Abstract
Two objective methods to determine texture of corn masa using the TA.XT2 texture analyzer were developed and compared with subjective evaluations of the texture and machinability of corn masas from nixtarnalized corn flours used for tortillas and tacos. Several methods to form masa in an objective repeatable way were developed during this study. The TPA analysis measurements included hardness, adhesiveness, cohesiveness, springiness, gumminess, and chewiness. The TPA hardness values were the most highly correlated with subjective texture values and had the lowest coefficient of variation. The TPA adhesiveness values were correlated with subjective masa texture measurements; however, the coefficient of variation was high (50%) which limited its acceptability for measuring masa stickiness. None of the other four TPA measurements were practical measures of masa texture. The adhesiveness force was significantly correlated with subjective evaluations of masa texture but it had a relatively high coefficient of variation (21%) which limited its effectiveness. Measurements from the adhesiveness test did not appear to be as good as the hardness values obtained from the TPA technique. The TA.XT2 texture analyzer was taken to a commercial tortilleria where the TPA and adhesiveness tests were used to determine-nine differences among commercial masas produced in the plant and the changes that occurred. Both methods could be used in the commercial tortilleria to obtain repeatable data. The TPA hardness and adhesiveness values increased and decreased, respectively, as masa was stored up to 24 hrs. No difference among fresh masas for different products were observed but fresh masa mixed with nixtamalized corn flours had significantly higher hardness values which was also noted by subjective observations. TPA hardness successfully detected differences in masas before and after pumping from the grinder to the sheeter. The hardness method is the most useful and reproducible measurement. None of the methods evaluated were effective indicators of masa stickiness although the adhesiveness test might have good potential provided the probe used in this test is redesigned using metal typically used in masa sheeting and pressing.
Bosiger, Irene (1997). Evaluation of masa texture. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -B67.