Sensory properties of virgin olive oil polyphenols: identification of deacetoxy-ligstroside aglycon as a key contributor to pungency

Polyphenols are an important functional minor component of virgin olive oils that are responsible for the key sensory characteristics of bitterness, pungency, and astringency. Polyphenols were isolated from virgin olive oils by using liquid/liquid extraction and then separated by using reverse phase HPLC followed by fraction collection. The sensory qualities of the isolated polyphenols were evaluated, and almost all fractions containing polyphenols were described as bitter and astringent. However, the fraction containing deacetoxy-ligstroside aglycon produced a strong burning pungent sensation at the back of the throat. In contrast, the fraction containing the analogous deacetoxy-oleuropein aglycon, at an equivalent concentration, produced only a slight burning/numbing sensation, which was perceived more on the tongue. No other polyphenol fractions from the analyzed oils produced the intense burning sensation; thus, deacetoxy-ligstroside aglycon is the polyphenol responsible for the majority of the burning pungent sensation found in pungent extra virgin olive oils.     

Soil carbon as affected by cover crops under no‐till under tropical climate

In tropical, low‐fertility soils, crop yields are dependent on soil carbon, and cropping systems under no‐till can increase soil C stocks. Plant residues supplied by cover crops in no‐till systems may improve aggregate stability and soil carbon, which may be further increased with the introduction of a legume in the cropping system. This research studied the effects of cover crops in rotation with soybean under no‐till on soil carbon and nitrogen, in Botucatu, Brazil, for 3 yr. The cover crops were millet (Penninsetum americanum Leek), cober crop (Sorghum bicolor × Sorghum sudanense) and sunn hemp (Crotalaria juncea L.), grown in the spring. Fallow without cover crops was used as a control. Grain sorghum (Sorghum bicolor L. Moench) and soybean (Glycine max (L.) Merril) were grown in fall–winter and summer, respectively. Generally, cover crops increased soil carbon contents, but soil N was only increased by sunn hemp in the particulate organic C fraction. An increase in the labile carbon fraction in the topsoil layers was closely related to cover crop root development. Fallow in spring should not be recommended in degraded soils with lowcarbon stock. Labile‐fractioned soil organic carbon and total carbon levels are more efficiently increased by grasses than by legumes in the short term, and grasses cropped in spring increase soil C/N ratio. Conversely, the introduction of a legume (sunn hemp) maintained a more stable C/N ratio, that is around 10, which would be more effective in increasing soil C in the long term.     

Effects of Dilution Rate on the Motility and Acrosome Morphology of Boar Spermatozoa Stored at 15 °C

The objective of this investigation was to establish the optimal extent of dilution for storage of boar spermatozoa at 15°C in Kiev diluent. The dilution titers used for the sperm-rich fraction of ejaculates from 8 boars ranged from 1:2 to 1:50. Seminal doses were stored for 10 days. Motility and acrosome morphology were evaluated after 1, 3, 5, 7, and 10 days of storage. The percentages of motile spermatozoa after 24 and 72 hours of storage were significantly higher for dilution rates between 1:7 and 1:11 than for dilution rates lower than 1:7 or higher than 1:11 (p < 0.05). The percentages of spermatozoa with normal acrosomes after 24, 72, and 120 hours of storage were significantly higher for dilution rates between 1:8 and 1:11 than for dilution rates lower than 1:8 or higher than 1:11 (p < 0.01 ).     

Laryngeal adenocarcinoma in a dog

Laryngeal adenocarcinoma was diagnosed in an eight-year-old female cocker spaniel presented with inspiratory dyspnoea and dysphonia. Nine weeks after surgical debulking, the neoplasm recurred. Post mortem examination revealed metastases in cervical lymph nodes and lungs.     

The effect of Mycoplasma bovis on fertilization processes in vitro with bull spermatozoa and zona-free hamster oocytes

The effect of Mycoplasma bovis (Donetta strain) on the ability of bull spermatozoa to interact with zona pellucida-free hamster oocytes was studied in an in vitro assay. Ejaculates of semen from a fertile Holstein bull were used fresh on the day of collection (unextended semen) as well as diluted with egg yolk-citrate and used the following day (extended semen). The addition of M. bovis to both unextended and extended semen at a mycoplasma to sperm cell ratio of 10:1 significantly reduced sperm penetration rates and the mean number of sperm per penetrated egg. Similarly, the ability of spermatozoa to form pronuclei and the activation of penetrated oocytes were adversely affected by M. bovis. No apparent effect on sperm motility was detected. When M. bovis was added to the oocytes, there was a marked reduction in the sperm penetration rates and fertilization processes suggesting that the organism affects certain oocyte function(s). The results indicate that the presence of M. bovis in semen or in the female reproductive tract may affect fertilization. Moreover, the in vitro assay with hamster oocytes was found to be useful for demonstrating the effects of contaminating microbial agents on bovine fertilization processes.     

Erosive colitis in experimental canine Leishmaniasis

Six 4 month-old beagles were inoculated with Leishmania infantum, three of them intraperitoneally (Group A) and the other three intravenously (Group B). The animals from Group A were killed at 109, 433 and 592 days after inoculation and animals from Group B 109, 171 and 334 days after inoculation. At 350 days (Group A) and 275 days (Group B) after inoculation, dogs started to develop a chronic large bowel diarrhoea. At necropsy a diffuse colonic and rectal wall thickening of gradually increasing severity was observed. Histological examination of the colon showed a diffuse inflammatory infiltration of the mucosa and submucosa by macrophages with amastigotes, lymphocytes, plasma cells and some neutrophils and eosinophils. The surface epithelium developed increasingly extensive degeneration, which caused the development of erosions on the mucosal surface. The crypts of Lieberkühn decreased in number and showed degeneration of the crypt epithelium.     

High genetic diversity in field isolates of Trypanosoma theileri assessed by analysis of cathepsin L-like sequences disclosed multiple and new genotypes infecting cattle in Thailand

In this study, we describe the first survey in Thailand of Trypanosoma theileri, a widespread and prevalent parasite of cattle that is transmitted by tabanid flies. Investigation of 210 bovine blood samples of Thai cattle from six farms by hematocrit centrifuge technique (HCT) revealed 14 samples with trypanosomes morphologically compatible to T. theileri. Additional animals were positive for T. theileri by PCR based on the Cathepsin L-like sequence (TthCATL-PCR) despite negative by HCT, indicating cryptic infections. Results revealed a prevalence of 26 ± 15% (95% CI) of T. theileri infection. Additionally, 12 samples positive for T. theileri were detected in cattle from other 11 farms. From a total of 30 blood samples positive by HCT and/or PCR from 17 farms, seven were characterized to evaluate the genetic polymorphism of T. theileri through sequence analysis of PCR-amplified CATL DNA sequences. All CATL sequences of T. theileri from Thai cattle clustered with sequences of the previously described phylogenetic lineages TthI and TthII, supporting only two major lineages of T. theileri in cattle around the world. However, 11 of the 29 CATL sequences analyzed showed to be different, disclosing an unexpectedly large polymorphic genetic repertoire, with multiple genotypes of T. theileri not previously described in other countries circulating in Thai cattle.