Rice And Oat Milling (Lecture 15)

Question 1

3 Cereal Grains That Retain Hull After Harvest

Answer 1

Rice, Barley, Oats

Question 2

Rice Kernel

Answer 2

Hull 20%
Endosperm 70%
Bran 7.5%
Germ 2.5%

Question 3

Six Steps in Rice Milling

Answer 3

Cleaning
Hulling
Milling
Polishing (Optional)
Grading
Sorting
Storage

Question 4

Cleaning and Hulling (Rice Milling)

Answer 4

Cleaning Removes foreign material
Hull Removal: Rubs excess husks of clan paddy
Brown rice is separated from the hull through aspiration

Question 5

Rice Milling- Hulling

Answer 5

Separates using density

Question 6

Rice Milling Whitening

Answer 6

Removes the bran layer from the brown rice
Bran separates from white rice using aspiration
Rice kernels pass between each other and a stationary screen by an aspiration surface

Question 7

Rice Milling Polishing

Answer 7

Removes inner pericarp
Polishing used gentle abrasion
Polish is separated by aspiration

Question 8

Rice Milling - Grading

Answer 8

Removal of the broken rice from milled rice
Head rice is the most desirable
Small broken - Called brewers rice

Question 9

Rice Milling - Sorting

Answer 9

Removes rice defects

Question 10

Finished Rice

Answer 10

Rice - 70 - 75 %
Rice Husk 20%
Rice Bran 5 - 10%

Question 11

The Oat Kernel Hull

Answer 11

30- 35%

Question 12

The Oat Kernel Bran

Answer 12

30-40%

Question 13

The Oat Kernel Endosperm

Answer 13

50-65%

Question 14

The Oat Kernel Germ

Answer 14

3-4%

Question 15

Oat Terminology

Answer 15

Oat- Still containing a hull/unprocessed
Groat - Oat with hull removed
Green Groat - Groat that hasn’t been Kilned

Question 16

Oat Milling

Answer 16

1. Cleaning
2. Hulling and Roughing
   A. Produces Groat
3. Kilning and Grading
4. Processing

Question 17

Oat Milling Cleaning

Answer 17

Removes non oats and non millable oats

Question 18

Low Quality Oats Unsuitable for Milling

Answer 18

Double Oats
Pin Oats: undeveloped w/ Missing Groat
Light Oats: Developed w/ no groat

Question 19

Oat Milling - Hulling

Answer 19

Impact dehulling uses centrifugal force

The impact force causes the hull to detach from the oat

Question 20

Oat Milling — Roughing

Answer 20

Process of removing loose hulls from groats and unhulled oats

Large density makes separation with air currents an efficient method of removing loose hulls

Infilled oats can be separated by length or by density

Question 21

Oat Milling — Kilning and Gradinh

Answer 21

Kilning Goals
Deactivated Enzymes that cause rancidity

Grading Goals
Kilned groats are graded by size using gravity tables

Question 22

Oat Milling — Cutting System

Answer 22

Minimize Fines
Remove Hulls

Question 23

Oat Milling — Flour Production

Answer 23

Flake the Groats
Grind the oat flakes and sift to meet granulation specifications
Used as an extrusion flour in breakfast cereals

Question 24

Paddy Rice

Answer 24

While rice kernel with hull intact

Question 25

Brown Rice

Answer 25

Rice kernel with hull removed but bran intact

Question 26

White Rice

Answer 26

Hull and bran removed

Question 27

What Grain Contains a Hard and Soft Endopserm

Answer 27

Corn and Sorghum