List of published practice abstracts

Practice abstract: The use of a specific glutathione-rich inactivated yeast to protect organic Catarratto grape must and wine from oxidation in the pre-fermentative phase

By Viola, E., Naselli, V., Prestianni, R., Matraxia, M., Pirrone, A., Craparo, V., … & Alfonzo, A. (2024). The use of a specific glutathione-rich inactivated yeast to protect organic Catarratto grape must and wine from oxidation in the pre-fermentative phase. Food Bioscience, 61, 104656. 

Summary

This study aimed to investigate the effects of using a specific glutathione-rich inactivated yeast (GIY) during the pre-fermentative stages of winemaking. The antioxidant properties of GIY were evaluated both alone and in combination with a selected strain of Metschnikowia pulcherrima, at various grape pressing stages. The assessment included measuring soluble oxygen levels and color browning in the musts. Additionally, the impact of different oenological protocols on the final aromatic profile of the wines was assessed through volatile organic compounds (VOCs) and sensory analysis. The results showed that inoculating M. pulcherrima during the pre-pressing phase, followed by GIY addition during the post-pressing stage, effectively reduced O₂ uptake (1.49 mg/L) and minimized browning (0.093 OD at 420 nm) during the pre-fermentative phase. Furthermore, the protocol involving GIY addition during pressing resulted in higher concentrations of specific compounds associated with fruity and floral aromas, such as ethyl octanoate (26.03 mg/L) and ethyl decanoate (26.87 mg/L). Sensory evaluations confirmed that all treatments had no off-odours or off-flavours, but the M. pulcherrima and GIY combination received the highest scores for smoothness and colour attributes. In conclusion, GIY treatments offer a promising alternative to enhance wine colour and mitigate oxidation effects, potentially reducing the reliance SO₂ in wine production.

Read more:  https://doi.org/10.1016/j.fbio.2024.104656

Practice abstract: Oenological Capabilities of Yeasts Isolated from High-Sugar Matrices (Manna and Honey) as Potential Starters and Co-Starters for Winemaking

By Craparo, V., Viola, E., Vella, A., Prestianni, R., Pirrone, A., Naselli, V., … & Alfonzo, A. (2024). Oenological Capabilities of Yeasts Isolated from High-Sugar Matrices (Manna and Honey) as Potential Starters and Co-Starters for Winemaking. Beverages, 10(3), 48. 

Summary

Non-Saccharomyces yeasts have recently garnered significant interest in oenology. When co-inoculated with Saccharomyces cerevisiae, they contribute to the improvement of wine quality from a sensory point of view. In the present study, a group of yeasts previously isolated from manna and honey by-products were subjected to a genotypic identification. The D1/D2 variable domains of the 26-sRNA gene and the ITS region of the 5.8S gene were sequenced. Additionally, a differentiation of strains was carried out by RAPD-PCR. All strains underwent in vitro screening. Subsequently, a micro-vinification experiment was conducted, focusing on strains with favourable technological characteristics: Lachancea thermotolerans, Starmerella lactis-condensi, and Candida oleophila. These strains were sequentially inoculated alongside a control strain of Saccharomyces cerevisiae. Technological screening revealed that some strains exhibited limited H₂S production, ethanol tolerance (up to 8% v/v), resistance to potassium metabisulphite (200 mg/L), osmotic stress tolerance (up to 320 g/L of glucose), and copper resistance (on average 5 mM). The findings from this study can guide the selection of new starters and co-starters for regional wine production.

Read more: https://doi.org/10.3390/beverages10030048

Practice abstract: Co-inoculation approach combining lactic acid bacteria and yeasts to enhance the production of Nocellara del Belice green split table olives

By Alongi, D., Pirrone, A., Naselli, V., Prestianni, R., Monte, M., Gaglio, R., … & Francesca, N. (2024). Co-inoculation approach combining lactic acid bacteria and yeasts to enhance the production of Nocellara del Belice green split table olives. Food Bioscience, 61, 104816. 

Summary

Table olives are among the most popular fermented foods in the Mediterranean area. In Sicily, split green table olives are produced on a small scale and are traditionally used as an ingredient in various recipes. In order to improve and standardise the production of Nocellara del Belice split table olives, experimental productions inoculated with a commercial LAB strain and two previously selected yeast strains were carried out. The experimental plan included the production of three experimental batches (SO, split olives): SO1, control production inoculated with the commercial strain Lactiplantibacillus pentosus OM13; SO2, L. pentosus OM13 was co-inoculated with Candida boidinii LC1; SO3, L. pentosus OM13 in co-inoculum with C. norvegica OC10. Throughout the 90-day fermentation period, pH, salinity, and microbiological populations were closely monitored. At the conclusion of fermentation, the olives were assessed for colour, pulp hardness, volatile organic compounds, and sensory characteristics. During the process, the inoculated lactobacilli and yeast strains became the dominant populations, reaching levels above 6 Log CFU/mL and dominance percentages exceeding 80%. In the in the co-inoculated trials, brine acidification achieved pH values below 4.5 after 75 days, compared to the control trial, which reached this level after 21 days. The co-inoculation approach effectively limited the growth of undesirable microorganisms, resulting in firmer pulp. This combination of inocula also allowed for aromatic differentiation between the trials. Sensory analysis revealed differences in texture, flavour, and overall appreciation, with no unpleasant odours or tastes detected.

Read more:  https://doi.org/10.1016/j.fbio.2024.104816

Practice abstract: Exploring the Addition of Mango Peel in Functional Semolina Sourdough Bread Production for Sustainable Bio-Reuse

By Chulibert, M. E., Roppolo, P., Buzzanca, C., Alfonzo, A., Viola, E., Sciurba, L., … & Settanni, L. (2024). Exploring the Addition of Mango Peel in Functional Semolina Sourdough Bread Production for Sustainable Bio-Reuse. Antioxidants, 13(11), 1278.

Summary

Mango, a tropical fruit celebrated for its delightful fragrance and high nutritional value, generates significant waste during processing, with approximately 35–60% of the fruit being discarded. However, this waste contains valuable components, such as fibre, carotenoids, polyphenols, and other bioactive compounds. In an effort to repurpose mango peel, this study dehydrated it to create mango peel powder (MPP), which was then incorporated into sourdough bread to produce functional breads with enhanced nutritional value. Semolina was replaced with MPP at levels of 5% (MPP-5) and 10% (MPP-10) (w/w). After dehydration, the mango peel had a yield of 22%, and the procedure used did not cause any organoleptic changes. The bread fermentation process was conducted at 30 °C for 8 h. During dough fermentation, the pH was monitored, showing a value of 4.14 ± 0.02 in the MPP-10 dough. Overall, the MPP-10 bread received a higher score (6.51) than the control (CTR) bread (5.6) and the MPP-5 bread (6.11). The total phenolic content of the fortified breads ranged from 44.760 to 98.931 mg gallic acid equivalents (GAE)/g, and the antiradical activity ranged from 15.213 to 29.461 mmol trolox equivalent antioxidant activity (TEAC)/100 g, depending on the percentage of enrichment.

Read more: https://doi.org/10.3390/antiox13111278

Practice abstract: Exploring the diversity of native Lachancea thermotolerans strains isolated by sugary extracts from manna ash to modulate the flavour of sour beers

By Pirrone, A., Naselli, V., Prestianni, R., Gugino, I. M., Viola, E., Amato, F., … & Alfonzo, A. (2024). Exploring the diversity of native Lachancea thermotolerans strains isolated by sugary extracts from manna ash to modulate the flavour of sour beers. Food Research International, 115328. 

Summary

The craft beer industry is becoming increasingly interested in the production of innovative beers. A novel approach, designated as “primary souring,” employs diverse yeast species, including Lachancea thermotolerans, to produce sour beers. Furthermore, there is a growing interest in utilising unconventional yeasts to produce beers with distinctive flavours. For the first time, yeast strains of L. thermotolerans, isolated from sugar extracts of manna ash, were evaluated for their ability to produce and improve the sensory properties of sour beers. In particular, five strains exhibited notable resistance to ethanol, sugar and hops, as well as comparable lactic acid production (ranging from 0.33 to 0.45 g/L). Experimental beers produced using MNF105 (T1) were perceived as the most “fruity”. This is the first study to examine the impact of this novel indigenous strain, derived from unconventional matrixes such as manna, on the organoleptic quality of craft sour beers. Consequently, elevated levels of ethyl decanoate, ethyl hexanoate, ethyl octanoate and ethyl nonanoate were found in T1 beer, exceeding the perception threshold. The ability of this strain to perform light bio-acidification is a valuable feature for the development of new brewing techniques, particularly for the creation of sour beers with balanced acidity and innovative flavours. The yeast L. thermotolerans MNF105, which is related to manna, has excellent technological properties and is a promising starter for beer production with the ability to light bio-acidify and modulate flavour.

Read more: https://doi.org/10.1016/j.foodres.2024.115328

Practice abstract: Replacing preservative E 252 with powdered dried sumac (Rhus coriaria L.) fruits in “Suino Nero dei Nebrodi” salamis: Effects on microbiological, physicochemical, and antioxidant properties

By Busetta, G., Garofalo, G., Ponte, M., Barbera, M., Alfonzo, A., Franciosi, E., … & Settanni, L. (2024). Replacing preservative E-252 with powdered dried sumac (Rhus coriaria) fruits in “Suino Nero dei Nebrodi” salamis: effects on microbiological, physicochemical, and antioxidant properties. Food Microbiology, 104684.

Summary

The aim of this study was to develop health-oriented fermented salamis by replacing synthetic preservative (E 252) with dried Sumac (Rhus coriaria) fruit powder (DSFP). The salamis were produced at an industrial scale using meat from the “Suino Nero dei Nebrodi” breed, without adding starter cultures. The experimental design included four different salami productions: CTR, control production without nitrate salt and DSFP; CMC, commercial control production with nitrate salt but without DSFP; EXP1, experimental production without nitrate salt but with DSFP; and EXP2, experimental production with both nitrate salt and DSFP. Plate counts showed that DSFP did not inhibit the growth of lactic acid bacteria (LAB), coagulase-negative staphylococci, and yeasts, all of which reached approximately 7.0 log CFU/g in 45 d ripened salamis. Except for the CTR production, Escherichia coli levels decreased to undetectable amounts at 30 d of ripening. Culture-independent methods identified 16 taxonomic groups, with LAB being the predominant group across all trials, comprising 46.05–81.81 % of relative abundance (RA) in 45 d ripened salamis. Physicochemical analysis indicated that adding DSFP increased antioxidant activity by nearly 30 % and reduced primary lipid oxidation to levels comparable to those achieved with nitrate salt. The addition of DSFP in CMC, EXP1, and EXP2 salamis resulted in an approximate 11 % increase in total terpene aromatic profiles. Sensory evaluation indicated that the addition of DSFP did not impact overall acceptability (p>0.05). Therefore, incorporating DSFP in fermented meat production offers a viable alternative to the use of synthetic preservatives.

Read more: https://doi.org/10.1016/j.fm.2024.104684

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