Effect of Drying Temperature Level on Vacuum Drying of Okra Combined with Far-infrared Radiation
Article Sidebar
Main Article Content
Abstract
This research aimed to study the effect of infrared radiation assisted vacuum drying on the change of moisture content of okra and to determine the electrical energy and specific energy consumption used for drying. The physical property in terms of the color of dried okra powder was examined. Okra sheets with a size of 30x30 (width x length) cm and a thickness of 5 mm were dried under an absolute pressure of the drying chamber of 7 kPa and the drying temperatures of 70, 80, and 90oC until the moisture content of the okra was lower than 10% wet basis. The experimental results showed that dried okra at high temperatures could reduce moisture faster than that at low temperatures. Drying okra at the temperature of 70oC had a significantly higher the electrical energy and specific energy consumption than that of 80 and 90oC (P£0.05). The electrical energy and specific energy consumption used for drying okra at 80 and 90oC were not significantly different (P>005). In addition, okra powder dried at high temperatures had significantly lower lightness (L* value) and greenness (-a* value) than that at low temperatures (P£0.05). Okra powder dried at the temperature of 70oC had significantly lower yellowness (b* value) than that of 90oC (P£0.05). However, the yellowness (b* value) of okra powder dried at the temperature of 80oC and okra powder dried at the temperatures of 70 and 90oC were not significantly different (P>0.05). Therefore, okra powder dried at an absolute pressure of the drying chamber of 7 kPa and the drying temperature of 70oC had the best color quality compared to that of 80 and 90oC.
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
ลิขสิทธ์ ของมหาวิทยาลัยเทคโนโลยีราชมงคลพระนครReferences
Office of Agricultural Economics, Okra, 1st ed. Bangkok: Office of Agricultural Economics, 2020.
P. Jitjaroenrungruang, “Development of polysaccharide from okra for cosmetic products,” Independent study, Dept. Cosmetic Sci., Mae Fah Luang University, Chiang Rai, Thailand, 2015.
S. Trakultaweepat, “Study on dried basil leaf with low temperature and relative humidity,” M.S. thesis, Dept. Energy Tech., King Mongkut's University of Technology Thonburi, Bangkok, Thailand, 2017.
S. Saksuwan, “Product development of dried mango without sugar added using combined microwave and hot air drying technique,” M.Eng. thesis, Dept. Energy Tech., King Mongkut's University of Technology Thonburi, Bangkok, Thailand, 2017.
P. Sa-adchom and T. Swasdisevi, “Pork slices drying using a combined vacuum and far-infrared radiation technique,” Industrial Technology Lampang Rajabhat University Journal, vol. 7, no. 1, pp. 83-97, Jan. 2014.
C. Rattanamongkol, “Drying kinetics of vacuum far-infrared drying of mango,” M.Eng. thesis, Dept. Food Eng., Maejo University, Chiang Mai, Thailand, 2018.
P. Kongpoopha, U. Tapai and P. Sa-adchom, “Effect of drying temperatures on charcoal briquettes drying using a combined solar energy and far-Infrared radiation dryer, and a far-infrared radiation dryer,” RMUTP Research Journal, vol. 10, no. 1, pp. 77-93, Mar. 2016.
W. Pumpho, V. Khon-ngam, S. Labuawong, P. Arwat and P. Sa-adchom, “Production of roasted chicken in jar using heat transfers from far-infrared ray,” RMUTP Research Journal, vol. 14, no. 2, pp. 85-97, Mar. 2020.
U. Teeboonma and S. Jongjam, “Ginger drying using infrared-vacuum technique,” Burapha Science Journal, vol. 15, no. 2, pp. 76-86, Jul. 2010.
S. Soros, P. Toomthong, S. Suayklang and N. Keeratiyadathanapat, “Infrared-vacuum drying machine,” Research report, Dept. Agricultural Machinery, Rajamangala University of Technology Isan Surin Campus, Surin, Thailand, 2013.
S. Sakaew, P. Toomthong and T. Homchampa, “Drying of herbal using infrared-vacuum,” Research report, Dept. Electrical Tech., Rajamangala University of Technology Isan Surin Campus, Surin, Thailand, 2014.
N. Keeratiyadathanapat, A. Leetrakool and S. Srina, “Hang-rice drying by Thai jasmine rice 105 using infrared-vacuum,” Research report, Dept. Mechanical Eng., Rajamangala University of Technology Isan Surin Campus, Surin, Thailand, 2015.
P. Praneetpolkrang and P. Leekun, “Khlu leave tea drying using infrared-vacuum technique,” Research report, Dept. Industrials Tech., Rambhai Barni Rajabhat University, Chanthaburi, Thailand, 2016.
S. Thanimkarn, “Drying of Cissus quadrangularis Linn. using vibration assisted infrared drying under vacuum conditions,” Ph.D. dissertation, Dept. Agricultural Eng., King Mongkut's Institute of Technology, Bangkok, Thailand, 2019.
K. Witinantakit, N. Uengkimbuan and S. Rungsawang, “Mathematical modeling of shiitake mushroom drying using infrared-vacuum technique,” SWU Engineering Journal, vol. 14, no. 3, pp. 1-13, Sep. 2019.
W. Manangan and K. Witinantakit, “Water lily drying using pulsed vacuum-infrared combined with silica sand embedding,” Kasem Bundit Engineering Journal, vol. 10, no. 3, pp. 84-98, Sep. 2020.
K. Witinantakit, W. Manantaphong, J. Sitranon and E. Boonthum, “The drying kinetic of ginger slices using pulsed vacuum dryer,” Industrial Technology and Engineering Pibulsongkram Rajabhat University Journal, vol. 3, no. 1, pp. 21-31, Jan. 2021.
S. Jaekhom, K. Witinantakit and E. Boonthum, “Herb drying using vacuum combined infrared radiation and hot air,” Industrial Technology and Engineering Pibulsongkram Rajabhat University Journal, vol. 3, no. 1, pp. 32-43, Jan. 2021.
C. Chucherd and N. Limtiyayothin, “The seasoned star gooseberry baked sheet product,” Special project, Dept. Food Services Industry, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand, 2016.
N. Jorntapha and A. Soponaumpornnara, “Production of crispy okra sheet by hot air oven dryer,” B.Sc. special project, Dept. Food Sci. & Tech., Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand, 2015.
W. Saengthongpinit, S. Thakham, P. Theptubtim and P. Fuengfu, “Development of okra (Abelmoschus esculentus (L.) Moench) and water spinach (Ipomoea aquatica Var. reptans) sheet as a healthy snack,” in Proceeding of the 7th NPRU National Academic Conference, Nakhon Pathom, 2015, pp. 771-780.
AOAC, Official Methods of Analysis of AOAC International, 19th ed. Virginia: Association of Official Analytical Chemists, 2019.
A. Panyayuen, J. Lek-ong, K. Kunsuwan and P. Sa-adchom, “The study of suitable drying time and physical characteristic of pork slices dried using microwave followed by hot air,” RMUTP Research Journal, vol. 13, no. 1, pp. 63-77, Jan. 2019.
P. Sa-adchom, T. Swasdisevi, T. Thomthong, P. Samuttharin and S. soponronnarit, “Drying of ground fish slices using superheated steam,” RMUTP Research Journal, vol. 7, no. 2, pp. 74-86, Mar. 2013.
P. Sa-adchom, P. Supavititpatana and T. Supavititpatana, “Effect of drying temperature on foam-mat tamarind drying using far-infrared radiation,” in Proceeding of the 18th TSAE National Conference and the 10th TSAE International Conference, Bangkok, 2015, pp. 277-282.
R. Yamsuan, K. Ruttarattanamongkol and R. Assavarachan, “Drying modelling and influence of temperature on physicochemical properties of soft dried pickled ginger,” Thai Society of Agricultural Engineering Journal, vol. 24, no. 1, pp. 47-57, Mar. 2018.