Improvement of edible quality and augmentation of the tasty constituent (umami) of harvested dehusked sweet corn by low intensity LED light irradiation at low temperature

Abstract

The present study was undertaken to develop an effective preservation system for sweet corn kernels by taking advantage of the properties of dim LED light and cool temperature. Dehusked sweet corns (Zea mays L. var. saccharata f. Peter corn) were stored at 5°C for 4 d under a photosynthetic photon flux density (PPFD) of 1μmol m-2 s-1 using red and blue LEDs. During storage, the Brix scale was measured daily, and an amino acid analysis was carried out after 4 d storage. The Brix scales were kept high under the blue LED irradiation and cool conditions (5°C) compared to those under dark-cool conditions.Similarly, sweet corn umami was enhanced by storage under the blue LED-cool conditions, which was in good agreement with the observed increase of aspartic acid and glutamic acid, a predominant amino acid, under the same conditions. Red LED-cool conditions had also a preserving effect on sweet corn kernels but not as pronounced as the blue LED-cool conditions. However it was much better than that of dark-room temperature conditions. These results suggest that light quality during storage determines the quality of sweet corn kernel and its umami constituents. The authors propose the blue LED-cool preservation as a practical and useful technique.