# Innovative Process for Dried Caper (_Capparis spinosa_ L.) Powder Production
## 1 Introduction  
In the last few years, the market of dried products has received considerable and increasing interest due to the fostered demand for healthy convenience foods with a longer shelf-life [1]. Dried fruits and vegetables are recognized as healthy for human consumption; the dehydration process, by lowering water activity, keeps fruits and vegetables healthy and safe, thereby prolonging their shelf-life [2]. Vegetable powders are widely used in many food sectors, mainly as functional ingredients for improving the nutritional value of a food product, as flavoring agents, or as colorants. The powder quality depends mainly on the drying method, but it is also dependent on the vegetable's physical and chemical composition and characteristics [3]. Air-drying methods are the most widespread techniques for the dehydration of vegetables since they are simple and cost-effective [4]. Recent studies deal with saving time and energy in conventional and innovative methods to obtain dried powders from different vegetables such as ginger, turmeric, chili, black pepper cardamom, garlic, and onions [5, 6]. However, a suitable drying technology must be selected in relation to the food matrix since it influences the powder's quality, such as its rehydration capacity, loss of taste, aroma, color, and nutritional value [7]. For this reason, sensory analysis and antioxidant activity are usually used for the quality evaluation of dried vegetables and powders [8]. _Capparis spinosa_ L. is a widespread plant throughout the Mediterranean area. Floral buds are its most used part. Before consumption, the buds are subjected to a dry-saltingferentation process that results in the development of volatile compounds that are responsible for its unique sensory features. The production process consists of a pre-treatment after harvesting, in which raw, fresh floral buds are mixed with marine salt (30-40% by weight) and shuffled for about 8 to 10 days. During this period, brine is formed, and fermentation occurs. Then, the brine is discarded, and the buds are treated with marine salt (20-25% by weight) for another 20 to 30 days to obtain the finished product, commonly referred to as carers [9]. The carers, usually packaged in plastic bags added with 25% marine salt by weight, must be sweetened by placing them in water to reduce their salt content before their consumption. Recently, an increasing interest in dried caper powder has been observed by gastrocnemius, bartenders, and professional chefs that normally prepare it by themselves starting from the traditional carers; in fact, it is scarcely industrially produced and present on the market at a very high price. The reason is that the production of dried caper powder is not economically advantageous since a long fermentation process is added to the cost of the energy-consuming drying procedure [10]. Nevertheless, the fermentation process is a crucial step in carers' aromatic and flavor development, and it cannot not be totally avoided; moreover, heat treatments can lead to the formation of compounds that interfere with carers' typical sensory properties [11]. In the context of an increasing interest in dried vegetables, the industrial production of dried caper powder could be of considerable commercial interest for two main reasons: on the one hand, there is a reduction in mass weight and, therefore, the possibility to trade in larger volumes, and on the other hand, it is an easy-to-use product (without the need of any pretreatment) with a longer shelf-life when compared to traditional carers. Regarding this matter, the aim of our research is to develop an innovative time, energy, and cost-saving production process to obtain a dried powder starting from the fresh _Caparis spinosa_ L. buds with sensory features that are acceptable by consumers. To the best of our knowledge, no information is available in the literature on the chemical and sensory features of dried caper powder nor on its production process.