Texture change effect

Irradiation has a serious effect on softening and texture changes of many fruits. The level required for disease control in grapes is too high to avoid extreme softening of the tissues. Therefore, irradiation does not appear possible for grapes. 

Moreover, the bread crumb s moisture loss during seven days of storage open to the air, also did not show a consistent dramatic effect on these two tensile parameters (Chen et al. 1994) as one would expect. The same can be said about the compression parameters, which too showed little correlation with the moisture loss, which was measurable, of course. These reported findings, if indeed representative of the three tested breads (white, Canadian and whole wheat), would suggest that the initial textural changes that accompany bread staling are quite subtle and hence cannot be always manifested in the described crude mechanical parameters. An alternative explanation is that the failure to find the expected trends was mainly due to the large scatter in the experimental results that masked the true trend, if it really existed. 

Now let us consider recent results from this laboratory concerning the effects of metal ions on the rates of texture changes in acidified cucumber tissue texture. To investigate the effect of NaCl on cucumber texture in the absence of enzymatic degradation, the firmness changes in blanched tissue under acid conditions, pH 3.2-3.8, were measured (43). The procedure was to blanch cucumber slices or mesocarp tissue pieces in boiling water for 3 min to inactivate pectinesterase (19). After cooling, the tissue samples were covered with a brine which contained acetic acid and S02, to equilibrate at 0.6% and 200 ppm, respectively, and the appropriate amount of NaCl. The tissue equilibrated with the brine in the cold and then samples were incubated at 44C so they would soften reasonably rapidly. Firmness of the tissue was evaluated at the... 

E.P. Raynes, Cholesteric texture and phase change effects, in A.R. Kmetz and... 

Lipid oxidation during frozen storage of fat and medium-fat fish is an important quality problem, primarily due to effects on sensory properties such as rancid off-odor (appearing earlier than off-flavor), orange-brown discoloration, and texture changes. Changes in peroxide value (PV) and carbonyl compounds such as anisidine value (AsV), benzidine value, carbonyl value, and thiobarbituric acid (TEA) proceed... 

Han, B. Z., Wang, J. H., Rombouts, F. M., Nout, M. J. R. (2003). Effect of NaCl on textural changes and protein and lipid degradation during the ripening stage of sufu, a Chinese fermented soybean food. Journal of the Science of Food and Agriculture, 83, 899-904. 

AG values are nonlinear functions of the titania content because of several effects caused by textural changes of the materials and the formation of new phases (amorphous titania, anatase, and rutile) with particles of different sizes formed in pores and at the outer surface of the silica gel particles. Water becomes more strongly bound with increasing titania content (Figure 2.73). However, the AG(C J curves for all the SGT samples are above the curve for silica gel. The secondary porosity of silica gel decreases due to grafting of titania, and the peak intensity at / =40 nm of textural pores decreases (Figure 2.74), but a peak at / = 30 nm appears because of partial filling of these broad pores by titania nanoparticles. 

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