1,721,045 research outputs found
Seasonal Variations of Milk Composition of Sarda and Saanen Dairy Goats
Full text linkTraditionally, in Mediterranean areas the goat population was composed of autochthonous breeds with strong milk production seasonality. In the last decades, high productive alpine breeds were introduced together with more widespread out-of-season milk production practices. This study is a large-scale survey on the seasonal variations of the main compositional characteristics of goat milk obtained from Sarda and Saanen breeds reared on the Mediterranean island of Sardinia (Italy). Analysis of data indicated that milk from the Sarda breed was significantly richer, at p < 0.001, in protein, fat, and lactose, and had a lower urea mean content than Saanen. Throughout the year, fluctuations of mean contents of the milk parameters were similar for the two groups of goats, indicating that, besides genetic intrinsic differences, climate and herbage growth influenced the Sarda as well as the Saanen goats. During the summer, milk from Saanen showed a marked drop in fat and protein contents, with 21% of samples showing a fat-to-protein ratio <1. No significant differences were found for the somatic cell count; however, the Sarda breed showed a higher bacterial count, suggesting improper milk handling and/or storage equipment more frequently encountered in extensive and semi-extensive farm systems
Mechanochemistry: Unravelling the Impact of Metal Leaching in Organic Synthesis
Full text linkSolvent-free techniques have gained considerable attention in recent years due to their environmental advantages and potential to enable chemical reactivities beyond the reach of traditional solution-based methods. Mechanochemistry has emerged as a groundbreaking approach to drive sustainable chemical processes. Despite its promise, some challenges still need to be explored, including the overlooked issue of material leaching during grinding, a phenomenon in which components from milling media or reaction vessels, such as stainless steel, unintentionally alter reaction outcomes. This study investigates the role of metal leaching in reducing arylnitrosamines by using a poorly soluble solid reagent, thiourea dioxide (TDO), focusing on stainless steel vessels. By comparing conventional mechanochemical methods with innovative solvent-free vibratory techniques, we assess the extent of metal contamination and its impact on reaction efficiency. These findings provide new insights into how material leaching influences chemical processes and offer valuable guidance for optimizing these forward-looking and green methodologies
Mukaiyama reagent: An efficient reaction mediator for rapid synthesis of 1,2-disubstituted-1H-benzo[d]imidazoles
No full textWithin the field of medicinal chemistry, 1,2-disubstituted benzimidazoles represent a privileged class of nitrogen-based heterocycles but, unlike 2-substitued derivatives, few synthetic methods have been reported. In this context, we developed a rapid, metal-free, and straightforward method to prepare a series of 1,2-disubstituted-1H-benzo[d]imidazoles starting from 1,2-phenylendiamines and various aromatic and aliphatic aldehydes in the presence of the Mukaiyama reagent. The reaction proceeded at room temperature with good product yields within few minutes
Cartap Hydrolysis Relative to Its Action at the Insect Nicotinic Channel
No full textThe insecticide cartap is the bis(thiocarbamate) derivative of 2-(dimethylamino)propane-1,3-dithiol, which on oxidation forms the natural toxicant nereistoxin (NTX) [4-(dimethylamino)-1,2-dithiolane]. Both cartap and NTX are ion channel blockers of the nicotinic acetylcholine receptor (nAChR). Cartap was originally proposed to act only after metabolic conversion to NTX and later suggested to block directly without activation. The present study uses a new approach to differentiate these hypotheses, that is, pH effects on channel-blocking activity and hydrolysis rates. As controls, mecamylamine (the classic channel blocker) and NTX are stable and similar in channel-blocking potency ([H-3]thienylcyclohexylpiperidine binding assay, honeybee nAChR) at pH 6.1-8.4. In contrast, cartap is >200-fold more effective at pH 7.4 than at pH 6.1, indicating that it undergoes hydrolytic activation. Cartap slowly hydrolyzes to cartap monothiol at pH 6.1 but quickly forms the dithiol and some NTX at pH 7.4. The relationship between potency and hydrolysis products at various pH ranges suggests that cartap dithiol is the most plausible blocking agent
Degradation and Persistence of Rotenone in Soils and Influence of Temperature Variations
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NMR metabolite profiles of dairy: A review
No full textNuclear magnetic resonance (NMR) spectroscopy, which is one of the most powerful “omics” analytical platforms, has been broadly adopted recently in foodomics. 1H NMR has been applied to the study of the metabolite profile of dairy products throughout the supply chain, in relation to different aspects such as animal health, milk quality, geographical origin and cheese ripening process. This review reports and discusses the literature on the topic, also collecting the identified metabolites in a descriptive table and depicting them in a Venn diagram for both milk and cheese; moreover, experimental details of the reviewed papers have been reported. The present review provides an exhaustive state-of-the-art in the field of dairy products, addressing both NMR experts and non-experts to the still unexplored potential applications of NMR in dairy characterisation, and in general in foodomics
Degradation of rotenone in soils and influence of temperature fluctuation on its persistence
No full textGC-MS metabolomics comparison of yoghurts from sheep's and goats' milk
No full textIn this study, the polar metabolite profile of commercial yoghurt samples produced in Sardinia (Italy)from milk of local sheep and goats was studied by GC-MS and multivariate statistical data analysis (MVA). Milks underwent the same manufacturing procedures and yoghurts were analysed one day post-manufacture. Results of discriminant analysis indicated that the two yoghurt types had very different metabolite profiles, with different levels of health promoting compounds. Goats' milk yoghurt was richer in free amino acids, γ-aminobutyric acid, pyroglutamic acid and β-phenyllactic acid when compared with yoghurt produced with sheep's milk. Sheep's milk yoghurt was characterised by higher levels of myo-inositol, N-acetylgalactosamine and N-acetylglucosamine. Comparing yoghurt metabolites with those of the original milk, it was found that goats' milk underwent stronger metabolite changes after inoculum. The comparison between the two yoghurt types gave us a deeper insight on the effects of manufacture on different milks
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