Impact of Different Drying Methods on the Microbiota, Volatilome, Color, and Sensory Traits of Sea Fennel (Crithmum maritimum L.) Leaves.

Sea fennel (Crithmum maritimum L.) is a strongly aromatic herb of the Apiaceae family, whose full exploitation by the modern food industry is of growing interest. This study aimed at investigating the microbiological quality, volatile profile, and sensory traits of sea fennel spices produced using room-temperature drying, oven drying, microwave drying, and freeze drying. All the assayed methods were able to remove moisture up until water activity values below 0.6 were reached; however, except for microwave drying, none of the assayed methods were effective in reducing the loads of contaminating microorganisms. The metataxonomic analysis highlighted the presence of phytopathogens and even human pathogens, including members of the genera Bacillus, Pseudomonas, Alternaria, and Cryptococcus. When compared to fresh leaves, dried leaves showed increased L* (lightness) and c* (chroma, saturation) values and reduced hue angle. Dried leaves were also characterized by decreased levels of terpene hydrocarbons and increased levels of aldehydes, alcohols, and esters. For the sensory test, the microwave-dried samples obtained the highest appreciation by the trained panel. Overall, the collected data indicated microwave drying as the best option for producing sea fennel spices with low microbial loads, brilliant green color, and high-quality sensory traits.

Impact of Saccharomyces cerevisiae and Metschnikowia fructicola autochthonous mixed starter on Aglianico wine volatile compounds.

Non-Saccharomyces yeasts are metabolically active during grape must fermentations and can contribute with enzymes and metabolites to enhance the complexity and to define the final wine aroma. Nowadays, the use of non-Saccharomyces yeasts in combination with Saccharomyces cerevisiae is a state-of-the art strategy to improve wine composition and/or wine sensory properties. The present paper deals with the new yeast strains of Metschnikowia fructicola and S. cerevisiae, that were selected as representatives of the yeast microbiota isolated from grapes and grape juice of Aglianico cultivar. S. cerevisiae was utilized both as single strain starter and in combination with M. fructicola in experimental fermentations of Aglianico must. The dynamic of yeast populations was evaluated during the fermentation process analyzing the wine volatile compounds profile. The volatile compounds were identified by SPME-GC/MS. The results, showed that the multiple indigenous yeast starter was able to modulate the volatile compounds profiles and improve the aromatic complexity of wine, with a higher content of esters and terpenes.

Conjugated linoleic acid prevents age-dependent neurodegeneration in a mouse model of neuropsychiatric lupus via the activation of an adaptive response.

Oxidative stress is a key mediator of autoimmune/neurodegenerative disorders. The antioxidant/anti-inflammatory effect of a synthetic conjugated linoleic acid (CLA) mixture in MRL/MpJ-Fas lpr mice (MRL/lpr), an animal model of neuropsychiatric lupus, was previously associated with the improvement of nuclear factor-E2-related factor 2 (Nrf2) defenses in the spleen and liver. However, little is known about the neuroprotective ability of a CLA mixture. This study investigated the age-dependent progression of oxidative stress and the hyperactivation of redox-sensitive compensatory pathways (macroautophagy, Nrf2) in old/diseased MRL/lpr mice brains and examines the effect produced by dietary CLA supplementation. Disrupted redox homeostasis was evidenced in the blood, liver, and brain of 21- to 22-week-old MRL/lpr (Old) mice compared with 8- to 10-week-old MRL/lpr (Young) animals. This alteration was associated with significant hyperactivation of compensatory mechanisms (macroautophagy, Nrf2, and astrocyte activation) in the brains of Old mice. Five-week daily supplementation with CLA (650 mg/kg-1 body weight) of 16-week-old (CLA+Old) mice diminished all the pathological hallmarks at a level comparable to Young mice or healthy controls (BALB/c). Such data demonstrated that MRL/lpr mice can serve as a valuable model for the evaluation of the effectiveness of neuroprotective drugs. Notably, the preventive effect provided by CLA supplementation against age-associated neuronal damage and hyperactivation of compensatory mechanisms suggests that the activation of an adaptive response is at least in part accountable for its neuroprotective ability.

Physico-chemical properties and fatty acid composition of pomegranate, cherry and pumpkin seed oils.

BACKGROUND: Nut and seed oils are often considered waste products but in recent years they have been receiving growing interest due to their high concentration of hydrophilic and lipophilic bioactive components, which have important pharmacological properties on human health. The aim of this work was to compare the physico-chemical and biochemical properties of pomegranate (Punicagranatum), sweet cherry (Prunusavium) and pumpkin (Cucurbita maxima) seed oils obtained by solvent extraction. RESULTS: High amount of linoleic acid was found in the cherry and pumpkin seed oils, while pomegranate seed oil showed relevant content of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) along to eicosapentaenoic acid (EPA) and nervonic acid. Pumpkin seed oil had high concentration of carotenoids, while pomegranate oil was the best absorber in the UV-A and UV-B ranges. CONCLUSION: Pomegranate, cherry and pumpkin seed oils can be an excellent source of bioactive molecules and antioxidant compounds such as polyphenols, carotenoids and unsaturated fatty acids. These seed oils can be included both as preservatives and functional ingredients in the food, pharmaceutical and cosmetic fields and can contribute to disease prevention and health promotion. Moreover, high absorbance of UV light indicates a potential use of these oils as filters from radiations in the food, pharmaceutical, and cosmetic fields.

Use of solid-phase microextraction coupled to gas chromatography-mass spectrometry for determination of urinary volatile organic compounds in autistic children compared with healthy controls.

Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders which have a severe life-long effect on behavior and social functioning, and which are associated with metabolic abnormalities. Their diagnosis is on the basis of behavioral and developmental signs usually detected before three years of age, and there is no reliable biological marker. The objective of this study was to establish the volatile urinary metabolomic profiles of 24 autistic children and 21 healthy children (control group) to investigate volatile organic compounds (VOCs) as potential biomarkers for ASDs. Solid-phase microextraction (SPME) using DVB/CAR/PDMS sorbent coupled with gas chromatography-mass spectrometry was used to obtain the metabolomic information patterns. Urine samples were analyzed under both acid and alkaline pH, to profile a range of urinary components with different physicochemical properties. Multivariate statistics techniques were applied to bioanalytical data to visualize clusters of cases and to detect the VOCs able to differentiate autistic patients from healthy children. In particular, orthogonal projections to latent structures discriminant analysis (OPLS-DA) achieved very good separation between autistic and control groups under both acidic and alkaline pH, identifying discriminating metabolites. Among these, 3-methyl-cyclopentanone, 3-methyl-butanal, 2-methyl-butanal, and hexane under acid conditions, and 2-methyl-pyrazine, 2,3-dimethyl-pyrazine, and isoxazolo under alkaline pH had statistically higher levels in urine samples from autistic children than from the control group. Further investigation with a higher number of patients should be performed to outline the metabolic origins of these variables, define a possible association with ASDs, and verify the usefulness of these variables for early-stage diagnosis.

Mild Approach for the Formulation of Chestnut Flour-Enriched Snacks: Influence of Processing Parameters on the Preservation of Bioactive Compounds of Raw Materials.

Third-generation snacks were developed from a triad of flours made up of chestnut, spelt, and chickpea flour. Optimal snack formulations and processing parameters have been established to ensure acceptable workability of the raw dough while protecting the bioactive components of the raw materials. The parameters examined were mixing time, speed, and temperature. The properties of the snack were evaluated by analyzing the expansion ratio, hardness, moisture content, and phenolic and volatile compounds. The optimal mixing conditions that ensure maximum expansion were a temperature of 30 °C, a speed of 30 rpm, and a time of 6 min. The results showed that the proper percentage of water and sodium bicarbonate was 35% and 2%, respectively, and that the developed snacks had an alveolar and homogeneous structure. The proposed approach brings several advantages, including the preservation of bioactive compounds during the production process. Furthermore, the mild operating conditions prevented the development of unwanted or unpleasant compounds, as confirmed by the analysis of volatile compounds. Therefore, this study opens new perspectives in the food industry, satisfying the growing demand for functional products and healthy snacks.

Olfactory Response of Sitophilus zeamais Adults to Odours of Semolina Pasta and Semolina Pasta Enriched with Different Amounts of Acheta domesticus Powder.

The behavioural response of adult maize weevil, Sitophilus zeamais, to different types of semolina pasta enriched or not enriched with increasing proportions (5%, 10%, and 15%) of house cricket (Acheta domesticus) powder was investigated in olfactometer arena bioassays by using trap devices. In the five-choice behavioural bioassays, the number of S. zeamais adults attracted to 100% durum wheat semolina pasta was significantly higher than those attracted to the other pasta types enriched with A. domesticus powder. In the two-choice behavioural bioassays, the Response Index for each pasta type was positive and significant. However, although not significant, there was a progressive reduction in the Response Index as the cricket powder content increased. In similar experiments, there were no significant differences between cricket powder alone and the control in the number of attracted S. zeamais, indicating a neutral effect towards insects. These observations suggest that the lower attractiveness of pasta enriched with house cricket powder is mainly due to the masking of host food odours. Solid-phase microextraction coupled to gas chromatography-mass spectroscopy identified a total of 18 compounds in the head-space samples of the different types of pasta, highlighting differences in volatile composition. Some volatile compounds were only present in the pasta produced with cricket powder. In particular, 1-octen-3-ol and phenol were present in the samples containing 5%, 10%, or 15% cricket powder; pentanal, benzaldehyde, and dimethyl disulphide were present in samples containing 10% or 15% cricket powder; and 2,5-dimethyl-pyrazine was present in the sample containing 15% cricket powder. Further investigation with individual compounds and mixtures is needed to define the chemical basis of the differences in the insect olfactory preference observed in this study.

Lacto-fermented garlic handcrafted in the Lower Silesia Region (Poland): Microbial diversity, morpho-textural traits, and volatile compounds.

The aim of the present study was to provide a first characterization of lacto-fermented garlic manufactured by local small-scale artisanal producers in the Lower Silesia Region (Poland). The lacto-fermented garlic samples showed high nutritional features in terms of antioxidant activity. A total of 86 compounds, belonging to various chemical classes, were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS). Most of these compounds belonged to six main classes, being sulfur compounds, esters and acetates, oxygenated monoterpenes, monoterpene hydrocarbons, and alcohols. Aldehydes, acids, ketones, furans, and phenols were also identified. In the analyzed samples, counts up to 8 log cfu g-1 were observed for lactic acid bacteria. Metataxonomic analysis revealed the presence of Levilactobacillus, Lactiplantibacillus, Latilactobacillus, Secundilactobacillus, Weissella, Leuconostoc, Lactococcus, Pediococcus, and Lacticaseibacillus among the major taxa. These results were confirmed by the isolation and characterization of viable lactic acid bacteria. Indeed, the presence of the closest relatives to Lacticaseibacillus casei group, Pediococcus parvulus, Levilactobacillus brevis, Levilactobacillus parabrevis, and Lactiplantibacillus plantarum group was observed. A good acidification performance in salty garlic-based medium was observed for all the isolates that, between 8 and 15 days of fermentation, reached pH values comprised between 4 and 3.5, depending on the tested species. Of note, 15 out of the 37 lactic acid bacteria isolates (Levilactobacillus parabrevis, Pediococcus parvulus, Lactiplantibacillus plantarum group, and Lacticaseibacillus casei group) showed the presence of the hdcA gene of Gram-positive bacteria encoding for histidine decarboxylase. Furthermore, for 8 out of the 37 isolates the in-vitro exopolysaccharides production was observed. No isolate showed inhibitory activity against the three Listeria innocua strains used as surrogate for Listeria monocytogenes.

Tasting of traditional Polish fermented cucumbers: Microbiology, morpho-textural features, and volatilome.

In the present study, naturally fermented and unpasteurized cucumbers (Cucumis sativus L.) collected from 4 producers located in different regions of Poland were studied. The fermented cucumbers were characterized by significant nutritional features in terms of polyphenols content and antioxidant activity. Microbiological analyses revealed active bacterial populations of lactococci, thermophilic cocci, lactobacilli, and coagulase-negative cocci. The microbiological characterization of cucumber and brine samples through metataxonomic analysis allowed the dominant species to be detected, being Lactococcus and Streptococcus in cucumbers, and Lactiplantibacillus, Leuconostoc, Pediococcus, Secundilactobacillus, and Lentilactobacillus in brine. The isolation activity offered a clear picture of the main active lactic acid bacteria at the end of fermentation, being Pediococcus parvulus and Lactiplantibacillus plantarum group. All the studied isolates showed a good attitude in fermenting a cucumber-based broth, thus suggesting their potential application as starter or adjunct cultures for guided cucumber fermentation. Moreover, for the same isolates, strong aminopeptidase activity (due to leucine arylamidase and valine arylamidase) was observed, with potential effect on the definition of the final sensory traits of the product. Only a few isolates showed the ability to produce exopolysaccharides in synthetic medium. Of note, the presence of the hdcA gene in some Pediococcus ethanolidurans isolates also confirmed the need for a thorough characterization of starter candidates to avoid undesired adverse effects on consumer's health. No isolate showed the production of bacteriocins against Listeria innocua used as surrogate for Listeria monocytogenes. Based on the results of Headspace Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry analysis, a rich and complex volatilome, composed by more than 80 VOCs, was recognized and characterized. In more detail, the detected compounds belonged to 9 main classes, being oxygenated terpenes, alcohols, terpenes, ketones, acids, aldehydes, esters, sulfur, and sesquiterpenes.

Development and Evaluation of a Fermented Pistachio-Based Beverage Obtained by Colloidal Mill.

The aim of the present study was to develop a fermented pistachio beverage as a plant-based alternative to milk-based drinks. For this purpose, a colloidal mill was used to finely grind and homogenize the pistachios to obtain a homogeneous consistency and prevent sedimentation. In addition, lactic acid bacteria fermentation was used to develop unique flavours and characteristics in the final product and to achieve microbiological stability for up to 30 days of storage a 4 °C. The formulated beverages were evaluated for chemical-physical characteristics (pH, organic acid production, and fructose, sucrose, and glucose content), nutritional profile (proximate composition, amino acid and GABA content), and volatile organic composition by HS-SPME-GC/MS analysis. The pistachio-based beverages were characterized by a good source of protein, fat, fiber, and minerals (mainly K and P). The colloidal mill contributed to creating a homogeneous texture and to making the nutrients readily available to the starter microorganisms, which reached concentrations above 108 ufc/mL in the final products. The beverages were characterized by pronounced acidity and some by the presence of acetoin and 2,3-butanedione, volatile components associated with a yogurt- or kefir-like aroma. This innovative approach provides an alternative to traditional milk-based beverages and highlights the role of LAB in the development of nutritious and attractive plant-based beverages.

Spotlight on autochthonous microbiota, morpho-textural characteristics, and volatilome of a traditional Polish cold-smoked raw sausage.

The aim of the present study was to obtain information on the bacterial diversity of traditional Polish cold-smoked raw sausages (Kielbasa polska wedzona) manufactured by two artisanal producers using different selective growth media and a metataxonomic analysis. Physico-chemical and morpho-textural characteristics were also carried out, together with Microextraction-Gas Chromatography/Mass Spectrometry (HS-SPMEGC/MS) to study the volatile organic compounds (VOCs). The results overall obtained allowed a picture of the microbiota, the morpho-textural characteristics, and the volatilome of traditional Polish cold-smoked raw sausages (Kielbasa polska wedzona) to be drawn for the first time. In more detail, viable counting revealed active populations of presumptive lactobacilli, enterococci, coagulase-negative cocci, and a few spoilage microorganisms typically occurring in raw meat products. The metataxonomic analysis revealed the dominance of Latilactobacillus sakei occurring with a relative frequency between 77% and 89%. Pediococcus pentosaceus, Weissella hellenica, and Leuconostoc carnosum were detected among the minority taxa. In the sausages herein studied, no histamine levels of concern were detected. The Principal Component Analysis (PCA) performed on the Amplicon Sequence Variants (ASVs) did not show significant differences in the microbiota composition among producers. The HS-SPMEGC/MS analysis allowed the detection and identification of more than 90 volatile components belonging to ten main classes, namely: aldehydes, ketones, esters and acetates, acids, alcohols, phenols, furans, sulphur compounds, terpenoids, and benzene derivatives. The detected VOCs originated from spices, smoke, and microbial metabolism. The PCA of volatile compounds allowed differences between the sausage samples of the two producers to be identified.

Exploitation of Black Olive (Olea europaea L. cv. Piantone di Mogliano) Pomace for the Production of High-Value Bread.

In this study, the morpho-textural features, total phenolic content (TPC), and antioxidant capacity (AOC) of bread fortified with olive (Olea europaea L.) pomace were evaluated. Fresh olive pomace was subjected to microbiological and chemical (TPC, AOC, and fiber) analyses; then, the same olive pomace was analyzed during 1 to 6 months of storage at 4 °C or -20 °C. All olive pomace samples were used in 10%, 15%, or 20% amounts to produce type 0 soft wheat (Triticum aestivum) and whole wheat bread samples. The volatile organic compounds (VOCs) in the bread samples were also analyzed to assess the effect of the addition of the olive pomace on the flavor profile of the baked products. The TPC and AOC evaluation of olive pomace showed no differences among the analyzed samples (fresh, refrigerated, or frozen). Regarding the bread containing olive pomace, the specific volume was not affected by the amount or the storage methods of the added pomace. Bread samples produced with soft wheat flour showed the lowest hardness values relative to those produced with whole wheat flour, irrespective of the amount or storage method of the olive pomace. Regarding color, the crust and crumb of the bread samples containing 20% olive pomace were significantly darker. The bread samples containing 20% olive pomace had the highest TPC. The bread samples with fresh olive pomace were characterized by terpenoids, ketones, and aldehydes, whereas the bread samples containing refrigerated olive pomace were characterized by alcohols (mainly ethanol), acids, esters, and acetate. Finally, the bread samples with frozen olive pomace showed a volatile profile similar to that of bread produced with fresh olive pomace. Olive pomace was shown to be a suitable ingredient for producing bread with high nutritional value.

Selection of Non-Saccharomyces Wine Yeasts for the Production of Leavened Doughs.

BACKGROUND: Non-conventional yeasts (NCY) (i.e., non-Saccharomyces) may be used as alternative starters to promote biodiversity and quality of fermented foods and beverages (e.g., wine, beer, bakery products). METHODS: A total of 32 wine-associated yeasts (Campania region, Italy) were genetically identified and screened for decarboxylase activity and leavening ability. The best selected strains were used to study the leavening kinetics in model doughs (MDs). A commercial strain of Saccharomyces cerevisiae was used as the control. The volatile organic profiles of the inoculated MDs were analyzed by solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS). RESULTS: Most of strains belonged to the NCY species Hanseniaspora uvarum, Metschnikowia pulcherrima, Pichia kudriavzevii, Torulaspora delbruekii, and Zygotorulaspora florentina, while a few strains were S. cerevisiae. Most strains of H. uvarum lacked decarboxylase activity and showed a high leaving activity after 24 h of incubation that was comparable to the S. cerevisiae strains. The selected H. uvarum strains generated a different flavor profile of the doughs compared to the S. cerevisiae strains. In particular, NCY reduced the fraction of aldehydes that were potentially involved in oxidative phenomena. CONCLUSIONS: The use of NCY could be advantageous in the bakery industry, as they can provide greater diversity than S. cerevisiae-based products, and may be useful in reducing and avoiding yeast intolerance.

Liquid sourdough from stone-ground soft wheat (Triticum aestivum) flour: Development and exploitation in the breadmaking process.

The aim of the study was to set up a liquid sourdough obtained using stone-ground soft wheat (Triticum aestivum) flour to be exploited in breadmaking. Therefore, a Type II sourdough (dough yield = 350) was developed from a stable stone-ground wheat Type I sourdough (dough yield = 156) used as inoculum. Both sourdoughs were analyzed for lactic acid bacteria (LAB) viable counts, pH and total titratable acidity (TTA), LAB biodiversity by a combined culture-dependent and -independent approach (PCR-DGGE) and they were tested for their breadmaking ability. In addition, the chemical and rheological features and volatile organic compounds of the stone-ground soft wheat flour used in the experiment were investigated. The flour had a high protein content, good bakery properties and it also presented a rich aroma pattern characterized not only by the prevalence of green grass, flowery, and sweet aromas but also nutty, roasted and popcorn aromas. The sourdoughs I and II used in the trial were characterized by viable LAB counts, pH and TTA values typical of mature sourdoughs, i.e., approximately 9 log cfu gr-1 and mL, pH 3.9 and 10 mL 0.1 N NaOH. In addition, Levilactobacillus brevis and Companilactobacillus paralimentarius species represented the LAB stable microbiota of both sourdoughs. Both sourdoughs efficiently produce acceptable experimental breads characterized by different volatile profiles thus indicating that the type of sourdough fermentation significantly influenced the features of the final products. Overall, for the first time in the present study stone-ground wheat flour and bread have been characterized for their volatile aroma profile and sensory properties.

Towards Green Strategies of Food Security: Antibacterial Synergy of Essential Oils from Thymus vulgaris and Syzygium aromaticum to Inhibit Escherichia coli and Staphylococcus aureus Pathogenic Food Isolates.

Foodborne diseases continue to represent an important public health issue. The control of food spoilage and pathogenic microorganisms is achieved mainly by synthetic chemicals, unfortunately associated to several undesirable aspects. The growing requirement for new and safe alternative strategies has resulted in the research of agents from natural sources with antimicrobial properties, such as essential oils (EOs). This study's purpose was to define the antibacterial profile of thyme (Thymus vulgaris) and cloves (Syzygium aromaticum) essential oils against both Gram-positive and Gram-negative important foodborne pathogenic bacteria. Gas chromatography mass spectrometry analysis was performed for EOs' chemical composition. Qualitative in vitro antimicrobial assays (i.e., agar well diffusion method and disk-volatilization method) allowed for verification of the efficacy of EOs, used individually and in binary combination and both in liquid and vapor phase, against Staphylococcus aureus and Escherichia coli food isolates. Minimal inhibitory concentrations and minimal bactericidal concentration values have been used to quantitatively measure the antibacterial activity of EOs, while the fractional inhibitory concentration index has been considered as a predictor of in vitro antibacterial synergistic effects. The microbiological tests suggest that thyme and cloves EOs, rich in bioactive compounds, are able to inhibit the growth of tested foodborne bacteria, especially in vapor phase, also with synergistic effects. Results provide evidence to consider the tested essential oils as promising sources for development of new, broad-spectrum, green food preservatives.

Unfolding microbiota and volatile organic compounds of Portuguese Painho de Porco Preto fermented sausages.

In the present study, bacterial and fungal diversity, as well as volatile profiles, of ready-to-eat Portuguese Painho de Porco Preto fermented sausages manufactured by two artisanal producers in the districts of Beja (producer A) and Evora (producer B) were studied. To this end, different selective growth media and a metataxonomic analysis were combined with Headspace Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS) analysis. The results of the microbiological viable counts revealed active microbial populations of lactic acid bacteria (up to 8 Log cfu g-1), coagulase negative cocci (up to 6 Log cfu g-1), and eumycetes (up to 6 Log cfu g-1). Bacterial populations were characterized by high relative frequencies of Latilactobacillus sakei (up to 72%), together with Weissella and Staphylococcus equorum. The mycobiota was mainly dominated by Debaryomyces hansenii (up to 55% of the relative frequency) and Kurtzmaniella zeylanoides (up to 24% of the relative frequency). Unexpected species as Wickerhamomyces subpelliculosus and Zygosaccharomyces rouxii were also detected. HS-SPME-GC/MS analysis allowed to identify a complex volatile profile, showing 159 volatile organic compounds (VOCs). VOCs belonged to twelve classes, such as aldehydes, ketones and lactones, esters and acetates, alcohols, terpenoids, sulfur compounds, aliphatic hydrocarbons, aromatic hydrocarbons, nitrogen compounds, acids, furans and pyrans, and phenols. The analysis of VOCs composition provided evidence that samples from the two producers (A and B) were different, as confirmed by the Principal Component Analysis. Hence, it is likely that the raw materials used, as well as variations related with the empirical practice of the butchers, strongly influenced the final product. The results obtained in the present study represent a further advancement in the knowledge on the biodiversity and VOCs composition of Portuguese fermented sausages. To better understand the interactions occurring between the autochthonous microorganisms and the meat batter in the Painho de Porco Preto fermented sausage, microbial and VOCs dynamics must be further deepened throughout the production process.

Unravelling microbial populations and volatile organic compounds of artisan fermented liver sausages manufactured in Central Italy.

The aim of the present study was to obtain information on the occurrence of bacteria and eumycetes in ready-to-eat fermented liver sausages manufactured by 20 artisan producers located in the Marche Region (Italy). To this end, culture-dependent analyses and metataxonomic sequencing were carried out. Physico-chemical parameters and volatilome of the fermented liver sausages were also studied. Finally, the presence of hepatitis E virus (HEV) was also assessed via real-time-RT-(q)PCR assays. Active microbial populations mainly represented by lactic acid bacteria, enterococci, coagulase-negative cocci, and eumycetes were detected. Enterobacteriaceae, Pseudomonadaceae, and sulfite-reducing anaerobes were not detected in most of the samples. Latilactobacillus sakei dominated in all the analyzed samples, reaching abundances up to 80%. Staphylococcus xylosus and Staphylococcus equorum were also detected. Among minority bacterial taxa, Weissella spp., Leuconostoc spp., Macrococcus caseolyticus, Brochothrix thermosphacta, Staphylococcus succinus, Lactobacillus coryniformis, Lactiplantibacillus plantarum, Lactococcus garviae, Psychrobacter spp., and Carnobacterium viridans were detected. The mycobiota was mainly composed by Debaryomyces hansenii that was present in all samples at the highest frequency. Among minority fungal taxa, Aspergillus spp., Penicillium spp., Kurtzmaniella zeylanoides, Candida spp., Yamadazyma spp., Scopulariopsis spp., Yarrowia spp., and Starmerella spp. were detected. Interestingly, associations between some taxa and some physico-chemical parameters were also discovered. The absence of HEV in all the samples attested a high level of safety. Finally, most of the VOCs detected in the analyzed fermented liver sausages belonged to six classes as: terpenoids, aldehydes, ketones, alcohols, esters, and acids. Nitrogen compounds, sulfur compounds, phenols, hydrocarbons, lactones, furans, and aromatic hydrocarbons were also identified. Several significant relationships were observed between mycobiota and VOCs.

Nutritional and Chemical-Physical Characterization of Fresh Pasta Gnocchi Prepared with Sea Water as New Active Ingredient.

This study shows the chemical-physical and nutritional results obtained using food-grade sea water for the preparation of fresh pasta Gnocchi with respect to those prepared with tap water. Gnocchi obtained by mixing the flour with seawater (GSW) were compared with traditional Gnocchi made with tap water (GTW). The contents of sodium chloride, macro and micro elements, volatile molecules profile, thermal properties, and morphological analysis were investigated in both Gnocchi types. The analysis of chlorides showed that the samples prepared with sea water had a significantly lower NaCl content after cooking in comparison with those prepared with tap water. These results were also confirmed by the inductively coupled plasma (ICP) analysis for sodium content. The profiles of the volatile molecules acquired by gas chromatography-mass spectrometry (GC-MS) evidenced significant differences between the groups of aromatic molecules of the two typologies of samples. Morphological analysis evidenced that both raw and cooked GSW Gnocchi were structurally tightened whereas GTW Gnocchi showed a labile and weak macromolecular network. In addition, GSW Gnocchi was more thermally stable than GTW Gnocchi, as evidenced by thermogravimetric analysis (TGA).

Portuguese cacholeira blood sausage: A first taste of its microbiota and volatile organic compounds.

Among typical Portuguese sausages, the cacholeira blood sausage undoubtedly represents one of the most popular preparations. To the authors' knowledge, a lack of information on both the microbiota and the volatile organic compounds (VOCs) of this blood-containing sausage emerges from the available scientific literature. This study represents the first characterization of physico-chemical, microbiological and volatile traits of Portuguese cacholeira blood sausage. To this end, ready-to-eat cacholeira blood sausages were collected from two production batches manufactured in summer (batch 1) and autumn (batch 2). Viable counts showed active microbial communities mainly composed by lactic acid bacteria, coagulase negative cocci, enterococci and eumycetes. The metataxonomic approach showed a simple bacterial composition, which was dominated by Lactobacillus sakei in both the analyzed batches (1 and 2) considered. Carnobacterium, Enterococcus, Kluyvera, Lactococcus and Serratia were found as minor genera. The mycobiota varied according to the production season. Batch 1 was dominated by Starmerella apicola, Debaryomyces hansenii and Candida tropicalis, whereas batch 2 was dominated by D. hansenii. Moreover, Aspergillus spp., Kurtzmaniella zeylanoides, Saccharomyces cerevisiae, Kurtzmaniella santamariae, Brettanomyces bruxellensis and Pichia kluyveri were detected in both the batches as minority species. Seventy-two volatile compounds were identified, including esters, phenols, terpenoids, acids, alcohols, ketones, aldehydes, lactones, furans, sulphur and nitrogen compounds. Significant differences were seen in the amount of some compounds, as a feasible consequence of differences in the raw materials, artisan production and seasonality.

Study of kefir drinks produced by backslopping method using kefir grains from Bosnia and Herzegovina: Microbial dynamics and volatilome profile.

Kefir is a well-known health-promoting beverage that can be produced by using kefir grains (traditional method) or by using natural starter cultures from kefir (backslopping method). The aim of this study was to elucidate the microbial dynamics and volatilome profile occurring during kefir production through traditional and backslopping methods by using five kefir grains that were collected in Bosnia and Herzegovina. The results from conventional pour plating techniques and amplicon-based sequencing were combined. The kefir drinks have also been characterized in terms of their physico-chemical and colorimetric parameters. A bacterial shift from Lactobacillus kefiranofaciens to Acetobacter syzygii, Lactococcus lactis and Leuconostoc pseudomesenteroides from kefir grains in traditional kefir to backslopped kefir was generally observed. Despite some differences within samples, the dominant mycobiota of backslopped kefir samples remained quite similar to that of the kefir grain samples. However, unlike the lactic acid and acetic acid bacteria, the yeast counts decreased progressively from the grains to the backslopped kefir. The backslopped kefir samples showed higher protein, lactose and ash content and lower ethanol content compared to traditional kefir samples, coupled with optimal pH values that contribute to a pleasant sensory profile. Concerning the volatilome, backslopped kefir samples were correlated with cheesy, buttery, floral and fermented odors, whereas the traditional kefir samples were correlated with alcoholic, fruity, fatty and acid odors. Overall, the data obtained in the present study provided evidence that different kefir production methods (traditional vs backslopping) affect the quality characteristics of the final product. Hence, the functional traits of backslopped kefir should be further investigated in order to verify the suitability of a potential scale-up methodology for backslopping.