Studies on umami taste. Synthesis of new guanosine 5'-phosphate derivatives and their synergistic effect with monosodium glutamate     

Cairoli P  Pieraccini S  Sironi M  Morelli CF  Speranza G  Manitto P 《Journal of agricultural and food chemistry》2008,56(3):1043-1050

A number of N2-alkyl and N2-acyl derivatives of guanosine 5'-phosphate (GMP) have been synthesized and tested for their synergistic effect with monosodium L-glutamate (MSG), the prototypical substance imparting umami taste to savory-based foods. Capacities to enhance the taste intensity of MSG (gamma values) were estimated through subjective comparisons of MSG/nucleotide mixtures in water with appropriate solutions of MSG alone. Assuming beta = gamma[nucleotide]/gamma[IMP], beta values of the N2-substituted GMPs were found in the range 1.2-5.7. Such values appear to be related to the chain length of the substituent in the 2-position of the purine nucleus and dependent on the replacement of a CH 2 group with an S atom and/or with an alpha-CO group. These findings indicate that the exocyclic NHR group of the guanine moiety is actively implicated in the synergism between GMP derivatives and MSG. Theoretical calculations suggest that an anti conformation is probably assumed by ribonucleotide molecules interacting with umami receptors.  相似文献   

Chemical markers for the evaluation of raw material hygienic quality in egg products     

Hidalgo A  Franzetti L  Rossi M  Pompei C 《Journal of agricultural and food chemistry》2008,56(4):1289-1297

The aim of this research was to study uracil and lactic and acetic acids as chemical markers for hygienic quality evaluation of raw material in liquid pasteurized egg products. Uracil, absent in sound whole eggs, was formed in raw and pasteurized egg products as a consequence of high microbial contamination (>10(6) cfu/g) after a sufficient lag time, remaining stable at 4 degrees C but disappearing after 7 days of storage at 25 degrees C. Both lactic and acetic acids, starting from initial values of 1-7 mg/kg dry matter, presented trends similar to that of uracil; however, acetic acid never decreased during the storage of raw egg products. With few exceptions, all three metabolites were produced by Enterobacter cloacae, Escherichia coli, Morganella morganii, Serratia liquefaciens, Aeromonas hydrophyla, Pseudomonas fluorescens, Enterococcus avium, and Enterococcus faecalis, separately inoculated in whole egg samples. Uracil seems to be the most sensible marker, with a suggested limit corresponding to the detectable level.  相似文献   

Optimization of color and antioxidant activity of peach and nectarine puree: scale-up study from pilot to industrial plant     

Lavelli V  Pompei C  Casadei MA 《Journal of agricultural and food chemistry》2008,56(16):7091-7099

The effects of an innovative process for the manufacture of peach and nectarine purees on the main quality indices, namely, color, consistency, carotenoid and phenolic content, and antioxidant activity, were studied using a peach cultivar that is optimal for nectar processing (cv. Redhaven) and peach and nectarine varieties that undergo a faster browning degradation. The innovative process, operating the pulping/finishing step at room temperature, was compared to the traditional process of hot pulping/finishing. The study comprised initial trials on a pilot plant scale and scaling up to industrial production of the puree and nectar. The quality of products was analyzed at the time of production and as a function of storage of both the puree and the nectar. With respect to the traditional process, the new process, scaled up to industrial levels, improved the color of peach and nectarine products (by increasing the L* value and decreasing the a* value), whatever the variety studied; maintained almost the same levels of carotenoids, hydroxycinnamates, flavan-3-ols, and flavonols; and reduced the level of cyanidin 3-O-glucoside. The presence of cyanidin 3-O-glucoside was correlated to an unstable and undesirable red hue of the products (even if its concentration was very low in all products), and the decreased level obtained by the innovative process was considered to be positive. On the basis of these results, new technology can be proposed for the processing of fruit varieties that are not suitable for puree production using traditional technology. This opens up two possibilities: (a) utilization of fresh market fruit surplus and (b) processing of selected fruit varieties that are rich in antioxidants but have a high browning potential, such as the Stark Red Gold nectarine. Furthermore, as the positive impact of the new technology is optimal at the beginning of storage, it is particularly suitable for fruit-based products with a short shelf life.  相似文献   

Effects of fly attack (Bactrocera oleae) on the phenolic profile and selected chemical parameters of olive oil     

Gómez-Caravaca AM  Cerretani L  Bendini A  Segura-Carretero A  Fernández-Gutiérrez A  Del Carlo M  Compagnone D  Cichelli A 《Journal of agricultural and food chemistry》2008,56(12):4577-4583

The phenolic fraction of virgin olive oil influences both its quality and oxidative stability. One of the principal threats of the quality of olive fruit is the olive fly ( Bactrocera oleae) as it alters the chemical composition. The attack of this olive pest has been studied in order to evaluate its influence on the quality of virgin olive oil (free acidity, peroxide value, fatty acid composition, water content, oxidative stability, phenols, and antioxidant power of phenolic fraction). The study was performed using several virgin olive oils obtained from olives with different degrees of fly infestation. They were acquired in different Italian industrial mills from the Abruzzo region. Qualitative and quantitative analyses of phenolic profiles were performed by capillary electrophoresis-diode array detection, and electrochemical evaluation of the antioxidant power of the phenolic fraction was also carried out. These analyses demonstrated that the degree of fly attack was positively correlated with free acidity ( r = 0.77, p < 0.05) and oxidized products ( r = 0.58, p < 0.05), and negatively related to the oxidative stability index ( r = -0.54, p < 0.05) and phenolic content ( r = -0.50, p < 0.05), mainly with secoiridoid compounds. However, it has been confirmed that the phenolic fraction of olive oil depends on several parameters and that a clear correlation does not exist between the percentages of fly attack and phenolic content.  相似文献   

Feline aelurostrongylosis and canine angiostrongylosis: a challenging diagnosis for two emerging verminous pneumonia infections     

Traversa D  Guglielmini C 《Veterinary parasitology》2008,157(3-4):163-174

Aelurostrongylus abstrusus and Angiostrongylus vasorum (Nematoda, Metastrongyloidea) are causative agents of verminous feline and canine pneumonia. Both are presently emerging in several geographical areas and are of major clinical importance. Given the range of parasitic and non-parasitic pathogens which may cause cardio-respiratory distress in dogs and cats, the unequivocal specific diagnosis of both diseases is pivotal for unravelling their epidemiology and central to therapy and control. Several conventional clinico-pathologic, diagnostic imaging and parasitological approaches are currently used in practice, but all have major limitations in the specific diagnosis of these diseases. Serological methods have shown promise in the diagnosis of A. abstrusus and A. vasorum infections, but no clinically useful tests are currently available. Additionally, there have been major advances in the development of novel molecular diagnostic tools for feline aelurostrongylosis, but efforts to develop molecular diagnostic tests are still preliminary for angiostrongylosis. This article provides a review of A. abstrusus and A. vasorum infections in cats and dogs, focusing on the advantages and shortcomings of classical diagnostic methodologies and on present diagnostic advances as well as future perspectives instrumental to epidemiological and clinical studies.  相似文献   

Occurrence of fatal canine Angiostrongylus vasorum infection in Italy     

Traversa D  Torbidone A  Malatesta D  Guglielmini C 《Veterinary parasitology》2008,154(1-2):162-166

A total of 469 fecal samples were collected from American minks (Mustela vison) on a farm in Hebei Province in China and examined for Cryptosporidium by Sheather's sugar flotation technique and 8 Cryptosporidim isolates were obtained. The partial 18S rRNA, 70 kDa heat shock protein (HSP70), Cryptosporidium oocyst wall protein (COWP) and actin genes of six isolates were sequenced. Sequence data were analyzed together with known Cryptosporidium spp. and genotypes. Results of this multi-locus genetic characterization indicated that the six Cryptosporidium isolates in this study shared the same sequences of the genes studied and were different from known Cryptosporidium species and genotypes. The closest relative was Cryptosporidium ferret genotype with 7, 22, 2 and 2 nucleotide differences in the 18S rRNA, HSP70, COWP and actin genes, respectively. The homology to ferret genotype at the 18S rRNA locus was 99.1%, which is comparable to that between C. parvum and C. hominis (99.2%), or between C. muris and C. andersoni (99.4%). Therefore, the Cryptosporidium in minks in this study is considered a new genotype, the Cryptosporidium mink genotype.  相似文献   

Hemorrhagic diathesis and bone marrow aplasia secondary to lomustine overdose in a dog     

Luan C. Henker  Regina T. Kemper  Simone P. Bianchi  Marcele B. Bandinelli  Saulo P. Pavarini 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2019,48(2):255-258

A 9‐year‐old mixed breed 13 kg spayed female dog was presented for evaluation of two masses in the right abdominal mammary gland region. Surgery was conducted to excise the masses. A grade I complex mammary gland carcinoma and high grade (grade III) mast cell tumor with an inguinal lymph node metastasis were diagnosed. Forty‐seven days after the surgical procedure, the mast cell tumor relapsed, and neoadjuvant treatment with lomustine (81 mg/m²) was prescribed. Thirteen days from initiation of lomustine therapy, the dog was re‐presented to the hospital with bloody diarrhea, hematemesis, epistaxis, an elevated rectal temperature, depression, severe dehydration, and marked dyspnea. The CBC showed severe thrombocytopenia and leukopenia. According to the owner, lomustine (45mg per os [PO]) was mistakenly administered daily for 10 consecutive days (total dose, 810 mg/m²). The dog died and a necropsy was performed. The main gross lesions consisted of severe multifocal hemorrhages in multiple organs, especially in the digestive system. Histopathologic evaluation revealed disseminated hemorrhages, as well as marked bone marrow aplasia. This report describes the clinical, hematologic, gross, and histologic findings in a fatal case of lomustine overdose in a dog.  相似文献   

Evidence of selective burning in Sardinia (Italy): which land-cover classes do wildfires prefer?     

Sofia Bajocco  Carlo Ricotta 《Landscape Ecology》2008,23(2):241-248

The objective of this paper is to identify land-cover types where fire incidence is higher (preferred) or lower (avoided) than expected from a random null model. Fire selectivity may be characterized by the number of fires expected in a given land-cover class and by the mean surface area each fire will burn. These two components of fire pattern are usually independent of each other. For instance, fire number is usually connected with socioeconomic causes whereas fire size is largely controlled by fuel continuity. Therefore, on the basis of available fire history data for Sardinia (Italy) for the period 2000–2004 we analyzed fire selectivity of given land-cover classes keeping both variables separate from each other. The results obtained from analysis of 13,377 fires show that for most land-cover classes fire behaves selectively, with marked preference (or avoidance) in terms of both fire number and fire size. Fire number is higher than expected by chance alone in urban and agricultural areas. In contrast, in forests, grasslands, and shrublands, fire number is lower than expected. In grasslands and shrublands mean fire size is significantly larger than expected from a random null model whereas in urban areas, permanent crops, and heterogeneous agricultural areas there is significant resistance to fire spread. Finally, as concerns mean fire size, in our study area forests and arable land burn in proportion to their availability without any significant tendency toward fire preference or avoidance. The results obtained in this study contribute to fire risk assessment on the landscape scale, indicating that risk of wildfire is closely related to land cover.  相似文献   

Enhanced pest control in cabbage crops near forest in The Netherlands     

F. J. J. A. Bianchi  P. W. Goedhart  J. M. Baveco 《Landscape Ecology》2008,23(5):595-602

Landscapes are composed of a multitude of habitat types which, potentially, can influence natural enemy populations. The contribution of specific habitat types to sustaining natural enemy populations in agricultural landscapes and the associated ecosystem service of pest control is not well understood. We investigated how landscape composition affected parasitism rates in 22 organic Brussels sprout fields in The Netherlands. Second and third instar larvae of Plutella xylostella were placed on experimental Brussels sprout plants in Brussels sprout fields and were recovered after two days in the field. Parasitism rates ranged between 4 and 94% and were related to landscape variables at a scale of 0.3, 1, 2 and 10 km. Univariate analysis using a generalized linear mixed model indicated that parasitism rates were positively related with area of forests at a scale of 1, 2 and 10 km, forest edges at a scale of 1 and 2 km and road verges at a scale of 1 km. Forest and road verges are likely to provide food and alternative hosts for parasitoids and are less disturbed habitats than agricultural fields. These results suggest that forests and road verges may play an important role in sustaining effective densities of parasitoids of P. xylostella in agricultural landscapes.  相似文献   

Spongiform neurodegenerative disease in a Persian kitten   总被引：1，自引：0，他引：1  

Salvadori C  Lossi L  Arispici M  Cantile C 《Journal of Feline Medicine and Surgery》2007,9(3):242-245

A congenital encephalopathy with spongiform degeneration and prominent neuronal apoptosis was observed in a 4-month-old Persian male cat with a history of depressed mental status and ataxia. On clinical examination, signs included right head tilt, ventroflexion of the head and neck, and tetraparesis. Histological examination of the central nervous system revealed multifocal, bilateral and symmetrical vacuolar degeneration of the neuropil, mainly involving the cerebellar and vestibular nuclei area, the caudal colliculi, the mesencephalic nuclei, the tegmental area and the deeper layer of the cerebral cortex. Accumulation of phosphorylated neurofilaments was detected in neuronal perikarya of the deep cortical layers, hippocampus and thalamus. Numerous pyknotic and apoptotic neurons were also observed in the cerebral cortex. These neuropathological changes differ from those observed in previous reports of spongiform degeneration of the grey matter in cats and were suggestive of a congenital neurodegenerative disease.  相似文献