Principles of Food Science Chapter 19: cereal, grains, legumes, and oilseeds Pg. 329, 335, 347,337,338

Milling of grains

- Modern milling replaces water driven mills with rollers

- Although not all grain is milled, most of the wheat used in the US has been milled to some extent

- Aim of millings to separate the bran covering, germ, and endosperm to the extent desired

Yield of grain if milling is adequate and correct?

o 100 pounds of wheat yields 72 - 75% straight flour

o The rest of the wheat kernel, the bran, the germ, and shorts used to be used only for cattle feed

o Now there is a sizeable market for bran and germ

What is Middling?

The inner portion of the kernel, which is granulated with difficulty

o After its separation from the bran, it is fed through a series of smooth rollers that further reduce the size of the particles and produce finer

flour

o About 6 - 8 streams of flour are obtained from the rolling and shifting of the purified middlings

A final stage in the product/ion of white flour is often _____________ and/or ______________

Bleaching and/or Maturing.

What substances has the FDA permits to be used for bleaching and maturing flour?

1) Nitrogen trichloride

2) Nitrogen tetroxide

3) Chlorine dioxide

4) Benzyl peroxide

5) Acetone peroxides

6)Azodicarbonamide

Flour must be labeled bleached.

What other effects do these substances have on flour besides bleaching and maturing?

Most of these substances have a maturing effect that improves baking qualities besides acting to

bleach the flour.

The endosperm represents about 84 percent of the total kernel, how much white flour should be obtained by milling?

84% of white flour should be obtained by milling, but in actual practice only 73 - 75 % is separated as white flour

The kind and composition of flour depends on these characteristics:

o Class of wheat used

o Conditions under which the wheat is grown

o Degree of fractionation

What is Corn Refining?

- Corn refining is today's leading example of value-added agriculture

- Over 1.2 billion bushels of corn are used to produce a broad array of food, industrial and feed products for the world market

Refiners separate corn into its components: What are the components?

Starch, oil, protein, and fiber

Refiners separate the corn into its components, and convert them into _____________________________.

higher value products.

Bioproducts of Corn Refining

- Most recognizable bioproduct is ethanol

- Fermentation of corn derived dextrose has

created an entirely new group of bioproducts:

organic acids, amino acids, vitamins, and food

gums

- Citric and lactic acid from corn can be found in

hundreds of food and industrial products

o Provide tartness to foods and confections

o Help control pH

o Themselves feedstock's for further products

Other Bioproducts of Corn Refining

- Amino acids from corn provide a vital link in

animal nutrition systems

- Economical corn-based lysine is now available

worldwide to help supplement animal feeds

- Vitamin C and E human nutritional supplements

are now derived from corn replacing old systems

that relied on chemical synthesis

- Corn refiners now have fully commercial

products to help deal with plastic disposal

problem and are developing an increasing array

of degradable plastic products