Effect of Natural Antioxidants Extracted from Simarouba glauca and Radermachera xylocarpa Deoiled Seed Cakes on the Oxidative Stability of Soybean Oil during Accelerated Storage
Bollampalli Anjaneyulu
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Fabrice Tonfack Djikeng
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India and School of Agriculture and Natural Resources, Catholic University Institute of Buea, P.O.Box 563, Buea, Cameroon.
Shiva Shanker Kaki
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Mallampalli Sri Lakshmi Karuna
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Enti Anjaneyulu
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Bhamidipati Venkata Surya Koppeswara Rao
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Vidavalur Siddaiah
Department of Organic Chemistry, Andhra University, Visakhapatnam, Andhrapradesh, India.
Sanjit Kanjilal
CSIR-Indian Institute of Chemical Technology, Centre for Lipid Research, Tarnaka, Hyderabad 500 007, India.
Hilaire Macaire Womeni *
Department of Biochemistry, Faculty of Science, University of Dschang, P.O.Box 67, Dschang, Cameroon.
*Author to whom correspondence should be addressed.
Abstract
Aims: The aim of the present study was to evaluate the protective effect of Deoiled seed cakes extracts of Simarouba glauca and Radermachera xylocarpa toward oxidation of soybean oil during accelerated storage.
Study Design: Seeds harvesting, oil extraction, natural antioxidants extraction from deoiled cakes, supplementation of soybean oil with the extract and evaluation of its oil stability during accelerated storages.
Place and Duration of Study: Council for Scientific and Industrial Research-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, India, from July 2015 to December 2015.
Methodology: Oils were extracted from the seeds on a Soxhlet apparatus. Deoiled cakes were then extracted with methanol. The obtained extract was used for phytochemical analysis, by colorimetry and high performance liquid chromatography (HPLC). After preliminary antioxidant tests, the extracts were respectively added in soybean oil at concentrations 200-1800 ppm. Oil containing butylated hydroxytoluene (BHT) and oil without antioxidants served as positive and negative controls respectively. The oxidative stability of these oil samples was evaluated by Rancimat and Schaal oven tests under forced storage conditions and measurement of oxidation parameters.
Results: The outcomes showed the total phenolic contents to be 19.22 and 9.87 mg GAE/g for Simarouba glauca (SG) and Radermachera xylocarpa (RX) respectively. Quercetine, Vanillic, caffeic, ferulic acids were the phenolic antioxidants detected in RX, while gallic acid and vanillic acid were those detected in SG. The induction times of soybean oil supplemented with the extracts of SG and RX were found to be in the range of 5.08-6.28 and 5.87-6.55 h respectively. Those of oil without antioxidant and oil supplemented with BHT were 4.84±0.03 and 6.42±0.12 h respectively. The extracts, at all concentrations, were efficient like BHT in delaying soybean oil oxidation during 21 days of storage at 65°C.
Conclusion: These extracts are viable sources of natural antioxidants for stabilization of soybean oil.
Keywords: Accelerated storage, natural antioxidant, oxidative stability, soybean oil, Simarouba glauca, Radermachera xylocarpa.