world bank document...semi-sifted meal meal from which part of the bran and germ (bolted meal) has...

TE WORLD BANK FAU9

FA U-09

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SECTORAL LIBRARYINTERNATIONAL BANK

FOR

RECONSTRUCTlON AND DEVELOPMENT

FEB 12 1986

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Agro-Industry ProfflesCORN

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PROFILES IN THIS SERIES:

OILCROPS - OVERVIEW ........... FAU-01

OIL SEEDS ................ . .. FAU-02

OIL PALM. ......... *e.o.......... FAU-03

COCONUT. ... . .e. * e ***** ***oFAU-04

SUGAR. sooe....... * .eo... .... **o FAU-05

ETHANOLo........e ee............. FAU-06

WHEATo........o.o..*.......o....o . FAU-07

RICEo....... .o..o.o.o.o.......... FAU-08

CORN. . . oo ooo.. . o.o. . o. . .. .FAU-09

CASSAVA .........ooo.......... oFAU-10

ANIMAL FEEDS ..o.... ..... ... oFAU-11

FRUITS AND VEGETABLES........FAU-12

RUBBER. ... ... ..........o..o ...oo. FAU-13

COFFEEo.....o.oo................... FAU-14

TEA ....oo.ooo.ooo...o.o.oo..o..FAU-15

COCOA. e.eoe......oooooe geooege..o.FAU-16

COTTON. .. .. ....o.........o...o .. *FAU-17

MEAT. ......... ..... .....o.oo oo s o. FAU-18

SPICES AND ESSENTIAL OILSo....FAU-19

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SABSTRACT

The objective of this Profile is to provide a review of the cornprocessing industry. It outlines the corn industry from theharvest and preparation of raw material to the milling andmarketing of the finished product. The Profile providesspecifications of composition, yields and uses, a glossary of keywords, and a bibliography of useful references. It traces themilling process and reviews marketing aspects, such asgrade/quality, uses and characteristics. Environmental concerns,economies of scale, and corn by-products are also discussed.Annexes showing conversion factors, conversion (Metric/US)tables, and examples of investment and operating costs areincluded at the end of the Profile.

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FOREWORD

The nature of project and sector work in the World Bank is suchthat staff are often called upon to work outside their majorfields of specialization, if only to make an initial judgement onthe utility of further, often costly, investigation. Under thesecircumstances, up-to-date and authoritative reference material isessential.

The profiles in this series are designed for use by operationalstaff with experience in the agricultural sector but who do nothave a technical knowledge of the particular commodity underdiscussion. Their purpose is not to substitute for technicalexpertise but to provide a reliable inhouse reference which willhelp Bank staff to determine when and what expertise is needed inthe detailed evaluation of investment proposals in agro-processing.

The conditions for any particular proposal are bound to be uniquein a number of respects, and the use of norms and general data inproject analyses could give rise to significant errors. On theother hand, by providing responsible staff with a guide to theissues on which appropriate expertise should be sought, theseprofiles can contribute to the overall quality of agro processinginvestment. Used with care, they should also facilitate broadpre-screening such as may occur during sector work andreconnaissance.

Questions, comments and further inquiries should be addressed to:Agro-Industries AdviserFinance and Agro Industry UnitAgriculture and Rural Development Department

The contribution of Ibberson International, Inc. in the review ofthis profile is gratefully acknowledged.

September 1985

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Corn

CONTENTS

DATA SHEET ............................----------

INTRODUCTION ........... 1GLOSSARY ............

RAW MATERIALS .......... 3

INTRODUCTION TO MILLING .......... 7WET MILLING ..........

8MARRKETING ASPECTS ............

1OTHER FACTORS ..........

15BIBLIOGRAPHY ..........

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ANNEX I INVESTMENT AND OPERATING COSTS

ANNEX II CONVERSION TABLES (METRIC/US)

ANNEX III CORN PRODUCT CONVERSION FACTORS

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Corn

DATA SHEET

Corn Yields (World Bank, 1982):

World Average (1979) - 3,270 kg/ha.Range - From a high of 6,700 kg/ha (the average among principalOECD-country producers) to 3,400 kg/ha (theaverage among principal producers in the centrally-planned economies) to 1,500 kg/ha (average amongprincipal developing-country producers).

Six types of corn are of major commercial importance (Considine,1982):

Dent - Hard grains, characterized by concavity of the kernelO resulting from shrinkage of the endosperm with the loss ofmoisture; the majority of U.S.-produced corn is Dent.

Flint - Early-maturing, very hard grains (more so than Dent), dueto the presence of a hard layer of starch beneath the endosperm;grown principally in Argentina and Africa.

Flour or Soft - Large, soft grains with friable endosperm,permitting easy grinding; grown largely in South and CentralAmerica.

Sweet - Soft, sweet kernels which contain a greater ratio ofsugar to starch than other corns; marketed fresh, canned, orfrozen for human consumption.

Popcorn - Very hard, small, elongated grains, which are consumedin puffed-kernel form.

Kwax - Waxy-textured grains often used in wet-milling productionof cornstarch.

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Typical corn kernel composition (Uhlig, 1979):

Bran - 6%, with a high fiber content;Germ - 12%, of which about 35% is oil; andEndosperm - 82%, of which about 86% is starch.

Dry milling yields are detailed in Table 1 below.

Particle size range YieldProduct Mesh* mm (% by weight)

Flaking grits 3.5-6 5.8-3.4 12Coarse grits 9-12 2.0-1.4 15 0Medium grits 12-16 1.4-1.0 60%Fine grits 16-26 1.0-0.65 23 Coarse meal 26-48 0.65-0.3 10Fine meal

(coarse cones) 48-90 0.3-0.17 10Corn flour through 80 below 0.17 5Germ 6.7-0.5 14Hominy feed --- 11

* Tyler Standard Screen Scale sizes

Table 1: Dry-Milled Maize Product YieldsSource: Kent (1983)

Wet Milling Yields (Considine, 1982):

A 56-lb (25.4 kg) bushel yields - 32 lb (14.5 kg) starch;- 14.5 lb (6.5 kg) feed and

feed products;- 2 lb (0.9 kg) oil; andwater.

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INTRODUCTION

(Note: This commodity is known as 'corn' among English-speakersof North America and as 'maize' among other English-speakers.The terms can be used interchangeably.)

Corn ranks third in world tonnage of grains produced, behindwheat and rice . The majority is consumed as an energysupplement in livestock and poultry feed where its advantages areease of digestion, high energy content, and price. In parts ofSouth and Central America and Africa, however, it is a staple ofhuman consumption.

While sweet corn is palatable to humans in its fresh state, itcomprises only a small portion of the total human consumption ofcorn products. Other corn varieties, the sugar content of whichis much lower, require processing prior to human consumption.Milling enhances the water absorption properties of maize starch,thereby expanding food preparation possibilities. It alsofacilitates the addition of supplemental vitamins and proteins to.S compensate for corn's nutritional deficiencies in these respects.

Additional information on corn milling processes is available inKent (1983), Technology of Cereals.

GLOSSARY

Amioca Starch obtained from wet-milling of waxymaize; makes a non-gelling paste character-ized by its clarity, fluidity, and adhesiveproperties.

Bran Thin outer coat of the kernel with a highfiber content.

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Corn Flour Fine, pulverized endosperm particles pro-duced by dry milling.

Decortication Removal of outer layers of bran from thegrain.

Degerminated Meal Highly refined meal from which bran and germhave been almost completely removed; particlesize and uniformity are controlled. Has lessthan 1.2% fiber and less than 2.25% fatcontent on a moisture-free basis.

Dextrose A sweetener which is about 75% as sweet as(Glucose) sucrose (sugar); formed when corn starch is

completely hydrolyzed; the main source ofbody energy.

Dextrose A measurement of the degree of conversion ofEquivalent starch, expressed as the ratio of the reduc-

(DE) ing power of the syrup to that of puredextrose.

Endosperm The starch and protein component of a cornkernel, contained within the bran walls.

Germ The embryo or sprouting section of the seed,distinguished by its high oil content.

HFCS High fructose corn syrup, an enzyme-convertedsyrup that is sweeter than traditional acid-converted syrups.

Hominy/Grits Degerminated coarsely-milled endosperm withbran removed; particle size ranges from5.8-0.65 mm; a product of dry-milling.

Hybrid The first generation of a cross thatinvolves two or more inbred lines; incor-porating a variety of desireable character-istics.

Instant Starch Pre-gelatinized starch obtained from heatedand dried maize starch/water slurries; thick-ens when mixed with cold water.

Maltodextrins Solutions having a DE of less than 20.

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Meal Ground endosperm, classified as coarse andfine, with particle size ranging from 0.65-0.17 mm.

Semi-Sifted Meal Meal from which part of the bran and germ(Bolted Meal) has been removed, and in which particlesize and uniformity have been partiallycontrolled. Max: 1.25% ash on a moisture-free basis.

Sweet Corn Soft grain corn characterized by a relativelyhigh glucose content; eaten as a vegetable,either fresh, canned, or frozen.

Syrups Solutions of starch and water (in which thestarch is broken down chemically by hydroly-sis) having a DE of 20 or more.

Whole Meal Milled product containing all parts ofthe grain, i.e., germ and bran as well asendosperm.

RAW MATERIALS

Corn is a warm weather plant grown in both temperate and tropicalclimates, in high and low rainfall areas, and in zones with longand short summers. It is a hardy plant, known to withstand evenextreme heat. The ideal temperature for germination is 86degrees F (30 C); slower germination rates result under lowertemperatures. Relatively warm day and night temperatures arerequired during the growing season, which is about 140 days fortraditional varieties, 90 to 200 for hybrids. A precipitationlevel of 25-50 inches (63-127 cm) is preferred (Considine, 1982).Corn is an annual plant belonging to the grass family. It rangesin height from less than 3 feet (0.9 m.) for dwarf varieties tomore than 15 feet (4.5 m.) for giant varieties (Ibid.). The stemis coarse, solid, and erect; narrow leaves alternate along itslength. Rows of grain develop on an elongated, enclosed ear.Grain color ranges from white to dark brown, purple, and red.

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Grain shape and size vary according to specie. Flint corn, forexample, is smooth, broad, and rounded while Dent corn is long,narrow, and marked by a 'dent' formed during ripening as its softstarch shrinks.

Hybrid corn is the result of a cross between inbreds. Inbreedingcan improve corn yields, pest and disease resistance, lysinecontent (and therefore protein quality), stress tolerance, andresistance of lodging, but inbreds are characterized by theirlack of vigor. Crossing of inbreds, resulting in hybrids,restores previous levels of vigor. With the commercialintroduction of hybrids in the early 1900s and their improvementin the years which followed, corn yield potentials have increasedsubstantially.

The kernel is composed of (1) endosperm, the starchy portioncontained within the bran envelope; (2) germ, which is unusuallylarge in corn, comprising 10-12% of the weight of the kernel and30% of its volume; amd (3) the hull (bran), a thin outer kernelcoating with'a high fiber content (ILO/JASPA, 1981).

Starch is the primary component of the corn kernel, making upabout 72% of its dry weight. The protein content is 10%; oil,4.5%; fiber, 3.5%; and miscellaneous, 10%. (Spaeth, 1982) Cornprotein is of relatively poor quality due to its deficiency ofthe essential amino acids, tryptophan and lysine. Use of cornflour for bread baking is limited by the lack of gluten-formingproteins.

Harvest and Preparation

Corn is harvested when accumulation of starch and protein in thegrains is complete. A dark spot on the grain opposite the germand a moisture content of 30-40% are signals of maturity (FAO,1981). When corn is harvested too early drying costs are higher;when harvested too late, the risk of damage by insects andadverse weather conditions increases. Manual harvesting resultsin fewer losses and a cleaner raw material, but mechanicalharvesting is the norm, except in small-scale agriculture..

Several steps are involved in the post-harvest, pre-millingpreparation of corn: drying, husking, shelling, and storage(optional).

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Drying can take place before or after husking. When long-termstorage is the objective, drying prior to husking is preferable,since the husk helps protect the grain from insects and breakage.However, the drying time involved is considerably longer withhusks than without. The moisture content of corn should bereduced to 13% or less for storage in bags and 12% or less forbulk storage (ILO/UNIDO, 1984). At these levels germination,micro-organism proliferation, and insect infestation areminimized.

Choice of drying method depends on resource availability,post-harvest weather, production levels, and intended use. Mostcommon in developing countries is sun drying. A description ofmechanical driers (batch and continuous) and a comparison withsun drying are provided in this series' Rice Profile.

Husking removes the leaf sheaths which surround the ears of corn.It can be done mechanically or manually. Manual husking isperformed either bare-handed or with a specially-designed huskinghook attatched to a glove.

Shelling removes the individual grains from the cobs. It shouldtake place as near as possible to the harvest site so as tominimize transport costs. A moisture content of 13-14% is bestfor shelling in order to avoid grain damage and high powerconsumption costs which result when the grain is too damp.(Ibid.)

The ILO (1984) lists and describes five types of corn shellers:(1) hand-held devices; (2) small rotary hand shellers; (3)free-standing hand shellers; (4) small-powered/largehand-operated shellers with cleaning and grading facilities; and(5) large-powered shellers with loading, cleaning, grading, andbagging facilities. Shelled corn output ranges from 15 kg/hr forhand-held devices to 4 tons/hr for large-scale shellers.

General problems of grain storage are discussed in the RiceProfile.

Quality

Corn grain quality is measured in terms of: (1) color, which iseither white, yellow, or mixed; (2) variety, where differentvarietal characteristics are demanded by different end-users; (3)test weight per bushel; (4) moisture; and (5) amount and natureof damage and non-corn impurities (Matz, 1969).

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Other factors are of interest to users with specific needs. Forexample, protein content is important when corn is to be used foranimal feed; starch type and content is critical when the corn isto be wet-milled; and lack of off-flavors is necessary forbreakfast cereal production.

Factors upon which grain quality depends are discussed at lengthin Matz (1969), Cereal Science.

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INTRODUCTION TO MILLING

Corn milling is of two types: Dry milling and wet milling. Theobjectives of dry milling are threefold: (1) to maximize theyield of grits while minimizing its impurity content; (2) tomaximize the grit (as opposed to flour) yield; and (3) tomaximize germ recovery in large-particle form, so as to minimizeoil losses. (Kent, 1983)

Dry millinq involves the following operations: cleaning andconditioning of the grain; degerming to remove germ and hulls,use of rolls to remove attached hulls and flatten attached germ,use of sifters to scalp flattened germ fraction and grade groundendosperm into grits, meal, cones and flour; use of aspirators toremove loose hulls from grits and dryers for finished productmoisture specifications. This process is very similar to that ofwheat dry milling, as described in detail in the Profile onWheat. (See Kent [1983] for more information.) It differs fromwheat dry milling in that the preferred final product for corn isgrits while that for wheat is flour. Wet cleaning is still usedin some cornmills to separate impurities.

Dry-milled corn products include grits (flaking, coarse, medium,and fine); meals (coarse and fine); and flour. Oil-containinggerm is the most important by-product. Most dry-milling productscan be consumed without further processing.

Wet millinq is a combination of physical and chemical operationswhich separate corn into its major components: starch, gluten,fiber, and germ. The principal products are starch, a source ofglucose, and germ, a source of corn oil.

Wet milling involves: cleaning and steeping; degerminating; germseparation; grinding; screening; and starch separation, washing,and drying, as illustrated in Flowchart 1. These wet-millingoperations are discussed in the remainder of this section.

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1Onnstw|stt"owwtr,;

Gr Cconcentrat s

O il xta.Cd@rift trf ai

Str t msing l

c o ldd glucose

I~~~~~~~~ ~~~~~~~ gir.ndingr

Clenin and Steeping nO I

Impurities~~ l9fondiconae siia Glto ths n ric andwet

Dextrn Corn syrup Corn syrup Iotfgn solids (liquid glue Solid glueas

(Adspted frolm Anom. FeiA 1958, 7- 291; Com ix /dny, 5dl edido, Ca 1ndusis Resxus:Funatio Inc., New Yodi; and S.A. Ma (EdL) OGm TrZboi Avn Publ. CAL Inc. WestpM on;Gn., U.S.A., 1970.)

Flowchart 1: Corn Wet-Milling ProcessSource: Kent (1983)

WET MILLING

Cleaning and Steeping

Impurities found in corn are similar to those in rice and wheat.They are removed by the same cleaning processes with oneexception (as mentioned above): wet cleaning is still used insome mills, but in most cases impurities are removed with acombination of vibrating sieves or oscillating sieves andaspirators.

Steeping is a conditioning operation whereby cleaned, shelledcorn kernels are softened. This is accomplished by soaking thecorn in a large tank filled with a warm (122 degrees F, or 50degrees C), circulating solution of water and 0.02-0.03% sulphurdioxide for 28-48 hours, until the moisture level of the kernelreaches 43-45% (Kent, 1983).

The objective of steeping is to (1) remove some of the solubles;(2) toughen the germ; and (3) soften the protein matrix whichbinds the starch granules in the endosperm. The weak sulphuric

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acid solution formed by the sulphur dioxide and water helps tocontrol fermentation and break down the protein matrix, therebyfacilitating its separation from the starch.

Steeping water contains approximately 6% solids, some 35-45% ofwhich is protein (Ibid). The high-protein solids are settled outof the solution, dried, and used as gluten for animal feed; thesteep water can then be re-used.

Degerming/Germ Separation

In degerming, the bran is loosened and the germ is separated fromthe endosperm with minimal crushing as the softened kernels aregently broken open. The objective is to remove the germ withoutbreaking it. Since the germ contains a high proportion of oil,its removal reduces the risk of rancidity in storage.

A Fuss mill is often used in the degermination process (Kent,1983). It consists of a chamber containing two upright metalplates, one of which rotates while the other remains stationary;each Eis covered with extruding metal teeth. A water and maizemixture is introduced into the chamber, where the grain iscracked open and coarsely ground. The germ is released in theprocess. The density of the corn/water solution is then adjustedto the point where the germ floats while grits and hulls sink.Separating troughs are used to settle the hulls and grits whilethe germ is drawn off the surface. In modern corn millshydrocyclones replace flotation equipment in separating the germ.These are less bulky, less costly to maintain, and more efficientin removing the germ.

Upon its removal, the corn germ is washed to remove any remainingstarch. Following water expulsion and drying of the germ, theoil is extracted and purified. (See Profile on Oilseeds formore information on this process.) The germ cake from which theoil has been removed is used for cattle feed.

Grinding/Screening

The solution of coarsely-ground, degermed endosperm, hull, andwater passes through a series of impact mills or attrition mills.These finely grind the endosperm, which remains suspended in a

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water slurry. Larger particles of hull and fiber are screenedout, while fine fiber particles are filtered out by means ofgyrating 'shakers' covered with finely-woven nylon cloth.

Starch Separation/Washing/Drying

The difference in specific gravity between the heavier starch andthe lighter gluten contained in the slurry makes it possible toseparate the two by centrifuging. First the density must beadjusted by dewatering (filtering) of the solution. Then thesolution is pumped into a continuous, high-speed centrifuge,which extracts the gluten. Re-centrifuging in hydrocyclonesremoves any gluten protein that remains. Often the starch isalso washed to remove any residual solubles.

Starch to be used in industrial applications is then dried to amoisture content of 10-12% in kilns, or in tunnel or flash driers(Ibid). The moisture content is further reduced (5-7% in theU.S.; 1-2% in the U.K.) by vacuum drying.

The remaining starch is used for conversion into a variety ofproducts, such as glucose syrups, dextrose, and high fructosecorn syrups (HFCS). It can also be used as a feedstock in theproduction of ethyl alcohol by a fermentation and distillationprocess.

The gluten is dried and will yield up to 60% protein. It ismarketed as gluten meal (60% protein), or it is used as aningredient in corn gluten feed (at 21% protein). Furtherseparation of the gluten, by means of solvent extraction andprecipatation, produces zein, an alcohol-soluble protein used asa protective coating for confections, grains, and nuts. It isalso used as a binding agent in the manufacture of pharmaceuticaltablets and for other industrial purposes.

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0MARKETING ASPECTS

Grade/Quality

Because most corn is traded in whole grain, rather than in milledform, accepted international standards are lacking. Of majorimportance, however, is the nutritional value of milled corn,especially in the developing countries of Africa and LatinAmerica, where corn is an important element in the diet of thepopulations. Three main types of corn meal are consumed indeveloping countries: whole meal, from which the germ has notbeen removed; bolted meal or partly de-germed meal; and de-germedor super-sifted meal, which contains little or no germ. Thenutrient composition of each is estimated in Table 2. While thecaloric content of the three is essentially the same, whole mealis preferred when nutritional concerns dominate. Furthermore,whole meal extraction rates, at 97-99%, are substantially higherthan those of either bolted meal (80-96%) or sifted meal (60-75%)(ILO/UNIDO, 1984). This must be weighed against the relatively. shorter shelf life of whole meal and, in general, consumerpreference for sifted meals.

Uses

The products of dry processing and their uses include:

Grits, used in the production of ready-to-eat cereals, as abrewing adjunct, and consumed directly as porridge. Industrialapplications include wallpaper paste and the manufacture ofsweeteners by direct hydrolysis.

Meal, used in bakeries as a raw material, in infant foods, and incereals. Industrial applications include use as a dusting agent,in soaps, and in floor wax.

Flour, used in making bread, infant foods, and cereals; and as afiller in meat products.

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Product/ Whole meal Bolted meal De-germed mealNutrient (partly de-germed) (super-sifted)

Moisture.(percentage) 12-13 12-13 12-13Calories per 100 gr 353-356 360 363Protein (percentage) 9.3-9.5 9.3 7.9-8.4Fat (percentage) 3.8-4.5 Variable 02) 1.2-2.0Carbohydrates (percentage) 73.4 Variable (74) 78.4Fibre (percentage) 1.9-3.0 0.7-1.0 0.6-0.7

Ash (percentage) 1.3 n.a. 0.5Calcium (mg per 100 gr) 7-17 6 5-6Iron (mg per 100 gr) 2.3-4.2 1.8 1.1-1.2Thiamine (mg per 100 gr) 0.3-0.45 0.35 0.14-1.18Niacin (mg per 100 gr) 1.8-2.0 1.3 0.6-1.0Riboflavin (mg per 100 gr) 0.11 0.09 0.08

Note:Variations in data according to sources may be explained by variations inthe raw materials analysed and/or variations in the quality of meal.

Sources: Schlage (1968); FAQ (1968); FAQ (1953); FAQ (1954); Uhlig and Bhat(1979).

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Table 2: Nutrient Composition of DifferentTypes of Corn Meal

Source: ILO/UNIDO (1984)

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Uses of starch produced in wet milling include:

Dry Starch (unmodified), with industrial applications in themanufacture of paper, textiles, adhesives, and packaged foods.

Sweeteners, i.e., corn syrups, such as HFCS, dextrose, andfructose, used in the production of processed foods.

Ethyl Alcohol, produced by fermentation and distillation usingcorn starch as a base.

Characteristics of the Market

Corn ranks third in world tonnage of grains produced, behindwheat and rice. The U.S. is the leading producer, supplyingnearly half of the world's total. The developing countries as agroup, led by Brazil, Argentina, Mexico, and South Africa,produce about 1/4 of the total; and the centrally plannedeconomies, led by China, produce about 1/6 (Considine, 1982).. Principal corn utilization categories include human food,industrial applications, animal feed, and seed. Table 3 showsthe domestic proportions of these categories for selectedcountries.

Table 3: Domestic Utilization of Corn in Certain CountriesSource: Kent (1983)

Total Percentage of total domestic usagedomestc Source

usage Human Animal ofCountry Year (thousand t) food Industrial' feed Seed data

EEC:Bel/Lux '79/80 1184 2 30 68 - IFrance '79/80 7294 1 8 89 2 1Germany, FR '79/80 3003 10 13 76 1 1Italy '79/80 9580 3 1 96 - INetherlands '79/80 2577 2 10 88 - IU. K. '79/80 3133 10 50 40 - 1,2Australia '78 155 39 - 61 < 1 3Austria '78 1270 1 7 91 < 1 3Canada '78 4476 18 - 81 1 3Japan '78 10,483 3 16 81 - 3Portugal '77 1770 15 < 1 83 1 3Spain '78 5493 - 8 92 < 1 3U.S.A. '78 111,891 8 3 88 <1 3Yugoslavia '78 9955 5 26t 68 1 3

lIncluding wate tlncluding 23% waste.

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Unlike trade in wheat and rice, trade in corn is generally inunprocessed, whole kernel form (Uhlig, 1979). This is because(1) most exports of corn go to industrialized countries to beused as animal feeds (animals are typically fed whole meals,which do not store well when milled); and (2) it is easier tohandle and transport corn in bulk form. It is estimated thatsome two-thirds of all corn produced is consumed as animal feed(Ibid).

The export market for corn is dominated by the U.S., whichsupplies almost three-fourths of the total (Ibid). Consequently,U.S. domestic supply and demand fluctuations substantially impactworld prices.

Retail prices of sifted meals are generally greater than those ofwhole meals at the domestic level, although they vary both inter-and intra-nationally. This difference reflects (1) the lowerextraction rate for sifted flour production; (2) the higherpackaging cost of sifted flour, which is generally available inone- or two-pound bags; (3) the added operating costs and profitmargins of intermediaries; (4) advertising; and (5) highertransport costs (sifted flours are often transported greaterdistances due to their better storage ability) (ILO/UNIDO, 1984).

Global consumption of corn has been growing by about 3.5% (perannum) since 1961 (World Bank, 1982). The U.S. alone accountsfor about half of total world consumption.

The U.S. is one of the few countries in the world in which cornsyrup sweeteners play a significant role; this is due to (1) thehigh support price for sugar; (2) the relative abundance and lowprice of corn in the U.S.; and (3) the high investment costs andhigh technology operations involved in its production. Whilecorn syrup sweeteners have been produced for over a century, itwasn't until the early 1970s that demand began to increaserapidly. Two factors contributed to this boom: First, a processwas developed whereby glucose, the principal ingredient ofconventional corn-syrup sweeteners, is converted to fructose,which is considerably sweeter. This led to the development ofHFCS, which now dominates the corn sweetener market. Second, andequally important, were the high international sugar prices of1974 (MacNally, et al, 1984). Whereas starch-based sweetenerscomprised 5% of total world sweetener consumption in 1970, by1980 this share had risen to 9% (Ibid). By 1990 this figure isprojected to increase to 11%.

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Aspartame, a synthetic, non-nutritive sweetener which is 150-200times as sweet as sucrose (Stegink and Filer, 1984), is expectedto make important inroads in the world sweetener market in comingyears. Its advantages over HFCS include (MacNally, et al, 1984):(1) it is cheaper to produce; (2) it is easier to handle; and (3)it can be used by households as well as industries since it isavailable in both dry and liquid forms. Unlike othernon-nutritive, low-calorie sweeteners such as cyclamates andsaccharin, there is no evidence of adverse health effects and nono unpleasant aftertaste.

OTHER FACTORS

Storage

Factors affecting storage potential of milled corn include fatand moisture content, the presence of contaminants, and storageconditions, including packaging material, air temperature, andlevel of humidity. Because the fat content of whole meal is sohigh (3-4%, or 2-3 times that of sifted meal), its storagepotential is significantly limited. Although experience varies agreat deal, periods of four to eight weeks for whole meal and sixmonths to two years for sifted meal can be used as indicative forstorage under good conditions.

Environmental Concerns

Unlike wheat milling, corn dry milling produces very little dustdue to the larger product granulation and the fat content of theproducts. Due to the extensive use of aspirators, fine dust isconstantly removed and collected into filters (cyclones).

Economies of Scale

Uhlig (1979) illustrates the potential impact of economies ofscale in corn dry-milling with the following example: A 120-tonper day (tpd), modern mill produces 2.4 times the output of a 50tpd mill, at only 1.4 times the cost. Economies of scale areeven greater in wet milling.

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By-Products

Principal by-products of wet-milled corn include:

Corn Oil, a high quality cooking oil extracted from the germ. Itis characterized by a golden color, delicate flavor, the presenceof polyunsaturated fatty acids, and high caloric and nutritionalvalue.

Corn Oil Cake, the residue from the germ once its oil has beenextracted. Because of its relatively high protein content (20%),it is a key ingredient in livestock feeds and pet foods.

Corn gluten, a residual of the wet milling process. It containssome 60-70% protein and consequently is valuable as an animalfeed ingredient. It is also an important source of energy,vitamins, minerals, and fiber. Corn gluten feed is frequentlyfed to dairy cows and poultry. Corn gluten is also used as acorkbinding agent, an additive for printing dyes, and in themanufacture of pharmaceuticals.

Zein, an alcohol-soluble protein which can be removed from thegluten. It is used as a binder in tablet making and as aprotective coating for confections and nuts.

Bran, which has a high fiber content, as well as about 9%protein. It is used in combination with gluten in the formationof corn gluten feeds.

Steepwater, the high-protein, dry solids portion of which issettled out, dried, and used in the production of animal feeds.The liquid which is not recycled (i.e., used for steeping) isconcentrated and used as a culture medium.

Corn Cobs, which are used in a variety of ways, e.g., as litterfor animals, mulch, an ingredient in animal feeds, fillers forexplosives, plastics, glues, and tires; in abrasives for soaps;in cleaning and polishing; and in the production of insecticidesand pesticides.

16

BIBLIOGRAPHY

* 01. Baron, C.G. (1980) Technology, Employment, and Basic NeedsFood Processing in Developing Countries.Oxford: Pergamon Press.

02. Berger, J. (1962) Maize Production and the Manuring ofMaize.Geneva: Centre D'Etude de L'Azote.

03. Christensen, C.M. (1982-3rd Edition) Storage of CerealGrains and their Products.St. Paul: American Association of Cereal Chemists, Inc.

04. Considine, D.M. (1982) Foods and Food Production Encyclo-pedia.New York: Van Nostrand Reinhold Company.

05. FAO (1981) Cereal and Grain-Legume Seed Processing: Tech-nical Guidelines.Rome: FAO.. 06. Horwitz, D. L. and J.K. Bauer-Hehrling (1983) Can Aspar-tame Meet Our Expectations?Journal of the American Dietetic Assn, 83 (2):142-146.

07. ILO/JASPA (1981) Appropriate Technologies in Cereal Millingand Fruit Processing Industries.Addis Ababa: JASPA.

08. ILO/UNIDO (1984) Small Scale Maize Milling.Geneva: ILO Office.

09. Kent, N.L. (1983-3rd Edition) Technology of Cereals.Oxford: Pergamon Press.

10. Leiva, J. Plant for the Combined Production of Wheat Flourand Precooked Cornmeal (Maizemeal). Diagram No. 68,September, 1979.

11. Matz, S.A. (1969) Cereal Science.Westport: The Avi Publishing Company, Inc.

12. MacNally, W., W. David, and D. Flood (1984) Sugar Study.Washington: World Bank

17

13. Pyke, M. (1981-4th Edition) Food Science and Technology.London: John Murray (Publishers) Ltd.

14. Roncaglia OPR (no date) From Maize/Corn to Flour.Modena (It): Officine Roncaglia.

15. Spaeth, R.W. (1982) Corn Wet Milling Processing and Productsin The China Encounter: Technical Papers from the FirstGrain Milling and Baking International Symposium.Kansas City: Sosland Co., Inc.

16. Stegink, L.D. and L.J. Filer (1984) Aspartame: Physiologyand Biochemistry.New York and Basel: Marcel Dekker, Inc.

17. Uhlig, S.J. and B.A. Bhat (1979) Choice of Technique inMaize Milling.Edinburgh: Scottish Academic Press.

18. USDA (1979) Conversion Factors and Weights and Measures forAgricultural Commodities and their Products.Washington: USDA.

19. World Bank, Commodities and Export Projections Division(1981) Sugar Handbook.Washington: World Bank.

20. World Bank, Commodities and Export Projections Division(1982) Grains HandbookWashington: World Bank.

21. World Bank, East Asia and the Pacific Projects Dept. (1976)Philippines: Appraisal of the 2nd Grain ProcessingProlect.Washington: World Bank.

22. Wyss, Ed. Development of Corn (Maize) Processing. BuhlerDiagram No. 58, November, 1974.

18

.

ANNEX I:

EXAMPLES OF INVESTMENT AND OPERATING COSTS

0

0

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CORN MILLINGEXAMPLE 1

Page 1 of 2

Representative Investment and Operating Costs

CORN (MAIZE) MILLING____________________

Establishment of a mill to process dried corn (maize)into flour.

COUNTRY: Kenya

NOTE: These data are intended as indicative only and are uniqueto the time, circumstance, and country of the identifiedinvestment. Their applicability to other situations mayvary considerably.

Annual Production at Full Development (in '000 tons):

672.00.2 Capacity Utilization at Full Development: 80.00%

US$ '000mid 1982 prices

TotalI. Investment Costs:

Land & Building 1.36Machinery

hammer mill & accessories 10.00other 0.53Sub-Total Machinery

10.53Transport 0.32Installation 0.27Pre-Operational Expenses 0.84

Total Investment Costs 13.32

-


Page 2 of 2


NOTE: These data are intended as indicative only and are uniqueto the time, circumstance, and country of the identifiedinvestment. Their applicability to other situations mayvary considerably.

US$ 'ooomid 1982 prices

Total

II. Annual Operating Costs at Full Development:(excluding raw materials)

-----------------------------------------------

Variable Costswages 2.91fuels 1.82consumables 0.33

Sub-Total Variable Costs 5.05Fixed Costsadministration & overhead 2.77maintenance & repair 0.14insurance 0.91depreciationbuildings 0.14machinery 1.46

Sub-Total Fixed Costs 5.41

Total Operating Costs 10.47

NOTES:Exchange rate - Kenya Shillings 11.00 US$ 1.00Detailed breakdown on local and foreign costs is not available.Details on raw material costs are not available.Depreciation at 10% on buildings and 12.5% formachinery & equipment.Full development production is achieved in the second year ofthe project.Data are net of contingencies.


Page 1 of 2

Representative Investment and Operating Costs…--------------------------------------------

CORN (MAIZE) MILLING

Establishment of a dry maize milling plant to produce maizeflour and maize bran and maize germ from by-products.

COUNTRY: Uganda (M/S Arocha Millers Ltd.)

NOTE: These data are intended as indicative only and are uniqueto the time, circumstances, and country of the identifiedinvestment. Their applicability to other situations mayvary considerably.

Annual Full Development Production (in tons):---------------------------------------------

maize flour 1600.00maize bran 220.00maize germ 180.00

Capacity Utilization at Full Development: 100.00%

…-----…US$ '000 …early 1984 prices

Local Foreign TotalI. Investment:______________

Land Acquisition/Development 1.00 1.00Building Construction 50.00 50.00Machineryimported 6.67 350.00 356.67local procurement 3.33 51.33 54.67Sub-Total Machinery 10.00 401.33 411.33Import Duties 16.00 16.00Utility Upgrade 5.00 5.00Pre-Operating Costs 97.13 97.13

Total Investment Costs 179.13 401.33 580.47

-~~~~~~~~~~~------------


Page 2 of 2


NOTE: These data are intended as indicative only and are uniqueto the time, circumstances, and country of the identifiedinvestment. Their applciability to other situations mayvary considerably.

US$ '000early 1984 prices

Total

II. Annual Full Development Operating Costs:---------------------------------------------

Variable Costsraw materials 233.33packing materials 36.67factory chemicals 2.67production labor 3.57electricity/water/fuel 22.93

Sub-Total Variable Costs 299.17

Fixed Costsoverhead salaries 5.37administration 21.47depreciation 109.20maintenance 6.57



NOTES:Exchange rate Ugandan Shillings 300 = US $ 1.00Details on foreign exchange component of operating costs notavailable.Full development is approximately four years after projectstart-up.Data are net of contingencies.


Page 1 of 3


MAIZE MILLING_____________

Establishment of a processing facility to produce grits and otherproducts from maize flour.

COUNTRY: Yugoslavia

NOTE: These data are intended as indicative only and are uniqueto the time, circumstance, and country of the identifiedinvestment. Their applicability to other situationsmay vary considerably.

Annual Full Development Production (tons):------------------------------------------

maize grits 1575.00 brewery grits 13875.00maize flour 150.00 corn meal 700.00corn flakes 550.00 maize gen 1250.00

livestock feed 12840.00

Capacity Utilization at Full Development: 100.00%

--------US$ 000-------end 1980 prices

Local Foreign TotalI. Investment Costs:____________________

Civil Workssilos 2595.19 1112.22 3707.41silo preparation 215.63 47.33 262.96workshop 125.00 41.67 407.41warehouse 305.56 101.85 129.63sewage system 105.00 24.63 37.04water system 30.00 7.04 318.52electric system 222.96 95.56 318.52processing plant 2307.41 988.89 3296.30

Sub-Total Civil Works 5906.74 2419.19 8477.78

S


Page 2 of 3

Representative Investment and Operating Costs---------------------------------------------


-------- US$ 000-------end 1980 prices

Local Foreign TotalInvestment Costs (cont'd)_________________________

Equipment & Machineryprocessing (domestic) 432.44 288.30 720.74processing (foreign) 1604.63 1604.63grain dryer 254.81 382.22 637.04boiler (coal) 299.15 365.67 664.81mechanical/electrical (silo) 971.22 827.37 1798.59installation 192.59 48.15 240.74transportation 116.67 12.96 129.63insurance 22.22 22.22

Sub-Total Equipment & Machinery 2289.11 3529.30 5818.41Engineering & Design 420.22 74.15 494.37Supervision & Start-Up 232.15 232.15Training 51.85 22.22 74.07Customs & Duties 529.52 529.52

Total Investment Costs 9429.59 6044.85 15626.30_ _ _ _ _ _ _ - - - - - - - - - - - - - - -

_ _ _ _ _ _ _ - - - - - - - - - - - - - - -


Page 3 of 3



US$ '000end 1980 prices

Total Cost

II. Full Development Annual Operating Costs:--------------------------------------------

Variable Costsraw materials

5967.22utilities 502.37packing materials 356.67production labor 165.19Sub-Total Variable Costs 6991.44

* Fixed Costsmaintenance

38.74insurance 59.48management staff 43.56common consumption 85.63Sub-Total Fixed Costs 227.41


DATA SOURCE: Adapted from World Bank project appraisal reportfor the Kosovo Agro-industries and AgriculturalDevelopment Project, (3286-YU), Volume II, WorkingPaper WP-3.10, Maize Processing Plant.

NOTES:Exchange rate - Dinar 27.00 = US $ 1.00Full production is approximately year five following projectstart-up.Details on foreign/local cost breakdowns for operating costsare not available.Data do not include contingencies.

I~~~~~~~~~~~~~~~~~~~~~

ri~~~~~~~~~~~~~~~~~~~~~~~~

* CORN MILLING

EXAMPLE 4Page 1 of 2


CORN (MAIZE) MILLINGEstablishment of a corn (maize) milling facility that willproduce corn starch, corn syrup, corn flour, and fructose.

COUNTRY: Korea (Doosan Grain Co., Ltd.)

NOTE: Data are intended as representative only and are uniqueto the time, country, and circumstance of the identifiedinvestment. Their applicability to other situationsmay vary considerably.

ANNUAL PRODUCTION AT FULL DEVELOPMENT ('000 tons):

corn starch 66.00 (64,000 tons will be used forproducts listed below)

corn syrup 19.80corn grits/flour 33.00O fructose 8.20high fructose 21.50

_~~

PER CENT OF FULL CAPACITY UTILIZATION:

corn starch 40% in 2nd year of project, rising at 10%/p.a.corn syrup 50% in 2nd year of project, rising at 10%/p.a.corn grits/flour 35% in 2nd year of project, rising at 5%/p.a.fructose/ 60% in 2nd year of project, rising at 10%/p.a.high fructose

--------US$ '000-------mid-1981 prices

Local Foreign Total

Investment Costs:_________________

land 877.19 877.19building 4334.80 4334.80. structures 1331.87 1331.87equipmentdomestic 5043.86 5043.86imported 4750.00 4750.00sub-total 5043.86 4750.00 9793.86


Page 2 of 2


NOTE: Data are intended as representative only and are uniqueto the time, country, and circumstance of the identifiedinvestment. Their applicability to other situationsmay vary considerably.

…------…US$ '000 …mid-1981 prices

Local Foreign Total

transport & installation 1346.49 1346.49equipment operation training 200.00 200.00utility upgrade 2141.81 2141.81pre-operational expenses 1418.13 1418.13

Total Investment Costs 16494.15 4950.00 21444.15

II. Full Development Annual Operating Costs(excluding raw materials)

-------------------------------------------

Fixed CostsAdministration & Overheads 2271.94Depreciation 1725.89


Variable CostsLabor 1286.64Other 1514.62

Sub-Total Variable Costs 2801.26


NOTES:1. Exchange rate - Korean Won 684 = US$ 1.00.2. Data are net of contingencies.3. Full development is year 4 after project start-up.4. Local/foreign cost breakdown for operating costs

is not available.

-

1'

'I

ANNEX II:

CONVERSION TABLES

.

vI~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

WEIGHTS AND MEASURES

avoirdupois

Ton: short ton 20 short hundredweight, 2000 pounds;0.907 metric tons;

long ton 20 long hundredweight, 2240 pounds;1.016 metric tons.

Hundredweight cwt;short hundredweight 100 pounds, 0.05 short tons; 45.359

kilograms;long hundred weight 112 pounds, 0.05 long tons; 50.802

kilograms.

Pound lb or lb av; also $;16 ounces, 7000 grains; 0.453 kilograms.

Ounce oz or oz av;16 drams, 437.5 grains; 28.349 grams.

Dram dr or dr av;27.343 grains, 0.0625 ounces; 1.771 grams.

Grain gr;0.036 drams, 0.002285 ounces; 0.0648 grams.

Troy

Pound lb t;12 ounces, 240 pennyweight, 5760 grains; 0.373kilograms.

Ounce oz t;20 pennyweight, 480 grains; 31.103 grams.

Pennyweight dwt also pwt;24 grains, 0.05 ounces; 1.555 grams.

Grain gr;0.042 pennyweight, 0.002083 ounces; 0.0648 grams.

METRIC SYSTEM

Square kilometer sq km or km2 ;1,000,000 square meters;0.3861 square mile.

Hectare ha;10,000 square meters;2.47 acres.

Hectoliter hl;100 liters; 3.53 cubic feet; 2.84 bushels;

Liter 1;1 liter; 61.02 cubic inches; 0.908 quart(dry); 1.057 quarts (liquid).

Deciliter dl;0.10 liters; 6.1 cubic inchs; 0.18 pint(dry); 0.21 pint (liquid).

Centiliter cl;0.01 liters; 0.6 cubic inch; 0.338fluidounce.

Metric ton MT or t;1,000,000 grams; 1.1 US tons.

Quintal q;100,000 grams; 220.46 US pounds.

Kilogram kg;1,000 grams; 2.2046 US pounds.

Gram g or gm;1 gram; 0.035 ounce.

0-

).

ANNEX III:

CORN PRODUCT CONVERSION FACTORS

.

is

Annex III

Conversion Factors for Corn and Corn ProductsSource: USDA (1979)

Faccors for converting--:Bushels of:Pounds of :Pounds of :Pounds of

Product : corn to : product : corn to : product:pounds of :to bushels:pounds of :to poundsDroduct of corn : product of corn

Corn, shelled 2/ ; 56.0 0.0179 1.00 1.00

Corn meal, degermed ; 31.6 .0316 .564 1.77Corn meal, nondegermed, regular : 50.0 .0200 .893 1.12Corn flour : 33.0 .0303 .589 1.70Corn grits or hominy grits : 29.0 .0345 .518 1.93Hominy, canned 145.0 .0069 2.589 .39Hominy, dry 27.3 .0366 .488 2.05

Cornstarch, 10 percent moisture 3/ 34.4 .0291 .614 1.63Cornstarch, pearl, 12 percent moistureor laundry starch 3/ 35.2 .0284 .629 1.59Corn sugar:

Dextrose, hydrate, 8 percent moisture : 30.0 .0333 .536 1.87Dextrose, anhydrous, moisture free 4/ 27.5 .0364 .491 2.04

Corn sirup, 43° Baume, 19.73 percentmoisture, 42 percent dextroseequivalent 3/ 37.6 .0266 .672 1.49

Corn flakes or corn cereal 21.5 .0465 .384 2.60Corn-soya cereal 5/ 33.6 .0297 .60 1.66

Precooked infant-type mixed cereal 500.0 .0020 8.929 .11Premixed cereal : 101.8 .0098 1.818 .55Pancake mix 330.0 .0030 5.882 .17Pudding powder, 33 percent cornstarch 103.8 .0096 1.854 .54Chocolate pudding powder, 18 percentcornstarch 186.6 .0054 3.333 .30Corn snacks : 67.5 .0148 .830 .1205Corn oil:

Refined 1.6 .625 .0286 35.0S Crude 1.8 .556 .0321 31.1

Corn feeds, gluten feed, gluten meal,and corn oil meal or cake 6/ : 14.9 .0671 .266 3.76Hominy feed : 20.0 .050 .357 2.30

1/ All factors are based on 56 pounds of shelled corn per bushel. Product spectrumvaries with corn milled and product mix sought. Factors presented are based on maxi-mum yield of product. 2/ Five bushels of shelled corn - 1 barrel; 10 bushels of earcorn - 1 barrel; 70 pounds of ear corn - 1 bushel of shelled corn. 3/ From 17-percentmoisture corn. 4/ Based on continued reprocessing of uncrystallized dextrose liquors.5/ Corn-soya cereal contains approxima.ely 34 percent sova flour. 6/ Conversion

factors cover all corn feeds combined. Data are not available to show separatecomponents of corn feeds, though gluten feed is generally about 55-60 percent of totalcorn feeds, gluten meal around 40 percent, and corn oil meal only about 2 percent.

world bank document...semi-sifted meal meal from which part of the bran and germ (bolted meal) has...

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