## 4 Health Benefits and Composition of Kiwi By-Products
### Kiwi Bioactives: From the Fruit's Bio-Waste to Functional Products Promoting Wellness  
Fruits, vegetables, and other nutritionally important foods are known contributors to wellness, as represented by their low position in the nutritional pyramid, pointing to their necessary frequent and/or daily consumption. Kiwi has received a lot of attention in recent years due to its therapeutic benefits, which are constantly being discovered by research. Its consumption is also linked, in the present work, to contributing in a multifaceted way not only to the proper maintenance of organism homeostasis, but also to the development of protection against chronic diseases. However, due to its nutritional profile, the fruit is not only intended for raw consumption as a simple food. Of course, its introduction into a person's diet should be promoted, but the maximization of its utilization is also necessary, aiming to enhance other foods, supplements, medicines, and cosmetics via the integration of its bioactive components. These bioactive compounds are not only found in kiwi flesh and juice, but also in the products exported from both industry and agricultural activities as waste. The peel, seeds, leaves, and pomace have an equally interesting composition, which does not seem to have been noticed by functional product companies. First, however, answers must be given to two basic questions that arise: \"What are the main properties of these compounds?\" and \"How transferable are they through different sources?\". Starting with the vitamins, specifically vitamin C, a good antioxidant, it is ideal for incorporation into face creams and cosmetic products, as it protects the skin from damage that can occur due to the sun's radiation, pollution, and aging. Its antiaging effects are correlated with increased collagen production in the body, as a result of the increased intake of this vitamin. In essence, collagen is a protein product that keeps the skin youthful and also regenerates it in cases of wounds and scars. Furthermore, with the production of collagen, the skin regains its firmness and a uniform soft texture, since the protein penetrates the tissues and acts as an embilient. Similarly, vitamin E and kiwi's amino acids also contribute to the improvement and regeneration of the skin. These vitamins appear both in the interior of the fruit and in the peel [31,45]. The fatty acids of actinium seeds, in particular, find applications in foods aimed at reducing cardiovascular diseases. Strokes and coronary heart disease are known to be delayed or even prevented with proper exercise and a healthy diet. Thus, the intake of good fatty acids, such as omega-3, found in seeds is guaranteed to have positive results to protect against heart diseases. These fatty acids, through extracts, can be applied to a series of foods and supplements that will act directly where needed [11,31,45]. In the same category for the protection against cardiovascular diseases, potassium can strengthen prevention attempts. Potassium seems to be obtained mainly from the peel, as it is one of the minerals contained in them. Its main action is essentially the removal of sodium that the body receives from other foods, thus, ensuring the proper functioning of the heart, which can be disturbed by the intake of sodium in our diet [45]. In combination with potassium, plant fibers also play a role in reducing heart disease by minimizing cholesterol and sugar levels. On the other hand, dietary fibers help the body in a lot of different ways, with the most important effect being protection against cancer. The anticancer property is mainly specialized in the intestine, due to the absorption \begin{table}
\begin{tabular}{c c c} \hline
**Composition** & **Amount** & **By-Product** \\ \hline Chlorogenic acid & 0.40 mg/g & Peels [44] \\ Catechin & 45 mg/g & Seeds [11] \\ P-couraric acid & 0.36 mg/g & Peels [44] \\ Hydroxybenzoic acid & 53 mg/g & Seeds [11] \\ Caffeic acid & 0.15 mg/g & Peels [44] \\ Epicatechin & 0.32 mg/g & Peels [44] \\ \hline \end{tabular}
\end{table}