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All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrition

PH

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Full-Text Articles in Life Sciences

Influence Of External Ph And Organic Acids On Internal Ph And Acid Anion Accumulation In Listeria Monocytogenes And Escherichia Coli, Savannah R. Branson Dec 2021

Influence Of External Ph And Organic Acids On Internal Ph And Acid Anion Accumulation In Listeria Monocytogenes And Escherichia Coli, Savannah R. Branson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Listeria monocytogenes and Escherichia coli are both among the most common microbial pathogens that cause foodborne illnesses and death. They both are capable of growing over a wide range of conditions. Organic acids are widely employed in the food industry to control growth of these pathogens to help prevent foodborne illnesses. There is substantial evidence that intracellular accumulation of organic acid anions is a major inhibitor to cell growth, and that many bacteria may combat anion accumulation by lowering their intracellular pH (pHi). In this study, we followed the accumulation of acid anion into the cell pellet and …


Influence Of Sodium Chloride, Calcium, Moisture, And Ph On The Structure And Functionality Of Nonfat Directly Acidified Mozzarella Cheese, Brian M. Paulson May 2004

Influence Of Sodium Chloride, Calcium, Moisture, And Ph On The Structure And Functionality Of Nonfat Directly Acidified Mozzarella Cheese, Brian M. Paulson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiment A explored the influence of sodium on direct acid, nonfat Mozzarella cheese. Cheeses with differing salt levels were obtained by varying dry salt applications (none, 0.5%, and 1.0% NaCl w/w) and hot brine stretching (0%, 5%, and 10% NaCl wt/v). Salt application and salt content influenced cheese moisture, meltability, expressible serum, micro- and ultra-structure, and color. Moisture was highest when cheese was salted before stretching (P = 0.03). Melt was lowest in cheeses that were unsalted (P = 0.05). Cheeses stretched in salt brine had < 1% of the amount of expressible serum found in unsalted cheese (P < 0.0001). Unsalted cheeses had a more open structure with pockets of serum distributed throughout the protein matrix giving it an opaque, white appearance. Salted cheeses had a more homogeneous protein matrix lacking light scattering surfaces, resulting in a translucent cheese. Neither salt concentration nor method of salting affected the calcium content of the cheeses (P > 0.05).

Experiment B explored the influence of calcium, moisture, and …


Effects Of Ph And Calcium Level On Extrusion-Textured Whey Protein Products, Andrea B. Hale May 2000

Effects Of Ph And Calcium Level On Extrusion-Textured Whey Protein Products, Andrea B. Hale

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of altering pH and calcium level during whey protein extrusion were assessed by measuring the protein solubility and WHC of the textured whey protein (TWP). TWP samples were produced by extruding dry mixtures of 2/3 WPC 80 (80% protein) and 1/3 cornstarch using screw speed of 200 rpms, feed rate of 23 g/min, water flow rate of 11 g/min, and product temperature of 150°C. The levels of acid and base were adjusted by adding concentrated HCl or NaOH, respectively, to the water source. Calcium was added to the raw mix in the form of calcium chloride dihydrate before …


Acceptability And Proximate Composition Of Meat-Vegetable Sticks Versus All-Meat Sticks Adjusted To Ph 4.6 Or 5.2 With Citric Or Lactic Acids, Ronnald Dean Quinton May 1996

Acceptability And Proximate Composition Of Meat-Vegetable Sticks Versus All-Meat Sticks Adjusted To Ph 4.6 Or 5.2 With Citric Or Lactic Acids, Ronnald Dean Quinton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new innovative product, stewsticks, made with beef, pork, spices, and dehydrated vegetables, was developed as a nutritious snack. Lactic or citric acid was added at pH 5.2 or 4.6 to both meatsticks and stewsticks. Meatsticks and stewsticks were prepared by mixing ingredients until a cohesive mass was obtained. This mixture was then extruded into sticks that were cooked to about 50% of original weight. Sticks were then cut to desired length, packaged, and stored. Then meatsticks (beef, pork, and spices) were compared to stewsticks for appearance, texture, flavor, and overall acceptability.

The stewsticks had excellent shelf life due to …


Effects Of Stabilizers And Ph Adjustments On Milk Proteins In Uht-Treated Citrus Juice/Skim Milk Blend Drink, Sandra M. Newman May 1992

Effects Of Stabilizers And Ph Adjustments On Milk Proteins In Uht-Treated Citrus Juice/Skim Milk Blend Drink, Sandra M. Newman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A UHT-processed skim milk (85%)/orange juice (15%) drink was developed. Product integrity and stability were maintained by two methods. Proper homogenization of the blend before UHT processing stabilized a drink formulation containing .25% carboxymethyl cellulose and .025% carrageenan. Adjusting the pH of the blend (pH 6.3 and 6.5) resulted in a different stabilization. After 28 days at room temperature, settling of milk solids was 5.2% of volume height in the prehomogenized sample and 86.9% of volume height in the same blend that had not been homogenized prior to UHT processing. After storage, the two treatments were analyzed to verify that …