Abstract
The objectives of the present study were to evaluate the chlorophyll content of green leafy vegetables found commercially
and carry out a comparative investigation between in vivo and in vitro data. The chlorophyll of green leafy vegetable can be used
as visible parameters of the quality of vegetables during storage, since it will be degraded gradually along with post-harvest
senescence. Therefore, the development of reliable in vivo chlorophyll measurement should be advantageous rather than visual
observation for the purpose of quality control and product sortation. Here, the existence of chlorophylls in ten green leafy
vegetables were reported as SPAD values of a handheld SPAD-502 chlorophyll meter and % N of an Agriexpert CCN-6000
nitrogen meter (in vivo data), as well as total peak area data of HPLC measurement for chlorophyll a and b after exhaustive
extraction using methanol (in vitro data). Both in vivo and in vitro measurement gave comparable grouping of vegetables with
high and low content of chlorophyll. Moreover, correlation plots between SPAD values and total peak area of HPLC showed
adequate linear correlation (R2 > 0.7), revealing the potency of in vivo observation for the prediction of actual chlorophyll content
in commercial leafy vegetables. SPAD values and % N presented strong linear relationship (R2 > 0.9), in which SPAD-meter
performed better detection at very low values. The calibration curve for each species of vegetable should be substantial to
overcome the limiting factors of in vivo observation, such as leaf size, tissue thickness, and variation of chloroplast distribution.