Controlled atmosphere storage of fresh-cut sweet corn kernels
G.S. Riad ,J. K. Brecht and S.T. Talcott
Univ. of Florida , Horticultural Scinces Dept., P.O. Box 110690, FL 32611-1690; Univ. of Florida, Dept. of Food Science and Human Nutrition , P.O. Box 110370, FL 32611-0370
2002
บทคัดย่อ
Fresh-cut sweetcorn kernels are a newly introduced product to the fresh-cut industry. It is a very perishable product since the kernels have a very high respiration rate that increases the rate of deterioration compared to intact sweetcorn. There are two main problems limiting development of this product; the severe loss of sugar and flavor (dimethyl sulfide, the main component of sweetcorn aroma), and the severe browning which can occur after cooking when the cut kernels are stored in air at higher than optimum temperatures (Riad and Brecht, 2001). Browning in plant material has many causes, such as oxidation of phenolic compounds (expecially in cut or injured tissues in which there may be an increase in phenolic production). The after-cooking browning could also be a result of the Maillard reaction (a nonenzymatic reaction between sugars and free amino acids). Maillard reactions are common in the fooe industry and are usually associated with thermal processing. This work is being carried out to determine the best method to reduce the loss of sugars and flavor in fresh-cut sweetcorn and to identify the cause of after-cooking browning and the best method to reduce its occurrence. An atmosphere of 2% O2 plus 10% CO2 at 1 0C reduced sugar and flavor losses and eliminated after-cooking in fresh-cut sweetcorn kernels after up to 10 days storage compared to storage in air or at 50C. Preliminary results indicate that 5-hydroxymethylfurfural (HMF), the final product of the Maillard reaction, is not present in cooker sweetcorn kernels exhibiting browing. The brown color appears to be due to several phenolic-protein complexes as yet unidentified.