Factors Associated With Potato Texture.

Abstract

The writers ' previous studies on starch content ( 2 ) and pectic materials (3) did not, in themselves, fully clarify the relationship of the texture of cooked potatoes with various chemical attributes. Consequently, the question arises whether differences in texture are related to differences either in the ease with which the cells can be separated or in the actual extent of cell separation in the tissues of the cooked potatoes.Various approaches to the problem of estimating the extent of intercellular spaces are possible. The most direct approach is a microscopic study of the tissues involved, as exemplified in the investigations of Reeve (13) and Personius and Sharp (9). However, because of the difficulty of cutting and handling the loose, cooked tissue, the study of internal spaces has also been attempted indirectly. The ingenious determinations of tensile strength by Personius and Sharp (7) measure "cell adhesion'' in cooked tissue and thereby the strength of the intercellular cementing bond. Presumably, where the bond is weaker, one could suppose that the cells are more likely to be separated easily.Similarly, the degree of sloughing (disintegration by fragmentation during boiling) may be a clue to the ease of cell separation. Thus, Sweetman (15) and Barmore (1) have reported a correlation between sloughing and mealiness and between sloughing and starch content. Likewise, Whittenberger (16) and Whittenberger and Nutting (17) found a general correlation between specific gravity and sloughing. In addition, Pyke and Johnson (11) showed that as calcium ion was added to the cooking water, the incidence of sloughing declined, thus indicating that the firming of the pectic materials of the middle lamella had increased the strength o f the intercellular bond. This finding confirmed the results of earlier work by Personius and Sharp (8).Freeman ( 4 ) made physical measurements of the volume of internal pores in dried slices of baked potato tissue. The resulting data were found to be significantly correlated with the organoleptic scores for texture. Thus, when soggy tissue was dried, the slice became a dense and horny vitreous sheet. On the other hand, mealy tissue produced a loosely porous mass.I n the present study, cooked and raw potato tissues have been subjected to mechanical tests to determine the degree of cell adhesion; the amount o f sloughing has been ascertained ; and the cooked tissues of different potato varieties have been analyzed microscopically. I n a general conclusion, multiple correlations have been computed for pertinent data, and the overall results evaluated. MATERIALS A N D METHODSMaterials. The first paper (2) of this series presents a detailed account of the samples used and the method of sample preparation and cooking.

Mealiness Detection in Agricultural Crops: Destructive and Nondestructive Tests: A Review

“…In the case of cell wall constituents, cell separation is thought to be due to middle cell wall and lamellar constituents. Sterling and Bettelheim () reported that a weak middle lamella allowed separation of cells. Dissolution of calcium‐pectic gel in the middle lamella has a significant role in its weakness and so results in the separation of cells (Jarvis and Duncan ).…”

Chemical composition of potato cell wall

“…The amount of soluble pectic substances in raw potato tuber is relatively small (Le Tourneau, 1956; Sterling and Bettelheim, 1955). We made no effort to determine its value, and much of its was undoubtedly lost.…”

“…k Ithough the cell wall and middle lamella of potato tuber tissue constitute only a minor portion of the total solids present in the tuber, this material has a profound effect on the textural properties of both the raw tuber as well as of the processed potato tissue. Sterling and Bettelheim (1955) succeeded in describing the principal factors determining the textural properties of cooked potatoes. Still, the detailed chemical composition of the cell wallmiddle lamella has yet to be described.…”

Chemical and Physical Attributes of Muskmelon Related to Texture

“…Any realistic attempt to determine the basis of texture must, therefore, consider a number of characteristics. Factors considered contributory to the texture of fruits and vegetables include cell wall polysaccharides (Albersheim, 1965;Joslyn, 1962; Sterling, 1963); cellular adhesion (Kertesz, 1951); starch content (Sterling and Bettelheim, 1955); and soluble solids (Hartman and Gaylord, 1941). While cell turgor is presumed to affect textural quality (Crafts et al, 1949;Strohmaier, 1953), the nature and extent of its relationship to texture has not been explored extensively in fruits.…”