# An Overview on Management and Valorisation of Winery Wastes
## 2 Winery Waste Composition and Source of Bio-Active Compounds
Chicken meat was efficiently fortified by a grape pomace extract added to the minced products up to a TPC (total phenolic content) of 60 mg/kg [77; 78], observing that the lipid oxidation decreased due to the strong antioxidant activity, but with colour and flavour changes [77]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Product** & **Grape Pomace Addition** & **Effects** & **Ref.** \\ \hline \multirow{3}{*}{Pork burger} & 0.06\% grape pomace extract & Positive: Increased lipid & \\  & added to product weight & oxidation inhibition and & \\  & & enhanced colour stability & \\ \hline \multirow{3}{*}{Pork sausages} & 0.5 and 1\% grape pomace & Positive: Decreased lipid & \\  & incorporated into the recipe & oxidationNegative: Induced & \\  & & colour change & \\ \hline \multirow{3}{*}{Pork loin marinade} & Pork loin was soaked in 0.5, & Positive: Inhibition of lipid & \\  & 1.0, 2.0, 20.0, and 40.0\% & oxidation and & \\  & grape pomace solution & microbial growth & \\ \hline \multirow{3}{*}{Chicken meat} & Grape pomace extract & Positive: Decreased lipid & \\  & adding up to & oxidationNegative: Induced & \\  & TPC = 60 mg/kg (in meat) & colour and flavour change & \\ \hline \multirow{3}{*}{Chicken meat} & Grape pomace extract & Positive: Decreased & \\  & adding up to TPC of 10, 20, & lipid oxidation & \\ \cline{1-1}  & 40, and 60 mg/kg (in meat) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Grape pomace effect on meat and products. Grape pomace was also used for yogurt fortification [55] and production of cheese [79]. For example, the coagulated milk was fortified with grape pomace solutions (1, 2, and 3%) [55]. It was observed that the total dietary fibre content increased with grape pomace concentration [55]. The disadvantage was that the fortified yogurt exhibited a darker colour [55]. The grape pomace extract (1%) addition to another yogurt formulation increased its antioxidant capacity and TPC [51]. A slight colour change was observed, but no sensory effects were registered [51]. Semi-hard and hard cheeses were fortified with 0.8 and 1.6% grape pomace, resulting in increased antioxidant activity and TPC, but no changes in physicochemical characteristics and microbial counts were observed [51]. Various compounds from wine may affect its quality and safety, including some metabolites (such as biogenic amines or obratoxin A) as well as metals [80]. The best option to remove these harmful substances is fining. The role and behaviour of grape pomace in the process of wine fining and clarification was first investigated in 2013 [81] using fibres extracted from Cabernet Sauvignon grape pomace. A decrease in phenolic concentration and in turbidity values in the treated wines was observed [81]. Furthermore, purified cell wall material was used for wine fining, positively affecting the wine phenolic content [82]. Cell wall purification and extraction represent a time-consuming process. In this respect, the wine repassage over grape pomace may decrease the ochratoxin A levels in must and wine during the vinicification process, but the effects on removing biogenic amines or metals were not studied [80]. Purified grape pomace was applied for wine fining, inducing a significant reduction in ochratoxin A, but also in histamine, K, and Ca, indicating that it can be considered an alternative for protein-based fining agents [80].