Ascorbic acid, nitrate, and nitrite concentration relationship to the 24hour light/dark cycle for spinach grown in different conditions.

Nitrate, nitrite and ascorbic acid (vitamin C) concentrations were determined for spinach (Spinacia oleracea L.) over a 24 h period to determine if light intensity (including dark periods) at time of harvest impacts concentrations in raw vegetables. Nitrate, nitrate and ascorbic acid concentrations varied significantly over the 24 h period and appeared to be related to changes in light intensity.

Changes in nitrate and nitrite concentrations over 24h for sweet basil and scallions.

Nitrate and nitrite concentrations were determined for sweet basil and scallions over 24h to determine if time of sampling or harvest impacts concentrations in raw vegetables. Also, nitrate and nitrite concentrations were determined separately for various edible parts of these plants. Basil had significant changes in nitrate and nitrite concentrations over a 24h period.