## 1 Introduction  
The volume of world vegetable production from 2000 to 2021 increased by 40%. Consumption of vegetables is very important for consumers. A 2021 study found that more than a quarter of the German and Australian populations mainly consume vegetables, fruits, and whole-grain products [1]. Vegetables are an important source of nutraceuticalials in the human diet, which are naturally occurring substances in food. Nutraceuticalials are important in the daily diet because they benefit the human body, improve physiological functioning, and improve overall health. Nutraceuticalials are ingredients such as antioxidants, vitamins, minerals, and natural pigments (e.g., carotenoids) [2]. Broccoli (_Brassica oleracea_ L. var. _italica_) is a popular vegetable worldwide. Its largest producers are China and India [3]. In the United States, broccoli consumption per capita in 2022 was 6.51 g per day, and a 2% increase over the previous year was observed [4]. Broccoli has high nutritional value because it contains bioactive compounds (e.g., sulforaphene, glucosinolate, flavonoids (kaempfer, quercetin), carotenoids (lutein)), and nutrients (i.e., dietary fiber, vitamins (A, C, and vitamin B complex), minerals (e.g., selenium, potassium), and amino acids) [3, 5]. Phytochemicals and nutrients in broccoli support well-being, reduce inflammation, and prevent cancer. Broccoli is characterized by antioxidant, anti-inflammatory, antimicrobial, and anticancer effects [6]. In addition, broccoli is low in calories, so it can be a healthy, light snack for people who want to maintain a normal weight, lose weight, or just eat healthy [7]. Courgette (_Cucurbita pepo_ L.) is a seasonal vegetable that is popular around the world [8]. In Australia in 2021/2022, the annual consumption of courgette was 17.520 tons, equivalent to 680 g/person per day [9]. Courgette is eaten raw, but due to its rapid loss of freshness, it is used for processing. Courgette contains about 93.5-95% water, so it has a very low energy value. Courgette plays an important role in a balanced diet due to its high nutrient content, including carbohydrates, protein, folic acid, fiber, vitamins, and minerals such as potassium, phosphorus, magnesium, and calcium [8; 10]. Red beetroot (_Beta vulgaris_ L.) is a valuable raw material used in the food industry. It is used to produce frozen, dried, preserved, and fermented food, as well as concentrates and juices [11]. The popularity of this vegetable is related to the content of many valuable nutrients, including vitamins (A, K, E, C, and B vitamins), minerals (potassium, sodium, magnesium, iron, zinc, boron, silicon, copper, selenium, and manganese) [12]. Red beetroot belongs to the group of health-promoting foods due to the content of the above-mentioned nutritional compounds and bioactive ingredients, i.e., phenols, betalains, and inorganic nitrates [13]. Betalanins, substances contained in beetroot, are used as natural dyes in food production. They are an interesting alternative to artificial dyes. Firstly, because of the possibility of changing the color of food products in a natural way, and secondly, because of the possible health benefits for humans [14]. Based on literature data, red beetroot has strong antioxidant, anti-inflammatory, anti-stress, anti-hypertensive, anti-viral, anti-obesity, anti-cancer, and anti-bacterial properties, as well as lowering lipid levels [15; 16]. All the health-promoting properties discussed confirm that red beetroot has great potential as a functional food ingredient. Most importantly, it is used in industry as a raw material for the extraction of a natural food additive, thanks to which it is possible to use beetroot juice to produce innovative, health-promoting food [17]. The development of techniques to extend the shelf life of fruits and vegetables is increasingly driving the food market [18]. Most vegetables and fruits are sourced seasonally, and, due to the high cost of storing fresh materials, they brown, lose firmness and rot quite quickly.