No abstract

Oil industry produces large volume of waste, which represents a disposal and a potential environmental pollution problem. Nevertheless, they are also promising sources of compounds that can be recovered and used as valuable substances. The aim of this work is to exploit solid olive by‐products, in particular dry olive paste flour (DOPF) coming from Coratina cultivar, to enrich fish burger and enhance the quality characteristics. In particular, the addition of olive by‐products leads to an increase of the phenolic content and the antioxidant activity; however, it also provokes a deterioration of sensory quality. Therefore, to balance quality and sensory characteristics of fish burgers, three subsequent phases have been carried out: first, the quality of DOPF in terms of phenolic compounds content and antioxidant activity has been assessed; afterward, DOPF has been properly added to fish burgers and, finally, the formulation of the enriched fish burgers has been optimized in order to improve the sensory quality. Results suggested that the enriched burgers with 10% DOPF showed considerable amounts of polyphenols and antioxidant activity, even though they are not very acceptable from the sensory point of view. Pre‐treating DOPF by hydration/extraction with milk, significantly improved the burger sensory quality by reducing the concentration of bitter components.

Olive leaves are rich in many compounds precious for human health. Due to this property, the current study was aimed to valorize the extract from this by-product in a cereal-based food, very popular all around the world, the “taralli”. To this aim, ultrasound-assisted extraction was applied to dried olive leaves to obtain the extract, used as “taralli” ingredient, instead of white wine. The “taralli” with and without extract was subjected to in vitro digestion to assess the quantity of polyphenolic compounds released in the gastrointestinal tract to become available for absorption. Total content of phenols and flavonoids, as well as the antioxidant capacity, was measured on both cooked and uncooked samples, before and after digestion. In addition, High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) of the three most abundant polyphenols present in olive leaf extracts, such as oleuropein, hydroxytyrosol, and verbascoside, was carried out at the three stages of the digestion process. The results showed that the substitution of white wine with olive leaf extract increased the total content of polyphenols and flavonoids and the antioxidant capacity. Bio-accessibility of the main phenolic compounds demonstrated that oleuropein resisted slightly after gastric digestion but was almost completely degraded in the intestinal phase, while hydroxytyrosol and verbascoside were not resistant to the digestion process from the gastric phase.

Production of the traditional Italian Focaccia bread (FcBread) requires reformulation to meet the new rules for healthier foods. We tested the applicability of a short-fermented (15 h) liquid sourdough (LS) (dough yield, DY, 250), obtained using quinoa (Q) or amaranth (Am) flour fermented with a Weissella cibaria strain (C43-11) producing exopolysaccharides (EPS) as fat replacer in yeast-leavened FcBread. The LSs were applied during the FcBread-making process at industrial pilot plant, reducing the added fat amount by 20% (FcBread-QLS and FcBread-AmLS) and products were compared with reference samples not containing EPS. All the products were analysed for physico-chemical properties (pH, TTA, organic acids, protein content and profile, instrumental colour), textural properties, sensory quality and glycemic index. The application of both pseudo-cereal-based W. cibaria LSs in FcBread allowed obtaining products with a reduced amount of fat, increased protein amount, mainly due to the albumin and glutenin/glutelin fractions, reduced glycemic index, improved texture and preserved in the traditional sensory profile of 'focaccia'.

The aim of the study was to investigate the effect of bread fortification with dry olive paste flour (DOPF), coming from Cellina di Nardò cultivar. Specifically, sensory and nutritional properties of enriched bread were investigated. In addition, the glycemic response and the bio-accessibility of polyphenols contained in the bread samples were also estimated. The addition of DOPF leads to an increase of the total phenolic compounds, total flavonoids and antioxidant activity, without compromising the final acceptability. The recovery of bio-accessible polyphenols from the simulated gastro-intestinal digestion was 59.3% for the control and 72.1% for the enriched bread. Also the glycemic response was improved in the enriched bread.