Research Interests:
In winemaking, the influence of Saccharomyces cerevisiae strains on the aromatic components of wine is well recognized on a laboratory scale, but few studies deal with the comparison of numerous strains on a pilot scale fermentation. In... more
In winemaking, the influence of Saccharomyces cerevisiae strains on the aromatic components of wine is well recognized on a laboratory scale, but few studies deal with the comparison of numerous strains on a pilot scale fermentation. In this scenario, the present work aimed to validate the fermentative behavior of seven wild S. cerevisiae strains on pilot-scale fermentations to evaluate their impact on the aromatic profiles of the resulting wines. The strains, isolated from grapes of different Italian regional varieties, were tested in pilot-scale fermentation trials performed in the cellar in 1 hL of Aglianico grape must. Then, wines were analyzed for their microbiological cell loads, main chemical parameters of enological interest (ethanol, total sugars, fructose, glucose, total and volatile acidity, malic and lactic acids) and volatile aroma profiles by GC/MS/SPME. Seventy-six volatile compounds belonging to six different classes (esters, alcohols, terpenes, aldehydes, acids, and...
Research Interests:
Research Interests:
Research Interests:
Food preparations, especially those based on animal products, are often accused of being responsible for the increase in food-borne infections, contributing to increased pressure on healthcare systems. The risk assessment in agri-food... more
Food preparations, especially those based on animal products, are often accused of being responsible for the increase in food-borne infections, contributing to increased pressure on healthcare systems. The risk assessment in agri-food supply chains is of utmost importance for the food industry and for policymakers. A wrong perception of risks may alter the functioning of supply chains; thus, efforts should be devoted to communicating risks in an efficient way. We adopt a multidisciplinary approach to investigate how consumers perceive different food risks. Our analysis shows that planning effective communication strategies is very much important for efficiently informing consumers on food risks. We also comment on potential innovative ways to better organise the supply chains.
Research Interests:
Research Interests: Biology and Germination
Graphical abstract
Research Interests:
Research Interests: Engineering and LAG
Research Interests:
A new technique for the immobilization of lysozyme onto the surface of polyvinylalcohol films is presented. The active compound was sprayed along with a suitable bonding agent onto the surface of the cross-linked polymeric matrix. Active... more
A new technique for the immobilization of lysozyme onto the surface of polyvinylalcohol films is presented. The active compound was sprayed along with a suitable bonding agent onto the surface of the cross-linked polymeric matrix. Active compound release tests determined the amount of lysozyme immobilized on the film surface. With the use of Micrococcus lysodeikticus, the antimicrobial activity of the films was determined and the results correlated with the amount of immobilized lysozyme. This new technique was effective for immobilizing the enzyme, and the developed films were active against the test microorganism. Results were compared with those obtained with a different immobilizing technique, in which the active compound was bound into the bulk of the polymeric film. As expected, the surface-immobilized lysozyme films have a higher antimicrobial activity than bulk-bound films.
Research Interests:
Research Interests: Microbiology, Environmental Science, Food Science, Food Safety, Soil, and 15 moreIrrigation, Industrial Biotechnology, Medicine, Food Microbiology, Listeria monocytogenes, Soil Microbiology, Salmonella, Brassica, Food Sciences, Seasons, Elsevier, Agricultural Irrigation, Pathogenic Bacteria, Lycopersicon esculentum, and Food crops
The influence of both postharvest treatments and film permeability on the quality decay kinetics of freshly processed grapes was addressed. Ethanol, chlorinated water and hot water were tested to reduce microbiological spoilage. The... more
The influence of both postharvest treatments and film permeability on the quality decay kinetics of freshly processed grapes was addressed. Ethanol, chlorinated water and hot water were tested to reduce microbiological spoilage. The treated grapes were packaged in two polyester-based biodegradable films (NVT1 and NVT2) and the composition of the atmosphere within the packages determined. A multilayer film, made by laminating an aluminium foil with a polyethylene film (aluminium) was used to evaluate separately the respiratory activity of the packed grapes, and the oxygen and carbon dioxide permeability coefficients of the investigated films under real working conditions. The quality decay kinetics of freshly processed table grapes packed at 5°C were assessed by monitoring the cell load of the main spoilage microorganisms (total mesophilic viable count, lactic acid bacteria, yeasts and moulds) and the product appearance for a period of about 30 days. Results suggest that ethanol was the most efficient treatment, as it successfully reduced the cell load of the spoilage microorganisms without affecting respiration of the packed food or its appearance. Differences between the investigated biodegradable films were not statistically significant.
Research Interests:
Oak barrels are commonly used in the aging of wines and spirits because of their positive effects on the product. In recent years the addition of oak chips has been used to introduce desirable wood aromas and flavours into wines. In this... more
Oak barrels are commonly used in the aging of wines and spirits because of their positive effects on the product. In recent years the addition of oak chips has been used to introduce desirable wood aromas and flavours into wines. In this study, oak chips in saline solution or laboratory medium were inoculated with Penicillium purpurogenum, Aureobasidium pullulans, Phialemonium obovatum, Phanerochaete chrysosporium and a combination of Ph. chrysosporium and A. pullulans. After 12 weeks of incubation, oak chips (2 g L(-1)) were macerated in a red wine for 17 days. Gas chromatography/mass spectrometry and high-performance liquid chromatography were used to evaluate 14 compounds, namely furfural, furfuryl alcohol, guaiacol, syringol, cis-β-methyl-γ-octalactone, 2-phenylethanol, 4-vinylguaiacol, benzyl alcohol, 2,3-butanediol, γ-butyrolactone, benzaldehyde, 4-ethylguaiacol, gallic acid and ellagic acid. The microfungal treatments increased the concentration of some components. In particular, P. purpurogenum resulted in a significant improvement in the levels of guaiacol, furfural, syringol, furfuryl alcohol and 2-phenylethanol. Penicillium purpurogenum and Ph. chrysosporium showed a constant trend (enrichment of furfural and benzaldehyde) independent to some extent of the medium used for chip treatment.
Research Interests:
Research Interests: Engineering, Chemistry, Food Science, Medicine, Wine, and 12 moreFood Analysis, Wood, Quercus, The, Penicillium, Inoculation, Eugenol, Vanillin, Lactones, Pyrogallol, Guaiacol, and food handling
Research Interests:
Thymol and carvacrol are some of the most important and used components of Essential oils (EOs); they are widely studied, and there are much data available in the literature. Their Minimal Inhibitory Concentration (MIC) values found in... more
Thymol and carvacrol are some of the most important and used components of Essential oils (EOs); they are widely studied, and there are much data available in the literature. Their Minimal Inhibitory Concentration (MIC) values found in the literature from 2005 to present were used to assess the bioactivity toward yeasts, molds, Gram-positive bacteria, and Gram-negative bacteria, as well as on some bacterial species/serotypes (Salmonella sp., Escherichia coli, E. coli O157:H7, lactic acid bacteria, Listeria monocytogenes, Staphylococcus aureus, S. epidermidis, etc.) to find possible common trends or differences between the two compounds and among the tested species. The results were quite interesting and pointed out that there is a common range for the MIC of thymol and carvacrol for some bacterial species (150–400 mg/L), with some exceptions to this generalized statement. In addition, the statistics pointed out that bacteria could experience homogeneous (S. epidermidis, E. coli O157...
Research Interests:
The main goal of this research was to study the effect of an Ultrasound (US) treatment on biofilm formation of Lactiplantibacillus plantarum (strains c19 and DSM 1055), Bifidobacterium animalis subsp. lactis DSM 10140, Bifidobacterium... more
The main goal of this research was to study the effect of an Ultrasound (US) treatment on biofilm formation of Lactiplantibacillus plantarum (strains c19 and DSM 1055), Bifidobacterium animalis subsp. lactis DSM 10140, Bifidobacterium longum subsp. longum DSM 20219, and Bifidobacterium longum subsp. infantis DSM 20088. From a methodological point of view, each microorganism was treated through six US treatments, different for the power (10, 30, or 50% of the net power, 130 W), the duration (2, 6, or 10 min) and the application of pulses (0 or 10 s). After the treatment, a biofilm of the strains was let to form on glass slides and the concentration of sessile cells was analyzed for 16 days. Biofilms formed by untreated microorganisms were used as controls. As a first result, it was found that US significantly increased the concentration of sessile cells of B. longum subsp. infantis, while for some other strains US treatment could not affect the formation of biofilm while improving it...
Research Interests:
The main goal of this paper was to assess the ability of a combination of Candida boidinii and Bacillus pumilus to remove phenol in table olive processing water, as a function of some variables, like temperature, pH, a dilution of waste... more
The main goal of this paper was to assess the ability of a combination of Candida boidinii and Bacillus pumilus to remove phenol in table olive processing water, as a function of some variables, like temperature, pH, a dilution of waste and the order of inoculation of the two microorganisms. At this purpose C. boidinii and B. pumilus were sequentially inoculated in two types of table olive processing water (fresh wastewater, FTOPW and wastewater stored for 3 months-aged wastewater, ATOPW). pH (6 and 9), temperature (10 and 35 °C) and dilution ratio (0, 1:1) were combined through a 2k fractional design. Data were modeled using two different approaches: Multifactorial Analysis of Variance (MANOVA) and multiple regression. A higher removal yield was achieved by inoculating B. pumilus prior to the yeast (192 vs. 127 mg/L); moreover, an increased efficiency was gained at 35 °C (mean removal of 200 mg/L). The use of two statistic approach suggested a different weight of variables; tempera...
Research Interests:
Many scientific studies reveal a significant connection between human intestinal microbiota, eating habits, and the development of chronic-degenerative diseases; therefore, alterations in the composition and function of the microbiota may... more
Many scientific studies reveal a significant connection between human intestinal microbiota, eating habits, and the development of chronic-degenerative diseases; therefore, alterations in the composition and function of the microbiota may be accompanied by different chronic inflammatory mechanisms. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), in which autoreactive immune cells attack the myelin sheaths of the neurons. The purpose of this paper was to describe the main changes that occur in the gut microbiota of MS patients, with a focus on both microbiota and its implications for health and disease, as well as the variables that influence it. Another point stressed by this paper is the role of microbiota as a triggering factor to modulate the responses of the innate and adaptive immune systems, both in the intestine and in the brain. In addition, a comprehensive overview of the taxa modified by the disease is presented, with s...
Research Interests:
Probiotics are gradually gaining importance in the field of psychiatry in the form of psychobiotics. Psychobiotics’ studies examine the existing relationship between gut microbiota and mental phenomena; the intake of certain strains of... more
Probiotics are gradually gaining importance in the field of psychiatry in the form of psychobiotics. Psychobiotics’ studies examine the existing relationship between gut microbiota and mental phenomena; the intake of certain strains of probiotics, such as Bifidobacterium and Lactobacillus, for example, allow the gut microbial system to be modified in order to provide benefits at the psychic, immune, hormonal, and mental levels. Those who suffer from forms of depression, anxiety disorders, chronic stress, low mood, but also people who do not suffer from such disorders, can therefore benefit from the use of psychobiotics. Thanks to probiotics, neurochemicals can in fact be produced within the gut microbiota and interact with receptors of the enteric nervous system that innervate the entire gastrointestinal tract. Once they enter the portal circulation, these substances go on to influence components of the nervous system and ultimately the brain, through what is called the gut–brain ax...
Research Interests:
Gut microbiota plays a significant role in the maintenance of physiological homeostasis, contributing to human health. Nevertheless, some factors (sex, age, lifestyle, physical activity, drug-based therapies, diet, etc.) affect its... more
Gut microbiota plays a significant role in the maintenance of physiological homeostasis, contributing to human health. Nevertheless, some factors (sex, age, lifestyle, physical activity, drug-based therapies, diet, etc.) affect its composition and functionality, linked to pathologies and immunological diseases. Concerning diet, it interacts with microorganisms, leading to beneficial or detrimental outcomes for the health of host. On the other hand, physical activity is known to be useful for preventing and, sometimes, treating several diseases of cardiovascular, neuroendocrine, respiratory, and muscular systems. This paper focuses on diet and physical activity presenting the current knowledge about how different diets (Western, ketogenic, vegan, gluten free, Mediterranean) as well as different types of exercise (intensive, endurance, aerobic) could shape gut microbiota.
Research Interests:
Predictive microbiology (PM) is an essential element in food microbiology; its aims are the determination of the responses of a given microorganism combining mathematical models with experimental data under certain environmental... more
Predictive microbiology (PM) is an essential element in food microbiology; its aims are the determination of the responses of a given microorganism combining mathematical models with experimental data under certain environmental conditions, and the simulation a priori of the growth/inactivation of a population based on the known traits of a food matrix. Today, a great variety of models exist to describe the behaviour of several pathogenic and spoilage microorganisms in foods. In winemaking, many mathematical models have been used for monitoring yeast growth in alcoholic fermentation as well as to predict the risk of contamination of grapes and grape products by mycotoxin producing fungi over the last years, but the potentialities of PM in wine microbiology are underestimated. Thus, the goals of this review are to show some applications and perspectives in the following fields: (1) kinetics of alcoholic and malolactic fermentation; (2) models and approaches for yeasts and bacteria gr...
Research Interests:
Research Interests:
Research Interests:
Alicyclobacillus acidoterrestris is a spoiling microorganism regarded as one of the most important causes of spoilage of fruit juices and acidic products. In this paper, four strains of A. acidoterrestris (type strain-DSM 3922; two wild... more
Alicyclobacillus acidoterrestris is a spoiling microorganism regarded as one of the most important causes of spoilage of fruit juices and acidic products. In this paper, four strains of A. acidoterrestris (type strain-DSM 3922; two wild strains isolated from soil-C8 and C24; wild strain isolated from a spoiled pear juice CB1) were treated through natural extracts/active compounds from essential oils (EOs), and physical treatments were used to assess their susceptibility and the presence of sublethal injury. The characterization of damage was also performed. The results suggest that it is possible to control A. acidoterrestris through alternative approaches, although the effect relied upon the age of spores. In addition to the mere antimicrobial effect, some treatments could cause a sublethal injury on spores. Lemon extract was the most effective treatment for both the antimicrobial effect and the sublethal injury, as evidenced by the release of proteins, and calcium dipicolinate [di...
Research Interests:
The present research was aimed to the optimization of the production of a fish fermented salami-like product using autochthonous Lactiplantibacillus plantarum starters. The activity was performed through two phases: (1) Optimization of... more
The present research was aimed to the optimization of the production of a fish fermented salami-like product using autochthonous Lactiplantibacillus plantarum starters. The activity was performed through two phases: (1) Optimization of fermented fish product composition by using a 2k-p Fractional Factorial Design: the variables tested were nitrites (0–150 ppm), salt (2.5–7.5%), sucrose (0–4%), white pepper (0–0.10%), and fermentation temperature (10–30°C); (2) Product realization and evaluation of its microbiological profile [aerobic microbiota (APC), Pseudomonadaceae (PSE), Enterobacteriaceae (E), and lactic acid bacteria (LAB) populations], chemico-physical parameters (pH and aw), and sensorial quality (odor, texture, color, and overall acceptability) during its storage at 4°C for 21 days. In the first step, the fish pulp was mixed with the appropriate amounts of ingredients, according to the experimental design; each batch was individually inoculated with the studied starter (L. ...
Research Interests:
This research was aimed at studying the effects of low intensity ultrasound (US) on some technological and functional properties of eight strains of Saccharomyces cerevisiae; namely, growth patterns (growth at 2–5% of NaCl or at 37 °C),... more
This research was aimed at studying the effects of low intensity ultrasound (US) on some technological and functional properties of eight strains of Saccharomyces cerevisiae; namely, growth patterns (growth at 2–5% of NaCl or at 37 °C), autoaggregation and tolerance to simulated gastrointestinal conditions were evaluated. A US treatment was applied at 20% of net power (130 W) by a modulating duration (2–10 min) and pulses (2–10 s). The viable count (4.81–6.33 log CFU/mL) was not affected by US, while in terms of technological traits the effect was strain specific; in particular, for some strains a positive effect of US was found with a significant growth enhancement (growth index > 120%). The treatment was also able to increase the autoaggregation of some strains, thus suggesting that US could represent a promising way to treat and select nonconventional functional yeasts for food applications.
Research Interests:
The inoculation of probiotics in beverages (probiotication) requires special technologies, as probiotic microorganisms can experience stress during food processing (acid, cold, drying, starvation, oxidative, and osmotic stresses) and... more
The inoculation of probiotics in beverages (probiotication) requires special technologies, as probiotic microorganisms can experience stress during food processing (acid, cold, drying, starvation, oxidative, and osmotic stresses) and gastrointestinal transit. Survival to harsh conditions is an essential prerequisite for probiotic bacteria before reaching the target site where they can exert their health promoting effects, but several probiotics show a poor resistance to technological processes, limiting their use to a restricted number of food products. Therefore, this paper offers a short overview of the ways to improve bacterial resistance: by inducing a phenotypic modification (adaptation) or by surrounding bacteria through a physical protection (microencapsulation). A second topic briefly addressed is genetic manipulation, while the last section addresses the control of metabolism by attenuation through physical treatments to design new kinds of food.
Research Interests:
This paper proposes the industrial validation of a functional strain of Lactobacillus plantarum (strain 178). First, acidification in a meat model medium and bioactivity towards Staphylococcus aureus, Salmonella sp., Listeria... more
This paper proposes the industrial validation of a functional strain of Lactobacillus plantarum (strain 178). First, acidification in a meat model medium and bioactivity towards Staphylococcus aureus, Salmonella sp., Listeria monocytogenes, and Escherichia coli were assessed; the performances of Lb. plantarum 178 were compared to those of a commercial Lb. sakei and a probiotic Lb. casei. Lb. plantarum 178 inhibited the pathogens and experienced a higher acidification at 15 °C. Lb. casei and Lb. plantarum were used for an industrial fermentation of traditional Italian sausages. The strains assured the correct course of fermentation and inhibited pathogens and enterobacteria. This study represents the scaling up and the validation of a promising strain at industrial level and shows the possibility of performing the fermentation of traditional Italian sausage through functional starter cultures, combining the benefit of a controlled fermentation and possible health benefits.
Research Interests:
ABSTRACTSome nonthermal technologies have gained special interest as alternative approaches to thermal treatments. High pressure homogenization (HPH) and ultrasound (US) are two of the most promising approaches. They rely upon two... more
ABSTRACTSome nonthermal technologies have gained special interest as alternative approaches to thermal treatments. High pressure homogenization (HPH) and ultrasound (US) are two of the most promising approaches. They rely upon two different modes of action, although they share some mechanisms or ways of actions (mechanic burden against cells, cavitation and micronization, primary targets being the cell wall and the membrane, temperature and pressure playing important roles for their antimicrobial potential, and their effect on cells can be either positive or negative). HPH is generally used in milk and dairy products to break lipid micelles, whereas US is used for mixing and/or to obtain active compounds of food. HPH and US have been tested on pathogens and spoilers with different effects; thus, the main goal of this article is to describe how US and HPH act on biological systems, with a focus on antimicrobial activity, mode of action, positive effects, and equipment. The article is...
Research Interests:
Research Interests:
SummaryFood contamination by toxins (both mycotoxins and bacterial toxins) represents a great challenge for their implications on health. Toxins could be removed during production, but many times, they enter the gut and act on the host.... more
SummaryFood contamination by toxins (both mycotoxins and bacterial toxins) represents a great challenge for their implications on health. Toxins could be removed during production, but many times, they enter the gut and act on the host. To some extents, a benefit of probiotics could be the removal/neutralisation of harmful compounds in the gut with an indirect health effect on the host. Some authors addressed the ability of yeasts and bacteria to remove mycotoxins and other toxins; however, to the best of our knowledge, there is not an overview on how and when mycotoxins and some other bacterial toxins (like cyanotoxins) can be removed by probiotics into the gut. Therefore, this topic is addressed in this paper. The manuscript is organised with an initial overview of the literature about probiotics, mycotoxins and cyanotoxins followed by a section on the ability of probiotics to remove toxins in vitro and in vivo.
Research Interests:
In recent years, there has been a growing interest in the design of novel nonthermal processing systems that minimally modify sensory, nutritional, and functional properties of fruit and vegetable juices and beverages. The benefits of... more
In recent years, there has been a growing interest in the design of novel nonthermal processing systems that minimally modify sensory, nutritional, and functional properties of fruit and vegetable juices and beverages. The benefits of nonthermal treatments are strongly dependent on the food matrix. Thus, an understanding of the effects that these technologies exert on the properties of juices and beverages is important to design and optimize technological parameters to produce value‐added products. This review covers research on nonthermal electrical treatments, high pressure processing, ultrasound, radiation processing, inert gas treatments, cold plasma, and membrane processing. Advances towards optimization of processing conditions, and combined technologies approaches have been also extensively reviewed. This information could be useful to: (1) manage processing systems and optimize resources; (2) preserve nutritional value and organoleptic properties, and (3) provide processing ...
Research Interests:
This paper proposes bio-preservation as a tool to assure quality and safety of Spanish-style table olives cv. Bella di Cerignola. 5BG was inoculated in ready to sell olives packaged in an industrial plant by using a half-volume brine (4%... more
This paper proposes bio-preservation as a tool to assure quality and safety of Spanish-style table olives cv. Bella di Cerignola. 5BG was inoculated in ready to sell olives packaged in an industrial plant by using a half-volume brine (4% NaCl; 2% sucrose). The samples were stored at 4°C. The survival of the inoculated strain, the microbiological quality, the sensory scores and the survival of a strain of inoculated in brines were evaluated. The persistence of the bio-preserving culture was confirmed on olives (≥6.5 Log CFU/g) and in brine (≥7 Log CFU/ml). Bio-preserved olives (SET1) showed a better sensory profile than chemically acidified control olives (SET2) and the texture was the real discriminative parameter among samples. Bio-preserved olives recorded better scores during storage because of their ability to retain good hardness, crunchiness, and fibrousness without cracks. The inoculation of positively acted on the safety of olives, as the -value of was reduced from 40 (SET2)...
Research Interests:
A response surface model was developed to describe the effects of temperature (35 to 55°C), pH (3.5 to 5.5), and water activity (aw, 0.960 to 0.992) on germination of Alicyclobacillus acidoterrestris spores. Germination and growth or... more
A response surface model was developed to describe the effects of temperature (35 to 55°C), pH (3.5 to 5.5), and water activity (aw, 0.960 to 0.992) on germination of Alicyclobacillus acidoterrestris spores. Germination and growth or viability loss depended, to varying extents, on the interactions among the independent variables and the complexity of the medium. In particular, maximum growth was achieved at temperatures between 35 and 42°C and at pH values from 3.5 to 4.5. The model was validated against data not used in its development. Bias factors of 0.999 and 0.817 for 2- and 7-day models, respectively, were obtained, indicating that the models were “fail safe.” Results indicated that the model provided reliable predictions of growth of A. acidoterrestris spores.
Research Interests:
Yeasts are eukaryotic organisms that are included in a group of organisms called “fungi,” which also includes molds and mushrooms. Yeasts can have both positive and negative effects on fermented products consumed by humans and animals.... more
Yeasts are eukaryotic organisms that are included in a group of organisms called “fungi,” which also includes molds and mushrooms. Yeasts can have both positive and negative effects on fermented products consumed by humans and animals. Yeasts are used as starter cultures in cheeses and bread, as well as wine, beer, and other alcoholic fermentation products, but they can also initiate spoilage in foods, such as yoghurt, fruit juice, salads, and mayonnaise. A group of authors have published a list of yeasts that are frequently associated with the spoilage of foods and beverages: to these lists of “dangerous” spoiling yeasts four other yeast species have also been added, which were the members of the “second-division spoiling yeasts.” The ability of some yeasts to survive in harsh conditions makes them potent food spoilage organisms responsible for large economic losses of some food products.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The main topic of this research was to select some suitable functional starter cultures for cereal-based food or beverages. This aim was achieved through a step-by step approach focused on the technological characterization, as well as on... more
The main topic of this research was to select some suitable functional starter cultures for cereal-based food or beverages. This aim was achieved through a step-by step approach focused on the technological characterization, as well as on the evaluation of the probiotic traits of yeasts; the technological characterization relied on the assessment of enzymatic activities (catalase, urease, β-glucosidase), growth under various conditions (pH, temperature, addition of salt, lactic and acetic acids) and leavening ability. The results of this step were used as input data for a Principal Component Analysis; thus, the most technologically relevant 18 isolates underwent a second selection for their probiotic traits (survival at pH 2.5 and with bile salts added, antibiotic resistance, antimicrobial activity towards foodborne pathogens, hydrophobic properties and biofilm production) and were identified through genotyping. Two isolates (Saccharomyces cerevisiae strain 2 and S. cerevisiae strain 4) were selected and analyzed in the last step for the simulation of the gastric transit; these isolates showed a trend similar to S. cerevisiae var. boulardii ATCC MYA-796, a commercial probiotic yeast used as control.
Research Interests:
Research Interests:
Five yeast strains (four wild Saccharomyces cerevisiae strains and a collection strain-S. cerevisiae var. boulardii) were encapsulated in alginate beads. Encapsulation yield was at least 60% (100% for some strains) and yeasts survived in... more
Five yeast strains (four wild Saccharomyces cerevisiae strains and a collection strain-S. cerevisiae var. boulardii) were encapsulated in alginate beads. Encapsulation yield was at least 60% (100% for some strains) and yeasts survived in beads for 30 days at 4 °C, although the viability was strongly affected during storage at 25 °C (3 log reduction after 7 days). The kinetic of cell release was studied under static and dynamic conditions, but the results suggest that, after 48 h, beads contained a high number of yeasts. Thus, their use is advisable as re-usable carriers of starter cultures or as a vehicle of probiotics into the gut. Finally, some functional properties (biofilm formation, hydrophobicity, auto-aggregation, survival during the transit into the gut) were evaluated on yeasts released by beads to assess if microencapsulation could negatively affect these traits. The results showed that yeasts’ entrapment in beads did not affect probiotic properties.
Research Interests:
Research Interests:
ABSTRACT This paper reports on the use of ultrasound, combined with either Na–benzoate or citrus extract, to inhibit Fusarium oxysporum in orange juice. In a preliminary step, spores of F. oxysporum were inoculated into distilled water... more
ABSTRACT This paper reports on the use of ultrasound, combined with either Na–benzoate or citrus extract, to inhibit Fusarium oxysporum in orange juice. In a preliminary step, spores of F. oxysporum were inoculated into distilled water and treated through an ultrasound equipment; the treatments differed for acoustic energy (the maximum power attained by the equipment was 130-W frequency, 20 kHz; the energy was reported as percentage of the maximum power, from 40% to 100%), pulse (2 and 10 s), and duration of the treatment (from 2 to 10 min).Then, the treatment was validated in orange juice, in combination with either benzoate (0–100 ppm) or citrus extract (0–1,800 ppm), using a mixture design called centroid. The most significant effects were time, as single term, and the interaction energy/time/pulse; concerning the possibility of extending juice shelf life, the use of benzoate and citrus extract controlled F. oxysporum growth in orange juice and achieved a reduction of 5 log cfu/ml for at least 14 days.
Research Interests:
The metabiotic effects of Fusarium proliferatum, F. avenaceum, and F. oxysporum on Escherichia coli O157:H7 and Listeria monocytogenes in fresh tomatoes were investigated. Tomatoes were preinoculated with the molds and incubated at 15... more
The metabiotic effects of Fusarium proliferatum, F. avenaceum, and F. oxysporum on Escherichia coli O157:H7 and Listeria monocytogenes in fresh tomatoes were investigated. Tomatoes were preinoculated with the molds and incubated at 15 degrees C for 7 days; then they were inoculated separately with the pathogens, packaged in air and modified atmosphere (5% O2, 30% CO2, and 65% N2), and stored at 4, 8, and 12 degrees C for 9 days. The cell loads of pathogens and lactic acid bacteria and the pH were evaluated periodically. The data were modeled through some different mathematical models to assess the shoulder length, i.e., the time before the beginning of the exponential death phase, the 1-log reduction time (s), and the pathogen death time (deltastand). The preinoculation of tomatoes with the molds enhanced the survival of E. coli O157:H7 by prolonging shoulder length and 8 parameters; this effect, however, was not observed for L. monocytogenes. pH values did not undergo significant changes within the storage time, and the lactic acid bacteria increased from 5 to 7 log CFU/g, without significant differences among the storage temperatures or the packaging atmospheres. The results of this research showed that the use of fresh tomatoes colonized by fusaria (even if the contamination is not visible) could increase significantly the risk of outbreaks due to some pathogens that could be on the surface of fruits and vegetables as a result of cross-contamination at home or incorrect postharvest operations.
Research Interests:
Essential oils (EOs) are liquid preparations, produced from plant materials. Although EOs showed a promising bioactivity in vitro, they could interact in foods with some components (fats, proteins, carbohydrates) and pH, thus many authors... more
Essential oils (EOs) are liquid preparations, produced from plant materials. Although EOs showed a promising bioactivity in vitro, they could interact in foods with some components (fats, proteins, carbohydrates) and pH, thus many authors have reported that a significant effect of EOs toward spoiling and pathogenic microorganisms could be achieved in vivo by using higher amounts of oils. Different methods can be used to assess the bioactivity of EOs (disk diffusion and agar or broth dilution methods); however, there is not a standardized test and researchers propose and use different protocols (evaluating the Minimal Inhibitory Concentration, studying the survival curves, analysis through the scanning electron microscopy, etc.). Thereafter, the scope of this review is a focus on interactions of EOs with proteins, carbohydrates, oils, NaCl, and pH, as well as a brief description on the different protocols to assess their bioactivity both under in vivo and in vitro conditions.
Research Interests:
The role of lactic acid bacteria for a correct course of fermentation of table olives has been extensively reviewed and it is a common idea that the inoculum of selected strains could exert a strong benefit for product quality; however,... more
The role of lactic acid bacteria for a correct course of fermentation of table olives has been extensively reviewed and it is a common idea that the inoculum of selected strains could exert a strong benefit for product quality; however, the basic assumption of this research is that a not-correct preparation of starter could affect its performances in brines and delay the benefit of a starter inoculum. Thus, some selected strains of LAB (lactic acid bacteria) and yeasts were inoculated into brines of Bella di Cerignola olives (Spanish style), as a single starter (LAB or yeasts) or a combined preparation (LAB + yeasts) and compared to a natural fermentation, focusing on the performances of the process (acidification, production of lactic acid) and trying to verify the basic assumption. LAB and yeasts were grown in the opportune lab media and then directly inoculated in brine after the lye treatment. LAB exerts a kind of benefit (increased content of lactic acid) only for 2 - 3 weeks; then, the inoculated samples behave in the same way as not-inoculated ones. Thus, this research underlined that a starter culture, not prepared in the correct way, could not be useful to guide the fermentation.