METHODS FOR MEASURING INTERNAL GASES OF CITRUS FRUIT AND DETERMINING PEEL PERMEANCE

摘要

A method for collection and 3-minute analysis of internal gas samples of citrus fruit is described in detail, including the handling of samples and analysis by gas chromatography with molecular sieve columns. A new method is presented for correcting internal O_2 concentrations of citrus fruit and apples for argon content. An internal-gas method is described for determining the barrier properties of fruit peel to movement of gases, including ethane and ethylene. Internal gas volume of fruit was measured by dilution of internal gases. It is well known that the quality of fresh citrus fruit, like that of many other fruits and vegetables postharvest, is much affected by the internal concentrations of CO_2 and O_2 (Ahmad and Khan, 1987; Hagenmaier, 20O_2). However, the measurement of internal gases is somewhat demanding in terms of proper technique, and no standard techniques are available. One of the goals of this paper is to present suitable techniques for measurement of internal gases of citrus fruit, and possibly other fruit as well. In addition, some other uses of internal gas measurements are presented.