Microbial destruction kinetics of high-pressure-processed sugarcane juice (Saccharum officinarum)

The efficacy of high-pressure processing (HPP) on inactivation of indigenous vegetative microorganisms in sugarcane juice was studied under the pressure range of 300–600 MPa for a treatment time of 1 s through 25 min at ambient temperature (30 ± 2 °C). No significant change in pH, total soluble solids (TSS) and titratable acidity were observed in the juice, whereas color variation was significant (p < .05) after HPP treatment. Application of HPP has significantly (p < .05) reduced the vegetative microbial count with the increase in pressure and treatment time. Isobaric destruction of microorganisms followed first-order kinetics. Among the group of natural microflora studied, coliforms were observed to be more sensitive whereas aerobic mesophiles were least sensitive with the z_p value of 846 MPa and the ΔV value of −6.85 × 10⁻⁶ m³/mol. High-pressure treatment of sugarcane juice at 600 MPa/20 min was sufficient to inactivate vegetative microorganisms effectively with minimal changes in physico-chemical properties of the juice.

Practical applications

Sugarcane juice is one of the nutritious natural drinks available in South-Asian countries. The shelf-life of sugarcane juice is limited due to high incidences of microbial contamination, which begin immediately after extraction. Thermal processing of sugarcane juice at high temperatures and processing times has a detrimental effect on sensory and nutritional qualities of the juice. The application of high-pressure processing (HPP) has proved to be a promising technology to produce microbial safe sugarcane juice with minimal changes in physico-chemical properties. HPP technology can provide a breakthrough in the beverage industries, in developing a “ready-to-serve” sugarcane juice for the commercialization and marketability of good quality sugarcane juice.