Management of in-Amphora "Trebbiano Toscano" Wine Production: Selection of Indigenous Saccharomyces cerevisiae Strains and Influence on the Phenolic and Sensory Profile.

The use of earthenware amphorae in winemaking can give wines unique attributes enhancing their typicity. Therefore, in this study, spontaneous and inoculated in-amphora fermentations of Trebbiano Toscano grape must were monitored to assess the Saccharomyces cerevisiae strains occurring in each fermentation as well as the chemical characteristics of the wines. Strain typing via Interdelta analyses pointed out that the commercial starters did not dominate, showing 24% and 13% implantation percentages, and that 20 indigenous strains were present at different percentages, ranging from 2 to 20%, in inoculated and spontaneous fermentations. The assessment of the technical characteristics of the indigenous strains via fermentations at lab and pilot scale (20 L amphorae) and the sensory analysis of the experimental wines allowed for the selection of two indigenous strains to be used as starter cultures in comparison to a commercial strain in 300-L-amphorae vinifications in the cellar. The observed fermentative performances and sensory analysis of the experimental wines highlighted that one indigenous S. cerevisiae strain dominated the process and conferred distinctive sensory characteristics to the Trebbiano Toscano wine, demonstrating its effectiveness in managing the in-amphora fermentations. In addition, the results demonstrated the ability of amphorae to protect the polyphenolic compounds from oxidation during wine ageing. Indeed, the concentration of both hydroxycinnamic acids and flavonols decreased, with an average reduction of 30% and 14%, respectively, while hydroxybenzoic acids remained unchanged.

Effect of consumption of ancient grain bread leavened with sourdough or with baker's yeast on cardio-metabolic risk parameters: a dietary intervention trial.

The aim of this study was to compare the effect of consumption of ancient grain "Verna" bread obtained by two different leavening agents, sourdough (SD) and baker's yeast (BY), on inflammatory parameters and cardiometabolic risk factors. Seventeen clinically healthy subjects were included to consume SD or BY bread for 4 weeks each, and blood analyses were carried out. The consumption of "Verna" bread obtained with both leavening agents led to a significant improvement of LDL cholesterol. A reduction of -10.6% and -8.53% was observed after replacement with SD and BY bread, respectively. A significant increase in fasting blood glucose (+6%) was observed only after the intervention with BY bread. A 10.7% decrease of vascular endothelial growth factor was found after the SD bread replacement period. The consumption of "Verna" bread resulted significantly associated with an improvement in the cardiometabolic and inflammatory profile. However, only consumption of BY bread determined a significant increase in blood glucose levels.

Antioxidant and anti-inflammatory properties of sourdoughs containing selected Lactobacilli strains are retained in breads.

Sourdough fermentation influences several properties of leavened baked goods also because Lactic acid bacteria (LAB) and yeasts produce bioactive peptides with a positive effect on human health. In an early study, three Lactobacilli strains (L. farciminis H3 and A11 and L. sanfranciscensis I4) possessing different proteolytic activities were used to produce sourdoughs containing peptides equipped with anti-inflammatory and/or antioxidant properties. This work was aimed to assess whether these properties could be retained after cooking. The selected LABs were used to produce breads from which low molecular weight (LMW-) peptides were extracted. The results provide solid proofs of keeping both antioxidant and anti-inflammatory activities of peptides from cooked products. Sequences of LMW-peptides either from doughs and breads were determined by mass spectrometry: differences have been noticed in amino acidic composition and in sequences, however, all the strains produce peptides equipped with antioxidant and anti-inflammatory activities.

Effect of selected strains of lactobacilli on the antioxidant and anti-inflammatory properties of sourdough.

Sourdough fermentation of cereal foods is an excellent source of obtaining peptides due to the ability of lactic acid bacteria to activate cereal proteases and produce strain-specific peptidases. With the aim of identifying the lactic acid bacterial strains potentially most effective in producing bioactive peptides, 131 lactobacilli isolates from Italian sourdoughs, used in baking technology, have been screened for proteolytic and peptidase activity. Of these, 23 strains were selected and singly inoculated in liquid sourdoughs from which a Low Molecular Weight fraction containing peptides was obtained. Evaluation of the antioxidant and anti-inflammatory activities of the extracts was performed on cultured cells (RAW 264.7 murine macrophage, murine H-end endothelium cells and Human intestinal Caco-2 cells) by assaying Reactive Oxygen Species (ROS) content, NFkB/IkB expression level and Interleukin-1ß production. As a result, three lactobacilli strains showed a high antioxidant and anti-inflammatory ability enabling the development of model sourdoughs that will potentially increase the nutritional benefits of bread.