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Drying Kinetics, Physicochemical Properties and Sensory Quality of the Instant Foxtail Millet as Affected by Drying Methods
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College of Agriculture and Forestry, Longdong University, 745000, Qingyang, China
Yingqiang Wang   

College ofAgriculture and Forestry, Longdong university, China
Submission date: 2021-11-26
Final revision date: 2022-01-22
Acceptance date: 2022-01-27
Online publication date: 2022-02-18
Publication date: 2022-02-18
Pol. J. Food Nutr. Sci. 2022;72(1):69–78
The instant foxtail millet was prepared using microwave vacuum drying (MVD), microwave-hot air drying (MHAD), hot air drying (HAD) and traditional roasting (TR). Their effects on drying kinetics, physicochemical properties as well as sensory quality were evaluated and compared. Results showed that the total drying time varied with the drying method used and was about 160, 100, 260, and 45 min for MVD, MHAD, HAD and TR, respectively. The effective moisture diffusion coefficients (Deff) were 6.57×10-9 m2/s, 9.80×10-9 m2/s, 4.14×10-9 m2/s and 6.20×10-9 m2/s for MVD, MHAD, HAD and TR, respectively. Drying resulted in a significant decrease in L* and an increase in a* and b* of the color of products. MVD, MHAD and HAD products had a comparable rehydration ratio and cooking time. Scanning electron microscopy and rehydration process revealed that MHAD and MVD samples had a similar structure with the HAD sample. Drying caused a loss of 6.5–54.9% in the total phenolic content and a loss of 38.4–62.2% in total yellow pigment content. MVD millet displayed the highest total phenolic content (142.56 mg GAE/100 g dry matter) and yellow pigment content (9.56 mg CE/kg dry matter). In sensory evaluation, MHAD, HAD and MVD samples had comparable scores and were all accepted by the panelists, either in dry or rehydrated form. MHAD and MVD can be used as an alternative to hot air drying or traditional roasting in the production of the instant millet due to shorter drying time and better product quality.
The authors gratefully acknowledged the financial supports provided by the National Natural Science Foundation of China (No.31460398 and No.32060544) and the Scientific Research Starting Foundation for Doctor (No.2014XYBY1) and Youth Science and Technology Innovation Project (No. XYZK1707) of Longdong University.
AOAC. 1997. Official Methods of Analysis of the Association of Official Analytical Chemists. 16th ed. Washington, DC.
Bi, S., Wang, A., Wang, Y., Xu, X., Luo, D., Shen, Q., Wu, J. (2019). Effect of cooking on aroma profiles of Chinese foxtail millet (Setaria italica) and correlation with sensory quality. Food Chemistry, 289(15), 680-692.
Chahbani, A., Fakhfakh, N., Balti, M.A., Mabrouk, M., El-Hatmi, H., Zourai, N., Kechaou, N. (2018). Microwave drying effects on drying kinetics, bioactive compounds and antioxidant activity of green peas (Pisum sativum L.). Food Bioscience, 25, 32-38.
Chong, C.H., Law, C.L., Cloke, M., Hii, C.L., Abdullah, L.C., Daud, W.R. W. (2008). Drying kinetics and product quality of dried Chempedak. Journal of Food Engineering, 88(4), 522–527.
Dhua, S., Kheto, A., Sharanagat, V.S., Singh, L., Kumar, K., Nema, P.K. (2021). Quality characteristics of sand, pan and microwave roasted pigmented wheat (Triticum aestivum). Food Chemistry, 365, art. no. 130372.
FAO (2005). Sorghum and millets in human nutrition. FAO Food and Nutrition Series, No.68. Rome, p. 277.
Hithamani, G., Srinivasan, K. (2014). Effect of domestic processing on the polyphenol content and bioaccessibility in finger millet (Eleusine coracana) and pearl millet (Pennisetum glaucum). Food Chemistry, 164, 55-62.
Hsu, R.J.C., Chen, H.J., Lu, S., Chiang, W.C. (2015). Effects of cooking, retrogradation and drying on starch digestibility in instant rice making. Journal of Cereal Science, 65, 154-161.
Jiao, A., Xu, X., Jin, Z. (2014). Modelling of dehydration–rehydration of instant rice in combined microwave-hot air drying. Food and Bioproducts Processing, 92(3), 259-265.
Kaya, A., Aydin, O., Demirtas, C., Akgün, M. (2007). An experimental study on the drying kinetics of quince. Desalination, 212(1-3), 328-343.
Le, T.Q., Jittanit, W. (2012). Drying characteristics of cooked jasmine brown rice and true densities of dried products. Kasetsart Journal (Natural Science), 46, 256-271.
Le, T.Q., Jittanit, W. (2015). Optimization of operating process parameters for instant brown rice production with microwave-followed by convective hot air drying. Journal of Stored Products Research, 61, 1-8.
Lenaerts, S., Borght, M.V.D., Callens, A., Van Campenhout, L. (2018). Suitability of microwave drying for mealworms (Tenebrio molitor) as alternative to freeze drying: Impact on nutritional quality and color. Food Chemistry, 254, 129-136.
Li, S., Zhao, W., Liu, S., Li, P., Zhang, A., Zhang, J., Wang, Y., Liu, Y., Liu, J. (2021). Characterization of nutritional properties and aroma compounds in different colored kernel varieties of foxtail millet (Setaria italica). Journal of Cereal Science, 100, art. no. 103248.
Lin, T.M., Durance, T.D., Scaman, C.H. (1998). Characterization of vacuum microwave, air and freeze dried carrot slices. Food Research International, 31(2), 111-117.
Luangmalawat, P., Prachayawatakorn, S., Nathakaranakule, A., Soponronnarit, S. (2008). Effect of temperature on drying characteristic and quality of cooked rice. LWT - Food Science and Technology, 41(4), 716-723.
Palamanit, A., Sugira, A.M., Soponronnarit, S., Prachayawarakorn, S., Tungtrakul, P., Kalkan, F., Raghavan, V. (2020). Study on quality attributes and drying kinetics of instant parboiled rice fortified with turmeric using hot air and microwave-assisted hot air drying. Drying Technology, 38(4), 420-433.
Pradeep, P.M., Sreerama, Y.N. (2015).Impact of processing on the phenolic profiles of small millets: Evaluation of their antioxidant and enzyme inhibitory properties associated with hyperglycemia. Food Chemistry, 169, 455-463.
Rewthong, O., Soponronnarit, S., Taechapairoj, C., Tungtrakul, P., Prachayawarakorn, S. (2011). Effects of cooking, drying, and pretreatment methods on texture and starch digestibility of instant rice. Journal of Food Engineering, 103(3), 258-264.
Ritudomphol, O., Luangsakul, N. (2019). Optimization of processing condition of instant rice to lower the glycemic index. Journal of Food Science, 84(1), 101-110.
Saleh, A.S.M., Zhang, Q., Chen, J., Shen, Q. (2013). Millet grains: nutritional quality, processing, and potential health benefits. Comprehensive Reviews in Food Science & Food Safety, 12(3), 281-295.
Schoessler, K., Jaeger, H., Knorr, D. (2012). Effect of continuous and intermittent ultrasound on drying time and effective diffusivity during convective drying of apple and red bell pepper. Journal of Food Engineering, 108(1), 103-110.
Sharma, N., Niranjan, K. (2018). Foxtail millet: properties, processing, health benefits, and uses. Food Reviews International, 34(4), 329-363.
Shen, R., Yang, S.P., Zhao, G.H., Shen, Q., Diao, X.M. (2015). Identification of carotenoids in foxtail millet (Setaria italica) and the effects of cooking methods on carotenoid content. Journal of Cereal Science, 61, 86-93.
Shingare, S.P., Thorat, B.N. (2013). Effect of drying temperature and pretreatment on protein content and color changes during fluidized bed drying of finger millets (Ragi, Eleusine coracana) sprouts. Drying Technology, 31(5), 507-518.
Singleton, V.L., Orthofer, R., Ramuela-Raventos, R.M. (1999). Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Oxidants and Antioxidants, 299(1), 152-178.
Sripinyowanich, J., Noomhorm, A. (2013). Effects of freezing pretreatment, microwave assisted vibro-fluidized bed drying and drying temperature on instant rice production and quality. Journal of Food Processing and Preservation, 37(4), 314-324.
Wang, Q., Li, S., Han, X., Ni, Y., Zhao, D., Hao, J. (2019a). Quality evaluation and drying kinetics of shitake mushrooms dried by hot air, infrared and intermittent microwave-assisted drying methods. LWT – Food Science and Technology, 107, 236-242.
Wang, Y., Zhao, H., Deng, H., Song, X., Zhang, W., Wu, S., Wang, J. (2019b). Influence of pretreatments on microwave vacuum drying kinetics, physicochemical properties and sensory quality of apple slices. Polish Journal of Food and Nutrition Sciences, 69(3), 297-306.
Wang, R.C., Chen, C., Guo, S.T. (2017). Effects of drying methods on starch crystallinity of gelatinized foxtail millet (α-millet) and its eating quality. Journal of Food Engineering, 207, 81-89.
Wang, L., Zhang, G., Bao, G., Zhang, L. (2013). Study on rehydration of instant millet gruel by microwave and hot air combined drying. Cereal and Feed Industry, 12(6), 25-28.
Wang, Y., Zhang, M., Mujumdar, A.S. (2013). Effect of cassava starch gel, fish gel and mixed gels and thermal treatment on structure development and various quality parameters in microwave vacuum-dried gel slices. Food Hydrocolloids, 33(1), 26–37.
Wang, Y., Zhang, M., Mujumdar, A.S., Mothibe, K.J. (2012). Quality changes of dehydrated restructured fish product from silver carp as affected by drying methods. Food and Bioprocess Technology, 6(7), 1664–1680.
Xing, L.J., Mu, T.H., Zhang, M., Yu, S.X., Chen, J.W., Yang, H.Y. (2015). Effects of different low-temperature and drying treatment on the properties of purple sweet potato starch noodle. Food Science and Technology, 40(3), 15-121.
Zogzas, N.P., Maroulis, Z.B., Marinos-Kouris, D. (1996). Moisture diffusivity data compilation in foodstuffs. Drying Technology, 14(10), 2225-2253.
Zhang, M., Tang, J.M., Mujumdar, A.S., Wang, S. (2006). Trends in microwave-related drying of fruits and vegetables. Trends in Food Science & Technology, 17(10), 524-534.
Zhang, L., Li, J., Han, F., Ding, Z., Fan, L. (2017). Effects of different processing methods on the antioxidant activity of 6 cultivars of foxtail millet. Journal of Food Quality, 2017(SI), art. no. 8372854.