Apples are the ideal fruit to eat at any time, having a positive role in the achievement of nourish balance. Their skin may be green, yellow or reddish, and the meat taste ranges from a bitter to sweet flavour. It is one of the most consumed fruit in the world. There is a great amount of varieties; thanks to that, apples are available all the year round. Apples are, along with bananas and citrus, one of the most consumed fruit in the world. In the N hemisphere they are, with no doubt, the fruit of which there exists more plantations. In the United Kingdom, the consumption per person a week is 175 g (according to National Food Survey 1996, quoted in Fresh Produce Desk Book 1988), representing an annual consumption of 9.1 kg. The German magazine ‘Der Mark – Obst und Gemüse 8/2000 ‘ shows a table with the consumption of apples per inhabitant a year in the last 5 years. During the periods 1995/96, 1996/97 and 1997/98 the consumption was, respectively, 19.5, 19.7 and 19.4. For 1998/99 the provisional data quoted is 20.2 and for 1999/2000 the forecast is 21,9. According to these data there is a slight increase in the European consumption. The apple has the advantage that it is easy to consume as table dessert, between hours, in school, in the office… Furthermore, it does not unbalance any slimming diet since it has a very low caloric content, less than 100 kcal.
In botanics, this type of fruit is denominated pomo. It is characterised because in its formation, along with the seeds and the ovary, other parts of the flower take part. The central part is divided in five hollow compartments containing the seeds. There exist multiple varieties of apples; they are distinguished by the shape of the fruit, rounded, elongate or flattened; by their colour, that varies from bright red to green; the colour of the pulp, its flavour – there are some apples in which sweetness predominates over acidity and some others, on the contrary, are very acid -; by the texture, that ranges from a very crisp to a mealy texture, although the latter may also be due to a storage problem; the period of maturation, the characteristics of the tree, suitability for storage, behaviour against diseases and pests, etc. Apples also defer in size, as much within the same variety as among varieties; the apples used for cooking are usually bigger than those for fresh consumption. The period of harvest extends from the end of summer to the beginning of autumn, but apples are available all the year round thanks to their excellent storage characteristics- it can be stored for a long time if the appropriate techniques are applied. At present they are exported from the S Hemisphere. Apples may last up to 6 months if they are stored in normal air and up to 10 months under controlled atmosphere. Nowadays, the consumer confers a ‘value’ to ‘fresh’ produce; transport facilities make it possible to find, all the year round, apples that have not practically been kept in storage rooms.
Apples are consumed as table dessert, whole or as part of fruit salads; they are also cooked whole, in purées or stewed; they are used in confectionery, preserved as purée or jam, dehydrated and used to process juice, cider and vinegar. The appropriate texture for apples consumed as dessert must be substantial and crisp and the taste must be preferably sweet, whereas apples intended for processing are usually more acid. Apples for cider may be more astringent. The apple pulp contains up to 25% of air lodged in the spaces between the cells; during processing, this air must be removed in order to avoid the spoiling of the produce.
Types and Varieties of Apples
The apple varieties are classified in five groups according to their visual appearance: yellow, red, green, bicolour and Reinette. Yellow apples are the prevailing in the French market. The variety Golden Delicious is the queen of the yellow varieties. The group of red apples is formed by the family of Red Delicious, the original variety, that has given rise to multiple varieties. Granny Smith is the most representative variety of the group of green apples. It is of an intense and uniform green colour and the fruit, of average size, has a firm, juicy and slightly acid flesh. Within the group of bicolour apples we classify all the varieties of more than one colour, except for Reinettes. In general, they are of a more or less dark red colour in one part of the fruit and yellow/green in the rest. In the same way that the apple is a very important fruit, the quantity of varieties that exists is extremely high – some estimations, quoted by Pijpers ET al., 1986, indicate that there may be around 5,000 and 20,000 -, although it is reduced to a commercial level. In the producing countries there is usually a group of varieties of local interest. The varieties preferred at the moment are the bicolour apples. The varieties of greater importance in international trade are those of the Delicious group (Red, Golden), Starking, Granny Smith and the recent new varieties Gala, Fuji, or Pink Lady, an Australian variety with registered genetic material and trade mark.
The varieties produced in Spain with greater marketing interest are Gallic Royal, Granny Smith, Golden Smoothee, Early Red One, Topred Delicious, Golden Delicious, Red Chief and Gray Reinette (R. from Canada).
In the United Kingdom, the varieties of greater importance at commercial level are, in alphabetic order, Bertane (French origin), Braeburn (French origin), Bramley (local and Irish origin), ‘ chocolate apples’ (local origin), Cox (from Belgium, Holland and local origin), Gala (Belgium, France and Spain), Golden Delicious (Belgium and France), Granny Smith (France), Jonagold (Belgium), Jonagored (also Belgium), Laxton Superb (local), McIntosh Red (United States), Paula Reds (Canada and the United States), Pink Lady (South Africa and the United States), Red Chief (France and the United States), Red Delicious (France and the United States), Red Pippin (local), Royal Gala (France and local), Russet, Spartan, Toffee and Worcester Pearmain (the last four varieties all of local origin). These varieties are gathered in the prices page of the United Kingdom wholesale markets, published in the issue of 13 October 2000 of the magazine Fresh Produce Journal; it refers, as indicated in all the cases, to this year’s harvest. The same study, carried out 6 months further on, would show a much clearer presence of fruit from the S hemisphere. At the moment, there is only one price for the South African Pink Lady.
As an example, the most important varieties imported to Sweden are Braeburn (coming from France), Elstar (mainly from Holland), Empire (the United States), Fuji (New Zealand, South America, the United States), Gala (France, Italy, Brazil, New Zealand), Golden Delicious (Europe, South Africa, the United States), Granny Smith (from many destinations: Europe, New Zealand, South America, South Africa and the United States), Ida Re, Jonagold and Jonagored are all of European origin, King David (Argentina and Chile), Red Delicious (Europe, the United States, South Africa, Argentina), Rome Beauty (Argentina), Royal Gala (New Zealand, South Africa, Europe, specially from France and Italy) and, finally, Winesap, red or black (from South America). In the campaign ‘ Frukt & grönt varje gång du äter! (Fruit and vegetables in every meal!) the picture of these varieties is shown in the brochures of the imported varieties.
To carry on with Sweden, it is mentioned that each country has, more or less, its local varieties; some varieties are more restricted, due to given circumstance such as a better adaptation to the culture conditions or the taste of the inhabitants. They are usually varieties of short conservation, and therefore badly adapted to storage and/or long transport. These varieties of restricted culture go along with other varieties found in the international trade. The varieties cultivated in Sweden are Alice (available from September to October), Aroma (September to November), Bella de Boskoop (January to April) and Cox Orange (November to January), that are both cultivated in other countries, Discovery (September), Gloster (December to March), found in international interchanges, Gravensteiner, red and green, from September to December, Ingrid Marie (local, from October to February; imported from January to April), Katja (September to November), Kim (December to February), Lobo (October to November), Mutzu (December to March), Signe Tillisch (October and November), Summerred (September and October) and, finally, Akero (October to December). There is also an illustration of all these varieties in the corresponding brochure of the campaign mentioned above.
The future will bring changes in the varieties of the European markets. According to a research carried out by Prognosfruit, in Austria, published by the Argentine magazine Informe Frutihortícola of October 2000, there are three large groups of varieties:
– Varieties that will show an increasing importance: Fuji has an estimate increase of 23%, Braeburn (+18%), Gala (+ 13%), Granny Smith (+ 10%), Reinette (+9%), Annurca (+3%)
– Small decrease: Golden and Red Delicious (they both lower -1%), Idared (-2%), Morgenduft (-3%),
– Intermediate and large decrease: Jonagold (-7%), Elstar (-9%), Boskoop (-13%), Gloster (-16%), Bramley (-27%), Cox Orange (-29%). The greatest decrease will be that of Jonnathan, -43%.
The most important varieties are described below:
Bella de Boskoop
The skin’s colour varies from greenish-yellow to red. It is a large apple with a firm, acid, juicy pulp of a yellow colour. It is suitable to be consumed fresh and also for all types of processing. It is a variety of Dutch origin, available in the markets of the N Hemisphere from October until April.
Belleza de Roma
Also known as ‘ Rome Beauty’, ‘ Morgenduft’, ‘ Imperatore’, ‘ Hoary Morning’, ‘ Gillet’s Seedling’ and ‘ Rimskaya Krasvita’. They are large apples, of rounded shape and somewhat flattened, well-coloured, with red streaks and quite attractive appearance. The pulp is white, of refreshing acid taste. It is apt for fresh consumption and for cooking. The mutations ‘ Gallia Beauty’, ‘ Carlson Red Rome’ and ‘ Red Rome’, among others, are usually those having the most intense and uniform red tonalities. It is well-stored in cool store rooms. It is of late maturation. The areas with greater production are Argentina, Italy and the south of Germany.
It is a large apple, slightly flattened and sometimes slightly asymmetric. It is green but it turns into yellow and it sometimes shows a reddish shade in the part where it has been exposed to the sun. It has a consistent and white flesh. The skin is quite thin. It has an acid taste and it is excellent for cooking. The name comes from the producer that developed this variety in the XIXth century. It is available in the North Hemisphere from October until April.
Cox’s Orange Pippin
It is one of the most popular varieties in the United Kingdom, Holland and Belgium. It was obtained in 1830 and it is of English origin. The fruit is red-stripped on a yellow and green background. It is rounded, very regular and of average size. It is very aromatic and it has a delicious taste.
Early Red One
Bright skin of an intense red colour, without streaks, all over the fruit, being a very attractive variety. Its meat is tender and firm; it has a sweet taste, although it is not very fragrant. Apart from its fresh consumption, it is widely used in cooking, roasted or stewed. In the N Hemisphere it is available from September until June.
It is a new variety obtained from the cross of ‘ Golden Delicious’ with some other varieties. It is a large apple of regular shape. It is golden yellow with a shade of reddish colour. The pulp is fleshy and crispy with a very pleasant characteristic fragrance. It is not very appropriate for processing. In the N Hemisphere markets it is available from November until mid April.
This variety is known from the beginning of the last century. It was first cultivated from a seed in the United States at the end of the XIXth century. It is also known as Golden, Golden Smoothee, Golden 972 and Golden B. The skin has a uniform greenish yellow colour; the part of the fruit that has been exposed to the sun shows some reddish tones. The lenticels are usually well-marked and they may be rough in some cases. It has a rounded and regular shape and a crispy, slightly juicy flesh, quite sweet, slightly acid and aromatic. It is consumed fresh or in juice and it is also used in confectionery for its slight acidity; however, it is less acid than Granny Smith. It is not suitable for purees, but it gives good results in cakes. In Spain, the period when Golden Delicious of local origin is available in the market is from September and August, in the N Hemisphere.
It has a very thin and bright skin. According to the stage of maturation, the colour ranges from green to yellow. It has a crispy, juicy, sweet and aromatic pulp. It is suitable for fresh consumption, for juice, fruit salads and cakes. In the North Hemisphere it is practically sold all the year round, from September until August.
It is known as the ‘ early Golden’. It is an attractive apple, of green skin with pink tonalities in one of its sides. It has globose shape and crispy, fleshy meat, with a slightly acid taste and scarcely aromatic. It is suitable for fresh consumption and found in the market from August until November
This is a variety of German origin, obtained from the cross between ‘Glockenapfel’ and ‘Red Delicious’. Gloster is a relatively large and elongate apple. Its colour ranges from purple red to dark red. The pulp is distinguished by its greenish white colour, its slightly acid taste and its firmness. It is recommended only for fresh consumption. In the N. Hemisphere it is available from November until March.
These apples are completely green, although they show some white clear lenticels. They have a white, very crispy, juicy and firm flesh with a pleasant and slightly acid taste. They are rounded-shaped, ideal for fresh consumption.
These fruits have a red uniform colour, although they sometimes show traces of yellow. Their pulp, of a cream colour, is firm, juicy and slightly acid. This variety is the result of the cross between Jonathan and Wagenerappel. In the N. Hemisphere it is available from October until July.
It is a very large apple. The yellow background colour is dyed with shades of red. The pulp is of a yellow whitish colour, with a pleasant sweet taste. It is the result of a cross between ‘Jonathan’ and ‘Golden Delicious’. It is both suitable for fresh consumption and processing. It is available between October and April in the N. Hemisphere.
It is rounded-shaped and of a red uniform colour. The meat is white and tasteful. It is suitable for salads, cakes and jams since its flesh does not oxidize as much as that of other varieties. It is also recommended for people with delicate or false teeth, because of its fragile skin and its soft flesh. It is original from Canada.
This is a variety of intense red colour, although not uniform, and bright skin. It has an elongate shape with strongly marked lobes. It is hardly aromatic but of sweet, tender and firm flesh. It is consumed fresh, stewed, cooked and roasted. It is available in the markets in September and it is sold, keeping all its quality, until June.
The colour of its skin is a smooth dark red, although it sometimes has streaks on a yellow background. It has a somewhat elongate shape. The pulp is of a white, smooth and uniform colour, although it softens very fast. It has a bad conservation. This variety is native to America and it is widely cultivated in Europe, mainly in France and Italy. The United States is also one of the main producers. It is also known as ‘Starkrimson’ and ‘Richared’. It is available all the year round.
This variety has a bright skin with red-orange streaks on a yellowish green background. Although it is very irregular, it has a conical shape. Its white, tender, crispy and firm flesh is aromatic and has an excellent taste. It is ideal for fresh consumption. It is harvested from the end of August until the end of December.
These apples have a bright skin of yellowish green colour with red streaks. The white, tender and firm has a smooth sweet taste. They are consumed in various ways: fresh, cooked, roasted or stewed. In the N. Hemisphere, they are available from September, their harvesting period, until June. It is an American variety that is also widely cultivated in Europe and available practically all the year round.
Is a large, elongate apple of intense red colour when it has enough hours of sunshine. Its firm and aromatic pulp is of a white colour. It is recommended for fresh consumption. It is marketed from September until mid October. It is a cross between ‘Golden Delicious’ and ‘McIntosh’.
‘Grey Reinette’ is distinguished for its grey golden, hard and rough skin. It has an irregular, strongly flattened shape, with a very short peduncle. Its fragrant and firm flesh has a marked acid taste. It is frequently used for confectionery and it is ideal for cooking. It is marketed from September until March.
Of red streaked, bright coloured skin. Its conical shape shows some prominent lobes. The tender and firm flesh may loose its texture after some time, although it always keeps a pleasant sweet taste. It is eaten raw, cooked, stewed or roasted, and it is sold from September, when it is harvested, until June.
The apple tree is a small tree not exceeding 10 m high, although at commercial level they use smaller varieties in order to make the harvest and other culture processes much easier. They also have the advantage of sun exposure on the fruit, that is greater than in larger trees, and for that reason the quality of the produce is much better. In order to obtain smaller trees, they use dwarfing rootstocks. The plant forms a globous crown and a straight trunk that may reach 2.5 m high. The oldest parts of the bark are scaly and of a greyish colour; on the contrary, the young branches are of an ash-grey colour with some greenish shades and small pores, called lenticels, that enable the gaseous interchange with the atmosphere. The leaves are elliptical-shaped with sawed margins of obtuse teeth. The showy flowers bloom some days before the leaves appear, conferring a showy appearance to the tree when it is completely bloomed. They gather in groups of 3 to 6 flowers, forming corymbs. They are hermaphrodite flowers, that is to say, one single flower has both sexes. The petals may be of a white to pale pink colour. The average shelf life of an apple tree ranges from 60 and 80 years old, although the commercial plantations are reduced to half or even less.
Origin and Production
The apple tree is original from the tempered areas of Europe, the west area of Turkestan and the south-east and centre of Asia. It has been consumed for a very long time. In Switzerland and Italy there are proofs of apple trees from about 4,500 years ago. The main producers are countries belonging to temperate climate regions like Europe, the United States, Turkey and China.
The world-wide production in 1999 is shown in the following table:
Source: Fresh Produce Desk Book (2001)
The 10 main producers, along with their production evolution in the last years, are shown in the following table:
|COUNTRY||PRODUCTION (thousand tons)|
Source: FAO Production Yearbook (1998)
As reflected in the table, China produces 4 times the amount of apples produced by the following country, the United States.
Therefore, the world-wide production of apples amounts for more than 53 million tons, of which 1/3 is harvested in Europe.
The 10 main exporters, with respect to the value in thousand $, in 1998 and 1999 are those indicated in the following table:
The amount of apples in tons of the previous countries in 1998 and 1999 is the following:
|The United States of America||582,234||638,926|
FAO Source, (fao.org )
The 10 main import countries, in metric tons, have been, in 1998 and 1999, the following:
|The United States||141,971||164,167|
FAO Source, (fao.org)
The European Union imports 2,100,000 tons, of which 600,000 come from the S. Hemisphere.
The 10 countries with greater import of apples, with respect to their value in thousand $, were, in 1998 and 1999, the following:
|The United States||95,390||134,484|
FAO Source, (fao.org)
Apples are available in the markets all the year round, because the different varieties are cultivated in many countries of different continents.
Apples are packaged in all types of packages to reach the consumer. Meshes with handles that make the product very easy to carry, with a plastic string where all the characteristics of the produce are explained. Plastic bags are one of the most economic and common ways to take apples home. These packages usually contain more than a kilogram; for smaller amounts, they use cardboard, plastic or expanded polystyrene trays – the common white trays, but that may also be presented in other colours -, wrapped in stretchable plastic film or packaged horizontally (flow-pack). In these small packages it is quite usual to mix different varieties or even various types of fruit (apples with bananas and citruses, for example), to take care of the needs of a small family, giving an option to diversity. When apples are not pre-packaged, the point of sale receives apples in packages of 7 to 20 kg; in the section on ‘ Availability’ there is a table with several examples. Fresh apples are also part of fruit salads that are sold already prepared; in the United States apple pieces are marketed in small bags for children to take to school or, in general, consumed as a snack. These pieces can even be sold with chocolate sauce, raspberry, etc.
In order to obtain an exact information on the regulation provisions for apple, it is recommended to consult the original source. The quality standards for apples are laid down in the Commission Regulation (EEC) No. 920/89 of 10 April 1989 on the quality standards for carrots, citruses and dessert apples and pears, that at the same time modifies the Regulation No 58. The quality standard for apples states that they must all be intact, sound, clean, practically free from damages caused by pests, free of abnormal external moisture and any foreign taste or smell. They must be harvested in such a state the enables them to continue maturation and to arrive in satisfactory condition at the markets.
Four classes are defined:
Extra Class – the apples of this category must be of superior quality. The peduncle must be intact. They must be free of any defect, except for very slight alterations of the epidermis.
Class I – These apples must be of good quality although some small defects like slight deformations, slight development defects or slight defects of coloration are allowed. The peduncle can be slightly damaged. The pulp must be kept sound all the year round, although some epidermic defects are allowed for each fruit provided they do not harm neither the general appearance nor the conservation. The defects allowed must be within the following limits: the elongated-shape defects will not exceed 2 cm in length for the rest of defects, the total surface must not exceed 1 cm2, except for scab, in which case only ¼ cm2 is allowed.
Class II – Defects of shape, development and coloration are allowed, provided they do not alter the fruit characteristics. There may be lack of peduncle provided there is no deterioration of the epidermis. The pulp must not show any important defect, although some defects are allowed in the epidermis of each fruit not exceeding:
4 cm long at the most for elongate defects
2,5 cm2 of the total surface for the rest of defects. Nevertheless, in the case of scab the length must not exceed 1cm2.
Class III – It is the produce of less quality, for which the greatest defects are allowed:
6 cm long for defects of elongate shape
5 cm2 of the total surface for the rest of defects, except for scab, that must not exceed 2,5 cm2. The standard explains how to grade apples. For this purple they set out a series of ranks from 10 to 10 mm for large fruit varieties and ½ cm for small fruits. An annex list indicates which varieties belong to ‘ large fruit’; some of the most well known are Braeburn, Fuji, Gloster, Granny Smith, Jonagold and Jonagored, Red Delicious and its mutations, Red Chief, Canada Reinette and Starkrimson. According to the varieties and periods, they decide the smallest size of fruit allowed for trade. For Class III the tolerances increase.
For all these definitions, tolerances are 5 or 10%, according to each case.
In the transport packages to which the quality standards refer, and even more important, in the fruit store’s shelves, the fruit must be uniform: same species, same variety, same origin and same quality, as well as similar stage of maturation. The class to which the produce belongs must be specified (Extra, I, II or III); in the case of Extra class, the fruit must also be arranged in rows and they must be uniform in coloration too. The package or the information for the consumer must also indicate the packer or sender of the apples, the origin (country or area of production), as well as the size or number of pieces for fruit arranged in layers. A series of provisions are applied to particular varieties of apples and there also exist some specifications regarding their colour. For instance, in the case of red varieties, the Extra class must have at least ¾ of the fruit surface of this colour; class I must have at least ½, whereas class II and III are allowed to have only ¼. The standard sets out which varieties belong to each colour group.
The rest of groups are:
varieties with streaks, slightly coloured
the rest of varieties.
The ‘russeting’ is a typical phenomenon occurring in apples, consisting of areas of the skin showing a thin cork layer. For some varieties this phenomenon is quite natural and it is not considered as a defect (the standards indicate which are those varieties). A relatively common apple in the Spanish market belonging to this group is Canada Reinette; the group of Boskoop also belong to this (where she is the Beautiful one of B.) and the group of the Cox. For the rest of varieties the tolerance limits are laid down according to the class.
Postharvest Atmosphere Management
Apples have a relatively high capacity of conservation and there are techniques that extend it. The storage in controlled atmosphere allows storage practically until the following year’s harvest. This fruit has also a high capacity to produce ethylene, which makes it necessary to control the concentration of this gas during the storage. The cold storage rooms keep the apples at temperatures slightly superior to 0ºC; according to the variety, the optimal temperature varies between -1ºC and 3º. Relative humidity in these premises is kept at 90-95%. In order to benefit apples as soon as possible from cold – prolonging their storage – the temperature must be lowered before they are introduced in the storage rooms. This is done by means of hydro pre-cooling or in rooms for air pre-cooling. In spite of their good capacity of conservation, as it happens with any other product, they tend to loose quality after a period of time. The ‘ farinose’ sensation in the apples is a varietal characteristic but it also increases with storage. This characteristic is caused by the pectin, a substance found within the cells that cements them. This substance is degraded and the cells become ‘ loose’. Apples have been widely researched on for their commercial importance, and nowadays we know the optimal conditions of storage for all the varieties of commercial interest.
Ethylene may accelerate the rate of senescence and loss of firmness in the ‘ Fuji’, ‘ Gala’ and ‘ Granny Smith’ types. The diminishing in the concentration of this gaseous hydrocarbon in these varieties may reduce their susceptibility to scald. The apples ‘Gala’ must be cooled very fast since they soften at great speed. Ethylene stimulates maturation in ‘ Golden Delicious’. The fruit of this cultivar that must be stored for more than a month shall benefit from the use of controlled atmosphere in terms of pulp firmness, acidity and colour of the skin. Under conditions of 1 to 3% of O2 and 1.5 to 3% of CO2 the maximum period of storage is 10 months. For Fuji apples, the recommended composition of controlled atmospheres must be less than 0.5% of carbon dioxide and 1.5 to 2.0% of oxygen. If these conditions are kept, storage may extend up to 8 months. It must be taken into account that Fuji apples of late harvesting (beyond 180 days from flowering) must not be subject to controlled atmosphere. Even with 0.5% of CO2 internal browning may occur. Controlled atmospheres in apples Gala have been used successfully at intervals of 1 and 2% of carbon dioxide and between 1.5 and 2.0% of oxygen. The storage may last up to 4 or 5 months. With regard to Granny Smith apples, the following composition of controlled atmospheres is recommended: 1.5% of oxygen and 1.0% of carbon dioxide. Controlled atmospheres maintain the firmness and acidity in the three above mentioned varieties, reducing the susceptibility to bitter pit and scald.
For the ‘ Red’ type apples, the recommended composition of controlled atmosphere is 1 to 2% of O2 and 2 to 4% of CO2. Those fruits that shall be stored for more than a month will benefit from controlled atmosphere in terms of firmness and acidity retention and reduction of the incidence and severity of scald. The potential period of storage in this atmosphere extends up to 10 months, whereas in conventional storage the duration is of 6 months.
The Web site of the postharvest section of the University of Davis, ( postharvest.ucdavis.edu/Produce/ProduceFacts / ) includes recommendations to maintain the optimal postharvest quality of the varieties Fuji, Gala, Granny Smith and Golden Delicious. This Web page contains, for each apple, the index of maturation, index of quality, optimal storage temperature and the relative humidity, respiration rates, rates of ethylene production, response to ethylene, response to controlled atmospheres, disorders or physiological alterations, microbial disorders, and specific recommendations for warehouse handling.
During transport, apples must be transported with the maximum care so as to reach the consumer in the best possible condition. They must be protected from the atmospheric agents and kept in the appropriate conditions of temperature, atmospheric composition and relative humidity. The transport vehicles for apples must be freezer trucks and they must maintain apples at temperatures slightly superior to 0ºC; according to the variety, the optimal temperature varies from -1ºC to 3º. These premises are kept at 90 to 95% of relative humidity.
Apples may undergo, after their storage, different physiological alterations or diseases.
Bitter pit – It consists of small spots – like freckles- that deepen in the skin; they are formed by corky tissue. This physiological alteration is caused by calcium deficiencies; it already occurs in recently harvested apples but it worsens if they are stored.
Scald – the skin shows a more or less extensive brown area on the surface of the fruit. It occurs in the warehouse; the reason why this occurs is not very clear, although it is thought that it is due to the ethylene that the apples emit, reaching high concentrations.
Brown core – the apples centre turns into a brown colour, caused by too low oxygen concentration in the storage room.
Blue rot – It is the commonest and more destructive disease in post-harvested apples. It is caused by the fungus Penicillium (the same sort of the cheese) giving rise to a bluish short hair.
Black rot – it is caused by the fungus Alternaria, that brings along some injuries covered by black short hairs, not very deep, without defined limits. Alternaria affects many other species.
Brown rot – cause by the fungus Monilia. On the surface of the wound appears a short hairy area of the colour that gives name to this disease.
Grey rot – it is caused by Botrytis, a fungus that produces a cottony down of grey colour that attacks many other products.
Core rotting – some varieties of apple keep the communication between the heart and the outside during development, through the chalice tube. In this type of apples occur the growth of fungi in the heart, next to the pips.
|Apple, Malus domestica / Fam.: Rosaceae|
| Note: Composition for 100 g. of fresh product
Values in ( min. – max. ) format.
Health Benefits of Apple
The apple has a long history in Europe, where it has always been related to good health, particularly for its reputation in preventing dental diseases. The content in fibre, mainly pectin, is considered beneficial for the gastrointestinal functions, and at the same time it helps to balance the levels of sugar in the blood and the cholesterol. More recently, it has been stated that apples contain high levels of some compounds that act as antioxidants, that provide protection against some cardiovascular diseases and cancer. These compounds, known as phytochemicals, include quercitin, ellagic acid and cafeic acid. Apples have a high water content and supply mineral salts like potassium, phosphorus, calcium and iron, along with vitamins A, B1, B2, B6, C and E, folic and nicotinic acid. The nicotinic acid is also known as niacin (vitamin B3). The apples have low content of protein, fat and sodium. The phosphorus is also important for health; its main source is the milk, although its content in the fruit is not very high. Three apples a day provide the necessary provision of vitamin C to the body.
There is a popular saying in English: ‘An Apple a day keeps the doctor away’. It is an example to show how rooted it is in the popular culture the idea that apples are very healthy and that they help to prevent many disorders and diseases; its therapeutic and nutritional value is well recognized. The apple is rich in mineral salts like potassium, phosphorus, calcium and iron; in vitamins A, B, C, E, niacin and sugars, mainly fructose and glucose. Its water content is also significant. The apple composition makes it one of the most complete fruits from the nutritional point of view. On the other hand, its low content in proteins and fats makes it suitable for people who wish to slim.
It is widely known in general culture that apples help in digestion, activating the secretion of the gastric juice. They are good regulators of the alimentary canal, they stimulate the kidneys, they ease diseases such as drop, arthritis and rheumatism. They are also recommended to fight hypertension and they reduce cholesterol, as well. Their phosphorus content helps to fortify the nervous system. Popular culture also states that apples in fasting are powerful natural purifiers. On the other hand, if they are consumed as table dessert, in bites and preferably without peeling them, they clean the teeth and fortify the gums, apart from fighting bad breath.
Since they have a high water content, apples relieve thirst and help to preserve the water of the body cells; therefore, they help to keep a hydrated and healthy skin.
Nutrition and Eating
Apples supply a great amount of vitamins and other nutrients to the human being, having multiple beneficial effects for health. Their fibre content acts as a regulator in multiple intestinal disorders. If consumed raw, they are an excellent natural toothpaste that cleans and whitens the teeth, favouring the gums.