Technology of semi-finished product from dried beetroot, pretreated by freeze-thaw method and food products using it

Abstract

The use of natural ingredients as preventative or therapeutic agents has drawn considerable attention on a global scale in recent years. Beetroot is a root vegetable containing betalain, ascorbic acid, polyphenols, flavonoids, saponins, carotenoids and a high content of nitrates. Beetroot provides a number of health benefits and can help prevent or be therapeutic for a variety of disorders and diseases due to its bioactive components. Meanwhile, due to its wide range of phytochemicals, beetroot is a potential source of nutraceutical substances that can be employed to create functional foods. In terms of pharmacology, beetroot has the potential to act as a powerful antioxidant, antimicrobial, anticancerous, hypocholesterolemic, and anti-inflammatory agent. Due to its growing popularity as a source of natural antioxidants, beetroot is increasingly being processed and used in products. Beetroot is intended for the food business and is used as a food coloring or additive in food products such as meat products, confectionery, bakery products, dairy products and other products. The beetroot extract is used to enhance the color in tomato pastes, soups, sauces, desserts, jams, jellies, candies and breakfast cereals. Fresh beetroot is exposed to spoilage due to its high moisture content. Drying is one of the oldest, widely-applied food preservation operations, which consists of the reduction in the water content slowing down microbial or enzymatic degradation oxidation. Drying methods applied may affect the color, shape, structure, nutritional and nutraceutical compounds in all kinds of ways. As a consequence, it is crucial to choose an optimal drying method. The optimization of the drying procedure is a critical step toward obtaining dehydrated beetroots with the lowest loss of the nutrients and maximum potential activities. The quality of the product obtained depends largely on the methodology used. The use of pre-treatments prior to drying is an alternative for better preserving fresh food attributes and reducing energy requirements. The results vary widely depending on the type of pre-treatments used and the product in question, although in some instances, an increase in drying rate and a greater retention of quality can be noted. The introduction and the first section presented the application of drying methods and pretreatments in beetroot processing, and application of beetroots in food industry and the development prospect of beetroots. Based on the review of literature sources, specific tasks and issues for further research are identified. Beetroot is a powerful dietary source of health-promoting substances with the potential to treat a variety of pathological conditions, and dried beetroot is promising as an economical, practical and, importantly, natural dietary product. In the second section, we introduced the experimental protocol in the study, defined the research topic and materials, described all the determination methods, and analyzed and processed the experimental data. The research was carried out at Hezhou University in China, Sumy National Agricultural University in Ukraine, the results of experiments are confirmed by relevant research protocols. In the third section, the scientific problem of different drying conditions on the physicochemical properties and antioxidant activity of beetroots have been discussed. For heat pump drying, the best drying process parameters were beetroot slices with thickness of 5 mm, drying temperature of 65 °C, and loading density of 2.0 kg/m2. Moreover, the most favorable conditions for vacuum microwave drying of beetroots were microwave power of 500 W, vacuum degree of –90 kPa, and sample thickness of 2 mm. Influence of different drying methods on quality parameters of beetroots were investigated. Different microwave-assisted drying methods, namely high-power microwave drying followed by low-power microwave drying (HMD+LMD), high-power microwave drying (HMD), low-power microwave drying (LMD), high-power microwave drying followed by hot air drying (HMD+HAD), hot air drying followed by low-power microwave drying (HAD+LMD), high-power microwave drying followed by vacuum drying (HMD+VD) and vacuum drying followed by low-power microwave drying (VD+LMD), on the quality characteristics of dehydrated beetroots were studied. According to the results, it was demonstrated that VD+LMD was the optimal microwave-assisted method for beetroot drying. Influence of different drying methods, namely heat pump drying (HPD), vacuum drying (VD), freeze drying (FD), microwave drying (MD), microwave vacuum drying (MVD) on the physical properties, bioactive compounds and antioxidant capacity of dehydrated beetroots were also investigated. Considering the quality attributes and drying time, the combined drying methods (HPD+MVD) may guarantee high quality of beetroots and a short drying time. In this section, freeze-thaw cycles such as freeze-thaw once (FT1), freeze-thaw two times (FT2), freeze-thaw three times (FT3), and without freeze-thaw pretreatment (FT0), different freezing temperatures (–4, –20, –50, and –80 °C), and different thawing methods (microwave thawing, water thawing, air thawing, refrigerator thawing, and ultrasonic thawing) on the physical properties, bioactive compounds and antioxidant capacity of dehydrated beetroots were studied. The results demonstrated that freeze thaw once (FT1) was the best number of freeze-thaw cycles, and the optimal freezing temperature was –20 °C, and water thawing was a more suitable way to thaw the frozen beetroots. In the fourth section presented the results of dried beetroot, pretreated by freeze-thaw method used in meat product and biscuits. Beetroot powder can improve the quality properties of the meat product, not only by increasing the sensory evaluation and increasing the protein content, but also by inhibiting the lipid oxidation of the meat product due to the presence of betalain. Also, betalain of beetroot powder is an effective antioxidant and food coloring in meat products and sausage products. It was revealed that the beetroot powder addition of 2.0% resulted in improve physicochemical properties of meat product. The results showed that the addition of dried beetroot, pretreated by freeze-thaw method to biscuits provides better sensory properties (color, taste and smell) and increases the nutritional value of biscuits. It was concluded that the substitution of low-gluten wheat flour with dried beetroot, pretreated by freeze-thaw method up to 10% into the formulation of biscuits could enhance the organoleptic properties and nutritional value of biscuits. This study can provide important information for the further use of Beetroot powder in the technology of minced meat products such as sausages and meet-containing breads. Degustation of biscuits and meat products with the addition of beetroot powder was carried out at Hezhou University in China. Degustation results were recorded in the relevant degustation protocols. In the fifth section, practical implementation of dried beetroot, pretreated by freeze-thaw method and food products using it were introduce. Determination of the socio-economic effect of the introduction of the semi-finished beetroot production technology. To calculate the full cost of production, we took into account the cost of all costs for the production and sale of manufactured products as of 2023 in Ukraine. Based on the implementation of the results of the innovative strategy of developing new products, conducted theoretical and experimental research, the technology of semi-finished beetroot and culinary products using it has been tested and implemented in the food industry. The profitability of the products from the sale of the research and industrial batch in the amount of 30 kg of finished products is at a high level.