## 1 Introduction  
According to data from the Food and Agriculture Organization of the United Nations (FAO), as much as 1/3 of the food produced globally annually is lost or wasted. This applies to the entire food chain, from primary production to households. Food production consumes large amounts of energy, water, and other raw materials and contributes to greenhouse gas emissions [1; 2]. For this reason, the problem of food waste is recognized as a key challenge on the way to sustainable resource management [3]. Losses and waste of raw materials and food products have a negative impact on the natural environment, the nutritional status of the population, and food security [4; 5; 6]. In countries with lower income, the largest losses are observed in the initial stages of production. This is due to financial and technical constraints and poor management. Limiting this phenomenon is important due to the big problem of maintaining food security in those societies [2; 7; 8]. While in middle- and high-income countries, most food losses occur at the consumer level. They result mainly from bad habits and insufficient awareness of people. The lack of cooperation between individual links in the food chain and the unfavorable conditions of contracts concluded between farmers and sellers also play a significant role [2; 6]. Food raw materials are sometimes rejected due to their visual unattractiveness and unusual shape or size [2; 6; 8]. Food waste prevention is considered a priority issue [3]. The world has limited natural resources, and on the other hand, the population is constantly growing, which requires increased food production to meet growing needs. The sustainable management of already produced foodstuffs seems to be crucial in efforts to ensure safe and nutritious food for all [2; 5; 9]. Recently, attention has been paid to the possibility of using innovative scientific achievements to prevent waste and to process by-products so that they are attractive products for consumption [6]. Currently, many scientific teams in the world are dealing with this issue. Particularly much interest is devoted to fruit and vegetable processing due to the abundance of valuable bioactive substances of a health-promoting nature. For example, attempts have been made to use apple pomace to produce a powder rich in polyphenols and fiber, to obtain blackcurrant seed oil, or to replace part of the flour in cookies with dried raspberry pomace [10]. In the process of producing functional food based on fruit and vegetables, which has a health-promoting effect, various drying methods are used, which allow for extending the shelf life and easier transport and marketing of the product. Longer exposure times result in significant changes (chemical and physical) in the character of products dried by convection. An alternative is, e.g., the freeze-drying process (using lower temperatures and reduced pressure), which is more expensive but allows for much better preservation of bioactive ingredients [11; 12]. Kiwifruit is most often eaten fresh, although over the years, it has also been used in the production of processed food, such as jams, juices, nectars, wines, or dried snacks [13]. It is worth noting that a certain limitation in the use of green kiwi varieties for the production of products with an extended shelf life is the phenomenon of chlorophyll degradation under the influence of heat treatment. As a result, a loss of the attractive intense green color is observed [14]. An interesting study on the use of the addition of kiwi puree to fruit juices as an ingredient with high acidity and viscosity was carried out by [PERSON] et al. [15]. In these studies, a number of parameters influencing the quality of apple juice produced by high pressure and stored at 4 \({}^{\circ}\)C were compared, enriching some of the samples with the addition of kiwi puree.