Influence of Fermentation Beetroot Juice Process on the Physico-Chemical Properties of Spray Dried Powder

Phenolic Compounds and Antioxidant Properties of Fermented Beetroot Juices Enriched with Different Additives

Fermented beetroot juice is a beverage obtained from the fermentation of beetroot, most commonly red beet (Beta vulgaris L. var. conditiva). Nowadays, this product is increasingly recognised as a functional food with potentially beneficial health properties. It has been suggested to have antioxidant, anti-inflammatory, anticancer, antihypertensive, immunomodulatory, and probiotic effects, among others. Moreover, with the increasing popularity of the drink, newer variants are appearing in the food market, obtained by modifying the traditional recipe, adding other raw materials, herbs, and spices. Therefore, the aim of this study was to evaluate and compare the antioxidant potential and phytochemical composition of the selected fermented beetroot juices in different flavour variants available in the Polish food market. The study material consisted of six fermented beetroot juices: traditional, with garlic, with horseradish, with acerola, without salt, and iodized. The obtained results showed that the addition of acerola, horseradish, garlic, salt, and iodine in the form of sodium iodide and potassium iodide influenced the composition and properties of fermented beetroot juice. The most promising product in terms of potentially beneficial health properties related to the prevention of free radical diseases was fermented beetroot juice without salt (FRAP-5663.40 µM Fe (II)/L, ABTS-96.613%, TPC-760.020 mg GAE/L, TFC-221.280 mg RE/L). Iodized fermented beetroot juice had the highest vitamin C content-51.859 mg/100 mL. However, all the products tested were characterised by a significant content of biologically active substances with antioxidant properties and showed a high antioxidant potential. Moreover, all the fermented beetroot juices were rated positively in terms of flavour intensity, sweetness, acidity, colour, and overall acceptability. They can, therefore, be a good source of antioxidants in the daily diet.

Non-Dairy Fermented Beverages Produced with Functional Lactic Acid Bacteria

At present, there is an increasing interest in beverages of non-dairy origin, as alternatives to those based on milk, but having similar health-promoting properties. Fermentation with specific bacteria or consortia may enhance the functionality of these products. In our study, selected lactic acid bacteria, that have been previously shown to possess functional properties (antimicrobial activity, probiotic potential), were used for the fermentation of wheat bran combined with root vegetables. Strains were investigated for their safety, while the obtained beverages were characterized in terms of microbial content, physical, chemical, nutritional, and functional properties. None of the strains harbors virulence genes, but all of them possess genes for survival at low pH, starch metabolism, and vitamin biosynthesis. Three strains (Lactiplantibacillus plantarum BR9, L. plantarum P35, and Lactobacillus acidophilus IBB801) and two substrates (5% wheat bran with 10% red beetroot/carrots) were selected based on a preliminary assessment of the beverage's sensory acceptability. These strains showed good growth and stability over time in the stored beverages. No enterobacteria were detected at the end of fermentations, while the final pH was, in most cases, below 3.5. Free phenolics, flavonoids, and DPPH scavenging effect increased during fermentation in all drinks, reaching 24h values that were much higher than in the unfermented substrates. Most of the obtained drinks were able to prevent the growth of certain pathogens, including Listeria monocytogenes ATCC 19111, Salmonella enterica ATCC 14028, Staphylococcus aureus ATCC 25923, and Escherichia coli ATCC 25922. The obtained beverages would combine the nutritiveness of the raw ingredients with the beneficial effect of fermentation (increasing shelf life, health-promoting effect, pleasant flavor, etc.). They would also fill a gap in the non-dairy probiotics sector, which is constantly increasing due to the increasing number of vegan people or people that cannot consume dairy products.

Sustainable Production and Characteristics of Dried Fermented Vegetables

The current fashion for healthy food and the increasing number of people with lactose intolerance make fermented vegetables increasingly important. On top of this, surpluses unused in the vegetable harvest can become a potential source of “green waste”. The use of fermentation and freeze-drying can result in a valuable, sustainable product that can solve the problems of spoiled vegetables and the need for refrigerated storage. Therefore, this study aimed to obtain sustainable dried fermented vegetables and to compare their selected physical and structural properties. Beetroot, carrot, and red pepper were selected for this purpose. These vegetables were subjected to a spontaneous lactic fermentation process. After the process, the vegetables were freeze-dried, and their structure and selected properties (color, dry weight, and the number of lactic acid bacteria) were determined. Fermented vegetables were found to differ from their raw sources in structure and color, the main discrepancies being shown by the b* factor (yellow-blue). Root vegetables had smaller pores of structure in the freeze-dried samples than red peppers. The freeze-drying process did not affect the number of bacteria. It can be concluded that both the fermentation and the freeze-drying processes affected the structure of the selected vegetables. All tested vegetables can be fermented and freeze-dried without major changes in color and microbiological properties and can be used as a potential source of lactic acid bacteria and health-promoting pigments, e.g., in the form of chips. In addition, their shelf life is extended.

The Impact of the Fermentation Method on the Pigment Content in Pickled Beetroot and Red Bell Pepper Juices and Freeze-Dried Powders

The beetroot and red bell pepper are vegetables rich in active ingredients, and their potential for health benefits are crucial. Both presented raw materials are rich in natural pigments, but are unstable and seasonal; thus, it was decided to take steps to extend their durability. Lactic fermentation has been recognized as a food preservation method, requiring minimal resources. The activities undertaken were also aimed at creating a new product with a coloring and probiotic potential. For this reason, the study aimed to evaluate the impact of the method of fermentation on the content of active compounds (pigments) in pickled juices and freeze-dried powders. The lactic acid fermentation guided in two ways. The second step of the research was to obtain powders in the freeze-drying process. For fermentation, Levilactobacillus brevis and Limosilactobacillus fermentum were used. In juices and powders, pigments, color, and dry matter were tested. In this research, no differences in fermented juice pigment contents were seen; however, the color coefficient differed in raw juices. The freeze-drying process resulted in lowering the pigment content, and increasing dry matter and good storage conditions (glass transition temperatures 48–66 °C). The selection of vegetable methods suggested the use of fermentation and mixing it with a marinade (higher pigments and lactic acid bacteria content). All powders were stable and can be used as a colorant source, whereas for probiotic properties, a higher number of bacteria is needed.