Novel Xanthine Oxidase (XO) inhibitory phenylindanes produced by thermal reaction of caffeic acid

The products from the thermal reaction of chlorogenic and caffeic acids, which is a model process of roasting coffee beans, exhibited xanthine oxidase (XO) inhibitory activity. From caffeic acid, six inhibitory phenylindanes were identified, and a new phenylindane displayed the highest inhibitory activity among them. The activity of these phenylindanes may contribute to XO inhibition-related functions of roasted coffee beverages.     

A study of chemical Composition,Antioxidants, and volatile compounds in roasted Arabic coffee

Coffea arabica (Rubiaceae) is a basic drink for all Gulf societies, especially Saudi Arabia, it is the main part of the Saudi tradition. This investigation was carried out to track the chemical composition, caffeine content by UV–visible spectrophotometer, acrylamide content by using a gas chromatograph, free radical scavenging capacity by DPPH methods as well as determined the browning index and separated the volatiles compounds using GC–MS for the most common three degree of roasted Arabic coffee; light (180 ± 10 °C; 6.0 ± 1.0 min), medium (180 ± 10 °C; 8.0 ± 1.0 min), and dark (180 ± 10 °C; 10.0 ± 1.0 min). Data revealed that light roasted coffee has the highest significant (p < 0.05) value of moisture content (4.80%), crude protein (13.05%), and lowest value of ether extract (10.39%) and crude fiber (24.24%). The caffeine content was found to be 1.13% in light coffee, which increased to 1.17% in medium coffee, then decreased to 1.08% in dark coffee. The quantity of acrylamide detected in light roasted coffee (0.41 mg/100 g) was the greatest, whereas medium roasted coffee comparatively produced low amounts (0.31 mg/100 g). The light roasted coffee gave the highest antioxidant activity (88.72 mg TE/g), while the dark roasted coffee gave the least activity (78.76 mg TE/g). Browning index increases with roasting time. Hydrocarbons, alcohols, and esters were the most represented in roasted coffee headspace. Silanes and sec-butyl nitrite compounds were absent in the medium roasted headspace. Except for amines, all 11 classes of volatile compounds were present in the headspace of dark roasted coffee.     

Aroma Constituents of Roasted Coconut

The volatile components of roasted and unroasted dried coconut shreds, isolated by steam distillation, were analyzed by GC and GC-MS. Seventeen compounds were identified from the unroasted coconut, and nine of them were newly identified in coconut meat aroma. Saturated delta-C₈, C₁₀, and C₁₂ lactones were determined as the main components giving the characteristic mild, sweet, and pleasant coconut flavor. The roasted coconut gave the strong characteristic sweet and nutty aroma, and the GC-MS indicated the saturated delta-lactones as main components, and six pyrazines, two furans, and two pyrroles also found seemed to contribute greatly to the nut-like aroma of roasted coconut. The defatted and roasted meal gave a strong nut-like and burnt odor, but not the characteristic sweet aroma. A large increase in pyrazines and other Maillard reaction products and an absence of lactones and fatty acid esters were observed in the volatiles of the roasted-defatted coconut meal.     

Volatile Components of Roasted Shrimp

The components of the strong and favorable aroma obtained from roasted shrimp were investigated. The aroma concentrate of roasted shrimp was isolated by combining the dichloromethane extract and carbon dioxide distillation methods. The concentrate was fractionated into acidic, basic and neutral fractions. Each fraction was analyzed by combined gas chromatography-mass spectrometry. Seventy-seven compounds were identified, among which isovaleric acid, alkyl pyrazines, isovaleramide, ketones and some sulfur-containing compounds were the main and characteristic constituents of the roasted shrimp aroma.

These constituents were compared with those of the volatiles of boiled shrimp, which was prepared by using simultaneous distillation and extraction methods in a modified Likens and Nickerson’s apparatus.     

Volatile components of cocoa with particular reference to glucosinolate products

The aroma volatiles of raw, fermented and roasted cocoa beans were extracted and concentrated to valid essences using well-established techniques. Analysis by GC and GC/MS showed at least 84 components of which 13 were identified for the first time as cocoa volatiles. In total, ca 5,66 and 65 μg of aroma components were obtained per g of raw, fermented and roasted cocoa beans, respectively. The most abundant groups of volatiles from fermented beans were alcohols (ca40%w/w of the total volatiles) and esters (ca 32%), whilst those from roasted beans were pyrazines (ca 40%) and aldehydes (ca 23%). Trimethyl- and tetramethylpyrazine were also detected in fermented beans, and it is suggested that they contribute to the noticeable cocoa/chocolate aroma of fermented unroasted beans. Phenylacetonitrile, benzyl isothiocyanate and benzyl thiocyanate were all identified amongst cocoa volatiles, together showing the presence of precursor benzylglucosinolate in cocoa. Glucosinolate products were detected in roasted beans, and it seems likely that the enzyme thioglucoside glucohydrolase survived the conditions of roasting. Benzyl thiocyanate was detected only in raw beans, showing that the glucosinolate ‘thiocyanate–forming factor’ did not withstand conditions of fermentation     

Digestion of Raw and Roasted Almonds in Simulated Gastric Environment

Knowledge of digestion kinetics of solid foods in human stomach, as affected by food processing methods, is critical in establishing processing conditions at the manufacturing stage to achieve desirable release of nutrients in the gastrointestinal tract. The objective of this study was to investigate how roasting affected disintegration and solid release properties of almond in simulated gastric environment. In vitro trials were performed for raw and roasted almonds by using static soaking method and a model stomach system. The changes in sample weight, dry mass, and moisture during the trials were determined. Both compression and penetration tests were used to investigate the texture of almonds with a focus on the influence of absorption of gastric juice. Light microscopy and transmission electronic microscopy were used to study the change in microstructure of the raw and roasted almonds after simulated digestion. The results suggested that the slow disintegration rate and the high amount of swelling of the almonds in the stomach may contribute to their high satiety property. Roasting significantly improved the disintegration rates of almonds and increased loss of solids during simulated digestion, which is well correlated with the decrease in the rigidity of almond samples after absorbing gastric juice. Microstructure of digested almonds showed breakage and breach of cell walls due to acid hydrolysis. Intercellular and intracellular channels formed in almonds during roasting are important for penetration of gastric juice that may facilitate an effective digestion.     

Studies on Flavor Components of Roasted Barley

Basic compounds in the volatiles of roasted barley were analyzed by a gas chromatograph and a combination instrument of gas chromatograph-mass spectrometer. As major components, the following nitrogeneous aromatic compounds were identified: pyridine, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, 2,3,5-trimethylpyrazine and a dimethylethylpyrazine. Ammonia was also detected in the volatiles of roasted barley by an amino acid analyzer.

The formation of 2,5-dimethylpyrazine from pyruvaldehyde-amino acid model systems during roasting was shown, and the possible formation mechanism of pyrazines was presented.     

Aroma of Roasted Green Tea (Hoji-cha)

Aroma components were isolated from roasted green tea (Hoji-cha) and identified by IR and GC–MS.

A total of 66 compounds including 21 pyrazines were identified.

On comparison of aroma pattern of Hoji-cha with that of original green tea, it was clear that pyrazines were produced significantly while alcohols were reduced remarkably by roasting.     

Ochratoxin A (OTA) in Kaffee — Vergleichende Auswertung bundesweiter Daten der Jahre 1995–1999 und 2000–2002

Ochratoxin A concentrations from a total of 1223 samples from green, roasted and ground, decaffeinated and low acid and instant coffee analysed during 1995–1999 and 2000–2002 by German Official Food Control Laboratories were compared. Median concentrations, determined by statistical process analysis decreased within each group from the early group up to 2002. The rates of rejection were calculated on the basis of the recent data for green and roasted and ground coffee which may occur when particular maximum residue limits were set. Contamination rates from green coffee showed significant differences in their OTA concentrations depending on their geographical origin.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

Composition of Semivolatiles from Roasted Tobacco

In order to examine the applicability of the exhaust gas components from the tobacco-roasting process as cigarette flavor ingredients, a preliminary study on the composition of the semivolatiles included in the volatiles from roasted tobacco was conducted. A relatively large quantity of sugar pyrolysates (furans, volatile ketones and lactones) in addition to lower fatty acids and the components of essential oils were found in the condensate of the volatiles from roasted flue-cured tobacco. The condensate from roasted burley tobacco contained nicotine and neophytadiene as major components, and a number of other components of essential oils were also found. The above mentioned compounds in the condensate from flue-cured tobacco were assumed to contribute to its burnt-sugar like aroma. A sweet note of the condensate from burley tobacco might be attributable to the high concentration of the components of essential oils.     

Physical Property Changes in Raw and Roasted Almonds during Gastric Digestion In vivo and In vitro

The rate of almond breakdown during gastric digestion may be influenced by structural changes that occur during roasting. The primary objective of this study was to investigate in vivo physical property changes of raw and roasted almonds during gastric digestion, using the growing pig as a model for an adult human. Seventy two male pigs were fed a meal of raw or roasted almonds and digested samples were taken 20, 60, 180, 300, 480, and 720 min after meal consumption from the proximal and distal stomach regions. Particle size distribution, rheological flow behavior, and textural attributes of gastric digesta were measured. Particle size distributions were fit to the Rosin-Rammler function to determine the median particle diameter (x₅₀) and distribution spread (b) parameters. Median particle diameter was statistically influenced by stomach region (p?<?0.0001). Evidence of gastric sieving was observed by an increased median particle diameter and narrower distribution spread in the distal region. To elucidate on textural changes of diced almonds during digestion, an in vitro study was conducted in a static gastric environment. Results indicated that a majority of textural changes occurred during the first hour of digestion, a trend unobserved in the in vivo trial. No significant differences in physical property changes were observed between raw and roasted almonds during gastric digestion in vivo as measured by particle size distribution, textural attributes, and rheological flow behavior. This suggests that raw and roasted almonds break down at a similar rate in the gastric environment.     

Genetic analysis for physical nut traits in almond

Almond breeding is increasingly taking into account kernel quality as a breeding objective. Although information on nut and kernel physical parameters involved in almond quality has already been compiled, the genetic control of these traits has not been studied. This genetic information would improve the efficacy of almond breeding programs. A linkage map with 56 simple-sequence repeat markers was constructed for the “Vivot” × “Blanquerna” almond population showing a wide range of variability for the physical parameters of nut and kernel. A total of 14 putative quantitative trait loci (QTLs) controlling these physical traits were detected in the current study, corresponding to six genomic regions of the eight almond linkage groups (LG). Some QTLs are colocated in the same region or shared the same molecular markers, in a manner that reflects the correlations between the physical traits, as well as with the chemical components of the almond kernel. The limit of detection values for any given trait ranged from 2.06 to 5.17, explaining between 13.0 and 44.0 % of the phenotypic variance of the trait. This new genetic information needs to be taken into account when breeding for physical traits in almond. Increases in the positive quality traits, both physical and chemical, need to be considered simultaneously whenever they are genetically independent, even if they are negatively correlated. This is the first complete genetic framework map for physical components of almond nut and kernel, with 14 putative QTLs associated with a large number of parameters controlling physical traits in almond.     

Ex situ volatile survey of ground almond and pistachio hulls for emission of spiroketals: Analysis of hull fatty acid composition,water content,and water activity

The spiroketal conophthorin has recently been implicated as an important semiochemical of the navel orangeworm moth (Amyelois transitella), a major insect pest to California tree nuts. Additionally, new evidence demonstrates that fungal spores in the presence of linoleic acid produce conophthorin. Numerous investigations have analyzed the volatile emissions of almonds and pistachios under varying conditions, yet there are few reports of conophthorin as a volatile component. Previous studies by our laboratories have suggested almond hulls may be a source of conophthorin production. Accordingly, the volatile emissions of ex situ almond and pistachio ground hulls were surveyed at several developmental stages. Each ground sample was analyzed at various intervals to determine if conophthorin was produced. The almond and pistachio samples were presumed to have a natural fungal bouquet present. Additionally, the fatty acid composition, water content, and water activity of the hulls were analyzed for each sample. Conophthorin and the structurally similar compound chalcogran were detected from almond hulls and shells, but not from the pistachio samples. The almond and pistachio hulls were investigated for four fatty acid components – palmitic, oleic, linoleic, and linolenic. The fatty acid composition of almond hulls varied greatly throughout the growing season, whereas the composition of pistachio hulls remained relatively constant. Both water content and activity were constant in early stages of almond growth then dropped in the later stages of hull split. Spiroketal emission along with other associated volatiles is discussed. This is the first report of the fatty acid composition, water content, and water activity of developing almond and pistachio hulls.     

A six locus phylogeny reveals high species diversity in Botryosphaeriaceae from California almond

Botryosphaeriaceae are important pathogens on a variety of woody hosts, including almond, a major crop in California. Almond is susceptible to Botryosphaeria dothidea that forms band cankers on almond trunks, and the same fungus was also isolated from cankers of the canopy. To study the diversity and host range of B. dothidea and allied species from almond we used 132 isolates from 36 plant hosts from five continents, including 45 strains from almond in California. Species were identified by comparison to 13 ex-type strains with phylogenetic analyses based on six loci, including the internal transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene repeat and portions of the coding genes elongation factor 1-alpha, glyceraldehyde-3-phosphate dehydrogenase, heat shock protein, histone-3 and beta-tubulin. Seven species were found from almond: Botryosphaeria dothidea, Neofusicoccum parvum, Neof. mediterraneum, Neof. nonquaesitum, Diplodia seriata and Macrophomina phaseolina were identified from band cankers, and B. dothidea, Neof. mediterraneum, Neof. parvum and Dothiorella sarmentorum from canopy cankers. All were capable of inducing cankers on inoculated almond branches in the field. All species found on almond also occurred on other hosts, suggesting that infected vegetation adjacent to almond orchards could serve as source of inoculum of virulent almond strains. Of the 19 monophyletic groups obtained at the species level, 13 contained ex-type strains, five were morphologically similar to established species and one was morphologically distinct from its closest relatives, Neof. andinum and Neof. arbuti, as well as from the more than 190 described species of Fusicoccum and Neofusicoccum, and thus was described as the new species, Neof. nonquaesitum. Evidence for cryptic speciation was found in B. dothidea, Neof. ribis and Spencermartinsia viticola. Botryosphaeria dothidea and Neof. ribis comprised lineages that formed the morphologically distinct Dichomera anamorph not found in any other isolates recognized as B. dothidea and Neof. ribis. An S. viticola isolate from California was phylogenetically divergent and had conidia that differed morphologically from the type. Neofusicoccum parvum was diverse but lacked any morphological features correlating with molecular diversity. Phylogenetic analyses of combinations of datasets showed that pooled analyses of all six datasets resulted in the highest number of supported branches, suggesting that addition of more data might yet improve phylogenetic resolution.     

Comparison of the volatile emission profiles of ground almond and pistachio mummies: Part 1 – Addressing a gap in knowledge of current attractants for navel orangeworm

Over the years various tissues of almond and pistachio have been evaluated for their ability to attract the navel orangeworm moth, a major insect pest in California tree nut orchards. Almond meal, which typically consists of ground almond kernels, is a monitoring tool for navel orangeworm populations in almond and pistachio orchards. Recently, ground pistachio and almond mummies have been re-visited in field trapping studies for their potential to attract navel orangeworm moths. Surprisingly, the volatile profiles of these two systems have not been reported. The objective of this study was to survey and then compare and contrast the volatile profiles of both ground almond and pistachio mummies over the course of a week. Principal component analysis (PCA) of the headspace volatiles showed a distinct difference between ground almond and pistachio mummies. The volatile emission profile of the almond mummies remained consistent over the one-week period, albeit in low content and composition; whereas the profile of the pistachio mummies changed over time as shown by PCA. Seven compounds were identified as being common volatiles to both matrices. These data may help explain results from recent navel orangeworm field trapping studies using almond and pistachio mummies, as well as with the formulation of future synthetic blends.     

Anwendung der automatisierten Festphasenextraktion bei der Bestimmung von Ochratoxin A

For some foodstuffs, determination of the mycotoxin ochratoxin A (OTA) requires time consuming clean up by means of solid phase extraction (SPE). Therefore a system for automated SPE was tested for cleaning up roasted coffee as a possible way of shortening preparation time. Validation of the method in accordance to the so called “Concept '98” led to a LOD of 0.2 μg/kg and a recovery rate of 92%. By using the described procedure with samples of roasted coffee the OTA contents varied between the LOD and 3.4 μg/kg. This method was also used to determine ochratoxin A in liquorice roots, ginger and valerian.

Presented at the 26^th Mykotoxin Workshop in Herrsching, Germany, May 17–19, 2004     

Development of SSR markers for the phylogenetic analysis of almond trees from China and the Mediterranean region.

Expressed sequence tag (EST) derived simple sequence repeats (SSRs, microsatellites) were screened and identified from 3863 almond and 10 185 peach EST sequences, and the spectra of SSRs in the non-redundant EST sequences were investigated after sequence assembly. One hundred seventy-eight (12.07%) almond SSRs and 497 (9.97%) peach SSRs were detected. The EST-SSR occurs every 4.97 kb in almond ESTs and 6.57 kb in peach, and SSRs with di- and trinucleotide repeat motifs are the most abundant in both almond and peach ESTs. Twenty one EST-SSRs were thereafter, developed and used together with 7 genomic SSRs, to study the genetic relationship among 36 almond (P. communis Fritsch.) cultivars from China and the Mediterranean area, as well as 8 accessions of other related species from the genus Prunus. Both EST-derived and genomic SSR markers showed high cross-species transferability in the genus. Out of the 112 polymorphic alleles detected in the 36 cultivated almonds, 28 are specific to Chinese cultivars and 25 to the others. The 44 accessions were clustered into 4 groups in the phylogenetic tree and the 36 almond cultivars formed two distinct subgroups, one containing only Chinese cultivars and one of unknown origin and the other only those originating from the Mediterranean area, indicating that Chinese almond cultivars have a distinct evolutionary history from the Mediterranean almond. Our preliminary results indicated that common almond was more closely related to peach (P. persica (L.) Batsch.) than to the four wild species of almond, (P. mongolica Maxim., P. ledebouriana Schleche, P. tangutica Batal., and P. triloba Lindl.). The implications of these SSR markers for evolutionary analysis and molecular mapping of Prunus species are discussed.     

Identification of crypto- and neochlorogenic lactones as potent xanthine oxidase inhibitors in roasted coffee beans

Xanthine oxidase (XO) inhibitory activity has been found in boiling water extracts from roasted coffee beans. Therefore, assay-guided purification of the extracts was performed using size-exclusion column chromatography, and subsequently with reversed phase HPLC to afford lactone derivatives of chlorogenic acids. Among the tested lactones, crypto- and neochlorogenic lactones showed potent XO inhibitory activities compared with three major chlorogenic acids found in coffee beans. These XO inhibitory lactones may ameliorate gout and hyperuricemia in humans who drink coffee.     

Collophora hispanica,a New Pathogen and Potential Threat to the Almond Industry in Iran

Trunk diseases are potential threats for almond productivity and longevity worldwide, including Iran. In a recent survey on fungal species associated with trunk diseases of almonds in north‐western Iran, Collophora isolates (tentatively identified as Collophora hispanica) were recovered with high frequency from wood samples with internal necrosis and brown to black vascular streaking of almond trees showing symptoms of decline. However, the pathogenic potential of Collophora isolates on almond trees in Iran remains unproven. In this study, the identity of the isolates was further confirmed as C. hispanica based on a combination of morphological data and sequence data of ITS‐rDNA region, and pathogenicity of C. hispanica isolates on almond was evaluated using excised shoot method and in greenhouse experiments. Collophora hispanica isolates induced lesions statistically different from the control, in both excised shoot method and greenhouse assays. Significant differences were observed among the isolates in the length of the lesion induced on wood. Collophora hispanica should be considered as the main trunk pathogens of almond trees in north‐western region of Iran. The distribution and host range of this new pathogen on almond remains to be studied.     

Effect of roasting on ochratoxin A level in green coffee beans inoculated with Aspergillus ochraceus

The heat stability of ochratoxin A in green coffee beans inoculated with Aspergillus ochraceus was studied. Heat treatment (roasting) at 200 °C for 10 or 20 min reduced the levels of ochratoxin A by only 0–12% in the dried whole beans. Almost all of the ochratoxin A was infused into the coffee decoction when the roasted samples were ground and extracted with boiling water. Therefore, the reduction of ochratoxin A concentration of contaminated coffee beans by roasting under these conditions is ineffective.