The training of cereal chemists - Journal of Chemical Education (ACS

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766

JOURNAL OQ CHEMICAL EDUCATION

JUNE. 1927

THE TRAINING OF CEREAL CHEMISTS C H BAILEY, UNIVERSITY OB MINNESOTA, UNIVERSITY FARM, ST. PAUL, MINNESOTA During the last twelve years cereal chemistry has emerged as a separate and well-defined sub-division from the larger division of food chemistry. That this is true is evident from the fact that a strong association of cereal chemists has been formed, in America, which supports its own journal. The factor chiefly responsible for this development was the interest manifested by the milling industry in the chemistry of flour manufacture and baking. Still more recently the merchandising of wheat on a basis of protein content has added further interest in the chemist and the chemical laboratory. The increase in the number of chemists specializing in this field has brought with it an increased demand for three types of special training. The first involved those who desired to become routine analysts in a protein laboratory. Many second millers and others suggested that they should be afforded an opportunity to become proficient in the art of "running a Kjeldahl." They entertained the feeling that courses in chemistry which did not have to do with the nitrogen determination were valueless. To their minds, three months of concentrated application should be adequate to satisfy their requirements. To meet such a situation in a university department of chemistry is a real problem. Most of the courses in chemistry are not organized to afford continuous laboratory exercises throughout the week. Consequently, certain industrial institutes, and trade schools undertook the training of this type of analyst. A university generally avoids the approval of a scientific training so narrow as this by granting credits, let alone a degree, to those who have no aspirations beyond the limits of one or two manipulations. It must be conceded, however, that many of the men so trained are very useful in certain industrial laboratories. They take pride in their ability to perform their tasks in an efficient manner. Be it said to their credit that some of the finest and most accurate work now being done in certain flour mills and grain-trade laboratories is performed by these analysts. In the second group we encounter those men and women who are approachmg the completion of a four- or five-year schedule or curriculum in a course leading to a bachelor of science degree in chemistry, or a chemical engineering degree. Many of these students have sensed the demand for chemists competent to organize and direct the work of a cereal laboratory. They realize that an intimate knowledge of the technology of milling or baking and the problems of industry is essential if they are to render service of immediate value. It then becomes necessary for their faculty advisor to arrange for them a rational sequence of advanced courses,

with possibly a special course in cereal chemistry if the latter is offered in the institution in question. As a usual thing, these students have already completed the courses in general chemistry, qualitative and quantitative analysis, and organic chemistry such as are included in the sequence for a major in chemistry. To this should he added physical chemistry combined with the requisite mathematics. Early in the fourth year, a course in biochemistry should he programmed. This may parallel a laboratory schedule in food analysis which acquaints the student not only with the conventional methods of proximate analysis and the detection of adulterants, hut also with the newer physico-chemical manipulations and apparatus. The polariscope, refractometer, viscometer, H-ion potentiometer, spectro-photometer, and surface-tension apparatus should become familiar tools for use in the solution of the problems of the laboratory. Policies will vary in different departments of chemistry respecting the particular courses into which such laboratory training can be fitted. This is not important, providing a competent instructor and well-selected experiments are utilized in introducing the student to these procedures. Because of the considerable interest manifested in cereal chemistry by the students of the University of Minnesota, and the extent to which its faculty engage in research in this field, i t has naturally followed that special courses for cereal chemists and technologists have been evolved here. A lecture course is offered which first acquaints the student with the laboratory methods available for use in the cereal industries; this is followed in the same course by a survey of the chemical technology of the production, marketing, grading, and milling of wheat, and the baking of flour mill products. A parallel laboratory course affords training in experimental or smallscale milling and baking; these processes are then subjected to a biochemical and physico-chemical study. The general outline of the laboratory schedule follows: I. Experimental milling.

A. Mill 2000 gram portions of the wheat samples furnished by the instructor. Record weights and compute percentages of the mill products. Retain all the patent flour, and 50 grams of the bran, and of the shorts. 11. Analysis of flours and feeds produced under I. A. Determine the percentage of crude starch in the bran and shorts. B. Determine the percentage of ash in the flours.

C. Subject the flours to experimental baking tests. 111. Analysis and testing of flour mill streams. A. Chemi.zl Analysis. Determine the percentage of (1) moisture, (2) ash, (3) crude protein, (4) gliadin, (5) glutenin, (6) albumin and glahulin, (7) nonprotein nitrogen. (8) titratable acidity.

B. Physico-chemical studies. Determine (1) electrolytic resistant or conductivity of water extracts. (2) H-ion concentration, (3) h&r index, (4) viscosity of acidulated water suspensions (leached). C. Technical tests. (1) Determine the percentage of wet and dry crude gluten; (2) the extensibility with the C h o ~ i nextensimeter: (3) diastatic activity;

IV.

V.

Separate gliadin from a sample of flour. in the preparation (dry basis).

Determine the percentage of nitrogen

Flour bleaching. A. Observe the operation of the several bleaching systems a t the mill. Sample the bleached and unbleached flour and record the dosage of bleaching reagent used in each instance. B. Determine the gasoline color value and the color analysis, spectraphotometrically, of the bleached and natural flour. C. Determine the H-ion concentration of flour before and after treatment with the bleaching reagents.

VI. Examination of cracker sponge and soda crackers. A. Titrate the acidity in a fermented cracker sponge and compute the dosax? of soda required to neutralize it.

B. Determine the H-ion concentration of baked soda crackers (1) clectrometrically, (2) by the use of phenol red and cresol red, using the extraction method of Johnson and Bailey, (3) by Bahn's spot test method. VII.

Conduct haking tests with the following yeast nutrients or flour improvers; (1) calcium acid phosphate, (2) n~ono-ammoniumphosphate, (3) ammonium persulfate, (4) ammonium chloride, (5) Arkady, in comparison with (6) a control.

Classes are large enough to permit of a detailed study of all the flour streams in typical roller mill, which study includes an observation of the behavior of these streams in the baking process. Each student works with about three flour streams of different characteristics. Data thus accumulated become available to the entire group. Five quarter credits are allowed for the completion of this extended schedule. Students are thus equipped with a fairly intimate knowledge of the fundamentals of milling and baking, and an appreciation of the problems which are likely to confront the operatives in the successful production of high quality flour and bread. These special lecture and laboratory courses have proved attractive to agronomists and plant breeders who are concerned with the production of wheat and other cereals. Home economics students, particularly those working in the field of food technology, have also evidenced an interest in these courses. A third group of students is interested in graduate study and research in the field of cereal chemistry. Certain of these graduate students merely desire advanced or special courses to supplement their under-graduate

work. Others wish to qualify as competent to conduct or direct research. Agricultural experiment stations, government bureaus, and many of the larger manufacturers of cereal products employ research chemists and for a time there was a scarcity of men and women capable of filling these positions. It is true of graduate study generally that no standardized schedule of work can be devised which will suit all cases. Usually the graduate student matriculates in a particular institution because he desires to engage in research under a certain member of the staff. In the land grant colleges, i t not infrequently happens that a sub-project or phase of one of the experiment station projects can be assigned to a graduate student. Care must be exercised by the student's graduate advisor to insure that the program of graduate courses is not too narrow. Many young chemists have an inadequate familiarity with biology. A combination of courses in plant physiology, advanced organic chemistry, and biochemistry have proved well-suited to many students who can spend two or more years in graduate study. Numerous fellowships supported by grants from industrial associations or large corporations have been provided for the support of research in these and related industrial fields. The interest thus manifested by the industries, and the financial aid afforded have done much to further the research in the particular field. Cooperation between the industries and universities is taking a more definite and tangible form in this, as in many other instances. Such an effort not only increases the volume of research activity, but has an important bearing on educational problems, since the number of research fellows can thus be increased, and better facilities for graduate study can be afforded.