The effects of slow heating during canning on the mouthfeel characteristics of sweet potatoes

An attempt was made to increase moistness of Jewel variety sweet potatoes by canning the product using a slow heat process allowing time for increased alpha-amylase activity and to assess the influence of this procedure on the classification of the canned product by mouthfeel. Moistness of sweet potato samples canned using 30, 60, and 90 minute holding periods in a hot water bath was compared with that of samples canned with no holding time. Both objective and sensory tests were employed to measure this moistness. Firmness of sweet potatoes canned by each method was compared using shear-press measurements. Viscometric determinations were taken to show the degree to starch conversion to soluble carbohydrate that occurred as a result of the slow heating. Drained weight determinations were used to indicate the degree of fragmentation occurring in sweet potatoes canned by each method. Canned products were exposed to mechanical abuse expected in transport to observe differences in product breakdown in the four variables. Panelists were asked to rank the samples as to observed breakdown. Dried weights were taken to determine the relationship between apparent moistness and actual water content. Two variations of panel evaluation were carried out to determine if mouthfeel differences in samples could be detected by panel members