540 Produce Degradation: Reaction Pathways and their Prevention
18.3 TEXTURAL CHARACTERISTICS
Produce texture is determined by tissue structure and physiology. Microscopy has
been used to relate tissue microstructure and texture by measuring tissue failure
under tension followed by observation of the areas of failure using various micros-
copy methods. Texture is largely dependent on cell structure and the relationships
between cells. Microstructural studies can show many of the characteristics giving
rise to texture in any given produce commodity.
All fruits and vegetables are composed of cells. Cell characteristics include cell
structure (composition, size, shape, type, water content); air spaces between cells; cell
wall structure, composition, and thickness; and adhesion between cells. Adhesion is
FIGURE 18.7Cucumber. Scanning electron micrographs showing the outer surface of the
epicuticular-wax-covered epidermis. (a) Fresh sample. (b) Aged sample showing “pools” of
differing electron densities (i.e., dark and light areas). (c) Close view of the dark and light
areas showing that the dark areas are devoid of epicuticular wax. (d) Dark area with only
patchy areas that contain epicuticular wax. (e) Top of the micrograph is the edge of a soft-
rot spot; fungi proliferate and the epidermis has debris and other irregularities on its surface.
(f) Close view of the fungal hyphae. Magnification bars: a, e, 1 mm; b, 200 μm; c, f, 50 μm;
d, 20 μm.