Vol. 11, Special Issue 1 (2022)

Author(s):
Sury Pratap Singh and Krishan Datt Sharma

Abstract:
Punjab – 8 variety of okra was dried in cabinet air dryer and solar tunnel dryer. The nutritional composition of cabinet air dried powder viz., moisture, protein, carbohydrate, fibre, ash, total polyphenolics, total carotenoids and antioxidant activity was 6.73%, 15.21%, 67.67%, 10.90%, 4.50%, 119.67 mg GAE/ 100 g, 29.0 mg/ 100 g, 57.0%, respectively while solar tunnel dried had 8.78%, 14.86%, 67.33%, 7.78%, 4.04%, 112.0 mg GAE/ 100 g, 27.30 mg/ 100 g, 38.63 per cent, respectively. The drying time for cabinet air dryer and solar dryer was 10.17 and 22.14 h, respectively. Based on these observations, we found that cabinet air drying method gave best result. Further, the dried powder was analysed for minerals like Na, Ca, K, Zn, Cu, Fe, Mn and Mg having content of 0.168%, 1.26%, 2.82%, 57.40 mg/ 100 g, 25.40 mg/ 100 g, 88.30 mg/ 100 g, 43.70 mg/ 100 g and 1.00 per cent, respectively. Heavy metals analysed by Inductively Coupled Plasma (ICP) revealed that the Cd, Co, Cr, Ni and Pb content per 100 g powder was 0.21 mg, 0.09 mg, 1.31 mg, nil and 58.40 mg, respectively. The morphology of the powder was examined under the Scanning Electron Microscopy (SEM) showed particles having broken glass structure and rough surfaces at the 500, 1200, 2000 and 4500 magnification at 15 working distance with overall observation that the cabinet dried powder was more visible in shape and size than solar dried powder. The Fourier transform-Infrared Spectroscopy (FT-IR) for the powder exhibited functional group like CH3, CH2, C=C, HC=CH for cabinet dried powder and CH3, C-O, C-OH, HC=CH for solar dried powder. The cabinet dried powder stored in polyethylene pouches up to 6 months at refrigerated (4 ⁰C) and ambient temperature had initial moisture, fibre, ash, total polyphenolics, total carotenoids and antioxidant activity as 6.73%, 10.90%, 4.50%, 119.67 mg GAE/ 100 g, 29.0 mg/ 100 g and 57.00 per cent, respectively and non-significant difference after 6 months was observed in most of the attributes except in moisture, total phenolics, total carotenoids and antioxidant activity i.e. 8.02%, 99.10 (mg GAE/ 100 g), 18.26 (mg/ 100 g) and 44.74 per cent, respectively were observed. Overall, the quality of the powder stored under refrigeration (4 ⁰C) was better than at ambient temperature (18-38 ⁰C).