**5. Examples of food applications utilising polyphenol extraction for lipid quality enhancement**

Various food applications have effectively utilised polyphenol extraction to improve lipid quality. These applications demonstrate the ability of polyphenols to enhance the sensory qualities, stability, and health-promoting properties of lipids. The following instances illustrate the efficacy of polyphenol extraction in various food contexts:

Olive Oil Enrichment Olive oil has been enriched with polyphenol-rich compounds derived from olive pomace or leaves. The incorporation of these extracts increases the lipid content of the oil by enhancing its oxidative stability and antioxidant capacity [19, 23].

Incorporating polyphenol extracts into meat and poultry formulations can improve lipid stability and prevent lipid oxidation [24, 25]. These extracts function as natural antioxidants, preventing the formation of rancid flavours and preserving the overall quality of the products.

To enhance the lipid quality of dairy products, polyphenol extracts from sources such as grape seeds and berry pomace have been added [26, 27]. These extracts can improve the oxidative stability and inhibit the development of off-flavours in dairy products such as yoghurt, cheese, and butter.

Polyphenol-rich extracts have been incorporated into the formulation of nutritional supplements, particularly those that target lipid metabolism and cardiovascular health. These extracts, derived from green tea, cocoa, or citrus fruits, contribute to the positive effects of supplements on lipid profiles and oxidative stress markers [28, 29].

Bakery and Confectionery Products: Polyphenol compounds have been added to bakery and confectionery products to improve lipid quality and extend storage life [30, 31]. These extracts can inhibit lipid oxidation and enhance overall oxidative stability, thereby preserving the sensory attributes and freshness of the products.

The impact of dietary polyphenols on gut microbiota compositions and how gut microbiota affect polyphenol metabolism are the main possible mechanisms of the gut microbiome. In combination, dietary polyphenols could be a helpful nutritional strategy for modifying lipid metabolism or treating obesity [32]. According to studies by [33], dietary TP appears to have had a major role in activating lipolysis and enhancing lipid metabolism in grouper given high-fat diets. For enhancing lipid metabolism in juvenile grouper high-lipid diets, 0.045–0.067% was advised based on the broken-line regressions analysis of the serous LDL and hepatic VLDL contents [34]. The effects of TP concentration (0, 100, and 400 mg/L), solution pH (3 and 7), and the addition of ethylenediaminetetraacetic acid (0 or 20 mol/L EDTA) were investigated on the antioxidant/prooxidant activities of TP in walnut oil-in-water

(O/W) emulsions under accelerated storage conditions (50°C for 0, 48, and 96 h). At pH 3, TP concentrations of 100 mg/L and 400 mg/L both showed better antioxidant activity for lipids and proteins, respectively.
