Development of a Machine for Expressing Vernonia amygdalina Leaf Juice
Keywords:
Vernonia amygdalina leaf juice, machine throughput, bioactive substancesAbstract
Vernonia amygdalina leaf juice is known for its nutritive value and as food supplement. There is therefore, a need for a simple processing device for the leaf juice expression. This study developed a machine for producing contamination-free V. amygdalina leaf juice. The design of the machine was based on the principle of a pressure deferential applied to the incoming leaf mash compared with that applied to the discharged material. Macerated leaves were compressed through a tapered screw conveyor; whose shaft terminates as a rising but short conical kink. The maximum juice yield of 41.39% was expressed from the leaf mash at pressing pressure and residence time of 6.09 MPa and 11 min, respectively. The throughput of the machine was 9.60 kg/h and the juice extraction rate was 1.86 /h at leaf to water ratio of 1: 0.8. The maximum juice expression efficiency was 15.54% at 1:1.2 leaf to water ratio, 60 rpm constant rotational motor speed and 11.99 kg/h feeding rate. Approximately 26.38% of the inherent moisture content of the leaf was expressed by the machine. It is expected that the machine may be used to express juice from other plant leaves having comparative physical properties. The machine therefore provides a viable technique for mechanical expression of good quality V. amygdalina leaf juice.
References
Aregbesola, O. A., Faborode, M. O. and Hounkanrin, B.A. Studies on the production of herbal tea from Hibiscus sabdariffa (Roselle) calyxes. 3rd Proceedings of Nigerian Institute of Agricultural Engineering, 210–213, 2009.
Arlabosse, P., Blanca, M., Kerfaïc, S. and Fernandezc, A. Production of green juice with an intensive thermo-mechanical fraction process. Part I: effect of processing conditions on the dewatering kinetics. Chemical Engineering Journal 168: 586–592, 2011.
ASAE Standards. Moisture measurement–forages, 47th edition. American Society of Agricultural Engineers, ASAE S358.2, St. Joseph, Michigan. 57–59, 2001.
Huffman, M. A. Animal self–medication and ethno–medicine: exploitation and exploration of medicinal properties of plants. Proceedings of the Nutrition Society, 62: 371–381, 2003.
Ivanov, E. V., Shvyrev M. V., Minina S. A., and Kochnev V. G. Method of medicinal plant material extraction in a planetary mill. Pharmaceutical Chemistry Journal. 38 (11): 29–32, 2004.
Kerfai S., Fernandez A., Mathe S., Alfenore S., Arlabosse P. Production of green juice with an intensive thermo-mechanical fraction process. Part II: effect of processing conditions on the liquid fraction properties. Chemical Engineering Journal 167: 132-139, 2011.
Kreshchenyuk, S. I., Litvinenko V. I. and Prokopenko A. P. Machines for grinding medicinal plant raw material. Khar,kov Scientific–Research Institute of Pharmaceutical Chemistry, 5 (6): 46–48, 1971.
Lebovka, N. I., Bazhal, M. I., and Vorobiev, E. Enhanced expression of juice from soft vegetable tissues by pulsed electric fields: consolidation stages analysis. Journal of Food Engineering 59: 309–317, 2003.
Ogblechi, S.R. Development of a Mechanical Extractor for Date Fruit Juice Processing. Unpublished M.Sc. thesis, Department of Agricultural Engineering, Obafemi Awolowo University, Ile-Ife. 72–75, 2006.
Oke, A. O. Development of a Machine for Expressing Vernonia amygdalina Leaf Juice. M. Sc. Thesis, Department of Mechanical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria, 2012.
Okoye, C. N., Jiang, J., Hui, L. Y. Design and development of secondary controlled industrial palm kernel nut vegetable oil expeller plant for energy saving and recuperation. Journal of Food Engineering, 87: 578–590, 2008.
Oyeleke, F.I. and Olaniyan, A. M. Extraction of juice from tropical fruits using a small scale multi–fruit juice extractor. African Crop Science Conference Proceedings. 8: 1803–1808, 2007.
Pirie N. W. An economical unit for pressing juice from fibrous pulps. Journal of Agricultural Engineering Research. 38: 217–222, 1987.
Sharif, H. I., Al–Mashat, and Carlos, A. Z. Stress relaxation behavior of apple pomace and effect of temperature, pressing aid and compaction rate on juice yield. Journal of Food Engineering. 20:247–266, 1993.
Singh, J. and Bargale P. C. Development of a small capacity double stage compression screw press for oil expression. Journal of Food Engineering. 43: 75–82, 2000.
Sinha, S., Sokhansanj, S., Crerar, W. J., Yang, W., Tabil, L. G., Khoshtaghaza, M. H. and Patil, R.T. Mechanical dewatering of chopped alfalfa using an experimental piston–cylinder assembly. Canadian Agricultural Engineering 42 (3): 153–156, 2000.
Tangka, J. K. Analysis of the thermal energy requirements for the extraction of leaf protein concentrate from some green plants. Biosystems Engineering, 86 (4): 473–479, 2003.
Tangka, J. K. and Penda, P.M. Development and performance evaluation of a medium–scale system for processing bitter leaf. Biosystems Engineering, 96 (2): 223–229, 2007.
