Food Science Commons^™

Effect Of Heating To 200 C On Casein Micelles In Milk: A Metal Shadowing And Negative Staining Electron Microscope Study, V. R. Harwalkar, Paula Allan-Wojtas, Miloslav Kalab

Food Structure

Milk was heated to 200 C for 3 min in sealed inverted-Y-shaped glass vials and reacted with a glutaraldehyde solution at that temperature. Electron microscopy of the metal-shadowed and negatively stained samples revealed that casein micelles in the milk did not disintegrate extensively at the high-temperature used but, rather, became enlarged. Some of them were found to be either clustered or distorted.

Composition And Some Properties Of Spray-Dried Retentates Obtained By The Ultrafiltration Of Milk, Miloslav Kalab, Marijana Caric, Mansour Zaher, V. R. Harwalkar

Food Structure

Retentates containing 20, 27, and 34% total solids, obtained on commercial scale by the ultrafiltration of milk were spray-dried on laboratory scale using centrifugal atomization and single stage drying with the inlet air temperature of 220 C and the outlet air temperature of 90 C.

The protein content in the powders was 31% to 35% compared to 24.8% protein in the control whole-milk powder. Lactose contents were markedly lower in the retentate powders (-10.6%) than in the milk powder (40.4%). Storage of the powders at 37 C resulted in a marked increase in the 5-hydroxmethylfural contents with doubling of this …

Measurement Of Proteins In Milk And Dairy Products, Marie K. Walsh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to develop a short, easy procedure to measure five major proteins in milk and to detect concentrations of added protein to dairy products. Combinations of casein or whey protein with nonfat-dry milk were made with concentration ratios from 0:10 to 10:0. Similar mixtures of defatted goat milk with defatted cow milk were prepared. Samples were hydrolyzed in 6 N HCl at 145°C for 4 h and analyzed for amino acid composition. Multiple regression equations were derived to estimate the relative content of whey protein or casein added to nonfat-dry milk and goat milk added …

Development Of Microstructure In Raw, Fried, And Fried And Cooked Paneer Made From Buffalo, Cow, And Mixed Milks, Miloslav Kalab, S. K. Gupta, H. K. Desai, G. R. Patil

Food Structure

Paneer was made from cow, buffalo, and mixed cow and buffalo milk by coagulation with citric acid at pH 5.5. All milk samples were heated to 90°C. Cow milk was coagulated at this temperature but buffalo and mixed milks were cooled to 70°C before coagulation. Differences in the composition and the treatments of the cow and buffalo milks were reflected in the composition and structure of the paneers. Electron microscopy revealed that raw paneer samples had a granular structure consisting of protein particles having a core-and-lining ultrastructure. Deep-frying in vegetable oil at 175'C for 4-5 min led to the compaction …

The Role Of B-Lactoglobulin In The Development Of The Core-And-Lining Structure Of Casein Particles In Acid-Heat-Induced Milk Gels, V. R. Harwalkar, Miloslav Kalab

Food Structure

Acid-heat-induced gels were obtained by coagulating casein micelle dispersions at 90 C using glucono-and-lactone. The casein micelles used were isolated from raw skim milk by centrifugation, washed free of whey proteins and soluble salts, and dispersed in water or a milk dialyzate. The pH values of the gels varied from 4.7 to 6.3. A core-and-lining ultrastructure developed in casein particles coagulated at pH 5.2 to 5.5 from casein micelle dispersions in the milk dialyzate provided that B-lactoglobulin or whey proteins (10 mg/ml) were added to them prior to coagulation. Addition of B-lactoglobulin to aqueous casein micelle dispersions led to the …

Effect Of Clotting In Stomachs Of Infants On Protein Digestibility Of Milk, S. Nakai, E. Li-Chan

Food Structure

Differences in clotting between human and cow's milk in the stomachs of infants are discussed. Gastric pH, after ingesting milk, of an infant up to 6 months of age stays at a pH range of 4-5, near the isoelectric point of casein, and never reaches the value of 2, which is found in adults. Pepsin C (or gastricsin) can hydrolyze proteins at this pH range. Gastric emptying time is shorter with human milk than with cow's milk which appears to be correlated to the smaller size of human milk clots. Elimination of a readily coagulable fraction of casein from cow's …

Lipolytic Changes In The Milk Fat Of Raw Milk And Their Effects On The Quality Of Milk Products, E. Kirst

Food Structure

Lipolytic changes in milk rat affect sensory attributes and techno logicaI properties of milk and milk products. They are affectcd by physiologal, thermal . and biochemical factors as well as by the mechanics of fluids Lipolytic processes in milk are intensified by modern processing methods.

In this review. special attention has been paid to runinant- related feeding of dairy cows. foaming of milk. mechanical and thermal influences and the growth of psycllrotrophic bacteria.

Feeds deficient in energy affect the chemical composition of the milk fat. Tests have shown that on an average. approximatey 55% of free fatty acids in the …

Characterisation Of Milk Proteins In Confectionery Products, J. F. Heathcock

Food Structure

The proteins from milk play an important part in the structural properties of confectionery products. These properties will in turn influence texture and flavour. Electron microscopy techniques have been used to examine milk chocolate, caramel and fudge and to locate and characterise the milk proteins within their structures. Following scanning electron microscopy examination of the products at low temperature, thin sectioning and freeze-fracture were used to resolve the fine ultrastructure of casein and whey proteins.

A chocolate prepared from milk crumb could be distinguished from one made with a dry milk powder on the basis of a more even distribution …

Observations On The Air-Serum Interface Of Milk Foams, B. E. Brooker

Food Structure

A new rapid method for the preparation of milk foams for transmission electron microscopy is described . The air-serum interface of foams made from skimmed milk consists of a uniform electron dense layer (5 nm thick) to which casein micelles become secondarily attached . Changes in bubble volume lead to the formation of folds of excess interfacial material which project into the aqueous phase. Using collapsed bubble ghosts to study the attachment of micelles to the airserum interface it was concluded that neither disulphide bridge formation nor hydrophobic interactions were of major importance. Similar preparations of interfacial material but without …

Effects Of Heat Treatment And Post-Treatment Holding Time On Rennet-Clotting Properties Of Milk, Zeynep Ustunol

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Samples of raw whole milk were heated at L5, 50 and 75 C for 0, 30, 60, llU and 240 min. After heat treatment each sample was subdivided and portions held at 0 C for 0, 30, 60 and 120 min. In a second experiment samples of milk were heated at 25 and 50 C for the same lengths of time as before but this time at 75 C for only 5, 10, 15 and 20 min. A constant holding time of 30 min was used after the heat treatments. Following the various heat treatments pH of each sample was …

A Method For Separating Casein Micelles From Whey Proteins For Determining Casein In Milk, Robert N. Carpenter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine if size exclusion chromatography could be used to separate casein micelles from whey proteins for a rapid, direct test to measure percent casein in milk. A size exclusion chromatography column was developed for the separation having dimensions 100 by .4 cm. Packing material selected was glycophase coated porous glass supports. A Beckman DU-8B spectrophotometer monitored the casein and whey protein peaks as they eluted and a Tektronix 4052 computer accepted data points every 4 sec, storing these on tape. Absorbances and areas of each peak were used in the evaluation of samples. …

Enzymic Milk Coagulation: Casein Micelle Aggregation And Curd Formation, Donald J. Mcmahon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enzymic milk coagulation was monitored by measuring changes in curd firmness and apparent absorbance of undiluted milk. Detection of coagulation, visually or rheologically, occurred after the milk changes from a system of aggregating particles to an extended space network. This change was observed as a shoulder in apparent absorbance plots and coagulation time was defined as the critical point in the aggregation process analogously to non-linear condensation polymerization reactions. It corresponds to the inflexion point during the period when apparent absorbance was rapidly increasing and can be calculated by fitting curd firmness data to an exponential equation.

Addition of calcium …

Seasonal Variation In The Ability Of Milk And Whey To Support Lactic Culture Growth, Rick Cameron Norton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Milk samples from two cheese plants with overlapping milk supplies were collected monthly for one year in an attempt to measure seasonal variation in the ability of milk and whey to support lactic culture growth . Treatments to control and minimize variability of milk or whey were evaluated to optimize stability in starter culture performance.

Raw milk samples were tested for somatic cell counts, activity tests (modified Horrall- Elliker), acid degree values, and total plate counts. Activity (modified Horraii-EIIiker) and inhibitory tests were also performed on pasteurized, pasteurized-vacuumized and high heat milk treatments.

Rennet whey (heated and unheated) was collected …

Ultrastructural Studies Of Milk Digestion In The Suckling Rat, P. B. Berendsen

Food Structure

The structure of milk in the stomach and proximal small intestine of suckling rats at 12 and 24 hours, 5, 10 and 15 days of age was examined by scanning and by transmission electron microscopy. The milk curd in the gastric lumen consisted of chains of casein micelles which entrapped milk fat globules. The appearance was similar to that reported for bovine milk curd and cottage cheese. The gastric milk curd at 12 and 24 hours also contained large masses of granules 4-8 nm in diameter. The relationship of these particles to casein micelles is unknown.

Casein micelles in the …

Milk Protein Analysis By Automated Ultraviolet Spectroscopy, R. Ford Wilkinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An automated continuous flow analysis for milk protein utilizing ultraviolet spectroscopy resulted in a correlation coefficient of 0.972 and a standard estimate of error of 0.082 percent protein when 30 samples were compared with the acid orange 12 dye binding method. Milk was solubilized in 95-105 volumes of acetic acid using the Technicon Auto Analyzer II and measured for absorbance at 274 nanometers. No deviation from the standard method due to mastitis and varying milk fat concentration was observed. A theoretical model indicated a possible standard estimate of error 0.059 percent protein due to inter- and intra-breed variation in milk …

Manufacture Of Monterey Cheese From Preacidified Milk, Faisal O. Mohamed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whole milk acidified to pH 5.3 with hydrochloric acid was used for the manufacture of Monterey cheese. The milk was inoculated with one and one-half percent lactic starter and set with 12.5 ml rennet per 1000 pounds of milk. Normal washing treatments resulted in cheese with moisture in excess of 44 percent. Moisture content was brought below 44 percent by using wash water at a temperature such that the water-curd-whey mixture was 35 C. The pH of cheese made by preacidification was all between 5.21 and 5.09. No acid defects were encountered. Preacidification eliminated chance of spoilage or losses caused …

Utilization Of Surplus Milk In The Small Dairy Plant: 4. Stirred Curd Types Of Cheese, P. A. Downs, K. Nilson

Nebraska Agricultural Experiment Station: Historical Circulars

In this series of publications an effort is made to describe how a variety of products can be prepared in plants where surplus milk is a problem. Each type of product is described in detail, methods of manufacturing are outlined, and the equipment and supplies needed are listed. As far as possible similar equipment is used for several products. In this publication the preparation of a group of stirred curd types of cheese is presented.

Utilization Of Surplus Milk In The Small Dairy Plant: 3. Old Fashioned Sage Cheddar Cheese, P. A. Downs

Nebraska Agricultural Experiment Station: Historical Circulars

The purpose of this series of publications is to describe how a variety of products can be prepared in plants where surplus milk is a problem. Each type of product is described in detail, methods of manufacturing outlined, and the equipment and supplies needed are listed. As far as possible similar equipment is used for several products. In this publication the preparation of a type of old fashioned sage and other flavored cheddar cheeses is presented.

Dishes Made With Milk And Cream For Everyday And Special Occasions :A Housewife Cookery Book, Rosemary Hume

Pamphlets

Specially written and presented with the November 1957 issue of Housewife Magazine, a monthly magazine for women with advice for homemakers.

The pamphlet was produced in association with the National Milk Publicity Council.

Contains some colour and black and white photographs of dishes.

Utilization Of Surplus Milk In The Small Dairy Plant: 2. Soft And Semi-Soft Hoop Drained Cheeses, P. A. Downs

Nebraska Agricultural Experiment Station: Historical Circulars

The purpose of this series of publications is to describe how a variety of products may be prepared in plants to more profitably utilize milk. Each type of product is described in detail, methods of manufacturing outlined, and the equipment and supplies needed are listed. As far as possible similar equipment can be used for several products. In this publication the preparation of a group of cheeses of the soft and semi-soft hoop drained type is presented.

Utilization Of Surplus Milk In The Small Dairy Plant: 1. Soft Cheeses, Spreading Types, P. A. Downs

Nebraska Agricultural Experiment Station: Historical Circulars

This is the first in a series of publications that describe how a variety of products can be prepared in dairy plants where surplus milk is a problem. Each type of product will be described in detail, methods of manufacturing will be outlined, and the equipment and supplies needed will be listed. In this publication, the general background of cheese making is discussed and the preparation of soft cheese of the spreading type is described.

Use Milk - An Essential Food, University Of Nebraska - Lincoln

Nebraska Agricultural Experiment Station: Historical Circulars

The purpose of this publication is to furnish the housewife with information on ways to utilize more milk in the home, especially in the farm home where milk is readily available and an economical source of vitality and greater health for all the family.

Milk, The Food Of Foods, Laura C. Pepper

Pamphlets

This pamphlet was published by the authority of the Hon. James G. Gardiner, Minister of Agriculture, Ottawa, Canada. It is recorded as Publication 635, Household bulletin 19.

The pamphlet was produced to promote the nutritional benefits and value of milk in the diet. The various types of milk are listed. There are chapters dealing with the care of milk from producer to consumer, consumption and uses of milk. There are recipes for sauces, soups, lunch and dinner dishes milk shakes and milk dishes for the convalescent.

Cooling, Storage, And Transporation Of Milk And Cream, P. A. Downs, F. D. Yung

Nebraska Agricultural Experiment Station: Historical Circulars

The care given milk and milk products should be such that they will be relished by young and old alike. Greater use of milk can be encouraged by serving fresh milk cold. Cooling of milk also insures a fine product several hours after production. This is important not only for milk that is to be used, but for milk or cream that is to be sold.

Pasteurized Versus Raw Milk In Brick Cheese-Making, Z. Doyle Roundy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The prime object of the work undertaken in the present study has been done with the view of determining whether or not the quality and yield of brick cheese may be improved by pasteurizing the milk from which the cheese is made. An effort should be made to put brick cheese-making on a more scientific basis and at the same time produce cheese of better and more uniform quality. Since milk, containing large numbers of undesirable microorganisms thus causing objectionable flavors and odors in dairy products, is frequently delivered to cheese factories to be processed, pasteurization seems to be one …

Bovine Tuberculosis, L. Van Es

Nebraska Agricultural Experiment Station: Historical Circulars

Tuberculosis affects all species of domestic mammals although with different degrees of intensity and frequency. Cattle and swine furnish the greatest number of cases.

Ice Cream Ingredients, H. P. Davis, B. Masurovsky, J. A. Luithly

Nebraska Agricultural Experiment Station: Historical Circulars

Ice cream is truly a frozen dairy product although other products than cream may enter into its make-up. The different ingredients that go into the ice cream mix exist in different qualities, grades, concentrations, and forms and it is desirable, therefore, for the ice cream maker to know something of them if a successful product is to be made.

Cooling Tanks And Milk Houses As Factors In Cream Improvement, J. H. Frandsen

Nebraska Agricultural Experiment Station: Historical Circulars

The dairymen of this country have suffered enormous losses due to the lower price received for poor butter. The present need is for a survey of the situation that shall result in a thoro understanding and cooperation of cream producers, creamery men, legislators, and educators.