Life Sciences Commons^™

Analysis Of Fruit Juices And Drinks Of Ascorbic Acid Content, Anna Man-Saw Liu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A total of 33 common fruit juices and drinks representing 15 different fruits were analyzed for ascorbic acid content by a slight modification of the method of Loeffler and Ponting (1942). The juices ranged from 0.96 to 50.88 mg per 100 ml. The drinks ranged from 2.12 to 66.10 mg. All the citrus juices ranked high in ascorbic acid content. One drink was fortified with sufficient ascorbic acid to contain considerably more vitamin than was found in pure orange juice.

The ascorbic acid values of different forms of orange drinks and pure orange juices were compared. Except for one brand, …

Survival And Distribution Of Rennin During Cheddar Cheese Manufacture, John Ta-Chuang Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Residual rennin in cheese whey and curd was measured by using a special sensitive substrate. The substrate was made by reconstituting 6 g NDM in 500 ml of buffer containing 0.2 M CaCl₂, 0.5 M cacodylic acid and 0.2 M triethanolamine at pH 5.7. Cheese curd was blended into a 1:7 slurry (1 part curd, 7 parts water), and 1.67% sodium chloride was added to the whey and slurry to liberate residual rennin from casein. The residual rennin in cheese whey and slurry were determined simultaneously with an identical sample containing known rennin activity. Samples with known activity …

Activation Of Prorennin, Nazar A. Shukri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Purified prorennin appeared to be homogeneous when subjected to chromatography on a Diethylaminoethyl-cellulose and to electrophoreses in starch-urea-gel. Crystalline rennin was heterogeneous, and was resolved into six components when analyzed electrophoretically. When crystalline rennin was chromatographed on a column of Diethylaminoethyl-cellulose two distinguishable peaks were observed which corresponded to B- and C-rennin. Unlike crystalline rennin, rennin freshly activated at pH 2.0 or 5.0 was essentially homogeneous.

Rennin resulting from activation at pH 2.0 and 5.0 appeared to be different. Rennin activated at pH 5.0 was eluted faster from Diethylaminoethyl-cellulose column, and moved slightly faster in starch-urea-gel electrophoresis, than rennin activated …

Rennin Content Of Abomasa From Bovine Fetuses, Suk Hoon Pang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rennet extract is an important commercial enzyme preparation which is indispensable to the cheese making industry, The term "rennet" is used to denote the enzyme system extracted from the fourth stomach (abomasum) of a suckling calf. Most of the enzymatic material in the extract is rennin. It also contains a small amount of pepsin(15) and some other proteolytic enzymes(4). The amount of pepsin in rennet extract appears to depend upon the age of the calves at the time of slaughter(31).

Quality Of Beef Roasts: Electronic Versus Conventional Cooking, Frances Glassett Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of breed, backfat thickness, and methods of cooking on quality of beef roasts was determined by sensory and objective methods. Arm and rib roasts from Hereford, Shorthorn, Charolais, and Shorthorn-Charolais animals were cooked by several methods.

Roasts of the ninth to twelfth ribs were all dry roasted at 325 Farenheit. Boned and unboned roasts (sixth to eighth ribs) were cooked by conventional and electronic methods. Only significant results are reported herein.

Objective tests using the Warner-Bratzler shear indicated roasts of Shorthorn animals to be the most tender of the four breeds.

Sensory analysis by an experienced panel of …

Effects Of Gamma Radiation In Concurrence With Certain Environmental Conditions On Lethal And Physio-Chemical Responses Of Penicillium Expansum L., Tsong-Wen Chou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In vitro investigations were conducted to study the lethal effect of gamma radiation on the fruit spoilage fungus Penicillium expansum under certain environmental conditions, and to study some physio-chemical changes in the fungus induced by the radiation which may be related to the death of the fungus or its ability to invade fruits.

The radiation sensitivity of P. expansum conidia was influenced by such factors as nutritional condition of the post-irradiation media, age of the spores, delayed plating, heat treatment, and chemical sensitizers. Higher survival was obtained when irradiated conidia were plated on Czapek solution agar (sugar-salts medium) than on …

Accounting For Milk Protein In Equivalents By Dye Binding Analysis Of Cheese And Whey, Prahlad H. Patel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Each of thirteen lots of Cheddar cheese was made from 430 lb. of milk, and the protein recovered in the cheese and whey was compared with that in the original milk. Protein determinations on the milk, cheese and whey were made by an acid orange 12 dye binding test, and by Kjeldahl analysis. Similarly fat recovery was determined by using the Babcock fat test on milk, the modified Babcock test on cheese, and the Mojonnier test on whey. The total weight recovered as cheese and whey was 99 ± .6% by Kjeldahl analysis and 97.7 ± .6% by the dye …

Development Of A Low-Fat Spread, Clair L. Hicks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A stable low-fat water-in-oil emulsion was satisfactorily prepared from milk-fat under laboratory conditions. The best product contained 40 per cent fat, 56.8-57.3 per cent water, 0.8 per cent sodium carboxymethyl cellulose, 0.7-1.2 per cent milk solids-non-fat, and 1.2 percent salt. The spread was prepared equally well from butter or high test cream. When the product was made from cream (containing 74 per cent milk-fat) it was necessary to convert most of the globular fat to free fat prior to forming an emulsion. Globular fat in cream was successfully changed to free fat by homogenization at 2500 pounds per square inch …