Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Sciences

Committee Chair(s)

B. Singh, D. K. Salunkhe


B. Singh


D. K. Salunkhe


G. H. Richardson


A. Mahoney


This study was undertaken to determine the effect of four different combinations of treatments and storage; i.e., controlled atmosphere (2.5 percent O2 and 2.5 percent CO2), controlled atmosphere in combination with phaltan (1,000 ppm), controlled atmosphere with packaging in polyethylene bags, controlled atmosphere with phaltan and packaging in polyethylene bags, as well as conventional refrigeration, on the chemical composition of lettuce heads (Cultivar "Great Lakes") during 75 days of storage. Analyses of total sugars, starch, reducing sugars, total organic acids, free amino acids, soluble proteins, pH, titratable acidity, and total carotenes were made on the fifteenth, thirtieth, forty-fifth, sixtieth, and seventy-fifth days of storage at 35 F.

There were no significant differences in total organic acids and free amino acids between the conventional refrigeration (35 F) and other treatments during the early stage of storage. They were, however, higher after 45 days of storage with phaltan treatments, although still not changed in controlled atmosphere and controlled atmosphere in combination with packaging.

The soluble proteins and the reducing sugars were lower in the controlled atmosphere lettuce than in the conventional refrigeration lettuce. The lettuce treated with phaltan or phaltan in combination with polyethylene packaging had higher amounts of soluble proteins.

Although pH of the lettuce heads was not changed throughout 75 days of storage, the titratable acidity was higher in all treatments during the storage.