Volatile Organic Compounds, Indole, and Biogenic Amines Assessment in Two Mediterranean Irciniidae (Porifera, Demospongiae)

Solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) was employed for the headspace determination of the volatile organic fraction emitted by two of the most common Mediterranean demosponges, Ircinia variabilis and Sarcotragus spinosulus, and of indole and some biogenic amines released by sponges in an aqueous medium. A total of 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane and 75 µm carboxen/polydimethylsiloxane fibers were used for the headspace extraction of low molecular weight sulfur compounds from a hermetically sealed vial containing sponge fragments, while the direct immersion determination of indole and biogenic amines was performed. The biogenic amines were extracted after in-solution derivatization with isobutyl chloroformate. All analytical parameters (linearity, limits of detection, and quantification, precision, and recovery) were evaluated for indole and biogenic amines. SPME-GC-MS proved to be a reliable means of highlighting the differences between molecules released by different sponges, principally responsible for their smell. The combined approaches allowed the identification of several volatile compounds in the headspace and other molecules released by the sponges in an aqueous medium, including indole and the BAs cadaverine, histamine, isobutylamine, isopentylamine, propylamine, 2-phenylethylamine, putrescine and tryptamine. The results obtained represent a further contribution to the picture of odoriferous molecules secreted by sponges.

High biodiversity in a limited mountain area revealed in the traditional production of Historic Rebel cheese by an integrated microbiota–lipidomic approach

Historic Rebel (HR) cheese is an Italian heritage cheese, produced from raw milk during the summer grazing period in the Alps. The aim of this work was (i) to characterize the cheese microbiota, by 16S rRNA gene amplicons sequencing, and the volatile and non-volatile lipophilic fraction, by Gas Chromatography and Dynamic Headspace Extraction-Gas Chromatography-Mass Spectrometry, and (ii) to evaluate their respective associations. HR cheese was dominated by Firmicutes phylum (99% of the entire abundance). The core microbiota was formed by Streptococcus, Lactobacillus, Lactococcus, Leuconostoc and Pediococcus genera together representing 87.2–99.6% of the total abundance. The polyunsaturated fatty acids composition showed a high PUFA n-3, PUFA n-6 and CLA content, two fold higher than typical plain cheeses, positively correlated with pasture altitude. A complex volatilome was detected, dominated in terms of abundance by ketones, fatty acids and alcohols. Total terpene levels increased at higher altitudes, being the main terpenes compounds α-pinene, camphene and β-pinene. The HR cheese showed a great diversity of bacterial taxa and lipophilic fractions among producers, despite belonging to a small alpine area, revealing a scarce cheese standardization and a chemical fingerprint of a typical mountain cheese produced during the grazing period. A deeper knowledge of the variability of HR cheese due to its composition in microbial community and volatile compounds will be appreciated, in particular, by elite consumers looking for niche products, adding economic value to farming in these alpine areas.

Optimization and Validation of HS-GC/MS Method for the Controlled Release Study of Microencapsulated Specific Bioattractants for Target-Plaguicide Production

Insect plagues are a problem often hard to solve due to the harmful effects caused by the pesticides used to combat them. Consequently, the pesticide market is increasingly trying to develop new technologies to prevent the unwanted effects that common plague treatments usually bring with them. In this work, four specific bioattractants of Musca domestica, extracted from fungi (β-ocimene, phenol, p-cresol, and indole) were microencapsulated with β-cyclodextrin in order to produce an economically and environmentally sustainable bait containing biocides in the near future. Cyclodextrins will retain these volatile compounds until their use by the consumer when the product comes into contact with water. Then, the bioattractants will be released in the medium in a controlled manner. An analytical methodology based on headspace extraction coupled to gas chromatography and mass spectrometry (HS-GC/MS) has been developed and validated following Environmental Protection Agency (EPA) and European Commission Directorate General for Health and Food Safety guidelines for the bioattractants controlled release study from the microencapsulated product. The analytical method has been shown to be accurate and precise and has the sensitivity required for controlled release studies of the four bioattractants analyzed. The release of the bioattractants from microencapsulated products achieved the “plateau” after 3 h in all cases.

High Biodiversity in a Limited Mountain Area Revealed in The Traditional Production of Historic Rebel Cheese By An Integrated Microbiota-Lipidomic Approach.

Historic Rebel (HR) cheese is an Italian heritage cheese, produced from raw milk during the summer grazing period in the Alps. The aim of this work was i) to characterize the cheese microbiota, by 16S rRNA gene amplicons sequencing and the volatile and non-volatile lipophilic fraction, by Gas Chromatography and Dynamic Headspace - Extraction Gas Chromatography- Mass Spectrometry, and ii) to evaluate their respective associations. HR cheese was dominated by Firmicutes phylum (99% of the entire abundance), with members of the Streptococcus, Lactobacillus, Lactococcus, Leuconostoc and Pediococcus together representing 87.2% - 99.6% of the total abundance. The polyunsaturated fatty acids composition showed a high PUFA n-3, PUFA n-6 and CLA content, two fold higher than typical plain cheeses. A complex volatilome was detected, dominated in terms of abundance by ketones, fatty acids and alcohols. The main terpenes compounds were α-pinene, camphene and β-pinene.The HR cheese showed a great diversity (P<0.05) of bacterial species and lipophilic fractions among producers, despite they belonging to a small alpine area, revealing a scarce cheese standardization and a chemical fingerprint of a typical mountain cheese produced during the grazing period. A deeper knowledge of the variability of HR cheese will be appreciated in particular by elite consumers looking for niche products, adding economic value to farming in these alpine areas.