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Calanchi (plural of calanco) are typical Italian badlands created by a combination of morphogenetic processes (rill and interrill erosion, gullying, piping, and mass movements) mainly originated by the effect of water. Calanchi are characterized by the sparse and patchy distribution of vegetation, and, in interplant areas, the soil surface is colonized by an association of organisms known as biological soil crust (BSC). A morphometric analysis of 45 basins in the studied calanchi area, based on a high-resolution digital elevation model, showed those basins are sediment removal systems characterized by rapid and relevant erosion processes. The goal of the current research is to evaluate the bacterial composition of BSC and to recognize its signature of land degradation processes in soil samples by a microbiological analysis (culture-dependent and culture-independent approaches). Soil bacterial distribution was investigated by a culture-independent approach, applying Illumina technology in soils with different vegetation cover. Four species were detected in site A (bare soil). In sites B (sparse vegetation) and C (densely vegetated soil) 19 and 18 bacterial taxa were detected, respectively. Sites B and C were characterized by 17 species in common. The microbial communities detected at sites B and C are typical of environments unable to support vegetation and microorganisms that are not specialized to live in these environments. Biodiversity analysis of the bacterial communities of biocrusts, done using richness and evenness indices, confirmed that the composition of the BSC communities can be a signature of the intensity of soil erosion processes.

Previous investigations on pizza dough lactic acid bacteria (LAB) revealed that facultative heterofermentative species (FHS) were more represented than obligate heterofermentative species (OHS) within the Lactobacillus genus. Thus, the main hypothesis of this work was that facultative and obligate heterofermentative Lactobacillus species can impact differently the appreciation of baked pizza. The performances of different Lactobacillus, including L. sanfranciscensis, L. brevis and L. rossiae among OHS and L. plantarum, L. graminis and L. curvatus among FHS were tested in single or multiple combinations during pizza production. The values of pH, total titratable acidity and LAB levels indicated that the acidification process was almost comparable among trials. The fermentation quotient of FHS trials was above 4.0. All trials were dominated by the added LAB and for the trials with the multiple strain starter inoculums, the species found at the highest cell densities were L. sanfranciscensis, L. brevis and L. plantarum. Significant differences among pizzas were found for weight loss, colour, morphology and volatile organic compounds (VOCs). The last analysis revealed the presence of eight chemical classes with aldehydes, esters, alcohols and acids as major compounds and allowed the separation of the trials FHS and OHS. Sensory attributes were significantly different for judges and pizzas and the most relevant differences were found for crust colour, presence of bubbles, resistance to tearing, crispness and chewiness. The overall assessment reached the highest scores for the mixed culture of OHS and FHS together.

“Spiritu re fascitrari” is a Sicilian alcoholic beverage obtained through distillation of a decoction of spontaneously fermented honey by-products (FHP). The production process often leads to sensorial defects due to the unstable alcoholic fermentation. The objective of this work was to select Saccharomyces cerevisiae strains from FHP to be used as starter in decoction fermentation. Based on chemical, microbiological and technological data, from a total of 91 strains three S. cerevisae were selected for further testing to produce FHP at laboratory scale level. After FHP distillation, the analysis of volatile organic compounds showed a complex mixture of sensory active molecules, mainly alcohols and aldehydes. Among the alcohols, 3-methyl-1-butanol, 2-methyl-1-butanol, phenylethyl alcohol, hexadecanol and octadecanol were found at the highest concentrations. Among the carboxylic acids, acetic acid was mainly detected in the spontaneously fermented samples. FHP fermented with the three selected strains were not characterized by the presence of off-odors or off-flavours. The results obtained in this work demonstrate that the selected S. cerevisiae strains are promising starters to stabilize the production of distilled alcoholic beverages produced from honey by-products.

The purpose of this study was to develop functional breads with powdered Pleurotus eryngii. The breads were produced applying the traditional Italian style sourdough technology. P. eryngii powder was added to flour of tender wheat varieties (Grano Dei Miracoli, Inalettabile, Mentana, Gentilrosso, Ardito and a mix of Rieti, Verna, and Mentana) or semolina of durum wheat landrace (Saragolla) and subjected to sourdough fermentation. Sourdough inoculum was produced with selected strains of lactic acid bacteria (LAB) belonging to the species Levilactobacillus brevis, Weissella cibaria and Leuconostoc citreum. The addition of Pleurotus powdered (PP) (10% w/w) did not influence the fermentation process, since LAB developed until 109 CFU/g after 8 h of leavening. The values of pH, TTA and organic acids of doughs prepared with PP were higher than those of control fermentation. All breads differed for height, weight loss, firmness, color and void fraction. Sensory evaluation indicated that the bread produced with Mentana flour added with PP was mostly appreciated by the judges. Hence, only the bread processed from this wheat variety was investigated for vitamins and microelements showing an increase in B1, B2, B3, and D vitamins, total polyphenols, and beta-glucans. This work provided evidences to perform PP supplementation to increase the functional aspects of bread.

Catarratto is one of the most common non-aromatic white grape varieties cultivated in Sicily (Southern Italy). In order to improve the aromatic expression of Catarratto wines a trial was undertaken to investigate the effect of yeast strain, nutrition and reduced glutathione. Variables included two Saccharomyces cerevisiae strains, an oenological strain (GR1) and one isolated from honey by-products (SPF52), three different nutrition regimes (Stimula Sauvignon Blanc™ (SS), Stimula Chardonnay™ (SC) and classic nutrition practice), and a specific inactivated yeast rich in reduced glutathione to prevent oxidative processes [Glutastar™ (GIY)] ensuing in ten treatments (T1-T10). Microbiological and chemical parameters demonstrated the aptitude of strain SPF52 to successfully conduct alcoholic fermentation. During fermentation, the Saccharomyces yeast populations ranged from 7 to 8 logarithmic CFU/mL. All wines had a final ethanol content ranging between 12.91 and 13.85% (v/v). The dominance of the two starter strains over native yeast populations was higher than 97% as estimated by interdelta analysis. The addition of nutrients SS or SC increased the aromatic complexity of the wines as reflected by volatile organic compounds (VOCs) composition and sensory profiles. In particular, 32 VOCs were identified; alcohols (62.46-81.1%), thiols (0.27-0.87%), ethers (0.09-0.16%), aldehydes (0-1.21%), ketones (0-2.28%), carboxylic acids (4.21-12.32%), esters (0-10.85%), lactones (0.9-1.49%) and other compounds (0.77-6.9%). Sensory analysis demonstrated a significant impact on wine aroma in relation to yeast starter strain used, the type of nutrition (SS, SC or classic nutrition) and the presence/absence of GIY. The wines produced with GR1 yeast strain and SS (T2), SPF52 with SC (T9) both in presence of GIY showed higher overall quality. Trials T2 and T9 showed the highest scores for 13 and 18 attributes, respectively. The different nutrition, addition of GIY and the yeast starter strains diversified and enhanced sensory expression of Catarratto wines.

The increasing interest in novel beer productions focused on non-Saccharomyces yeasts in order to pursue their potential in generating groundbreaking sensory profiles. Traditional fermented beverages represent an important source of yeast strains which could express interesting features during brewing. A total of 404 yeasts were isolated from fermented honey by-products and identified as Saccharomyces cerevisiae, Wickerhamomyces anomalus, Zygosaccharomyces bailii, Zygosaccharomyces rouxii and Hanseniaspora uvarum. Five H. uvarum strains were screened for their brewing capability. Interestingly, Hanseniaspora uvarum strains showed growth in presence of ethanol and hop and a more rapid growth than the control strain S. cerevisiae US-05. Even though all strains showed a very low fermentation power, their concentrations ranged between 7 and 8 Log cycles during fermentation. The statistical analyses showed significant differences among the strains and underlined the ability of YGA2 and YGA34 to grow rapidly in presence of ethanol and hop. The strain YGA34 showed the best technological properties and was selected for beer production. Its presence in mixed- and sequential-culture fermentations with US-05 did not influence attenuation and ethanol concentration but had a significant impact on glycerol and acetic acid concentrations, with a higher sensory complexity and intensity, representing promising co-starters during craft beer production.

Powdered mealworm (MW) and buffalo worm (BW) larvae were used to functionalize sourdough Italian-style breads. Sourdough inoculum was started with Levilactobacillus brevis, Weissella cibaria and Leuconostoc citreum. The doughs were SBS (semolina plus powdered BW larvae and sourdough) and SMS (semolina plus powdered MW larvae and sourdough) whose pHs (4.32 and 4.21, respectively) were higher than that of control (3.81). The highest fermentation quotient (lactate/acetate molar ratio) was recorded in SMS (4.46). LAB reached viable counts of about 109 CFU g−1 in almost all doughs. Insects impacted bread VOCs with dodecanal, 2.4-dodecadienal and 2-octenal-2-butyl. SBS and SMS increased the antioxidant capacity of breads by 42 and 69%, respectively. SMS decreased the glucose release in the bio-accessible fraction by 70% reducing the glycemic index of bread. Control breads were more appreciated by the sensory panel than insect-containing breads, though SMS breads were characterized by a slightly lower overall assessment.

A commercial biodegradable starch-based polymer (Mater-Bi) was activated with carvacrol to develop a biodegradable and compostable polymer to be used in food packaging. Based on previous tests, carvacrol was added at 20 % weight of foam. MB foams, with and without carvacrol, were tested for their morphological characteristics, mechanical tests and kinetics of carvacrol release under refrigerated storage conditions. Carvacrol slightly increased the porosity of the foams, induced a reduction of the compressive elastic modulus (Ecom) of foamed MB from 6 to ∼ 3.4 MPa and a decrease of the tensile elastic modulus from ∼70 MPa to ∼16.5 MPa. Carvacrol release from the foam at 4 °C was almost 7% of the initially loaded amount at the fifth hour, while 35.4 % at the end of the test (900 h). MB containing carvacrol was active against several pathogenic and spoilage bacteria in vitro. Trays made of MB containing carvacrol were put in contact with meat, fish and vegetable food systems, artificially contaminated with Pseudomonas poae 4G558 and Listeria monocytogenes 13BO. No antimicrobial effect of MB foams was registered for ham and salmon trials, while a clear inhibitory effect of carvacrol activated MB foams was observed for contaminated melon and pumpkin in which both bacteria decreased of about 1 log cycle after 3 d and completely disappeared from the 7th d of refrigerated storage. This study provided evidences on the suitability of MB foams containing 20 % carvacrol as active packaging systems for vegetables even though it negatively affected their physicochemical parameters and overall quality.

The “Spiritu re fascitrari” (SRF) is a typical Sicilian distillate obtained from the by-products of traditional process of honey production. Although some alcoholic fermentation of honey based products have been described, the present research represents the first investigation on the yeast ecology and the physico-chemical characteristics of honey by-products subjected to an alcoholic fermentation followed by distillation. All samples collected during manufacturing process were analysed for the count of total, osmophilic and osmotolerant yeasts. The honeycombs and equipment surfaces showed the presence of yeasts that was 1.7 and 1.1 Log (CFU/mL), respectively. After enrichment, yeast populations increased and a significant increase of yeasts was registered during the alcoholic fermentation (AF), reaching loads higher than 7 Log CFU/mL after day 6. A total of 2816 colonies of yeasts were isolated from the count plates and the following species were genetically identified: Lachancea fermentati, Pichia anomala, Pichia kudriavzevii, Saccharomyces cerevisiae, Wickerhamomyces anomalus, Zygosaccharomyces bailii and Zygosaccharomyces rouxii. During the spontaneous AF process, the species S. cerevisiae, Z. bailii and Z. rouxii were mainly isolated and the feed conversion ratio of sugars into ethanol was about 53%; high contents of acetic acid and glycerol were also found. The highest concentrations of volatile organic compounds (VOCs) were registered for esters, alcohols and aldehydes (346.55, 331.041 and 13.65 μg/L, respectively). Many VOCs identified as “specific floral markers” such as nonanal and 1-hexanol, 1-octanal and linalool oxide were found. Although more studies are needed, our results suggested that the S. cerevisiae strains isolated in this study must be evaluated in situ for their potential to act as starters for the continuous production of SRF. This because these strains are expected to drive the fermentation process reducing the risk of off-odour and off-flavour formation.

In this work, the feasibility of antibacterial biopolymeric foams containing carvacrol (CRV) for potential food packaging applications was investigated. Sodium bicarbonate (SB) was chosen as foaming agent and a commercial biodegradable polymer, Mater-Bi® (MB), as a matrix. MB/SB and MB/SB/CRV systems were prepared by melt mixing and the foaming process was conducted in a laboratory press. The influence of foaming agent and antibacterial additive content was investigated. The foamed samples were characterized through morphological analysis, mechanical tests and measurements of CRV release kinetics. Moreover, a mathematical model, i.e. power law model, was used to fit the release data in order to investigate the release mechanism. The antibacterial activity of foams containing CRV was tested in vitro against pro-technological, spoilage and pathogenic bacteria applying the disc diffusion method. The results showed that by using 3% of SB it is possible obtain foams with a porosity of about 40%. The presence of carvacrol, strongly influenced the properties of the biopolymeric foams but at the higher content ensured antibacterial activity of the samples.