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Influence of Process Parameters Variation on Hybrid Nonstationary Drying
Published in M. Azharul Karim, Chung-Lim Law, Intermittent and Nonstationary Drying Technologies, 2017
M. Azharul Karim, Chung-Lim Law, Stefan Jan Kowalski, Justyna Szadzin´ska, Andrzej Pawłowski
Retention is understood as the retained number of bioactive compounds after processing. Fruits and vegetables are rich in vitamins, minerals, trace elements and terpene compounds, flavonoids, tannins, quinones, and phytoncides. The most frequent reason for the loss of many nutrients is thermal processing, including drying. Quality evaluation of dried products is usually carried out on the basis of thermolabile components content such as vitamins, for example, vitamin C. Vitamin C participates in many biochemical reactions, removes free radicals, affects immunity, and is one of the most important antioxidants. In addition, vitamin C possesses bacteriostatic and bactericidal properties and lowers the risk of cancer development. Natural dyes are unstable and easily degraded (oxidation) during processing (including drying) and storage due to the influence of oxygen, light, temperature, and pH, resulting in changes in color and smell. The color of fresh and processed fruits and vegetables is mainly due to carotenoids, chlorophylls, anthocyanins, and betalain pigments. Betalain pigments include reddish-violet betacyanins and yellow betaxanthins. The source of these dyes is red beetroots. Betanin gives a specific and attractive red color and moreover has health-promoting properties, is a strong antioxidant, and has anticancer, antibacterial, and antiviral effects (Harmer 1980; Dreosti 1993; Asard et al. 2004; Prakash et al. 2004).
Utilisation of Bioactive Compounds Derived from Waste in the Food Industry
Published in Quan V. Vuong, Utilisation of Bioactive Compounds from Agricultural and Food Waste, 2017
Quan V. Vuong, Mirel la A. Atherton
Anthoxanthins comprise of flavones, flavonols and flavonones and they are responsible for the cream or white color of cauliflower, white potato and turnips. Under acidic conditions, anthoxanthins can be whiter; however, they might turn into an undesirable yellow color in alkaline water. They even change to blue-black or red- brown under excessive heating or in the presence of iron or copper (Brown 2008). Betalains comprise two groups of pigments: the red–purple betacyanidins and the yellow betaxanthins, which are water-soluble. Betacyanidins are conjugates of cycloDOPA and betalamic acid, whereas betaxanthins are conjugates of amino acids or amines and betalamic acid (Mortensen 2006). Under acidic conditions, Betalains can change the purple-red to a brighter red color, whereas the red color can change to yellow in an alkaline medium (Brown 2008).
Reaction Kinetics in Food Systems
Published in Dennis R. Heldman, Daryl B. Lund, Cristina M. Sabliov, Handbook of Food Engineering, 2018
Ricardo Villota, James G. Hawkes
Their sensitivity to environmental factors such as temperature, light, oxygen, and humidity has limited their application as food colorants. A better understanding of their kinetic stability will facilitate their wider application in the food industry and may potentially displace the application of synthetic dies. On the other hand, betalains are compounds with antioxidant activity, and, thus, have gained great interest in human nutrition. Betanin and betanidin in very small concentrations have been found to inhibit lipid peroxidation and heme decomposition (Kanner et al, 2001). Red beet products in the diet have been suggested as having protection against oxidative stress-related disorders in humans, since they are good electron donors. Stintzing et al. (2005) substantiated the antioxidant properties of betalains, as found in cactus pear clones. The authors pointed out that this plant was a good economical source of betalains but content was dependent upon individual plant species. Other sources of betalains as food colorants have been investigated. Cai and Cork (1999), for instance, carried out a comparative stability of Amaranthus betacyanin pigments against a radish anthocyanin and a synthetic FDA Red No. 3 as added to different food types such as ice cream, jelly, and model beverage, with pH adjusted to 5–6.0. They found similar stability of the amaranth to the anthocyanins, but less stability compared to the synthetic dye. In general, there has been a great deal of interest in betalains, not only as a source of natural colorant, but also as a nutraceutical. Red pigments from beets are pharmaceutically interesting, as they have not only been reported as antioxidants, but also as having anticarcinogenic properties (Kapadia et al., 2003). Currently, extracts from beets are the only betalain colorants permitted in the United States. Commercial beet powders generally contain about 0.4–1.0% pigment, 80% sugar, 8% ash, and 10% protein with citric acid and/or ascorbic acid as a preservative (Francis, 2000a).
Chemical and physical properties of vacuum-dried red beetroot (Beta vulgaris) powders compared to other drying methods
Published in Drying Technology, 2020
William L. Kerr, Audrey Varner
Red beetroot (Beta vulgaris) contains betalains, a class of aromatic indoles that give color to plants in the Caryophyllales family. They consist of the red-purple betalains such as betanin, isobetanin, and probetanin, as well as the yellow-orange betaxanthins such as vulgaxanthin, miraxanthin, and indicaxanthin. Due to their stability over a range of pH values, betalains are used as a source of natural color in foods such as yogurts, ice cream, candies, and jellies in either powder or liquid form. Beet products have also been studied for their beneficial effects on hypertension and athletic performance.[1,2] These benefits are likely related to nitrates in the beets that are converted to nitric oxide in the body, or through the direct action of betain on homocysteine – a compound that promotes blood vessel inflammation.[3] The dehydration of beets into powdered ingredients is one method of increasing and diversifying products available for consumption. However, betalains are heat labile, thus creating a challenge for processors.
Influence of pretreatment with ethanol and drying temperature on physicochemical and antioxidant properties of white and red pulp pitayas dried in foam mat
Published in Drying Technology, 2022
Cintia da Silva Araújo, Jefferson Luiz Gomes Corrêa, Satyanarayan Dev, Leandro Levate Macedo, Wallaf Costa Vimercati, Cassiano Rodrigues de Oliveira, Leila Aparecida Salles Pio
Betalains are a group of water-soluble pigments present in the cellular vacuum of flowers, fruits, roots and leaves of some plants. The plants that have these pigments belong to only 10 families of the order Centrospermae. In this group of pigments, there are betacyanins and betaxanthins, which are responsible for giving, respectively, the colors red-violet (mainly betanins) and yellow-orange. In addition to the coloring effect, betalains perform antioxidant functions by two main mechanisms: induction of antioxidant defense and elimination of free radicals.[29,30]
Hot air drying of red beet: Process and product quality monitoring by digital images and near infrared spectroscopy
Published in Drying Technology, 2023
Pedro Renann de França, Jam Pier Cruz-Tirado, Douglas Fernandes Barbin, Louise Emy Kurozawa
The average initial TB was 4.00 ± 0.03 mg. g−1 db. The retention of betalains at the end of drying was 49.8 ± 1.6%, 43.7 ± 1.7%, 35.3 ± 3.3%, and 25.7 ± 3.1% for 40, 50, 60, and 70 °C, respectively (Figure 3). Gandía-Herrero et. al [20] points out that temperature is the main factor that affects the stability of betalains, with a significant degradation of these compounds accompanied by losses of color and antioxidant capacity.