Optimization of brinjal pickle production for improved quality and shelf life

M.A. Rahman, M.A. Hossain, M.S. Arfin, A.L. Acedo, W. Easdown, J.A. Hughes, J.D.H. Keatinge
Brinjal (Solanum melongena) pickle is a popular non-fermented product in Bangladesh, but the conventional practice needs to be improved to enhance sensory quality and the shelf life of the product. This study optimized the process of pH adjustment by using food-grade glacial acetic acid at three concentrations: 12, 15 and 18 mL kg-1 raw material. Commercially mature fruit of a popular local brinjal cultivar at 15 kg per treatment were secured from a local market and washed with clean water. Fruit were then cut in half longitudinally and roasted in mustard oil. The recommended amount of spices and condiments was followed, ground separately, roasted in oil, and mixed with the sliced fruit during cooking followed by adding ground mustard and salt. Acetic acid was later added and stirred thoroughly before terminating the cooking process. The prepared products were then poured into sterilized glass bottles, immersed in oil to avoid contact with air, and capped properly. Hot bottles with pickles were cooled and kept in a dry place for storage at ambient temperature. The pH of pickle products as a function of acetic acid concentration was found to be significantly different, showing values of 4.2, 4.04 and 3.87 for 12, 15 and 18 mL kg-1 acetic acid, respectively. Total soluble solids and ascorbic acid contents did not differ significantly with treatment. The ideal pH for preserving the overall quality of brinjal pickle was found to be 4.04, which could be maintained by adding acetic acid at 15 mL kg-1 brinjal. Moreover, the microbial load at that pH was a minimum even after 5 months of ambient storage at 24-30°C.
Rahman, M.A., Hossain, M.A., Arfin, M.S., Acedo, A.L., Easdown, W., Hughes, J.A. and Keatinge, J.D.H. (2017). Optimization of brinjal pickle production for improved quality and shelf life. Acta Hortic. 1179, 249-254
DOI: 10.17660/ActaHortic.2017.1179.39
Solanum melongena, pH optimization, value addition, non-fermented product

Acta Horticulturae