## 1 Introduction  
Poland is the second largest producer of raspberries in Europe and the fifth in the world after the Russian Federation, Mexico, Serbia, and the United States according to data offered by the National Support Centre for Agriculture. Poland produces about 100,000 tons per year, of which almost half is exported, mainly in frozen form, to Western Europe [1]. Due to the low durability of fresh fruit, only a small proportion of raspberries are eaten fresh (8-13%) and for a limited time. Significant amounts of fruit are processed industrially (about 78%), e.g., in production of juices (18-27%), which generates pomace [2]. Industrial processing of fruit, especially for juices, generates huge amounts of waste. They pose a considerable environmental problem and generate high disposal costs. Most often, the waste is used in animal nutrition or as a fertilizer. On the other hand, pomace is an extremely rich source of compounds with documented biological activity. A very good way to use waste from fruit processing is to make bakery products, especially shorthead cookies, muffins, or wafers [3, 4, 5]. Raspberry pomace is a valuable source of nutrients and bioactive ingredients. It contains significant amounts of carbohydrates, proteins, fats, fiber, flavors, pectins, and vitamins [3]. About 77% of the dietary fiber content of fresh fruit remains in the pomace [6]. Similarly, phenolic compounds, including anthocyanins, but also ellagitannins (sanguain H6 and lambertianin C), proanthocyanidins, and phenolic acids (mainly ellagic acid) remain in the pomace [7]. Up to 80% of raspberry pomace are seeds. Raspberry seeds are approximately 23% oil, a very rich source of polyunsaturated fatty acids (PUFAs), of which the main ingredients are essential fatty acids (linoleic and \(\alpha\)-linolenic acid), as well as tocopherols. When eaten as a whole, they pass through the digestive tract undigested, hence the bioactive compounds present in them are not digestible. However, after drying and grinding, the bioavailability of bioactive compounds from raspberry pomace increases [8]. Raspberry by-products are not widely used in industry, but their potential is being increasingly recognized. Raspberry pomace is a good source of dietary fiber and can be used as a food additive. Due to its ability to inhibit the growth of _Clostridium_, _Enterococcus_, _Escherichia_, _Mycobacterium_, _Salmonella_, and _Staphylococcus_ species by ellagitannins, raspberry pomace is a promising new source of phenolic antimicrobial compounds. Raspberry seed oil from raspberry by-products is very important for its potential application in food, pharmaceutical, and cosmetic products [3]. The research also proves that pomace as a source of biologically active compounds can be used in the prevention or treatment of civilization diseases, because of its positive effect on blood plasma enzymatic antioxidant status and lipid profiles of tested laboratory animals [7; 8]  
By-products from berries are very rich in polyphenols, especially anthocyanins (flavonoids) and possess high antioxidant capacity. Analysis of the Phenol-Explorer database indicates that fruit pomace remaining after juice production belongs to the 100 richest sources of polyphenols [9]. Due to their strong antioxidant properties, phenolic compounds have recently been considered preventive agents in many free radical-induced civilization diseases, such as cardiovascular diseases, cancers, type 2 diabetes, neurodegenerative diseases, or osteoporosis [10; 11]. The effectiveness of polyphenolic compounds is largely related to their molecular weight, concentration, and, above all, the structure itself--the presence of hydroxyl groups involved in the reduction of free radicals. During this reaction, the polyphenolic compound donates one electron, transforming into an aroxyl radical, which is stabilized by the presence of an aromatic ring. Flavonoids most easily bind hydroxyl radicals, superoxide anion radicals, singlet oxygens, and lipid radicals.