# Table Olive Flours\": An Ingredient Rich in Bioactive Compounds?
## 1 Introduction  
Consumer preferences, expectations, and dietary patterns are a constant challenge to food industries [1]. Consumers are seeking uniqueness, and the use of traditional products in new presentations and applications to fully value these products is a great possibility. There is a concern to solve nutritional issues such as dietary imbalances (lack of specific nutrients, antioxidants, and vitamins), and the needs of consumers of new ingredients which are practical and easy-to-use that also meet environmental and sustainability concerns. Thus, more innovations are needed, particularly in the direction of plant-based products that are healthy, as well as towards the use of clean labels [2]. Consumers recognize plant-based diets as ethical, healthy, and environmentally friendly [2]. Furthermore, fruit and vegetable by-products may be transformed into fiber-rich flours and bioactive compounds [3]. Consumers also look for convenient, tasty plant-based products based on simple ingredient lists [2]. Table olives are included in this group, recognized as havinghigh nutritional value, healthy fat, and a considerable amount of antioxidants. Some preparations of table olives are recognized to be more beneficial to human health than others. The natural table olives obtained by natural fermentation [4] do not use additives other than salt. However, using high sodium chloride levels as a preservative has been one of the negative aspects which has been highlighted as limiting their consumption. Some reviews have revealed that the applied processing method influences the nutritional properties of table olives; nevertheless, some preharvest factors such as irrigation and fruit ripening stage may have a certain weight. The nutritional value of table olives depends mainly on the balanced profile of polyunsaturated and monounsaturated fatty acids, as well as the contents of health-promoting phenolic compounds [5,6]. Thus, new forms of presentation must be considered. It is also necessary to make table olives production more sustainable, in addition to finding ways to value smaller fruits and/or olives with small defects, which do not allow them to be marketed in that way. The production of \"table olive flour\" can be an interesting method to obtain a product that can be added to other dishes or products (such as sauces) to enrich their bioactive properties. Furthermore, a product with lower salt content than the fresh olives can be obtained since, before producing the flour, the fruits can be soaked to remove a large part of the salt present in the fruit. Likewise, the olive fruits' phenolic composition is well studied and documented [4,7,8,9,10,11,12], bringing benefits to human health. Several phenolic compounds such as hydroxytyrosol, tyrosol, rutin, luteolin-7-O-glucose, verbascoside, oleuppein, comselogoside, and ligstroside have been reported in olives. Concerning table olives, those produced through natural fermentation are the most prominent, as processes involving oxidation steps such as the California style may cause a significant reduction in the phenolic contents [4]. It is also known that the maturation index influences the antioxidant content [11], and the applied technological processes to produce edible table olives can also influence the final product [4,8,12]. The development of dried products based on table olives will allow for their consumption. So far, some studies on table olives drying by hot air have been carried out [13,14,15,16,17,18,19]. Temperatures at 40 [19], 45 [14], and 50 \({}^{\circ}\)C [13,15,18], as well as ranges between 40-70 \({}^{\circ}\)C [16,17], have been applied; however, only in the studies performed by [PERSON] et al. [14], [PERSON] et al. [18] and [PERSON] [19] were the total phenols or individual phenols analyzed. In general, the hot air drying caused a decrease in phenol levels. Freeze-drying may be a good alternative to hot air drying. This technology has been applied to olives, preserving antioxidants [12,20], but it has not yet been explored for drying table olives.