## 4 Health Benefits and Composition of Kiwi By-Products
### Kiwi Bioactives: From the Fruit's Bio-Waste to Functional Products Promoting Wellness

Table 3: _Cont._of cellulose, hemicellulose, and pectin. Antimutagens prevent the change in genomes before the initiation of cancer. Kiwi, thus, performs a cytotoxic function on malignant cells that tend to differentiate. In addition, due to their antimicrobial actions, these fibers also contribute to the prevention of bacterial colonization in the intestinal space. Mutagenesis, which could be caused by bacterial infections, is also controlled in this way. In addition to cancer, simpler disorders, such as constipation, are also regulated [45; 46]. The phenolic profile of both the fruit and its by-products provides the greatest number of beneficial actions, since they are natural antioxidants and anti-inflammatory agents. The main sources of these actions are the peel of the kiwi fruit and other by-products. Thus, the enrichment of new products with their extracts will lead to increased levels of antioxidant and anti-inflammatory abilities. These actions have been tested in in vivo and in vitro models. In a study, it was found that the polyphenols of the seeds helped eliminate the pro-inflammatory cytokines IL-1\(\beta\) and TNF-\(\alpha\), which polysaccharides create in macrophage cells. The above test showed their anti-inflammatory action, since phenolic components protect against the appearance of inflammation in the cells of the organism they have entered. Polyphenols derived from fruit skin can replace synthetic antioxidants. Various phytochemical factors cause the formation of free radicals that destroy cell wall membranes. For the preservation of food or other oxidation-sensitive products, the use of additives is recommended. An extract of kiwi peel can act as a natural antioxidant additive, ideal for protecting food, for e.g., from lipid oxidation [11; 46]. In addition, a class of anthocyanins contained in the fruit may be applied to cosmetic and skin care products, due to its tyrosinase-inhibiting property. Tyrosine is an enzyme that contributes to the process of melanin production. However, hyperpigmentation, i.e., the appearance of increased levels of melanin, is a phenomenon that causes skin irregularities, such as spots and bruises [46; 47]. The proteins, mainly actinidin, in kiwi fruit, also have important applications, especially in the meat industry. The main ability of actinidin, as far as meat optimization is concerned, is the change in myofibrillar components. The sarcomere is a muscle functional unit that consists of four proteins: myosin, actin, tropomyosin, and troponin. The system involves myofibrils. Actinidin, therefore, affects this system and helps make the meat tender. Also, this ability of the enzyme is due to water retention, with a parallel increase in nitrogen solubility. Other researchers have commented on how the presence of actinidin enhanced the aroma of the food, while in milk products, it dissolves as a volatile that forms a casein clot, which undergoes serum separation. Thus, a kiwi extract, for example from its seeds, can increase the nutritional value of dairy products, the tenderness of meat, and the aromatics of other products [11; 46; 48]. To achieve these applications, the recovery of each component is required, through a process specific to each one, to form an extract that contains each of the compounds that are to be used. In regard to the phenolic components, the most observed extraction is the subcritical water-soluble extraction. It is an ecological and efficient technique that leads to obtaining the best antioxidant activity in relation to conventional processes. The use of organic solvents does not need to cease, but it can be considered certain that solvents such as water and ethanol are not only more effective but are indicated as preferred when the extracts are intended for applications in food, cosmetics, and pharmaceutical products. Moreover, for compounds with antioxidant actions, a low temperature of 30-37 \({}^{\circ}\)C during the extraction is observed.