|Truong V D, - NCSU|
|Walter W M Jr,|
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 1994
Publication Date: N/A
Interpretive Summary: Although the sweetpotato is a nutritious food containing significant amounts of beta-carotene, it is an under-utilized crop. A major reason for this is that there are very few frozen sweetpotato convenience products available at the retail level. This is because very little research directed toward development of restructured sweetpotato products has been conducted. A product of excellent quality which compares favorably with freshly baked sweetpotatoes was obtained when cooked sweetpotato puree was combined with binding agents and sugar, cold-extruded into edible casings, and frozen. For eating, the frozen material was baked for 15 min. We found that either methyl cellulose or methylhydroxypropyl cellulose at 0.25% by weight was an excellent binder. Although we developed a prototype baked sweetpotato, other types of formed products could easily be prepared using this technology. A further advantage of this process is that all grades of sweetpotatoes can be used, thus allowing utilization of the entire crop. This type process will permit processors to develop different types of restructured products, thus providing consumers with high quality, nutritious products which are easily prepared in the home.
Technical Abstract: The beneficial effects of methylcellulose (MC) or methylhydroxypropylcellulose (MHPC) added to sweetpotato puree on the texture of a simulated baked sweetpotato product were clearly observed when the instrumental texture profiles were analyzed at elevated temperatures. Gelation of the gum-puree formulations was at 30-38 degrees C, reached maximal elastic rigidity (G') values at 60-70 degrees C, and melted upon cooling. A texture profile panel rated the 60 degrees C samples of the 0.25-0.50% MC or MHPC formulations with nearly equal scores to baked roots for several texture notes. The formulations also had significantly higher scores for flavor and overall acceptability than baked roots. Scanning electron micrographs showed that the added MC or MHPC formed a mesh-like network which held the gelatinized starch granules together, and probably provided a rigidity to the product.