# Use of Bilberry and Blackcurrant Pomace Powders as Functional Ingredients in Cookies
## 1 Introduction  
Cookies and biscuits are one of the most popular quick snacks worldwide due to their ready-to-eat nature, affordability, wide availability, relatively long shelf-life, and assortment diversity [1, 2]. Although widely appreciated and consumed by different age and socio-economic groups, cookies are rich in sugar, sodium, saturated fats, and energy value and are poor in micronutrients, fiber, and bioactive compounds [3]. As a result, their excessive consumption can lead to chronic non-communicable diseases such as cardiovascular diseases, cancer, and diabetes [4, 5]. As consumers become more health-aware and interested in the active role of food to prevent lifestyle diseases, there is a need to improve the nutritional and functional value of these food products while maintaining good sensory and structural qualities [1, 6]. Cookies have proven to be a good vehicle for the delivery of dietary fiber and bioactive compounds from the fruit processing industryto consumers [7; 8]. The fruit processing industry generates large amounts of by-products with valuable nutritional and functional properties, as justified by their richness in fiber, micronutrients, and bioactive compounds [9]. Currently, there is a growing trend towards their valorization to produce dietary supplements and nutraceuticals or to be used as natural food ingredients [6; 10]. A good strategy in cookie and biscuit production involves the inclusion of functional ingredients in their composition by partially replacing the wheat flour with powders from fruit processing by-products [11]. Many studies have been dedicated to the innovation of cookies and biscuits by partially replacing wheat flour with fruit processing by-products such as pomace flour from orange [12], avocado, kiwifruit, pineapple and pomegranate [2; 3; 13], apple [14; 15; 16; 17; 18; 19], tomato [20; 21], blueberry [1; 8; 22; 23], melon [14], grape [5; 24; 25; 26], grapefruit [6], pear [11], and raspberry, red currants, and strawberry [8; 27]. Bilberry (_Vaccinium myrtillus_ L), also known as huckleberry, whortleberry, or European blueberry, is a perennial dwarf shrub belonging to the _Ericaceae_ family, genus _Vaccinium_, originating from northern Europe and North America [28]. From ancient times, bilberries, the blue/black fruits of bilberry, are known for their benefits in treating various conditions such as hemorrhoids, vomiting, diarrhea, skin ulcers, and mucosal tissue inflammation [29]. The health-promoting effects of bilberries have been attributed to their phenolic compound content, comprising anthocyanins, terpenoids, flavonoids, tannins, coumarins, phenolic acids, and resveratrol. Delphinidin and cyanidin are predominant among anthocyanins, followed by petunidin, peonidin, and malvidin, which are mostly glycosylated by galactose, glucose, and arabinose [30]. Due to the abundance of anthocyanins and of the other health-promoting compounds with antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, cardioprotective, neuroprotective, and anticancer activities, bilberries have been awarded the title of \"super food\" or \"functional food\" [31; 32; 33; 34]. Bilberries are available fresh, dried, or frozen, but most often, they are used to produce juices, jams, alcoholic beverages, violet pigments, or food supplements [35]. The residue from bilberry juice processing is the pomace, consisting mainly of skins and seeds, which is a valuable source of vitamins, fibers, and minerals. But what distinguishes bilberry pomace is its huge content of anthocyanins and other phenolic compounds with strong antioxidant properties. Moreover, bilberry pomace was reported to contain significant amounts of polyunsaturated fatty acids (including n-3 PUFAs) from the seed oil [36]. [PERSON] et al. [37] obtained the highest yields of polyphenols in extracts from wild bilberries among five _Vaccinium_ spp. berry pomaces and demonstrated the strong antioxidative, hypoglycemic, and hepatocyte properties of bilberry pomace extract.