Saccharomyces cerevisiae and Hanseniaspora uvarum mixed starter cultures: Influence of microbial/physical interactions on wine characteristics

The growing trend in the wine industry is the revaluation of the role of non-Saccharomyces yeasts, promoting the use of these yeasts in association with Saccharomyces cerevisiae. Non-Saccharomyces yeasts contribute to improve wine complexity and organoleptic composition. However, the use of mixed starters needs to better understand the effect of the interaction between these species during alcoholic fermentation. The aim of this study is to evaluate the influence of mixed starter cultures, composed by combination of different S. cerevisiae and Hanseniaspora uvarum strains, on wine characteristics and to investigate the role of cell-to-cell contact on the metabolites produced during alcoholic fermentation. In the first step, three H. uvarum and two S. cerevisiae strains, previously selected, were tested during mixed fermentations in natural red grape must in order to evaluate yeast population dynamics during inoculated fermentation and influence of mixed starter cultures on wine quality. One selected mixed starter was tested in a double-compartment fermentor in order to compare mixed inoculations of S. cerevisiae/H. uvarum with and without physical separation. Our results revealed that physical contact between S. cerevisiae and H. uvarum affected the viability of H. uvarum strain, influencing also the metabolic behaviour of the strains. Although different researches are available on the role of cell-to-cell contact-mediated interactions on cell viability of the strains included in the mixed starter, to our knowledge, very few studies have evaluated the influence of cell-to-cell contact on the chemical characteristics of wine.

Exploitation of technological variability among wild non-Saccharomyces yeasts to select mixed starters for the production of low alcohol wines

Increase of the sugar content in grape must, and consequently, alcohol levels in wine are some of the principal problems affecting the winemaking industry. High alcohol content can compromise wine quality, creating sensory imbalances, as well as decreasing the perception of some flavors. The technological approaches proposed at this aim, although allowing achievement of the purpose, can determine negative influence on quality of wine. A promising strategy is based on the use of specific microorganisms, such as selected yeast strains, mainly non-Saccharomyces, able to convert grape must sugars towards secondary metabolites rather than ethanol. This study aims at screening of wild non-Saccharomyces strains in order to identify those suitable for the use in mixed starter for the production of wine with reduced alcohol content and, at the same time, with improved aromatic characteristics.

Use of Saccharomyces cerevisiae var. boulardii in co-fermentations with S. cerevisiae for the production of craft beers with potential healthy value-added

In recent years, the awareness of consumers about the impact of food on health is constantly increasing. A high amount of dietary antioxidant intake can be supplied by beverages widely consumed, such as wine, coffee, beer. Recently, an increase in the consumer interest was observed for beer, in consequence of the high phenolic antioxidants and low ethanol content present in this beverage. Among all beer types, in recent years, consumption of craft beers has gained popularity. Being an unpasteurized and unfiltered, craft beer is potentially a new vehicle for delivering health effects. While health benefits of lactic acid bacteria as probiotics are well known, few data are available on probiotic yeasts in fermented food. Therefore, this study was aimed to analyse the effect of integrating the well-known probiotic yeast strain of S. cerevisiae var. boulardii (S.b) in mixed cultures with S. cerevisiae strains for production of beers with increased healthy benefits. The probiotic strain of S.b was tested in mixed cultures with selected S. cerevisiae strains, during wort fermentation. As the viability during processing operations is one of the criteria for selecting suitable strains of probiotic microorganisms, the survival of probiotic yeast during the fermentation and the presence of highly viable cells at the end of fermentations were evaluated. In almost all the mixed fermentations, at the end of the process the probiotic yeast was predominant on S. cerevisiae strain, and the experimental beers contained a high number of viable cells of S.b strain (ranging between 8 × 10⁶ and 7.0 × 10⁷/mL). The analysis of experimental beers for the content of main volatile compounds showed that the inclusion of S.b strain in mixed starter did not affect negatively beer aroma. Moreover, the inclusion of S.b strain in mixed starters determined an increase in the antioxidant activity and polyphenols content, in comparison to beers from single starter fermentations, indicating the influence of S.b strain on these parameters. Some mixed starter cultures tested in this study resulted a very promising tool to increase the healthy quality of the product, such as the improve the antioxidant activity and polyphenols content of beer.

The influence of processing and preservation on the retention of health-promoting compounds in broccoli

In this work the effects of common household practices such as chilling, freezing, and cooking on vitamin C retention in broccoli (Marathon cv.), as well as their influence on the release of sulforaphane upon enzymatic hydrolysis of glucoraphanin by the endogenous enzyme myrosinase, were investigated. When chilled at 6 degrees C and 95% R.H. for 35 d, broccoli showed a vitamin C and sulforaphane loss of about 39% and 29%, respectively, while storage at -18 degrees C for 60 d resulted in similar losses, but mainly due to the blanching step. Boiling, steaming, microwaving, pressure-cooking, and the combined use of pressure and microwaves were the cooking methods investigated. Boiling and steaming caused significant vitamin C losses, 34% and 22%, respectively, while with the other treatments more than 90% retention was observed. Sulforaphane was no more detectable after boiling or steaming, while pressure/microwave cooking did not cause any significant loss. The quantitative distribution of these moieties in the florets and stems of fresh and chilled broccoli was also investigated.

Prevalence of obstructive sleep apnea syndrome in a cohort of 1,207 children of southern Italy

STUDY OBJECTIVE

To determine the prevalence of sleep-related breathing disturbances in a large cohort of school-aged and preschool-aged children of Southern Italy.

DESIGN AND SETTING

This cross-sectional prevalence study was designed in two phases: a screening phase aimed to identify symptomatic children from a cohort of 1,207 by a self-administered questionnaire, and an instrumental phase for the definition of sleep-related disorders.

PATIENTS AND METHODS

One thousand two hundred seven children were screened by a self-administered questionnaire. There were 612 female children (51%) and 595 male children (mean age, 7.3 years; range, 3 to 11 years). According to answers, children were classified in three groups: nonsnorers, occasional snorers, and habitual snorers. All habitual snoring children underwent a polysomnographic home evaluation, and those with an oxygen desaturation index > 2 were considered for nocturnal polygraphic monitoring (NPM). Children with an apnea/hypopnea index > 3 received a diagnosis of obstructive sleep apnea syndrome (OSAS).

RESULTS

A total of 895 questionnaires (74.2%) were returned and scored; 710 children (79.3%) were identified as nonsnorers, 141 children (15.8%) were identified as occasional snorers, and 44 children (4.9%) were identified as habitual snorers. The percentage of male children who were habitual snorers was higher than the percentage of female children who were habitual snorers (6.1% vs 3.7%, respectively; p < 0.09). OSAS was diagnosed in nine children by NPM.

CONCLUSION

The lower limit of prevalence of OSAS in childhood is 1% (95% confidence interval [CI], 0.8 to 1.2). If we add the five children who underwent adenoidectomy and/or tonsillectomy because of worsening clinical condition and the two children who were shown to have evidence of OSAS on domiciliary oximetry, then the prevalence is 1.8% (higher limit of prevalence; 95% CI, 1.6 to 2.0).

[Unusual cause of upper digestive hemorrhage: gastric lipoma. Report of a case]

Lipomas are benign tumors that are common in other sites but rare in the stomach. They are usually submucosal and, when symptomatic, are most often accompanied by gastrointestinal bleeding from ulceration of gastric mucosa overlying the mass or by symptoms of obstruction. A 55-year-old male with epigastric abdominal pain and upper gastrointestinal hemorrhage due to a gastric lipoma is presented; endoscopic and x-ray examinations revealed a submucosal tumor on the posterior wall of the gastric corpus, with ulceration in the mucosa covering it. Biopsies of the mass were nondiagnostic. The patient underwent a complete submucosal excision: the intraoperative histologic study established the diagnosis of gastric lipoma. The post operative period was uneventful. A review of the clinical, diagnostic and therapeutic aspects of this rare disease is reported.

[Esophageal achalasia: etiopathogenesis and possibility of treatment. Review of the literature and presentation of a clinical case]

The Authors report a particular case and make a careful international literature regarding etiopathogenesis and surgical treatment of oesophageal achalasia. First they consider the infection mechanisms as the cause of underlying motor disturbances of the oesophagus. Afterwards holding as parameters of reference for the evaluation of effectiveness of the therapy both the relief of dysphagia and the appearance of postoperative RGE, the various surgical options are then examined: pneumatic dilatation as opposed to surgery; the approach to thoracic and abdominal surgery and the possible assembly of a reflux protection mechanism. Finally, they propose the discussion on the challenge that the new technological systems have opened to the international surgical scene: the minimal-access surgery.

[Role of parenteral feeding in an operative protocol of total artificial nutrition]

Two cases of enterocutaneous fistula treated with mixed artificial diet (NP + NE) where enteral nutrition played the principal role in weaning from i.v. nutrition have been examined. Gradual transit was possible to normal diet, demonstrating ease of use and effectiveness of the nutritional contribution.