Patè Olive Cake: Possible Exploitation of a By-Product for Food Applications

Abstract

Patè Olive Cake (POC) is a new by-product derived from recently introduced new decanters in the olive oil production process. POC, is essentially composed of water, olive pulp and olive skin, and is rich in several valuable bioactive compounds. Moreover, it still contains about 8–12% residual olive oil. We characterized the main bioactive compounds in POC from black olives (cv. Leccino and Cellina di Nardò) and also verified the biotechnological aptitude of selected yeast and lactic acid bacteria from different sources, in transforming POC into a new fermented product. The strategy of sequential inoculum of Saccharomyces cerevisiae and Leuconostoc mesenteroides was successful in driving the fermentation process. In fermented POC total levels of phenols were slightly reduced when compared with a non-fermented sample nevertheless the content of the antioxidant hydroxytyrosol showed increased results. The total levels of triterpenic acids, carotenoids, and tocochromanols results were almost unchanged among the samples. Sensory notes were significantly improved after fermentation due to the increase of superior alcohols, esters, and acids. The results reported indicate a possible valorisation of this by-product for the preparation of food products enriched in valuable healthy compounds.

Bioactive Compounds and Stability of a Typical Italian Bakery Products “Taralli” Enriched with Fermented Olive Paste

“…Taralli obtained adding fermented OP contained several beneficial compounds, including polyphenols (1377 µg/g dried weight (DW) in taralli OPC and 1016 µg/g DW in taralli OPL), triterpenic acids (80.26 µg/g DW in taralli OPC and 80.92 µg/g DW in taralli OPL), typically absent in conventional taralli [13], isoprenoids, such as tocochromanols (30.27 µg/g DW in taralli OPC and 22.22 µg/g DW in taralli OPL) and carotenoids (1.17 µg/g DW in taralli OPC and 1.03 µg/g DW in t aralli OPL). In conventional taralli, the amount of these isoprenoids were lower.…”

“…Triterpenic acids, from olive by-products, such as maslinic and oleanoic acids, are mainly concentrated in the skin of drupes [11,13,32,33]. These compounds have received great attention because of their functional properties and biological importance [34].…”

“…The recently introduced multi-phase decanter technology for olive oil industrial extraction generates large quantities of a novel by-product (olive paste—OP) made up of the partially defatted wet drupe pulp containing very low or any traces of the kernel. Recently, Padalino et al [11], Cecchi et al [12], and Tufariello et al [13] reported that OP is an excellent natural source of unsaturated fatty acids and biologically active substances, including polyphenols, triterpenic acids, tocochromanols, and carotenoids.…”

“…The yeast strain Saccharomyces cerevisiae KI-30-1 and the strain Leuconostoc mesenteroides BC-T3-35 were selected among other candidates as the best performing microorganisms for their metabolic activities able to consume sugars, to produce important organic acids and volatile compounds, and to substantially modify phenolic profiles, by improving nutritional traits of the final product. Indeed, fermented OPs obtained from black olives of the cultivar Cellina di Nardò (OPC) and Leccino (OPL) were shown to represent a good source of bioactive compounds [13]. These strains were used for the first time as starters for pilot-scale fermentations of OP following a sequential inoculation approach, by mimicking the already described process in table olives fermentation, since yeasts are fundamental to modify the product and to prepare the subsequent lactic acid bacteria (LAB) fermentation [13,17,18].…”

“…Indeed, fermented OPs obtained from black olives of the cultivar Cellina di Nardò (OPC) and Leccino (OPL) were shown to represent a good source of bioactive compounds [13]. These strains were used for the first time as starters for pilot-scale fermentations of OP following a sequential inoculation approach, by mimicking the already described process in table olives fermentation, since yeasts are fundamental to modify the product and to prepare the subsequent lactic acid bacteria (LAB) fermentation [13,17,18].…”