## 6 OMWW as Replacer of Synthetic Additives
### Application of OMWW as Food Supplement  
In several studies, olive oil by-products have been added as concentrates or ingredients in the formulation of novel foods in different agro-food supply chains (Table 2). In a review, [PERSON] [131] collected data related to the addition of OMWW extracts (but also of other oil industrial by-products) to fortify meat and meat products. The results showed that the obtained antioxidants induce an improvement of hygiic conditions and rheological characteristics of the final products. Olive phenols have shown better performance in raw meat treatment [132] as they were able to hinder lipid oxidation. To evaluate such an effect, an oxidation test with a thiobarbituric acid reaction (TBAR) was applied for a storage period of 72 h at 4 \({}^{\circ}\)C. Results in limiting lipid oxidation appear to be dependent on the concentration of phenols (500 mg ascorbic acid or catechin/L and 100 mg olive phenols/L). [PERSON] et al. [133] and [PERSON] et al. [111] recently applied OMWW-extracted polyphenols in fermented sausages and white meat buyers, improving quality parameters and extending their shelf life. In particular, the addition of the extracts inhibited the fungal growth and spore germination in fermented sausages by performing a dose- and species -dependent activity both in vitro and in situ tests. In particular, the treatment with 2.5% of OMWW extract strongly inhibited in situ growth of _Cladosporiados, Penciillium urantiogriseum_, _Penicillium commune_, and _Eurotium amstelodami_. [PERSON] et al. [111] evaluated the effect of OMWW-extracted polyphenols in white meat burgers, wrapped in PVC, on improving sensorial and hygiic characteristics. The addition of the phenolic extract at different concentrations (0.75 and 1.50 g/kg) delayed the growth of mesophilic aerobic bacteria, highlighting a dose-dependent behavior, with a 24 h extension of shelf life, compared with both the control and sample treated with the lowest concentration. In addition, [PERSON] et al. [130], according to [PERSON] et al. [134], found that a 38.6 g/L concentration of phenolic extract was effective in increasing fresh chicken breast shelf life. Samples were immersed in a solution containing the extract for a few seconds, before packing and storage at 4 \({}^{\circ}\)C. The results showed a delay of growth of both Enterobacteriaceae and _Pseudomonas_ spp. with at least a 2 day increase in shelf life, compared with the control. In addition, the treatments were shown to positively affect the odor of meat, decreasing the TBARS value. [PERSON] et al. [135] proposed the addition of lard with olive phenols as a \"novel food\", showing that the natural antioxidants of OMWW were highly effective in oxidative stabilization of lard. The phenol extract significantly increased the oxidative stability of lard, and the applied doses (100-200 ppm) were not cytotoxic when tested on mouse cell lines (embryonic fibroblasts). In addition, several studies have tested phenol extracts in dairy products to enhance antioxidant activity and better stabilize the products. [PERSON] et al. [136] tested the antioxidant activity of OMWW phenolic extract in UHT milk samples, on inhibition of the Maillard reaction (MR), by adding phenolic extract at 0.1 and 0.05% _w/v_, revealing the reduction of reactive carbonyl species formation in samples before heat treatment, inducing a greater stability without any detrimental sensorial effects. Phenol extracts (100 and 200 mg/L) from OMWW have also been added in a functional milk drink (similar to yogurt) and fermented with a GABA-producing strain (_L. plantarum_ C48) and a LAB strain of human origin (_L. paracase_ 15N). The results showed that the addition of phenolic compounds did not interfere with either the fermentation process or the activities of functional LAB [134].