OIL AND FAT OIL AND FAT TECHNOLOGY TECHNOLOGY

LECTURES LECTURES II II

(Handling & Storage of (Handling & Storage of

Oil-Bearing Materials - Pretreatments)Oil-Bearing Materials - Pretreatments) Prof.Dr.Aytaç SAYGIN GÜMÜŞKESENProf.Dr.Aytaç SAYGIN GÜMÜŞKESEN

Yrd.Doç.Dr.Fahri YEMİŞÇİOĞLUYrd.Doç.Dr.Fahri YEMİŞÇİOĞLU

Handling & Storage of Handling & Storage of Oil-Bearing MaterialsOil-Bearing Materials

The handling and storage of oil-bearing materials The handling and storage of oil-bearing materials is one of the most important phases of oil seed is one of the most important phases of oil seed processing. processing.

The vegetable oils and feed industries are The vegetable oils and feed industries are dependent for successful operation upon dependent for successful operation upon obtaining high yields and product of good obtaining high yields and product of good quality from their raw material.quality from their raw material.

Excessive biological activity in the seeds, either Excessive biological activity in the seeds, either in the field prior to harvesting or subsequently in the field prior to harvesting or subsequently during storage, will result in a reduction both in during storage, will result in a reduction both in the quality and the yield of oil and meal. the quality and the yield of oil and meal.

The handling and control of the raw The handling and control of the raw materials for the oil seed industry can materials for the oil seed industry can be primarily characterized by the short be primarily characterized by the short harvest season, by the necessity to harvest season, by the necessity to move them into protected storage in move them into protected storage in minimum time, and by the required care minimum time, and by the required care before they can be processed. But they before they can be processed. But they can be treated and stored successfully can be treated and stored successfully with minimal deterioration long enough with minimal deterioration long enough to allow the processing industry to to allow the processing industry to operate throughout the year. operate throughout the year.

Sunflower seed, sSunflower seed, soybeans, cottonseed, oybeans, cottonseed, rape seedrape seed and other oil seeds are subject and other oil seeds are subject to damage primarily from biological to damage primarily from biological actions, which are accelerated by actions, which are accelerated by high high moisture content, foreign material, moisture content, foreign material, physical damage, and such adverse physical damage, and such adverse climatic conditions as frost or rain before climatic conditions as frost or rain before harvest. harvest.

Effects accompanying deterioration of seed Effects accompanying deterioration of seed during storageduring storage

Respiration :Respiration : In the presence of oxygen as the In the presence of oxygen as the oxidizing agent, organic food stuffs are oxidized to oxidizing agent, organic food stuffs are oxidized to form water and carbon dioxide as the end product.form water and carbon dioxide as the end product.

exothermic reactionexothermic reaction

CC6 6 HH1212OO 6 6 + O + O22 6 CO 6 CO2 2 + 6 H+ 6 H22O + energyO + energy

Respiration intensity;Respiration intensity;

Sound seed – low m.c. 0.1ml COSound seed – low m.c. 0.1ml CO2 2 /g seed.day/g seed.day

Damaged seed – high m.c. 5.0ml CODamaged seed – high m.c. 5.0ml CO2 2 /g seed.day/g seed.day

The respiratory quotientThe respiratory quotient, defined as the , defined as the ratio of carbon dioxide evolved to ratio of carbon dioxide evolved to oxygen absorbed, is an indication of the oxygen absorbed, is an indication of the class of substances undergoing class of substances undergoing oxidation. oxidation.

In aerobic respiration; In aerobic respiration; it is theoretically it is theoretically unityunity if the subctances if the subctances

are are carbonhydratescarbonhydrates, , but but less than unityless than unity if they are if they are proteins or proteins or

fatsfats, which are less rich in oxygen., which are less rich in oxygen.

Enzymes :Enzymes :

(a)(a)LipaseLipase.. This enzyme catalyzes the reaction; This enzyme catalyzes the reaction;

11 glycerol + 3 fatty acid triglycerid + 3 waterglycerol + 3 fatty acid triglycerid + 3 water 22

1 synthesis t.g 2 hydrolysis t.g1 synthesis t.g 2 hydrolysis t.g

(b) (b) Catalase and peroxidaseCatalase and peroxidase.. Both of these enzymes react Both of these enzymes react with hydrogen peroxide.Catalase will decompose with hydrogen peroxide.Catalase will decompose hydrogen peroxide while peroxidase utilizes it for hydrogen peroxide while peroxidase utilizes it for further oxidation.further oxidation.

2 hydrogen peroxide 2 water + oxygen2 hydrogen peroxide 2 water + oxygen

Influence of moisture content : Influence of moisture content :

Oil seeds are best stored at low moistures where Oil seeds are best stored at low moistures where respirotary and enzymic activities, germination respirotary and enzymic activities, germination and mold growth are inhibited. This maximum and mold growth are inhibited. This maximum acceptable moisture level is known as acceptable moisture level is known as “critical “critical moisture level (CML)moisture level (CML) ”. ”.

The moisture content of the non-oil portion of the The moisture content of the non-oil portion of the seed rather than the whole seed is the important seed rather than the whole seed is the important factor in oil seed deterioration. factor in oil seed deterioration.

CML is relatively high for seeds of low oil CML is relatively high for seeds of low oil content.content.

CML is relatively low for seeds of high oil CML is relatively low for seeds of high oil content.content.

Safe humidity for starchy food grains Safe humidity for starchy food grains

16%16%

Oil content of soybean ……. 22%Oil content of soybean ……. 22%

Non-oily part of soybean ……. 78% Non-oily part of soybean ……. 78%

Critical moisture level 0.78 x 16% = Critical moisture level 0.78 x 16% = 12.5%12.5%

CML of oil seedsCML of oil seeds

Hulls (%) Fat (%) CML(%)Hulls (%) Fat (%) CML(%)

Rape seedRape seed 14 40 7.0 14 40 7.0

Palm kernelPalm kernel - 52 8.0 - 52 8.0

Sunflower seedSunflower seed 28 43 8.5 28 43 8.5

CottonseedCottonseed 48 18 10.0 48 18 10.0

Soya beansSoya beans 8 20 12.0 8 20 12.0

Influence of temperature.Influence of temperature.

In the case of soya beans and similar oilseeds where In the case of soya beans and similar oilseeds where deterioration appears to be primarily a result of the deterioration appears to be primarily a result of the growth of microflora, the storage temperature does growth of microflora, the storage temperature does not appear to be a major factor. not appear to be a major factor. However, temperature However, temperature is very important factor in storage of cotton seed. The is very important factor in storage of cotton seed. The respiration of cotton seed is markedly temperature-respiration of cotton seed is markedly temperature-dependentdependent. . The insulating effect of linters on The insulating effect of linters on cottonseed contributes to the peculiar tendency of cottonseed contributes to the peculiar tendency of this seed to heat in storage. this seed to heat in storage.

It is because of the undesirable effect of high It is because of the undesirable effect of high temperature that most seed houses are equipped with temperature that most seed houses are equipped with aeration ducts and large ventilating blowers to cool aeration ducts and large ventilating blowers to cool the seed. the seed.

Storage methodStorage method Warehouses (Muskogee type seed Warehouses (Muskogee type seed

houses)houses)Bulk storage in warehouses on flat floors Bulk storage in warehouses on flat floors

has the advantage of easy control of oil has the advantage of easy control of oil seeds, like cottonseeds, sunflower seeds, like cottonseeds, sunflower seed, corn germ, further meals etc. To seed, corn germ, further meals etc. To prevent self heating or autocombustion prevent self heating or autocombustion of the seeds, recycling by horizontal of the seeds, recycling by horizontal and vertical transportation means is and vertical transportation means is recomended.recomended.

Muskogee type seed storeMuskogee type seed store

Belt conveyer

Section through storage building

Oil seed

Oil seed bulk

Preparation of Oil-bearing Preparation of Oil-bearing MaterialsMaterials

Cleaning foreign materials

Delinting for cottonseed lints

Dehulling hulls

Flaking

Cooking moist

CLEANING

Cleaning is important not only to ensure the good quality of the final products oil and meal but also to avoid premature wear of the preparation equipment.

The removal of foreign materials from oil seeds is done by cleaning machines working on mechanical, pneumatic and magnetic principles.

Cleaning machines;ScreensAspiratorsMagnetsShape sorters

SCREENSSCREENS

Screening is the seperation of mixtures of Screening is the seperation of mixtures of different sizes into fractions; the portion different sizes into fractions; the portion staying behind being oversize, the staying behind being oversize, the portion passing through being portion passing through being undersize.undersize.

Rotating screensRotating screens Vibrating screensVibrating screens

Drum screen

Vibrating screenVibrating screen

ASPIRATORSASPIRATORS

In order to seperate impurities or fractions In order to seperate impurities or fractions of different density, pneumatic means, of different density, pneumatic means, like air nozzles and aspirators are used.like air nozzles and aspirators are used.

MAGNETSMAGNETS

Permenant or electromagnets enclosed in Permenant or electromagnets enclosed in a rotating aluminium drum are used in a rotating aluminium drum are used in feeders to distribute the material feeders to distribute the material uniformly over the whole active width of uniformly over the whole active width of the drum. The magnetic material the drum. The magnetic material collected is removed by a blade on the collected is removed by a blade on the ono-magnetized half and, in this way, it ono-magnetized half and, in this way, it remains seperated even in the case of remains seperated even in the case of power failure.power failure.

Self cleaning rotary magnetsSelf cleaning rotary magnets

Seed inletaspirator

Rotating drum

Stationary magnet

İron parts

Cleaned seed

DELINTINGDELINTING

(for cottonseed) (for cottonseed)

cottonseed

lints (8-12%)

Hull (40-45%)

Delinting process to remove the remaining lint from cotton seed

DelinterDelinter

A method of delinting cotton seed A method of delinting cotton seed comprises comprises the steps of passing the the steps of passing the cotton seed through a saw delinter to cotton seed through a saw delinter to remove a substantial portion of the remove a substantial portion of the lint, preferably at least 40%, therefrom, lint, preferably at least 40%, therefrom, and thereafter passing the partially and thereafter passing the partially delinted seed through a brush delinter delinted seed through a brush delinter to remove substantially all of the to remove substantially all of the remaining lint therefrom. remaining lint therefrom.