EFFECT OF FERMENTATION TEMPERATURE ON CUCUMBER PICKLE (KHALPI) FERMENTATION KINETICS

Abstract

The aim of this work was to investigate the kinetics of lactic acid production and the growth of lactic acid bacteria during the fermentation of radish pickles. The pickles were prepared following a traditional pickle-making process. Over a fermentation period of sixteen days, changes in lactic acid bacteria counts, titratable acidity (expressed as lactic acid), pH, TSS, and sensory attributes were systematically analyzed. The fermentation was conducted under anaerobic conditions using airtight jars, with samples incubated at both a controlled temperature of 37°C and room temperature 28 ± 6 °C. Over the 16-day fermentation period, acidity, pH, total soluble solids (TSS), lactic acid bacteria (LAB) count, and sensory scores of Khalpi were evaluated under two different temperature conditions, revealing distinct variations. The acidity, expressed as % lactic acid, increased from 0.236% on Day 1 to 1.5733 ± 0.0116% at 37°C and from 0.2333% to 1.6467 ± 0.0058% at room temperature by Day 16. Time and temperature significantly (p > 0.05) affected acidity in both fermentation conditions. TSS rose from 8.766°Bx on Day 1 to 12.23 ± 0.057°Bx at 37°C and from 8.76°Bx to 12.03 ± 0.057°Bx at room temperature by Day 16, with a significant (p > 0.05) impact of time and temperature. The pH decreased from 5.216 on Day 1 to 3.81 ± 0.015 at 37°C and to 3.74 ± 0.017 at room temperature by Day 16, with significant (p > 0.05) effects of both factors.LAB counts increased from 4.505 Log CFU/mL on Day 1 to 10.4623 Log CFU/mL on Day 10, followed by a decline to 5.06 Log CFU/mL on Day 16 at 37°C. Similarly, LAB counts rose from 4.4913 Log CFU/g on Day 1 to 9.176 Log CFU/g on Day 10, then dropped to 5.535 Log CFU/g by Day 16 at room temperature, with significant (p < 0.05) differences observed among all samples during fermentation. Sensory scores for overall acceptance improved from 3.80 ± 0.45 on Day 1 to 8.00 ± 0.71 at room temperature and 7.80 ± 0.83 at 37°C on Day 16. While time significantly (p > 0.05) influenced overall acceptance, temperature had no significant effect.