EFFECT OF DIFFERENT BLANCHING TREATMENTS ON ASCORBIC ACID RETENTION IN GREEN LEAFY VEGETABLES

P.B. PATEL¹, P.V. PATEL², S.B. JOSHI³*, D.D. PANDYA⁴, M.K. CHAUDHARY⁵, B.G. PATEL⁶, A.B. JOSHI^7
1Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
²Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
³Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
⁴Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
⁵Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
⁶Department of Food Science and Nutrition, ASPEE College of Home science and Nutrition, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
⁷Department of Physiology and Biochemistry, College of Veterinary Science & Animal Husbandry, S.D. Agricultural University, Sardarkrushinagar, Gujarat 385506, India
* Corresponding Author : jsumit291@gmail.com

Received : 27-06-2016     Accepted : 12-08-2016     Published : 27-10-2016
Volume : 8     Issue : 51       Pages : 2353 - 2355
Int J Agr Sci 8.51 (2016):2353-2355

Keywords : Leafy vegetables, Ascorbic acid, Steam blanching, Chemical blanching, Microwave blanching, Peroxidase inactivation.
Academic Editor : Prajapati Mayurkumar Manibhai
Conflict of Interest : None declared
Acknowledgements/Funding : None declared
Author Contribution : None declared

A field experiment was conducted on Department of Food Science and Nutrition, ASPEE College of Home Science and Nutrition, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar to study the, effect of different blanching treatments on micronutrient retention in green leafy vegetables. Blanching is a prerequisite for preservation of green leafy vegetables. However, it may cause partial destruction of some nutrients like ascorbic acid, which is highly oxidizable with time in the post-harvest period on atmospheric exposure. The objective of the present study was to identify a suitable blanching treatment and conditions (temperature, time and media) for commonly consumed green leafy vegetables that ensures enzyme inactivation and maximum ascorbic acid retention. Twelve treatment combinations consisting of four commonly consumed leafy vegetables, viz. spinach leaves (Spinacia oleracea), Fenugreek Leaves (Trigonella), Drumstick Leaves (Moringa oleifera) and Amaranth Leaves (Amaranthus gangeticus Linn.)were blanched for 1, 2, and 4min at 80 ÌŠC and 90 ÌŠC in water and chemical media, steamed for 5 and 10 min with and without chemical treatment and microwaved for 1 and 1.5 min, unblanched greens served as control. Retention of ascorbic acid was reduced as the blanching time and temperature increased in all greens. It was comparatively higher in chemically treated samples both in conventional and steam blanched samples. Steam blanched samples (5 min) had a higher level of ascorbic acid than conventional blanched samples irrespective of blanching media. Ascorbic acid content of microwave-blanched samples was better in some greens compared to conventionally blanched greens. Blanching at 80 ËšC for 1 min, steaming for 5 min and microwaving for 1 min was sufficient to inactivate peroxidase in all except two green leafy vegetables irrespective of the blanching media. From the nutrition point of view, chemical blanching proved to be advantageous both in steam and conventional blanching for short period and it also ensured enzyme inactivation.