Research of physicochemical properties and antioxidant activity of beetroots as affected by vacuum microwave drying conditions
DOI:
https://doi.org/10.15587/2706-5448.2021.243069Keywords:
dried beetroots, vacuum microwave drying, betalain, total flavonoid, colorimetric methods, antioxidant activityAbstract
The object of research is the beetroots, dried by vacuum microwave drying at different conditions. Physicochemical properties and antioxidant activity of beetroots were studied using vacuum microwave drying at different microwave power (500, 1000, and 1500 W), vacuum degree (–0.05, –0.07, and –0.09 MPa) and sample thickness (2, 4, and 6 mm). A colorimeter was used to evaluate the color quality of beetroots. Colorimetric methods were used to determinate contents of betalain, ascorbic acid and total flavonoid, and antioxidant activity (ferric reducing antioxidant power assay) of beetroots.
Results showed that the drying time decreased with increasing microwave power and vacuum degree, while increased significantly with the increase of sample thickness. The lightness (L*) of dried beetroots was higher than that of fresh beetroots. The values of redness (a*) increased with the increase of vacuum degree. The values of yellowness (b*) increased with the growth of vacuum degree and microwave power, while reduced as the sample thickness added. The total color difference (∆E) of dried beetroots reduced with increasing vacuum degree, and displayed the lowest value (5.95) at a vacuum degree of –0.09 MPa as compared to fresh beetroots. The content of betacyanin, betaxanthin and ascorbic acid displayed a declining tendency with the growth of microwave power, while increased with the increase of vacuum degree. And the total flavonoid content of beetroots illustrated a decreasing tendency with the increase of vacuum degree, microwave power and sample thickness. The ferric reducing antioxidant power (FRAP) of dried beetroots decreased significantly with the increase of microwave power, and showed the highest value (14.70 mg trolox equivalents/g) at a microwave power of 500 W.
The most favorable conditions for vacuum microwave drying of beetroots were microwave power of 500 W, vacuum degree of –0.09 MPa and sample thickness of 2 mm. It leads to better physicochemical properties of bioactive compounds and higher antioxidant activity of dried beetroots. The dried beetroots can be used as functional foods and value-added food products.
References
- Chhikara, N., Kushwaha, K., Sharma, P., Gat, Y., Panghal, A. (2019). Bioactive compounds of beetroot and utilization in food processing industry: A critical review. Food Chemistry, 272, 192–200. doi: https://doi.org/10.1016/j.foodchem.2018.08.022
- Paciulli, M., Medina-Meza, I. G., Chiavaro, E., Barbosa-Cánovas, G. V. (2016). Impact of thermal and high pressure processing on quality parameters of beetroot (Beta vulgaris L.). LWT – Food Science and Technology, 68, 98–104. doi: https://doi.org/10.1016/j.lwt.2015.12.029
- Fu, Y., Shi, J., Xie, S.-Y., Zhang, T.-Y., Soladoye, O. P., Aluko, R. E. (2020). Red Beetroot Betalains: Perspectives on Extraction, Processing, and Potential Health Benefits. Journal of Agricultural and Food Chemistry, 68 (42), 11595–11611. doi: https://doi.org/10.1021/acs.jafc.0c04241
- Slavov, A., Karagyozov, V., Denev, P., Kratchanova, M., Kratchanov, C. (2013). Antioxidant activity of red beet juices obtained after microwave and thermal pretreatments. Czech Journal of Food Sciences, 31 (2), 139–147. doi: https://doi.org/10.17221/61/2012-cjfs
- Hadipour, E., Taleghani, A., Tayarani‐Najaran, N., Tayarani‐Najaran, Z. (2020). Biological effects of red beetroot and betalains: A review. Phytotherapy Research, 34 (8), 1847–1867. doi: https://doi.org/10.1002/ptr.6653
- Nemzer, B., Pietrzkowski, Z., Spórna, A., Stalica, P., Thresher, W., Michałowski, T., Wybraniec, S. (2011). Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts. Food Chemistry, 127 (1), 42–53. doi: https://doi.org/10.1016/j.foodchem.2010.12.081
- Scaman, C. H., Durance, T. D. (2005). Combined Microwave Vacuuum-drying. Emerging Technologies for Food Processing, 507–533. doi: https://doi.org/10.1016/B978-012676757-5/50021-9
- Bórquez, R. M., Canales, E. R., Redon, J. P. (2010). Osmotic dehydration of raspberries with vacuum pretreatment followed by microwave-vacuum drying. Journal of Food Engineering, 99 (2), 121–127. doi: https://doi.org/10.1016/j.jfoodeng.2010.02.006
- Shu, B., Wu, G., Wang, Z., Wang, J., Huang, F., Dong, L., Zhang, R., Wang, Y., Su, D. (2020). The effect of microwave vacuum drying process on citrus: drying kinetics, physicochemical composition and antioxidant activity of dried citrus (Citrus reticulata Blanco) peel. Journal of Food Measurement and Characterization, 14 (5), 2443–2452. doi: https://doi.org/10.1007/s11694-020-00492-3
- Li, B., Fei, L., Liu, B., Nan, H. (2010). Microwave-vacuum drying characteristics and process optimization of Agaricus bisporus slices. Transactions of the Chinese Society of Agricultural Engineering, 26 (6), 380–384. doi: https://doi.org/10.3969/j.issn.1002-6819.2010.06.066
- Monteiro, R. L., Link, J. V., Tribuzi, G., Carciofi, B. A. M., Laurindo, J. B. (2018). Microwave vacuum drying and multi-flash drying of pumpkin slices. Journal of Food Engineering, 232, 1–10. doi: https://doi.org/10.1016/j.jfoodeng.2018.03.015
- Wang, J., Fang, X.-M., Mujumdar, A. S., Qian, J.-Y., Zhang, Q., Yang, X.-H., Liu, Y.-H., Gao, Z.-J., Xiao, H.-W. (2017). Effect of high-humidity hot air impingement blanching (HHAIB) on drying and quality of red pepper (Capsicum annuum L.). Food Chemistry, 220, 145–152. doi: https://doi.org/10.1016/j.foodchem.2016.09.200
- Stintzing, F. C., Herbach, K. M., Mosshammer, M. R., Carle, R., Yi, W., Sellappan, S., Akoh, C. C., Bunch, R., Felker, P. (2004). Color, Betalain Pattern, and Antioxidant Properties of Cactus Pear (Opuntia spp.) Clones. Journal of Agricultural and Food Chemistry, 53 (2), 442–451. doi: https://doi.org/10.1021/jf048751y
- De Souza, V. R., Pereira, P. A. P., da Silva, T. L. T., de Oliveira Lima, L. C., Pio, R., Queiroz, F. (2014). Determination of the bioactive compounds, antioxidant activity and chemical composition of Brazilian blackberry, red raspberry, strawberry, blueberry and sweet cherry fruits. Food Chemistry, 156, 362–368. doi: https://doi.org/10.1016/j.foodchem.2014.01.125
- Benzie, I. F. F., Strain, J. J. (1996). The Ferric Reducing Ability of Plasma (FRAP) as a Measure of «Antioxidant Power»: The FRAP Assay. Analytical Biochemistry, 239 (1), 70–76. doi: https://doi.org/10.1006/abio.1996.0292
- Tian, Y., Wu, S., Zhao, Y., Zhang, Q., Huang, J., Zheng, B. (2015). Drying Characteristics and Processing Parameters for Microwave-Vacuum Drying of Kiwifruit (Actinidia deliciosa) Slices. Journal of Food Processing and Preservation, 39 (6), 2620–2629. doi: https://doi.org/10.1111/jfpp.12512
- Ng, M. L., Sulaiman, R. (2018). Development of beetroot (Beta vulgaris) powder using foam mat drying. LWT–Food Science and Technology, 88, 80–86. doi: https://doi.org/10.1016/j.lwt.2017.08.032
- Sremet (Ceclu), L., Nistor, O.-V., Andronoiu, D. G., Mocanu, G. D., Barbu, V. V., Maidan, A., Rudi, L., Botez, E. (2020). Development of several hybrid drying methods used to obtain red beetroot powder. Food Chemistry, 310, 125637. doi: https://doi.org/10.1016/j.foodchem.2019.125637
- Székely, D., Vidák, K., Furulyás, D., Ribárszki, Á., Stéger-Máté, M. (2019). Effect of drying methods on physicochemical parameters of different red beetroots (Beta vulgaris L.) species. Periodica Polytechnica Chemical Engineering, 63 (3), 485–490. doi: https://doi.org/10.3311/PPch.13104
- Handwerk, R. L., Coleman, R. L. (1988). Approaches to the citrus browning problem. A review. Journal of Agricultural and Food Chemistry, 36 (1), 231–236. doi: https://doi.org/10.1021/jf00079a057
- Ravichandran, K., Saw, N. M. M. T., Mohdaly, A. A. A., Gabr, A. A. A., Kastell A., Riedel, H., Cai, Z. Z., Knorr, D., Smetanska, I. (2013). Impact of processing of red beet on betalain content and antioxidant activity. Food Research International, 50 (2), 670–675. doi: https://doi.org/10.1016/j.foodres.2011.07.002
- Vega-Gálvez, A., Di Scala, K., Rodríguez, K., Lemus-Mondaca, R., Miranda, M., López, J., Perez-Won, M. (2009). Effect of air-drying temperature on physico-chemical properties, antioxidant capacity, colour and total phenolic content of red pepper (Capsicum annuum, L. var. Hungarian). Food Chemistry, 117 (4), 647–653. doi: https://doi.org/10.1016/j.foodchem.2009.04.066
- Zielinska, M., Zielinska, D. (2019). Effects of freezing, convective and microwave-vacuum drying on the content of bioactive compounds and color of cranberries. LWT–Food Science and Technology, 104, 202–209. doi: https://doi.org/10.1016/j.lwt.2019.01.041
- Nguyen, T.-V.-L., Nguyen, Q.-N., Nguyen, P.-B.-D., Tran, B.-L., Huynh, P.-T. (2020). Effects of drying conditions in low–temperature microwave–assisted drying on bioactive compounds and antioxidant activity of dehydrated bitter melon (Momordica charantia L.), Food Science and Nutrition, 8 (7), 3826–3834. doi: https://doi.org/10.1002/fsn3.1676
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