Bruno Zanoni

Radio frequency treatment for postharvest disinfestation of dates

Radio Frequency Treatment for Postharvest Disinfestation of Dates Francesco Garbati Pegna*, Patrizia Sacchetti, Valentina Canuti, Serena Trapani, Carlo Bergesio, Antonio Belcari, Bruno Zanoni, Ferdinando Meggiolaro a GESAAF Department of Agricultural, Food and Forestry Systems Università degli Studi di Firenze, Italy b DISPAA Department of Agri-food Production and Environmental Sciences Università degli Studi di Firenze, Italy c Stalam S.p.A. Nove, Italy francesco.garbati@unifi.it

An effective HPLC-based approach for the evaluation of the content of total phenolic compounds transferred from olives to virgin olive oil during the olive milling process: Phenols transfer from olives into olive oils

BACKGROUND Several studies demonstrate a strong interest in learning more about phenolic transfer during oil extraction, with the main goal of increasing the phenolic concentration in olive oils. We aimed to propose and apply a new methodological approach for evaluating phenolic transfer from olives into oil during milling, based on the quantification of phenolic content in whole lyophilized fruits and the corresponding oils and considering the oil extraction yields. RESULTS We investigated the phenols transferred into the oil during olive milling in continuous extraction systems in Tuscany. In 2012, oils were extracted from cultivar Frantoio by a two-phase extraction system; in 2016, oils were extracted from cultivars Leccio del Corno and Arbequina by a three-phase extraction system. Results highlighted very low percentages of extracted phenols: up to 0.40% by the two-phase system and up to 0.19% by the three-phase system (0.08% for cultivar Arbequina and 0.19% for cultivar Leccio del Corno). CONCLUSION The usefulness of a simple and effective methodological approach for evaluating the extracted phenols was highlighted. Values of extracted phenols were up to 25 times lower than previous literature data. The proposed approach is applicable in all types of milling processes.

Enhanced utilisation of nonmarketable fish: physical, nutritional and sensory properties of ‘clean label’ fish burgers

Four ‘clean label’ formulations for fish burgers made with mechanically separated fish meat were characterised in sensory, textural and chemical terms. The formulations differed in the ratios of European sea bass to rainbow trout (50:50 and 30:70) and the ratios of fish to potato flakes (dry matter ratio, DMR: 2.5:1 and 1.5:1). The sensory profile was mainly influenced by DMR. Recipes with the higher DMR were positively correlated with sandy, dry and crusty attributes, salty taste and overall flavour. Soft texture was perceived for recipes with the lower DMR, although no differences in texture were detected by a texturometer. Lowering DMR increased ash and water content and decreased protein content, as expected. The results indicated that 100 g of burger provided more essential fatty acids than the recommended daily intake, irrespective of formulation. In conclusion, multiple factor analysis indicated that the main changes detected and perceived were due to DMR.

A Naturally Occurring Antioxidant Complex from Unripe Grapes: The Case of Sangiovese (v. Vitis vinifera)

The wine industry is well known for its production of a large amount of wastes and by-products. Among them, unripe grapes from thinning operations are an undervalued by-product. Grapes are an interesting source of natural antioxidants such as flavonoids, non-flavonoids and stilbenes. A potential strategy to exploit unripe grapes was investigated in this study. Juice from unripe grapes, v. Sangiovese, was obtained by an innovative technique of solid-liquid extraction without the use of solvents. The juice was dried by a spray-drying technique with the addition of arabic gum as support to obtain powder; juice and powder were characterized for antioxidant activity, phenolic concentration and profile. Phenolic acids, flavonols, flava-3-ols, procyanidins and resveratrol were detected in the juice and powder. The powder was used as anti-browning additive in white wine to test the potential re-use of the unripe grapes in the wine industry. The results indicated that the antioxidant complex from unripe grapes contributed to increasing the anti-browning capacity of white wine. Other applications, such as food and nutraceutical products development, can be considered for the antioxidant complex extracted from unripe grapes. In conclusion, the method proposed in this study may contribute to the exploitation of unripe grapes as a by-product of the winemaking process.

ENOLOGICAL ELIGIBILITY OF GRAPE CLONES BASED ON THE SIMCA METHOD: THE CASE OF THE SANGIOVESE CULTIVAR FROM TUSCANY

Sangiovese is the most widespread Italian red grape cultivar and it constitutes the basis of internationally known wines. It has a large diversity of clones whose performances vary with environmental conditions due to interaction with the weather and soil. In this study, the performance of grapes from seven Sangiovese clones was evaluated by analyzing grapes from four vineyards in the Chianti Classico Region in Tuscany over the ripening period. In order to assess the enological eligibility of grape clones, a grape reference model was developed using chemical parameters from commercially available Sangiovese wines, by performing a soft independent modeling of class analogy (SIMCA).

A Multivariate Methodological Approach to Relate Wine to Characteristics of Grape Composition: The Case of Typicality

Typicality is defined as the characteristics of a Protected Designation of Origin (PDO) wine related to a terroir. In the context of a PDO, a typicality assessment can be used to assess the global quality of a PDO wine. This study used a two-phase method to identify the distinctive characteristics of a PDO wine and then apply those findings to a case study of Chianti Montespertoli DOCG wine, where DOCG is the Italian acronym for PDO. A panel of wine professionals evaluated the typicality of a series of selected PDO wine samples, and a partial least squares (PLS) regression model was used to associate wine typicality and chemical composition. The model was used to predict wine typicality from the chemical composition of experimental wines (2009, 2010, and 2011 vintages) produced from grapes growing in the PDO area. Finally, regression coefficients of the PLS model were analyzed to select which grape chemical parameters were significant in describing the typicality of the wine. These highlight the most important factors to manage during winemaking to ensure the typicality of this wine.

Optimisation of olive paste expression : a study of variables affecting expression yield

The influence of some operating variables on olive paste expression rate and yield has been investigated using a laboratory expression apparatus. Results show that compaction rate and cake thickness have a primary importance in determining the extraction rate. Temperature has a limited effect. A pressure increase beyond 50.7 x 10 5 Pa is also of little benefit. Data on product variables show that the rigid solids play an important role and that the natural pit fragments content in olives is well below the optimal value. An extraction yield as high as 95% was obtained by adding pit fragments up to 40% by volume of olive paste. This value is noteworthy because it was obtained during the expression phase carried out at constant flow rate, while the expression phase carried out at constant pressure was not taken into account. Based on these results, an optimisation experimental design will be presented and validated in a following work.