Improvement of coconut water shelf-life through low-temperature concentration process: Understanding impact of non-thermal process on shelf-life

Abstract

Fruit juice concentration gains popularity due to the reduced shipping costs for concentrated products. However, the main drawback of the widely used thermal concentration process is the degradation of product's quality parameters. Lyophilization, or the freeze-drying process, is applied to concentrate coconut water to demonstrate that the quality of the coconut water can improve even when a significant fraction of pure water is removed from it. The measurements of antioxidant activities, total phenolic content (TPC), pH, and titratable acidity are investigated to understand process efficiency without compromising the original quality of coconut water. Study applies first order kinetics to assess the coconut water's shelf-life, using pH and Brix as critical parameters. Results suggest that Brix, TPC, antioxidant activity (AAO), total dissolved solids (TDS), and potassium increase with increase in lyophilization time, where pH remains the same. The shelf-life of concentrated product increases to double that of raw coconut water.

Practical applications

Coconut water has very large worldwide demand as health drink across all ages and all societies, particularly has great demand in sport/health sectors. The raw coconut is inconvenient to transport long distances because of its bulky volume. Further, coconut grows in a very limited area, it needs to travel long distance to reach customers across globe. So business with packed concentrated coconut water would be profitable for food industries. There is no study that has proven that concentrated coconut water through non-thermal processes can actually improve its shelf-life drastically. This study suggests that Brix, TPC, AAO, total dissolved solids, and potassium ions were concentrated with the increase in lyophilization time, where pH remains same due to an undisturbed natural buffering system. Non-thermal freeze-drying techniques proved that non-thermal treatment like polymeric/ceramic membrane treatment would be beneficial for industry to sell packed coconut water without adding preservatives.