Effects of the storage temperature and humidity on shelf life of ginger (Zingiber officinale Roscoe)

Abstract

Ginger (Zingiber officinale Roscoe), has been used for a very long time as food ingredient, in food preservation and in pharmaceutical products. Nevertheless, the processing part has not been well researched. Ginger consists of two main constituents; ginger oleoresin and ginger oil. Ginger storage method has become necessary since this rhizome are transported worldwide for long period and not classified as perishable goods since it has the ability to stay fresh up to three months at suitable condition. This study emphasized on the importance of determining the right temperature and humidity for a simpler and more applicable storage method thus extending the commodity's shelf life. Treatments applied were storage at 5±1 °C, 15±1 °C, and 25±1 °C with different relative humidity ranging from 75±2% to 90±2%. The parameters measured were percentage of weight loss, firmness, total colour changes, pH, total soluble solid (TSS) and water content, at weekly intervals for four weeks. The data collected from all the analyses were analyzed using the analyses of variance (ANOVA). The significant differences (P<0.05) between the treatments were determined using Tukey Test. After four weeks of storage, there were no significant difference among the treatments in the ginger firmness and water content where TSS, pH and weight loss showed significant difference. The lowest storage temperature and the highest relative humidity (5±1 °C; 90±2%) showed the best quality retention in ginger during storage.