eng Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 2021-10-19 9 10 523 530 10.12691/jfnr-9-10-4 JFNR20219104 article Haq Nawaz haqnawaz@bzu.edu.pk 1 Raheela Jabeen 2 Rana Farhat Mehmood 3 Misbah Irshad 4 Muhammad Imran Irfan 5 Madiha Shahid 5 Mubashir Nawaz 5 Department of Biochemistry, Bahauddin Zakariya University, Multan-60800, Pakistan Department of Biochemistry and Biotechnology, The Women University Multan, Multan-60000, Pakistan Department of Chemistry, Dera Ghazi Khan Campus, University of Education, Lahore Department of Chemistry, Division of Science and Technology, University of Education, Township, Lahore Institute of Chemistry, University of Sargodha, Sargodha-40100, Pakistan Background/Objective: Repeated freezing and thawing results in the structural, compositional, and functional modifications in food materials. The present study was designed to optimize the effect of Freeze-thaw treatment (FTT) on free radical scavenging and linoleic acid reduction potentials of Nelumbo nucifera rhizome starch (NNRS). Methodology: A 4-factorial response-surface central composite design (CCD) based on three levels of each of the four input factors including freezing temperature (FT: -40, -20, and 0°C), freezing time (Ft: 24, 48, and 72 h), thawing time (Tt: 2, 4, and 6 h), and number of freeze-thaw cycles (FTC: 2, 4, and 6) was constructed. The NNRS was treated at different combinations of input variables as selected by CCD. The Freeze-thaw-treated N. nucifera rhizome starch (FTT-NNRS) was analyzed for antioxidant potential. Principle Findings: A statistically significant main effect (p=0.0017-0.0029) of FTT was observed on free radical scavenging and linoleic acid reducing potential (LARP) of NNRS. The 2, 2-diphenylpicrylhydrazyl (DPPH) radical scavenging potential was found to be a linear positive function of FT and Ft while hydroxyl radical scavenging potential showed a linear linear negative response towards FT and linear positive response towards FTC. The LARP also showed a linear positive response towards FT and Tt and quadratic positive response towards FT. Conclusion: FTT significantly affected the free radical scavenging potential and LARP of NNRS that may be attributed to the time-dependent variation in the structure of starch and exposure of some antioxidant residues after repeated freezing and thawing treatments. http://pubs.sciepub.com/jfnr/9/10/4/jfnr-9-10-4.pdf free radical scavenging potential Freeze-thaw treatment Linoleic acid-reducing potential Nelumbo nucifera rhizome starch Response surface methodology