Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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European countries as well as in the USA in the past

decade. For instance, in The Netherlands, among

subjects aged 19 years and over, the proportion of

obese subjects has increased during the last 10 years

from 6.0% (1987–1988) to 10.4% (1997–1998). At

the same time, in The Netherlands, a decrease in

energy intake and fat consumption was observed.

Data from DNFCS-1 (1987–1988) and DNFCS-3

(1997–1998) suggested that energy intake decreased

from 2308 kcal day (9677 kJ) to 2190 kcal day

(9191 kJ). This reduction of about 120 kcal day

(485 kJ) was attributable to a decrease in fat con-

sumption (protein intake increased, and carbohydrate

intake and alcohol consumption remained constant).

This may imply that daily energy expenditure has

decreased during the same period and may include

an increased sedentary behavior. Findings of the stat-

istical office confirmed a decrease in physical activity

in leisure time.

0025 Obesity is associated with several specific health

risks, including an increased incidence of hyperten-

sion, increased noninsulin-dependent diabetes and

high levels of cholesterol and other lipids. Corrected

for these factors, obesity in itself has been reported to

be an independent factor for cardiovascular disease.

In most industrialized countries, a higher prevalence

of overweight and obesity is observed among subjects

with a lower socio-economic status.

0026 Higher rates of mortality and morbidity have been

found among lower socio-economic groups, as com-

pared with higher socio-economic groups. In several

studies, food-consumption patterns and nutrient

intakes have been more consistent with current diet-

ary guidelines among people with a higher socio-

economic status. Recent analyses of 33 studies in 15

European countries, conducted within the framework

of the European Union’s FAIR program (FAIR-97-

3096), showed that, particularly in the north and

west of Europe, people with a higher education tend

to consume more vegetables and fruits and less fats

and oils. Table 4 presents some selected results. Other

studies also found that people with a higher socio-

economic status have reported eating more whole-

meal and brown bread and less whole milk, eggs,

and meat. A higher socio-economic status has been

associated with a lower intake of fat, saturated fatty

acids, and refined sugars, and a higher intake of fiber,

although mostly, differences in nutrient intake levels

have been quite small. In general, food disparities in

relation to consumption levels might possibly explain

some of the higher rates of mortality and morbidity

among lower socio-economic groups.

0027Concerning micronutrients, in most countries, the

average intake of most minerals and vitamins appears

adequate for the population. In general, iron is an

exception in that many subjects have a low iron

intake in comparison with recommended values. In

most countries, groups with a low intake are young

children, adolescents and women of child bearing

age. Moreover, the intake of vitamins (e.g., vitamin

A and its precursors, vitamin B

, vitamin C, folic

acid), minerals, and/or trace elements (e.g., calcium,

magnesium, zinc, iodine) might be not always ad-

equate among certain population groups in several

countries. However, it should be noted that the con-

firmation of nutritional risk obtained by biochemical

data is essential for assessment of risk areas and risk

groups.

Nutritional Surveillance in the Future

0028A growing awareness of potential relationships be-

tween diet (as part of lifestyle) and health is accom-

panied by an increasing demand for (comparable)

data. Research in the field of molecular genetics and

nutrient–gene interactions is promising. Monitoring

systems may also provide more information on vari-

ations within the human genome. This will enable us

increasingly to focus on the specific needs of the

individual at potential risk.

0029Since it might be expected that in the coming years,

bioactive components, additives, and contaminants

will become increasingly a topic of interest, future

food-consumption databases should allow also the

tbl0003 Table 3 Prevalence of obesity (BMI 30 kg m

2

) in some

countries

Country Year Age(years) Men (%) Women (%)

Austria 1993 19–65 6 5

England 1994 16–64 15 16

Finland 1991 20–75 14 11

East Germany 1992 25–65 20.5 26.8

West Germany 1991 25–65 16.0 21.4

The Netherlands 1992 19–65 5.5 9.2

USA 1988–1994 20þ 22.3 25.0

tbl0004Table 4 Average difference (95% confidence intervals) in

consumption of selected foods (grams per person per day)

between the highest and lowest educational level in nine

European countries

Education (highest minuslowest level)

Men Women

Fruit þ24 (þ19.0; þ29.0) þ26.7 (þ21.7; þ31.8)

Vegetables þ12.1 (þ8.3; þ15.8) þ17.5 (þ13.7; þ21.2)

Fats and oils

(added)

2.9 (4.0; 1.9) 3.1 (3.9; 2.3)

Meat 32.6 (36.0; 29.1) 24.3 (26.9; 21.8)

Milk total þ46.9 (þ38.0; þ55.9) þ39.9 (þ33.2; þ46.6)

Cheese þ9.9 (þ8.4; þ11.4) þ10.6 (þ9.3; þ11.8)

Source: Roos and Pra

tta

(1999): Fair-97-3096 project.

4204 NUTRITIONAL SURVEILLANCE/In Industrialized Countries

assessment of these nonnutrients. Therefore, there

will be a need for more descriptive specificity, such

as brand names and more information on the food

composition. The use of computer technology and

advanced statistical methods may facilitate wider

applications of survey data and cost-effective data

fusions.

0030 To improve valid comparisons between diet and

health at the international level, a better harmoniza-

tion of data collection, methodology and standard-

ization of data analysis will be needed. Since 1990,

this concept has already been implemented in the

National Nutrition Monitoring and Related Research

Program (NNMRRP) in the USA; in Europe, an

increasing number of initiatives as to Pan-European

projects are coming up with results.

See also: Cholesterol: Properties and Determination;

Coronary Heart Disease: Etiology and Risk Factor;

Diabetes Mellitus: Etiology; Dietary Surveys:

Measurement of Food Intake; Surveys of National Food

Intake; Surveys of Food Intakes in Groups and Individuals;

Food Composition Tables; Hypertension: Physiology;

Nutrition Policies in WHO European Member States;

Nutritional Assessment: Importance of Measuring

Nutritional Status; Obesity: Etiology and Diagnosis;

World Health Organization

Further Reading

Becker W and Helsing E (1991) Food and Health Data.

Their Use in Nutrition-policy Making. WHO Regional

Publications, European Series, No. 34. Copenhagen:

World Health Organization.

Briefel RR (1996) Nutrition monitoring in the United

States. In: Ziegler EE and Filer LJ (eds) Present

Knowledge in Nutrition. Washington, DC: ILSI Press.

FAO (1977, 1981, 1988) Review of Food Consumption

Surveys. Nos 1, 27, 35, 44/Rome: Food and Agriculture

Organization.

FAO/ WHO (1992a) International Conference on Nutri-

tion. Major Issues for Nutrition Strategies. Promoting

Appropriate Diets and Healthy Life-styles. Theme Paper

No. 5. Rome: Food and Agriculture Organization.

FAO/ WHO (1992b) International Conference on Nutri-

tion. Nutrition and Development: a Global Assessment.

Rome: Food and Agriculture Organization.

Hulshof KFAM and Lo

wik MRH (1995) Nutritional prob-

lems in the industrialized world. In: Velden van der K,

Ginneken van JKS, Velema JP, Walle de FB and Wijnen

van JH (eds) Health Matters. Public Health in North–

South Perspective, pp. 162–172. Bohn Stafleu Van

Loghum: Houten/Diegem.

Kuczmarski RJ, Carroll MD, Flegal KM and Troiano RP

(1997) Varying Body Mass Index cutoff points to describe

overweight prevalence among U.A. adults: NHANES III

(1988–1994). Obesity Research 5: 542–548.

wik MRH and Brussaard JH (eds) (2002) EFCOSUM:

European Food Consumption Methods. European Jour-

nal of Clinical Nutrition 56( Suppl. 2): 51–596.

Nelson M and Bingham SA (1997) The assessment of food

consumption and nutrient intake. In: Margetts BM

and Nelson M (ed.) Design Concepts in Nutritional

Epidemiology. Oxford: Oxford University Press.

Network for the Pan-European Food Data Bank based on

Household Budget Surveys. DAFNE II (1998). Brussels:

Commission of the European Union.

Roos G and Pra

tta

R(1999)Disparities in Food Habits.

Review of Research in 15 European Countries. FAIR-97-

3096 Project. Helsinki: National Public Health Institute.

Seidell JC and Flegal KM (1997) Assessing obesity: classifi-

cation and epidemiology. British Medical Bulletin 53:

238–252.

Trichopolou A and Lagiou P (1998) Methodology for the

Exploitation of HBS Food Data and Results on Food

Availability in Six European Countries. EUR 18357 EN.

Brussels: Commission of the European Union, Research

DG/B.I-I.

WHO (1976) Methodology of Nutritional Surveillance.

Report of a Joint FAO/UNICEF/WHO Expert Commit-

tee. World Health Organization Technical Report Series

593.

NUTS

R A Stephenson, Maroochy Research Station,

Nambour, Queensland, Australia

Introduction

0001 Human consumption of nuts has been recorded from

the earliest times and nuts continue as an important

component of many diets throughout the world.

Despite this, relatively few nut crops have become

major commodities on world markets. In fact, most

of the lesser known nuts, particularly those from

warm climates (Table 1), are restricted to traditional

diets, usually within relatively narrow regional

boundaries. Consequently, information on them, in-

cluding their composition and nutritional value, tends

to be superficial. Only two of the lesser-known nuts

of warm climates – macadamia (Macadamia integri-

folia) and pistachio (Pistacia vera) – have developed

NUTS 4205

tbl0001 Table 1 Some lesser-known edible nuts of warm climates

Nameandoriginofnut Features

Almondettes (Buchanania lanzan Spreng., family Anacardiaceae) Related to pistachio nut; medium-sized tree; black, single-seeded

fruits; pear-shaped kernels, 1 cm, eaten raw or roasted,

delicious (combination of almond and pistachio flavor); 51.8%

oil, 12.1% protein, 21.6% starch, 5% sugars

Southern Asia

Bunya nut (Araucaria bidwillii, family Araucariaceae) Large pine tree; large cones bear starchy nuts c.53 cm,

usually roasted, flavor resembling that of chestnutsAustralia

Candle (Tung) nut (Aleurites spp., family Euphorbiaceae) Attractive tree; fleshy fruit, containing a single nut, globose,

c. 3 cm; hard, thick shell; soft, oily white kernel (c. 5 g); must

be cooked, moderately poisonous raw, often used for oil

China, South-east Asia, Indonesia

Cut nut (Barringtonia procera, B. edulis, B. novae-hiberniae, family

Lecythidaceae, Brazil nut family)

Confusion with taxonomy until recently, variable nut

characteristics, trees are easy to propagate from seed or

cuttings, common in coastal villages, B. procera is a more

prolific bearer than the other two species – the fruits are a bit

smaller (61 cf. 99 g) but have a higher kernel recovery (9%) and

hence higher kernel production per tree (up to 50 kg fruit, 5 kg

kernel), irregular bearing up to three times a year, high

moisture content when fresh so shelf-life is limited, tasty,

nutritious kernels, good nutty taste and long shelf-life when

processed, relatively low oil content

Pacific region

Elaeocarpus spp., including silver, blue or bush quandong

E. grandis, blueberry ash or blue oliveberry, E. cyaneus , and

E. dentatus, family Elaeocarpaceae)

Over 200 species, often attractive flowering trees producing blue

berries from 12 to 25 mm, usually cooked before eating

Australia, New Zealand, Solomon Islands

Finschia nut (Finschia chloroxantha, family Proteaceae) Relative of macadamia

Solomon Islands

Galip nut (Canarium indicum L., family Burseraceae, also

including related Java almond, C. commune and pili nut,

C. ovatum Engl., adoa/bush ngali found only on Bougainville

Island, C. salmonense) and C. harveyi from the Solomon Islands,

Vanuatu, and Fiji

Tall, buttressed tree; roundish, dehiscent fruit bearing a single

5.5 2 cm nut, yield up to 300 kg nut in shell, hard,

nonperishable shell, triangular in cross-section, c.3g,

delicious, sweet almond-like flavor; 70–80% oil, 13% protein,

7% starch; remove testa before eating, raw or roasted, oil used

for cooking and cosmetics, oleoresin burnt for lighting and

incense or used to caulk boats, commercial production in

Western Melanesia c. 100 000 tonnes nut-in-shell (16 000 t

kernel, kernel recovery at 16%) from 2 million trees

Philippines, Moluccas (Indonesia), Papua New Guinea, Solomon

Islands, Vanuatu

Galo nut (Anacolosa frutescens (Blume) Blume, family Olacacae) Erect shrub or tree, hard wood used for building, fruit is a drupe

(up to 18 g); the green-colored pulp and kernel can be eaten

fresh but boiling brings out the delicious taste of the fruit;

kernel often roasted; dry pulp and kernel contain respectively

9.5% and 10.7% protein, 4.5 and 7.5% fat, 70.8 and 75.5%

carbohydrates, 7.2 and 3.7% fiber, and 7.9 and 2.9% ash;

kernel recovery is high (73–85%)

South-east Asia, Philippines

Gnetum nut (Gnetum gnemon) Some cultivation

Papua New Guinea, Solomon Islands

Heritiera littoralis Common on seashore; some records of being eaten

Solomon Islands

Kauri pine nut (Agathis spp., family Araucariaceae) Attractive rainforest tree; overexploited for timber; limited use as

a food source in the Pacific region onlyPacific region

Lotus seeds (Nelumbo nucifera Gaertn., family Nymphaceae) Water lily revered by Buddhists; white, single-seeded carpers

embedded in flat-topped, fleshy receptacle which dries when

mature so that l-cm seeds rattle in their cavity; bitter green

embryos removed before eating; eaten raw before fully ripe;

nutty flavor, roasted or boiled when mature; rich in vitamin C,

58% carbohydrate (starchy), 17% protein, 2.5% fat

Asia, Papua New Guinea

Macadamia nut (Macadamia integrifolia Maiden and Betche,

M. tetraphylla, family Proteaceae)

Evergreen tree adapted to the fringes of subtropical rainforests;

spherical kernel enclosed by a thick, stony shell in a fibrous

single-sutured husk; high oil content (>72%); distinctive,

delicate flavor

Australia

Moreton Bay chestnut (Castanospernum australe, family

Fabaceae)

Fine spreading tree, large glossy fern-like leaves, deep green but

lighter underneath, thick pea-pods with 5-cm ‘chestnut’ seeds;

must be soaked and cooked before eatingAustralia Pacific region

Neisosperma oppositifolia Seashore habitats; small kernel

Continued

4206 NUTS

Nameandoriginofnut Features

Okari nut (Terminalia kaembachii Warb., family Combretaceae,

also T. catappa L., the tropical, Indian or sea almond, and

T. impedians)

Tall tree easy to propagate; leaves clustered at twig tips; yields

up to 100 kg large (up to 200 g) flattened, ellipsoid fruit with up

to 10% kernel recovery; yields once (March to August) but sea

almond bears sporadically throughout the year in low latitudes;

stony endocarp encloses white kernel (up to 15 g) consisting of

a leaf-like coiled cotyledon, c.82 cm, 1.5–10 g; delicate

almond flavor; contain about 50% sweet, colorless, nondrying

edible oil; eaten raw or roasted, dry for long-term storage

Papua New Guinea, Vanuatu, South-east Asia, India

Omphalea queenslandiae Woody climber; kernel needs processing

Solomon Islands

Oyster nuts (Te l f a ir i a p e d a t a (sm. ex Sims) Hook, family

Cucubitaceae)

Woody stemmed climbing vine, dioecious; large (< 15 kg),

deeply ridged, dehiscent gourds containing up to 140 pale

yellow seeds (nuts) enclosed in a strong, bitter-tasting, fibrous

husk; nuts are flat and circular (3–4 15 cm thick); washed,

sun-dried and dehusked before eating; raw or roasted;

palatable, flavor similar to Brazil nuts; nutritious, c. 62% fat,

27% protein, rich edible oil

Tropical East Africa

Pandanus nuts (various species, Pandanus jiulianettii Martelli,

family Pandanaceae)

Wide ecological adaptation from coastal areas up to 1800 m,

dioecious ‘screw’ pine; large, dense multiple fruit (syncarp) up

to 30 cm diameter and 16 kg; individual fruits (c. 50 or more)

separate easily, up to 10 cm long, 1.5 cm in diameter; contain

two to four sweet seeds with a coconut taste; oily endosperm;

normally roasted, fruitlet flesh of some species can also be

eaten; dry seeds for long-term storage; oil content from 10 to

60%; depending on species, hardy stems and leaves also used

for handicraft, furniture, and building materials

Papua New Guinea, Pacific region

Pangi, Sis (Pangium edule, family Flacourtiaceae) Berry an important food source in parts of Papua New Guinea

Papua New Guinea, Solomon Islands

Paradise (Sapucaia) nut (Lecythis usitata Miers., family

Lecythidaceae)

Tall Amazon rainforest tree, related to Brazil nut but with

superior, sweet delicate flavor (N.B.: some species

poisonous); large, dehiscent woody fruits containing 30–40

irregular, oblong nuts resembling Brazil nuts but more

rounded with a thinner, softer shell; white, creamy textured

kernels; highly nutritious, 62% fat, 20% protein; eaten raw or

roasted; edible oil

Brazil, Guyana

Pistachio nut (Pistacia vera L., family Anacardiaceae) Small, deciduous, dioecious tree; resin ducts through all tree

organs; bunches of nuts near shoot tips; harvesting at the

correct stage of maturity is critical; fleshy hull surrounds

dehiscent, bony shell which encloses the kernel; high in

carbohydrates, mainly sucrose (16%), oil, largely unsaturated

(55%), and essential amino acids (25%)

Central Asia, the Middle East and Mediterranean basin

PNG oak (Castanopis acuminatissima) Of minor importance; sometimes cooked before eating

Papua New Guinea

Quandong (Santalum acuminatum Sprague and Summerhayes,

family Santalaceae)

Small, semiparasitic trees of desert regions; globular, edible,

fleshy fruits; kernel enclosed in pitted, stony shell; oily; harsh

aromatic flavor; nutritious, 60% fat, 25% protein; generally

roasted

Australia

Sago plum (Cycas revoluta and other Cycas spp., family

Cycadaceae)

Glossy, fern-leaved plant with sturdy trunk, slow-growing,

primitive seed plant. A sago-like meal is made from large

seeds; must be soaked for a long time before eatingAustralia, Papua New Guinea, Pacific region and East Asia

Souari nut (Caryocar nuciferum L., family Caryocaraceae) Attractive, large tree; fruits round, soft-wooded capsules, c.15cm

diameter, containing two to five large, brown, kidney-shaped

nuts up to 5 cm long; edible yellow pulp surrounding nut; kernel

enclosed in hard, woody, warty shell up to 1 cm thick, hard to

crack; kernel has soft, white, sweet, almond-like flavor; eaten

raw or roasted; edible oil

Brazil, Guianas

Tahiti (Polynesian) chestnut (Inocarpus fagiferus (Parkinson)

Fosberg., family Fabiaceae)

Moderate-sized tree; stout, large (10 10 cm) green/brown

kidney-shaped, nondehiscent, single-seeded pods borne in

terminal clusters; fleshy ‘nuts,’ boiled or roasted when nearly

ripe, taste like chestnuts, palatable, sometimes hard to digest;

staple food on some islands; moderately nutritious, 80%

carbohydrates (starch), 10% protein, 7% fat

Pacific Islands

Table 1 Continued

Continued

NUTS 4207

as commercial crops and will be discussed in more

detail. Some commercial processing and marketing of

local Canarium, Terminalia, and Barringtonia species

has been initiated in the Solomon Islands, Vanautu,

and Papua New Guinea in recent years. The pistachio

is a temperate crop but has been included because of

its requirement for long, hot, and dry summer and

autumn seasons for commercial yields of acceptable

quality.

The Macadamia Nut

0002 The macadamia is considered to be one of the world’s

finest gourmet nuts because of its unique, delicate

flavor, its fine crunchy texture and rich, creamy

color. These features, together with relatively low

volumes of production, have led to the successful

promotion of macadamia as a luxury dessert nut.

Macadamia nuts account for about 2.2% of the

world’s total tree nut production – approximately

17 800 t of kernel in 1998–99.

Origin

0003 The macadamia nut is the only commercial food

crop indigenous to Australia, originating along the

fringes of rainforests in south-east Queensland and

north-east New South Wales, from 25



Sto28



latitude and within 24 km of the Pacific coast. Of

the three species of macadamia, only two are edible

– the smooth-shelled M. integrifolia and the rough-

shelled M. tetraphylla. Only the former has been

developed commercially. The rough-shelled macada-

mia, although producing a raw kernel of excellent

eating quality, often contains a higher percentage of

sugars which may caramelize on roasting, thus de-

tracting from its appearance. The wild M. ternifolia

produces a small, unpalatable, bitter kernel.

Botanical features

0004 The evergreen macadamia tree is medium to large,

attaining a height of up to 18 m and a spread of up to

15 m. It produces a number of vegetative growth

flushes per year, with peaks of flushing in late summer

and spring in Australia. The oblong to oblanceolate

leaves are arranged in whorls of three and often have

spiny, dentate margins, and short (5–15 mm) petioles.

Three buds are arranged longitudinally in the axil of

each leaf. Multiple branches and inflorescences may

therefore be produced from each node. The pendu-

lous racemes, 10–15 cm long and bearing up to 200

creamy white flowers, are borne on older wood.

Although floral induction occurs in autumn, cool

temperatures induce a period of dormancy. Racemes

commence growing slowly in late winter and anthesis

occurs in early spring. Fewer than 5% of flowers set

fruit and many of these abscise 5–6 weeks after

anthesis, coinciding with the stage of endosperm

development and the commencement of rapid nut

growth. Nuts take 6 months to mature.

0005Nut set is enhanced by cross-pollination. It is there-

fore recommended that at least two varieties be

grown in orchards, often in alternate rows. Activity

of pollinating insects, mainly native and domestic

bees, is encouraged.

0006The fruit is a globose follicle in which only one of

two ovules develops. In some varieties, however, a

small percentage of the nuts produced are twins,

resulting from the development of both ovules.

Twins are undesirable because of the difficulty of

extracting whole kernels. Mature fruits usually, but

not always, abscise when the fibrous husk is still

green. As the husk dries, it splits along a single suture

to release the nut, consisting of a hard, thick, rough,

stony, light-tan shell that encloses the kernel.

0007The rough-shelled macadamia is readily distin-

guished from the smooth-shelled species. The leaf

margins are more serrated, with up to 40 spines on

each side, and whereas new leaf growth of M. integ-

rifolia is pale green in colour, young M. tetraphylla

leaves are an attractive pink to red color. Racemes are

longer (up to 30 cm) and bear up to 500 reddish-pink

flowers.

Ecology

0008The macadamia occurs naturally in the fringes of

subtropical Australian rainforests. Temperature is

the major climatic variable determining growth and

productivity, the optimum being 25



C. Although the

Nameandoriginofnut Features

Tallow nuts (Ximenia americana L., family Olacaceae) Densely branched shrub, usually deciduous; egg-shaped, juicy,

fleshy fruits contain a large, oily seed; white kernels;

palatability varies; nutritious, rich in protein and oil; eaten raw

or roasted; cooking oil

Widespread throughout Tropics

Water chestnut, Chinese water chestnut (Tr a p a spp., family

Trapaceae)

Aquatic plant; not a true nut; hard-shelled, woody fruit with four

woody, spiny horns contains a single large white starchy

kernel; eaten raw, roasted, or boiled; c. 16% starch,

3% protein; not particularly nutritious

Tropical Africa, Central Europe, eastern Asia

Table 1 Continued

4208 NUTS

mature macadamia is capable of withstanding frosts

as low as 6



C for short periods, longer periods or

lower temperatures may severely damage or kill

mature trees. Developing inflorescences are particu-

larly susceptible to frost damage. However, there is a

low temperature requirement for flowering, the crit-

ical minimum above which flowering is suppressed

being 20



C. On the other hand, continuous and pro-

longed exposure to temperatures greater than 35



often produces chlorotic and sometimes distorted

growth.

0009 The macadamia tree has several features suggesting

adaptation to relatively harsh environments, includ-

ing sclerophyllous leaves and dense clusters of fine,

proteoid roots which develop to enhance nutrient

uptake from poor soils, particularly those low in

phosphorus. The conditions required for optimum

production, however, are quite different from those

for survival. Macadamia can be grown in a wide

range of soils but not on heavy, impermeable clays

and saline or calcareous soils. The trees are most

suited to deep, well-drained soils with good organic

matter content (3–4% carbon), medium cation

exchange capacity with pH of 5.0–6.0.

Production

0010 The commercial development of macadamia occurred

in Hawaii where most of the crop is sold locally to

tourists as ‘suitcase exports’ and, to a lesser extent,

exported to the mainland USA domestic market

where they comprise fewer than 3% of all tree nuts

consumed. Australia and Hawaii dominate the world

market, with 42% and 33% of the world’s total

production respectively. Australia produced 7500 t

kernel from 12 200 ha in 1998–99, followed by

Hawaii (5900 t), South Africa (1700 t), Kenya

(950 t), Malawi (700 t), Costa Rica (450 t), Guate-

mala (450 t), and Brazil (180 t).

0011 Over the last decade, macadamia production has

more than doubled and will continue to increase as

young plantings throughout the world come into

production. The already intense competition from

established nut crops has highlighted the need to

develop new markets and promote more widespread

consumption.

Composition

0012 The quality of the macadamia nut is related to its oil

content and composition. Mature nuts contain at

least 72% oil (specific gravity, or SG < 1.0) for opti-

mum eating and processing quality. Kernels with SG

of 1.0–1.025 are classed as second-grade but can be

used for lower-grade products. Third-grade kernels

(SG > 1.025) are commercially unacceptable. Oil

accumulation does not commence until the nuts are

fully grown and the shell hardens. It accumulates

rapidly in the kernel during late summer when the

reducing sugar content decreases.

0013The composition of mature, roasted, and salted

macadamia nuts is shown in Table 2. As with many

oil seeds, the protein is low in methionine. Fresh

kernels contain up to 46% sugar, mostly nonreducing

sugar. The oil consists of mainly unsaturated fatty

acids and is similar in both species, although the

proportion of unsaturated to saturated fatty acids

appears to be slightly higher in M. integrifolia (62:1

compared with 48:1). Detailed fatty acid composition

is shown in Table 3. The fatty acid composition and

the absence of cholesterol may lead to the promotion

of macadamias as a high-energy health food. The

major volatile components in roasted macadamia

kernels are apparently similar to those found in

other roasted nuts, although little detailed informa-

tion on these is available.

tbl0002Table 2 Nutritive value per 100-g sample of macadamia nuts

(roasted in oil and salted) and pistachio nuts (dried and shelled)

Macadamia Pistachio

Water (%) 2 4

Food energy (kJ) 3064 (c.732 kcal) 2465 (c.589 kcal)

Protein (g) 7.1 21.4

Fat (g) 78.6 50

Fatty acids (g)

Saturated 11.4 6.1

Monounsaturated 61.1 33.2

Polyunsaturated 0.14 7.5

Cholesterol (mg) 0 0

Carbohydrate (g) 14.3 25

Calcium (mg) 46.4 135.7

Phosphorus (mg) 203.6 510.7

Iron (mg) 1.8 6.8

Potassium (mg) 332.1 1107.1

Sodium (mg) 264.3

Sodium (unsalted

raw kernel) (mg)

7.1 7.1

Vitamin A

IU Trace 250

RE Trace 25

Thiamin (mg) 0.21 0.82

Riboflavin (mg) 0.11 0.18

Nicotinic acid (mg) 2.14 1.07

Ascorbic acid (mg) 0 Trace

Magnesium

(mg) 0.12

Zinc

(mg) 1.4

Manganese

(mg) 0.38

Copper

(mg) 0.33

From Wenkam NS and Miller CD (1965) Composition of Hawaii Fruits.

Hawaiian Agricultural Experiment Station bulletin no. 135. Honolulu.

RE, retinal equivalents. International units, (IU) are used to express

vitamin A activity based on a bioassay technique which is calibrated with

actual concentration in mg g

1

Data from Gebhardt SE and Matthews RH (1989).

NUTS 4209

Harvesting and Storage

0014 Macadamia nuts fall from the tree naturally when

they are mature. They are either hand-harvested or

picked up by machines; efficient machine harvesting

requires a smooth, clean orchard floor.

0015 Freshly fallen mature nuts may contain 25% mois-

ture. The husk must therefore be removed as soon as

possible to prevent overheating, mold development,

and deterioration in quality. The dehusked nuts are

initially dried, either artificially or air-dried, to 10%

moisture or less before delivery to processors. The

nuts are then further dried in silos to 10–15%

moisture for longer-term storage, for most efficient

cracking of the shell and thus more completed recov-

ery of whole kernels. Drying is performed in stages (at



C down to 45% moisture and then at 77



C down

to 15% moisture) to avoid adverse effects on kernel

quality. After cracking and separation of shell from

kernel, the product can then be lightly roasted and

salted, or packaged raw in bulk in vacuum-filled,

foil-laminate bags that help to prevent development

of rancidity. Traditionally, kernel has been roasted in

coconut oil, although dry-roasting techniques are now

more popular. The packaged product is then kept in

cold storage to prolong shelf-life. Under these condi-

tions, kernel can be safely stored for at least a year.

The Pistachio Nut

0016 The pistachio has a unique flavor and is popular as a

gourmet nut, particularly in the USA. The crop has

exacting environmental and cultural requirements for

commercial production and these probably limit

industry expansion.

Origin

0017 Although the popularity of the pistachio has been

recorded from the earliest times, its place of origin is

uncertain. The genus Pistacia consists of 11 edible

species which are widely distributed, including the

USA, Africa, and central and eastern Asia. P. vera

produces the largest nut and is the only species which

has a dehiscent shell.

0018The pistachio appears to have originated on the

slopes and plateau country of Iran, Turkestan, and

Afghanistan south of the central Asian desert but is

found growing wild as far east as India and Pakistan.

It is widely cultivated in the Mediterranean basin, and

more recently in Asia, the USA and, to a lesser extent,

in Australia.

Botanical Features

0019The pistachio tree is small, dioecious and deciduous.

It seldom exceeds 5 m in height and 10 m in diameter.

The tree is hardy and can withstand extreme tempera-

tures.

0020The leathery leaves with raised veins consist of one,

three, or five leaflets. Juvenile leaves and those in

environments with inadequate chilling have single

leaflets, whereas mature leaflets in environments

with adequate chilling have five. Resin ducts occur

throughout tree tissues, and resin is exuded from any

damaged parts.

0021In spring, inflorescent buds break first and there is

often a delay of up to 7 days before vegetative buds

break. Flowering may continue through to the latter

part of spring, sometimes extending over a 2-week

period, depending on variety and season. The transfer

of pollen from male to female trees is by wind. Male

pollinizer trees must be selected to flower at the same

time as female trees in commercial orchards. One

male tree per 10 female trees is required. The branched

inflorescences are produced in clumps from several

nodes just below the shoot tips. Bunches of nuts

develop rapidly after pollination, the outer shell

often attaining full size within a few weeks. The

kernel, however, continues to develop over a 3–

4-month period.

0022The nuts are mature when the outer skin of the

husk changes from translucent to opaque. At this

stage the husk is readily separated from the shell.

The shells of good-quality nuts split to expose the

edible kernel which is green or yellow in color with

a green or reddish testa. Maturity of different var-

ieties occurs at different times, up to 5 weeks apart,

and each must be harvested at optimum maturity.

Staining detracts from the appearance and the quality

of the nut, resulting in much lower prices. Staining of

shells is particularly a problem in humid or showery

weather that also predisposes the development of

aflatoxin-producing fungi. (See Mycotoxins: Occur-

rence and Determination.)

0023Apart from differences in time of flowering, matur-

ity, and yield, varieties vary in the size and shape of

tbl0003 Table 3 Fatty acid composition (methyl esters) of macadamia

nut oil

Fattyacidtype Content (%)

Oleate 67.14

Palmitoleate 19.11

Palmitate 6.15

Eicosenate 1.74

Stearate 1.64

Arachidate 1.59

Linoleate 1.34

Myristate 0.75

Laurate 0.62

Data from Cavaletto CG, Dela Cruz A, Ross E, and Yamamoto HY (1966)

Factors affecting the stability of macadamia nuts 1. Raw Kernels. Food

Te c hn o l o g y . 20:108–111.

4210 NUTS

nuts produced, the percentage of split, empty, and

stained shells, and the proportion of shell to kernel.

Ecology

0024 Although essentially a subtropical, semiarid Mediter-

ranean species, the pistachio is grouped with warm

climate nuts because of its requirement of long, hot,

and dry summers and autumns with an average daily

mean of 30



C for 3 months for good commercial

yields. It requires a frost-free period of about 200

days to insure that developing inflorescences are not

damaged in spring or by very cold winters. It does,

however, require chilling during winter for satisfac-

tory flowering. A total of 1000 h per year below

7.5



C is required.

Production

0025 The world production of in-shell pistachios in 1998–

99 was 232 000 t, of which 157 000 t were exported.

The main producing countries are Iran, Turkey, and

the USA. The pistachio tree commences bearing at 5

or 6 years and increases from only 1 or 2 kg per year

to levels of up to 50 kg of fresh nuts at 15–20 years.

There is a tendency for pistachio to be a biennial

bearing crop. The pistachio is particularly popular

in the USA where it accounts for 9% of total nut

consumption. Pistachios are usually marketed in

shell and less frequently as kernel, often lightly

roasted and salted.

Composition

0026 The pistachio has a similar energy value to many

nutmeats such as almonds but is lower than that of

macadamia (Table 2). It is high in carbohydrate,

mainly sucrose (16%). The fatty acids are essentially

monounsaturated, although its polyunsaturated fatty

acid content is higher and its saturated fatty acid

content lower than in macadamia nuts.

0027 The pistachio is high in minerals, particularly in

potassium. A 100-g portion of pistachio kernels pro-

vides 92% of the daily thiamin requirement. Refer to

individual nutrients.

Harvesting, Handling, and Storage

0028 Mature nuts hang on the tree well under normal

conditions and may be left until most are ripe. Under

some situations, however, if the harvest is delayed, the

husk dries on to the nut. Consequently the nut is

stained and quality is lowered. Ripe nuts are readily

dislodged by light shaking. Young trees may be har-

vested by hand but mechanical harvesting is normally

used in commercial orchards.

0029 The nuts must be husked and dried as soon as

possible after harvesting to maintain high quality

and an unblemished appearance and to avoid spoil-

age. The husked nuts may be sun-dried but drying

artificially in silos between 65 and 72



C is preferred

for large commercial orchards. Freshly harvested nuts

can contain as much as 45% moisture. This is reduced

to about 5% in 10 h.

0030Some cultivars produce up to 25% empty shells in

which kernels have failed to develop. These blanks

must be removed from sound nuts prior to drying by

flotation separation.

0031The dried nuts are sorted to remove those with

blemishes. They are graded according to size, roasted,

salted, and packaged. Most pistachios are marketed

in their shells in snack packs.

Future Prospects for Lesser-Known Nuts of Warm

Climates

0032Both pistachio and macadamia nuts are expensive

compared with the major nuts. Future expansion of

these industries may result in reduced prices and per-

haps on promotion of the health benefits of nuts

which is now generating a lot of nutritional research

activity. As the volume of these commodities entering

world trade increases, greater emphasis will be

needed on market development and promotion to

insure that they can compete with other nut products.

It is unlikely that any of the other lesser-known nuts

will develop significantly beyond their present

regional boundaries.

See also: Carbohydrates: Classification and Properties;

Fatty Acids: Properties