Understanding the material properties of corn tortillas processed by high pressure

Physio-chemical properties of corn tortillas with the addition of glycerol, salt, and high pressure

  • Investigate the anti-staling properties of glycerol in corn tortillas using thermal and textural analysis.
  • Determine the optimal percentages of glycerol and salt to minimize textural and flavor changes and maximize anti microbial activity.
  • Investigate the effects of high pressure processing on the microbial activity, texture, flavor, and shelf stability of corn tortillas.
  • Determine the optimal results of using glycerol, salt, and high pressure as a means of increasing shelf stability and decreasing staling rate while maintaining characteristics similar to a freshly homemade tortilla.

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Effect of CMC on the physico-chemical properties of masa-water mixture

Carboxymethyl Cellulose (CMC) is a widely used hydro colloid to maintain the softness and increase the shelf life in corn tortilla. CMC changes the rheological and thermal properties of the masa (dough) and the resulting tortillas. It increases the viscosity of the masa and during thermal processing, it is hypothesized to compete with the masa constituents for the water. Also during storage, the gum may inhibit retro gradation of gelatinized starch granules, influencing the flexibility of tortilla. Little is known about the interaction of the different components in the masa system at the super-structural level. The objective of this study was to better understand the effect of CMC concentration on the physico-chemical properties of masa-water mixtures during storage using thermal analysis techniques.

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Characterization of the physical properties of soy bread

Research Focus:

  • The effect of physico-chemical changes in soy bread during storage on isoflavone content and distribution.
  • To compare the physical states of whole wheat and soy breads and their components during storage using thermal analysis and NMR.

Joint Research Projects:

  • To determine the effects of digestion on the quantity and the relative stability of isoflavone present in soy bread.
  • To evaluate the isoflavone content of a soy-rich bread and to determine the effects of its major soy ingredients on the proliferation of a human prostate cancer cell line.

Related Articles:

  • Bread lowers risk of heart disease (see about our research)

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Characterization of the physical properties of frozen soy dough

Research Focus:

  • Understand the physico-chemical changes occurring in soy-bread dough upon freezing using thermal analysis techniques.
  • Compare the physico-chemical changes occurring in wheat and soy bread doughs after storage for up to 2 months at –40 °C.

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Characterization of the physical-chemical properties of tomato juice/soup containing soy

Research Focus:

Research suggests that consumption of tomato or soy-based foods is associated with a reduced risk for a number of chronic diseases, including cancer and heart disease. Isoflavones (i.e. daidzein and genistein) and carotenoids (i.e. lycopene) found in soy and tomato-products, respectively, have been identified as potential health promoting components. However, the nutritional and health benefits associated with the consumption of new food products combining soy and tomatoes have not been investigated. Our laboratory's part in this multi-disciplinary study is to determine the specific physico-chemical properties that influences the relative availability and bioavailability of carotenoids and isoflavones.

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Characterization of soy beans and isoflavones

Research Focus:

Soy possesses chemopreventive agents (isoflavones such as genistein and daidzein) that may significantly impact upon health. Baked products such as bread made with soy ingredients, offer a much more attractive alternative as isoflavone delivery systems due to their popularity in Western diets. The general goal of this research is to obtain sensorially acceptable products with high isoflavone contents. This study will therefore include: Screening various Ohio grown soybeans for protein content and isoflavone content and composition; study effects of growing location and soybean processing on isoflavone levels; developing health-promoting bakery products using unique varieties of Ohio soybeans containing various levels of protein and isoflavones and characterizing and optimizing the functionality (physico-chemical properties) of soy flour obtained from the different soybean varieties in bakery products.

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Understanding the impact of high pressure processing on the physico-chemical properties of rice

Research Focus:

Currently, ready-to-eat rice products are heat treated to gelatinize the starch and then dried, canned or frozen prior to storage. Significant physico-chemical and quality changes occur in the product during storage (including starch retrogradation), and nutrient decomposition. High pressure processing may improve the quality of rice cooking (texture, nutrients) and preservation (texture, microbiological). This study is designed to characterize the physico-chemical properties (firmness, starch retrogradation) of high pressure-processed rice during storage.

Understanding the functionality of soymilk powder in soy bread

Research Focus:

  • Evaluate the effects of soluble and insoluble soy dietary fibers on the physical, chemical, mechanical and thermal properties of soy bread.
  • Determine the functionality of partly denatured and undenatured SPIs in soy bread during storage as compared to control soy bread and soy bread with SMP.
  • Understand the impact on soy bread physical properties upon addition of soymilk powder.

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Effect of almond addition to the chemical and physical properties of soy bread

Research Focus:

  • Investigate changes induced by the addition of raw ground almond to loaf quality.
  • Investigate the effect of the almond addition to soy bread on lipid and water mobility using relaxation NMR and MRI.
  • Determine changes in isoflavones profile, between regular soy and almond –enriched soy bread, due to the addition of beta-glucosidase naturally present in almond kernels.

Understanding the effects of starch type and moisture content on the physical and chemical properties of soft jellies

Research Focus:

Specialty starches are often used in place of gelatin as gelling agents in soft jelly (gummi-like) confections. Starches impart unique thermo-rheological properties to soft jellies which can be investigated using thermal analytical techniques. While the dynamics of hard candies have been investigated, the interactions between water, sugars, and starches in soft jelly candies are not well-understood. The objective of this study is to determine the effects of starch type and moisture content on the physico-chemical properties of soft jellies using thermal analysis techniques.