys.     

Characterization of carrot root oil arising from supercritical fluid carbon dioxide extraction

Carrot root oil (SCO), obtained by supercritical fluid carbon dioxide (SC-CO2) extraction, was characterized and compared to a commercial carrot oil (MCO) and a virgin olive oil (VOO) (cv. Coratina). SCO showed much higher contents of carotenes, phenolics, waxes, phytosterols, and sesquiterpene and monoterpene volatiles. In SCO, the most prominent components present in the fully investigated analytical fractions (fatty acids, triglycerides, waxes, phytosterols, long-chain aliphatic alcohols, superior triterpene alcohols, and volatiles) were, respectively, linolenic acid, trilinolein, waxes C38, beta-sitosterol, campesterol and stigmasterol, 1-hexacosanol, 24-methylencycloartanol and cycloartenol, beta-caryophyllene, alpha-humulene, alpha-pinene, and sabinene. In VOO, the major constituents of the above analytical classes were, respectively, oleic acid, trilinolein, waxes C36, unsaturated volatile C6 aldehydes (trans-2-hexenal most markedly), and the same prominent sterols and superior alcohols found in SCO. In MCO, which also contained a proportion of unknown plant oil, several components showed magnitudes that were lower compared to SCO but higher with respect to VOO. The last had the aliphatic and triterpene alcohol concentration higher compared to that of both SCO and MCO. Several chemometric methods, applied to different analytical data sets, proved to be effective in grouping the three oil kinds.     

Toxic secondary metabolite production in genetically modified potatoes in response to stress

Potatoes produce a number of toxic secondary metabolites, which are divided into two groups: the sesquiterpenes and the glycoalkaloids (PGAs): whereas PGAs are largely preformed and present in toxic quantities in both the foliage and "green" potatoes, it is well documented that the levels of PGAs and sesquiterpenes are effected by many biotic an abiotic stresses. The development of genetically modified potato varieties has made it prudent to ascertain whether there may be changes in the amounts or types of these secondary metabolites either as a direct effect of the transgene or due to its interactions with environmental variables. Transgenic potato lines were exposed, along with nontransgenic lines, to a range of biotic and abiotic stresses and a range of environmental conditions in the field and store. Following stressing, a comparison was made of levels of potato glycoalkaloid and sesquiterpene levels between the two groups. Significant differences were observed in the levels of both glycoalkaloid and sesquiterpene levels between transgenic and control material and between infected and noninfected material.     

Changes of the volatile profile and artifact formation in Daidai (Citrus aurantium) cold-pressed peel oil on storage

The chemical changes and artifact formation in daidai (Citrus aurantium L. var. Cyathifera Y. Tanaka) cold-pressed peel oil upon storage at 20, 5, and -21 degrees C for 3, 6, and 12 months were investigated using capillary gas chromatography (GC) and GC-MS. Major changes occurred in the oil stored at 20 and 5 degrees C. No changes were found at -21 degrees C. Monoterpene hydrocarbons decreased from 98.0 to 66.4% upon 12 months at 20 degrees C, while sesquiterpene hydrocarbons and alcohols increased from 0.1 to 2.4% and from 0.3 to 7.9%, respectively. Notable decreases of germacrene D, myrcene, linalyl acetate, and limonene occurred. Prominent increases of cis-carveol, trans-beta-farnesene, trans-p-2,8-menthadien-1-ol, linalool, and beta-caryophyllene were found. Thirty-four artifact compounds constituting 17.0% of the total volatile compounds were formed upon 12 months at 20 degrees C. The artifacts consisted of 13 alcohols (6.0%), five carbonyl compounds (5.3%), seven esters (4.9%), three epoxides (0.4%), four hydrocarbons (0.3%), and two unidentified. The prominent artifact compounds were (+)-carvone, trans,trans-farnesyl acetate, sabinene hydrate, 1-octen-3-ol, cis,cis-farnesyl acetate, and dihydrocarveol acetate. The results could be applied for monitoring and control of the flavor quality of daidai essential oil and related products.     

Separation of Fiber from Distillers Dried Grains with Solubles (DDGS) Using Sieving and Elutriation

A process was developed to separate fiber from distillers dried grains with solubles (DDGS) in a dry‐grind corn process. Separation of fiber from DDGS would provide two valuable coproducts: 1) DDGS with reduced fiber, increased fat, and increased protein contents; and 2) fiber. The process, called elusieve process, used two separation methods, sieving and elutriation, to separate the fiber. Material carried by air to the top of the elutriation column was called the lighter fraction and material that settled to the bottom of the column was called the heavier fraction. We evaluated the compositions of fractions produced from sieving and elutriation. Two commercial samples of DDGS were obtained from two dry‐grind corn plants. Sieving over four screens (869, 582, 447, and 234 μm openings) created five size categories. The two smallest size categories contained >40% (w/w) of the original DDGS and had reduced fiber and increased protein and fat contents relative to the original DDGS. Elutriation of the remaining three size categories increased protein and fat contents and reduced fiber contents in the heavier fractions. Elutriation at air velocities of 1.59–5.24 m/sec increased the protein content of the heavier fraction by 13–41% and increased the fat content of the heavier fraction by 4–127% compared with the bulk fractions of each size category. This process was effective in separating fiber from both DDGS samples evaluated. Elusieve process does not require changes in the existing dry‐grind process and can be implemented at the end of the dry‐grind process.     

Tracer studies on the incorporation of [2-14C]-DL-mevalonate into chlorophylls a and b, alpha-chaconine, and alpha-solanine of potato sprouts

Chlorophyll and glycoalkaloids are synthesized in different parts of the potato plant including leaves, tubers, and sprouts. Although light stimulates the biosynthesis of both constituents, the question of whether the two biosynthetic pathways are under the same genetic control has not been resolved. This study investigated the dynamics of incorporation of labeled [2-(14)C]-DL-mavalonate into chlorophyll a, chlorophyll b, and the glycoalkaloids alpha-chaconine and alpha-solanine in potato sprouts after 7 and 14 days of storage in the light and in the dark. No chlorophyll synthesis occurred in the dark. Fractionation of the "glycoalkaloid" extract followed by high-performance liquid chromatography produced four peaks. The fractions were collected and analyzed for radioactivity. About 80% of the radioactivity resided in fraction 1, the composition of which is unknown. Two of the fractions, with 1-14% of the original label, were alpha-chaconine and alpha-solanine. The radioactivity derived from mevalonate largely resides in unidentified compound(s) eluting as a single peak on the HPLC column before the peaks associated with the glycoalkaloids. The specific radioactivity of alpha-chaconine and alpha-solanine increased approximately 2-fold in going from 7 to 14 days of exposure in the light and in the dark. These and additional observations point to the near identity of the dynamics of biosynthesis of the two glycoalkaloids. These data also implicate a non-mevalonate pathway for the synthesis of both chlorophylls and the glycoalkaloids and are consistent with independent genetic control of the concurrent formation of the two classes of compounds during greening of potatoes.     

Leaf volatile compounds of seven citrus somatic tetraploid hybrids sharing willow leaf mandarin (Citrus deliciosa Ten.) as their common parent

Volatile compounds were extracted by a pentane/ether (1:1) mixture from the leaves of seven citrus somatic tetraploid hybrids sharing mandarin as their common parent and having lime, Eurêka lemon, lac lemon, sweet orange, grapefruit, kumquat, or poncirus as the other parent. Extracts were examined by GC-MS and compared with those of their respective parents. All hybrids were like their mandarin parent, and unlike their nonmandarin parents, in being unable to synthesize monoterpene aldehydes and alcohols. The hybrids did retain the ability, although strongly reduced, of their nonmandarin parents to synthesize sesquiterpene hydrocarbons, alcohols, and aldehydes. These results suggest that complex forms of dominance in the mandarin genome determine the biosynthesis pathways of volatile compounds in tetraploid hybrids. A down-regulation of the biosynthesis of methyl N-methylanthranilate, a mandarin-specific compound, originates from the genomes of the nonmandarin parents. Statistical analyses showed that all of the hybrids were similar to their common mandarin parent in the relative composition of their volatile compounds.     

Effects of nucleo-cytoplasmic interactions on leaf volatile compounds from citrus somatic diploid hybrids

Three diploid citrus somatic hybrids (cybrids) were produced by fusions combining nucellar callus-derived protoplasts of Willow Leaf mandarin (Citrus deliciosa Ten.) and Commune clementine (Citrus clementina Hort. ex Tan.) with, respectively, leaf protoplasts of Eureka lemon [Citrus limon (L.) Burm.] and Marumi kumquat [Fortunella japonica (Thunb.) Swing.] and leaf protoplasts of Marumi kumquat. Ploidy and origins of the nuclear, chloroplastic, and mitochondrial genomes were investigated by flow cytometry and nuclear and cytoplasmic simple sequence repeat analyses. Volatile compounds were extracted from the leaves of the three cybrids by a pentane/ether (1:1) mixture, analyzed by GC-MS, and compared to those of their parents. The cybrids were found to be very close to their nucleus-giving parent, suggesting that the main information for volatile compounds biosynthesis is contained in the nucleus. However, nucleo-cytoplasmic interactions occurred: the (mandarin + lemon) cybrid, possessing nucleus and chloroplasts of lemon and mitochondria from mandarin, synthesizes more monoterpene alcohols and esters than its nucleus-giving parent; the (clementine + kumquat) cybrid, possessing nucleus from kumquat and organelles from mandarin, synthesizes more monoterpene and sesquiterpene hydrocarbons and sesquiterpene alcohols than its nucleus-giving parent.     

Distribution of potassium fractions in sweet potato (Ipomoea batatas) garden soils in the Central Highlands of Papua New Guinea and management implications

Previous studies indicated that potassium (K) deficiency is an important soil‐related factor for yield decline of the sweet potato gardens in the Central Highlands of Papua New Guinea, where sweet potato is an important staple food crop. An effort was made to characterize various fractions of K in the diverse soils of this region under sweet potato, to ascertain the probable reasons behind the observed K deficiency and its relationship to decreasing yield trends. Soils from two depths (0–10 cm) and (10–20 cm) in two types of gardens (old and new gardens) were assessed for different fractions of soil potassium in volcanic and non‐volcanic soil groups. Volcanic soils (Hydrandepts and Andaquepts) were significantly lower (P < 0.05) in exchangeable K than the non‐volcanic soils (Dystropepts, Tropoqualfs and Eutropepts). Mean exchangeable K content of the non‐volcanic soils was 95.5 mg/kg, whereas that of volcanic soils was 72.4 mg/kg. Similarly, new gardens had an average exchangeable K content of 94.1 mg/kg, which was significantly greater than 71.6 mg/kg soil of older gardens. Non‐exchangeable K content differed significantly (P < 0.001) between the soil types; mean K content was 85.9 mg/kg for the volcanic soils, whereas in non‐volcanic soils, it was 184.9 mg/kg. Garden types also differed significantly (P < 0.05) with respect to non‐exchangeable K content; new gardens registering higher average values (by almost 20%) than the older gardens. Multiple regression analysis showed that variability in the tuber yield was as a result of variability of water soluble and exchangeable K (up to 22%), non‐exchangeable K (2%), mineral K (4%) and leaf K concentrations (10%). Older gardens, which are in volcanic soil groupings, are more susceptible to the K depletion problem because of continuous sweet potato cultivation, possibly owing to their lower K reserves. Such gardens should be managed either with sufficient fallow periods for regeneration of soil fertility or with suitable application of mineral K fertilizers to enhance productivity.     

Identification and quantification of impact odorants of aged red wines from Rioja. GC-olfactometry, quantitative GC-MS, and odor evaluation of HPLC fractions.

An XAD-4 extract from a 5-year-old wine from Rioja (Spain) was analyzed by aroma extract dilution analysis. Most of the odorants were quantified by GC-MS. A second extract was fractionated in an HPLC system with a C-18 semipreparative column. Fifty fractions were recovered, their alcoholic degree and pH were further adjusted to those of the wine, and those fractions that showed strong odor characteristics were further re-extracted and analyzed by GC-O and GC-MS. Reconstitution experiments were carried out to confirm the role of the odorants detected in the fractions. Fifty-eight odorants were found in the Rioja wine, 52 of which could be identified. Methyl benzoate was found to be a wine aroma constituent for the first time. The most important odorants are 4-ethylguaiacol, (E)-whiskey lactone, 4-ethylphenol, beta-damascenone, fusel alcohols, isovaleric and hexanoic acids, eugenol, fatty acid ethyl esters, and ethyl esters of isoacids, Furaneol, phenylacetic acid, and (E)-2-hexenal. Comparison among the three techniques shows good agreement and demonstrates that they are complementary.     

Pentasaccharide glycosides from the tubers of sweet potato (Ipomoea batatas)

Sweet potato ( Ipomoea batatas) has been used as food and herb in many countries. In this research on the active constituents of sweet potato, nine compounds were isolated and identified, including seven new resin glycosides, batatosides A-G (1- 7), along with two known compounds, batatinoside I ( 8) and simonin IV ( 9). The structures of 1- 9 have been established by a combination of spectroscopic and chemical methods. The major characteristics of the new compounds are the presence of three different substituents. The absolute configuration of aglycones was established as S by Mosher's method. Batatoside E ( 5) showed weak cytotoxic activity against Hep-2 cells.     

Composition of the essential oil of Citrus tamurana Hort. ex Tanaka (Hyuganatsu)

The composition of the essential oil of Citrus tamurana Hort. ex Tanaka (Hyuganatsu), isolated by the cold-pressing method, was investigated by capillary GC and GC-MS. The effects of harvesting time, degree of freshness, and size of fruits on the composition of Hyuganatsu peel oils were also determined. A total of 126 volatile constituents were confirmed in the Hyuganatsu oils. The Hyuganatsu oils contained hydrocarbons (95.95-96.95%), aldehydes (0.33-0.62%), alcohols (1.91%-2.64%), ketones (0.40-0.62%), esters (0.28-0.39%), oxides (0.04-0.06%), acids (0.01%), and trace amounts of fugenol methyl ether. Monoterpene hydrocarbons were predominant. Limonene (80.35-82.39%), gamma-terpinene (7.71-9.03%), myrcene (2.11-2.28%), linalol (1.37-2.01%), and alpha-pinene (1.17-1.43%) were the most abundant components in Hyuganatsu oils. The principal sesquiterpene hydrocarbon was trans-beta-farnesene (0.60-1.04%), and its content in Hyuganatsu oils was higher than in oils of other citrus fruits. The number of ketones and the content of l-carvone in Hyuganatsu oils were higher than in other citrus oils.     

Isolation and identification of organosulfur compounds oxidizing canine erythrocytes from garlic (Allium sativum)

Five compounds oxidizing canine erythrocytes were isolated from an aqueous ethanol garlic extract by silica gel column chromatography and preparative thin-layer chromatography. On the basis of nuclear magnetic resonance, infrared spectroscopy, and mass spectrometry, they were identified as three known compounds: bis-2-propenyl trisulfide (1), bis-2-propenyl tetrasulfide (2), and bis-2-propenyl pentasulfide (3) as well as two novel compounds, bis-2-propenyl thiosulfonate (4) and trans-sulfuric acid allyl ester 3-allylsulfanyl-allyl ester (5). A mixture of compounds 1-3 and compounds 4 and 5 induced methemoglobin formation in canine erythrocyte suspension in vitro resulting in the oxidation of canine erythrocytes. These groups of characteristic organosulfur compounds contained in garlic probably contribute to oxidations in blood. The constituents of garlic have the potential to oxidize erythrocytes and hemoglobin, suggesting that foods containing quantities of garlic should be avoided for feeding dogs.     

Nutritional utilization by the rat of diets based on lentil (Lens culinaris) seed meal or its fractions

The nutritional effects in the rat of raw lentil meal or its fractions have been evaluated in three feeding trials. Growth, gain/feed ratio, apparent N digestibility, and N retention were significantly (p < 0.05) reduced by the inclusion of whole lentil meal, dehulled lentil meal, or ethanol-extracted lentil meal as the sole source of protein in the diet. Pure lentil lectin and lectin-depleted albumin proteins had no significant negative effect on nutritional performance. In contrast, growth, gain/feed ratio, protein conversion efficiency, N digestibility, and N retention were significantly (p < 0.05) reduced by diets containing lentil globulins or lentil hulls. The poor nutritional quality of raw lentil meal for rats is therefore likely to be primarily due to the combined effects of these two components.     

Selective feeding of the earthworm Hormogaster elisae (Oligochaeta,Hormogastridae) in laboratory culture

Selective feeding of the earthworm Hormogaster elisae was investigated by granulometric analysis, chemical fractionation and physical fractionation of the soil in which representatives were cultivated, and of their casts. H. elisae behaved as an endogeic species, mainly consuming soil from which it weakly but positively selected the organic fractions of greatest size (mainly free organic matter) and negatively selected the largest mineral fraction (coarse sand). No significant selection of intermediate size fractions was recorded. The 0–2 μm granulometric fraction (clays) was also selected; the results suggest that some of the organic components of this size fraction can also be used by the species.