GRADING AND PACKAGING

o 산지에 따라 다르게 분류된다
o Vanillin함량 ,크기, 색, 풍미, 수분함량
   Vanillin함량 : 0.5 ~ 2.5%
Vanilla beans differ in chemical, physical and organoleptic properties not only according to the species, but also within a species, depending on the geographical source and the physical form or grade. Consequently, consumers for particular types for certain applications express preferences.

After conditioning, the cured beans are given an airing and are restraightened by drawing through the fingers. The beans are then subjected to a final sorting into grades, and according to their length, prior to bundling and packaging for shipment. The length of the beans is an important determinant of the price which the whole beans will fetch.

Grading systems differ somewhat between producing countries but beans are generally classified into three categories: unsplit beans, split beans and 'cuts' .The last type has traditionally consisted of beans which have been attacked by mould and have had the infected portion cut away. Very small and broken beans of poor aroma quality are usually combined with the 'cuts' from mouldy beans. It should be noted that the 'cuts' do not always consist entirely of poor quality beans. In Mexico, 'cuts' usually comprise 10 to 20 per cent of production in a normal year but, in years of good prices, the smaller curing firms would often cut all their beans prior to curing because drying times were shortened. Also, the artificially dried cut beans, which have entered the market in recent years, are of a good aroma and flavour quality and are produced specifically for extraction.

Mexican vanilla
Prior to the early 1950s, Mexican vanilla was exported in five grades but the system was then extended to embrace seven grades. The seven grades for whole beans in descending order of quality are 'Extra', 'Superior', 'Good-Superior', ‘Good', 'Medium-Good, 'Medium' and 'Ordinary'. This grading is on the basis of moisture content, colour, general appearance and aroma quality. The moisture content of top-grade beans is around 35 to 40 percent and that of the poorest grades can be as low as 10 per cent.

'Extras' are thick beans, which have a dark-brown to black colour, glisten with oil, and are free from warts and other blemishes. They are entirely flexible along their whole length. The aroma is clean and delicate.

'Superiors' are similar in properties to 'Extras' but are not quite so thick and are of a less exceptional appearance, 'Extras' and ‘Superiors, rarely have a coating of vanillin crystals.

The 'Good' grade consists of beans of a slightly paler colour and which have a poorer lustre and flexibility. The body is less thick than the top grades and there are some slight surface defects.

The 'Ordinary' grade beans have a poorer colour, dull appearance, surface blemishes and a weak aroma, The body is thin, tending towards rigidity and is rather desiccated.

These seven grades are further reclassified into various sizes ranging in length from 16.5 cm to 24 cm. The beans are then made up into bundles with the stem-ends together and the bundles are tied with black string at the top, middle and bottom. The straightest beans are placed in the centre of the bundle and those with the best appearance on the outside. Bundles of 'Extras' contain about 70 beans, 'Good' about 95 and 'Ordinary' about 130.

The bundles are packed into tin boxes lined with waxed paper, which take 40 bundles in rows of 10. The boxes are marked with the grade and the length of the beans.

'Cuts' are graded into qualities corresponding to those of whole beans and are also classified into 'longs' and 'shorts'. 'Superior cuts' are regarded as comparable in quality to the corresponding whole beans and often have a surface coating of vanillin crystals. 'Ordinary cuts’, include not only true cuts of lower grade beans but also very small beans (less than 15 cm) and broken beans of poor aroma quality. They are packed in loose layers in tin boxes lined with waxed paper.

Bourbon vanilla
The vanilla of Madagascar, the Comoro Islands and Reunion is classified into five main grades of whole and split beans plus an additional category known as ‘bulk’, which is comprised of cuts.

The minimum acceptable length for the top five grades in the major producing area of Madagascar is 12 cm while for Nossi-Be and the Comoro Islands it is 10 cm.

Madagascan beans are first sorted to separate beans below 12 cm in length and then the whole and split beans are classified into grades according to their aroma, moisture content and appearance.

The five main categories for Madagascan whole beans are :

'Extra' - Whole, supple, unsplit beans, free of blemishes, possessing a uniform chocolate-brown colour and an oily lustre. The aroma is clean and delicate.

‘1st ' - Similar to the 'Extra' grade but not quite so thick and of a less exceptional appearance.

'2nd' - Somewhat thinner beans with a chocolate-brown colour but with a few skin blemishes. The aroma is good.

'3rd' - Thinner, more rigid beans with a slightly reddish chocolate- brown colour. The aroma is fair.

'4th' - Rather dry beans with a reddish colour and numerous skin blemishes. The aroma is ordinary.

Splits are sorted into categories corresponding to those for whole beans. ‘Foxy’ splits are thin, hard and dry, short types with a reddish-brown colour.

After sorting into qualities, the whole and split beans are re-classified according to length into various sizes between 12 and 26 cm and are then made up into bundles. Each bundle contains 70 to l00 beans and weighs between 150 to 500 g. The bundles are packed into tin boxes lined with waxed paper, which take between 20 to 40 bundles, weighing 8 to 10 kg. Six tins are fitted into a wooden case for shipment. More recently, cardboard boxes have been widely used for the external packaging instead of wooden cases.

Beans remaining over from the sorting and grading described above are combined to form an additional category called 'bulk'. This consists of cuts, broken and very short beans and those with sub-standard colour and aroma. The constituents of the 'bulk' category are not tied up in bundles prior to packaging. A batch of Bourbon vanilla consisting of the various categories may be sold as a 'head to tail' lot.

Bourbon vanilla tends to have somewhat higher moisture content than the corresponding Mexican grades and it is often 'frosted' with vanillin crystals.

Tahiti vanilla
The beans are sorted into whole and splits and are then graded according to quality and size.

　

There are five main categories of whole and split Tahitian vanilla, which are distinguished by the colour of the label.

Blue for ‘Extra’ with exceptional appearance and superior quality and a minimum size of 20 cm, Red for ‘1st’ Similar to Extra with a minimum size of 18 cm, White for ‘2nd’, ‘Good quality’ beans with a minimum size of 14 cm, Yellow for ‘3rd’, ‘Fair quality’ with a size less than 14 cm and Green for ‘4th’, ‘Inferior quality’, thin or recured beans of any length.

A sixth category exists, distinguished by a black label, which comprises
badly damaged and very poor quality beans.

The top five grades of beans are made up into bundles and are tied at the top and bottom. The bundles are packed according to the grade into a waxed-paper lined, large tin box, which weighs about 40 kg when full.

Guadeloupe vanilla
'Vanillons' is packed separately from true vanilla and is sorted into three categories: Firsts, Seconds and Reddish. The beans are short in length (8 to 14 cm) and broad (up to 2.5 cm). The bundles are tied with string at each extremity. A distinguishing feature of vanillons used to be that each bean had a string tied around its middle to prevent splitting but this practice has become less prevalent.

Types of vanilla products  :  flavouring applications

Vanilla Extracts : 1~ 4 fold
Vanilla Concentrates : 5 ~ 15 fold
Vanilla Oleoresins : 16 ~ 20 fold
Vanilla Powders : 1 ~ 4
* 1X (Single Fold) 3/4 pound (13.35 ounce) of vanilla beans per gallon of alcohol

'Vanilla extract'
This is a hydroalcoholic solution containing the extracted aroma and flavour of vanilla beans and may also contain added sweetening / thickening agents such as sugar and glycerine. Conventional vanilla extracts have a minimum ethyl alcohol content of 35 per cent and contain the soluble extractives from 1 part by weight of vanilla beans in 10 parts by volume of aqueous alcohol. In the United States, the largest market for vanilla extract, the composition requirements are strictly defined. Vanilla extract may be prepared by direct extraction (maceration) or by dilution of concentrated vanilla extract, concentrated vanilla flavouring or vanilla oleoresin. The direct extraction procedure provides a product with the best aroma and flavour, closely resembling that of vanilla beans.

'Vanilla flavouring'
This is similar to 'vanilla extract' but contains less than 35 per cent ethyl alcohol by volume.

‘Vanilla tincture'
This is prepared by maceration from 1 part of vanilla beans by weight to 10 parts of aqueous alcohol by volume and contains added sugar. It differs from 'vanilla extract' in having an ethyl alcohol content of atleast 38 per cent. It is mainly used for pharmaceutical purposes.

'Concentrated vanilla extract' and 'concentrated vanilla flavouring'
These products are prepared by stripping off a part of the solvent from solvent extracts to concentrate the vanilla constituent content. They have the same alcohol content as the corresponding 'vanilla extract' or vanilla flavouring.

'Vanil!a oleoresin'
This is a semi-solid concentrate obtained by complete removal of the solvent from a vanilla extract. Aqueous isopropanol is frequently used instead of aqueous ethyl alcohol for the extraction step. Owing to unavoidable evaporation losses during the solvent stripping step, 'vanilla oleoresin' is inferior in aroma-flavour character to conventional, unconcentrated 'vanilla extract' prepared by maceration.

'Vanilla-vanillin extract and flavouring'
These products are fortified with synthetic vanillin and the natural component is usually obtained by dilution of 'vanilla oleoresin'.

'Vanilla powder'
This may be pure powdered vanilla but it is more usually a mixture of vanilla powder or vanilla oleoresin with sugar, food starch or gum acacia.

'Vanilla-vanillin powder'
This product is fortified by the incorporation of synthetic vanillin.


Solvent-extracted products for perfumery applications :

'Perfumery vanilla tincture'
This is prepared by maceration of vanilla beans with perfumery alcohol, and has an ethyl alcohol content of around 90 per cent.

Vanilla absolute
This is prepared by direct alcohol extraction of vanilla beans followed by solvent stripping or by alcohol washing of an oleoresin prepared by extraction with a hydrocarbon solvent. It is the most concentrated form of the vanilla aroma, being 7 to 13 times stronger than good-quality vanilla beans, but it has a less well-rounded character.
　

Vanilla Extract

In the United States, Government regulations require that vanilla extract should have an ethanol content of no less than 35 per cent by volume and that 1 gallon (1 US gallon = 0.833 Imperial gallons) i.e.
3.79 litres of extract should contain the soluble extractives from a minimum of 13.35 ounces (377.8 g) of vanilla beans of not more than 25 per cent moisture content (or their equivalent). The only other permitted ingredients are water and glycerine or propylene glycol or sugar or dextrose or corn syrup. An extract conforming to this specification is known as 'singlefold' and one prepared from double the quantity of beans is known as 'doublefold'. The maximum concentration possible by straightforward aqueous ethanol extraction is fourfold.

In practice, many manufacturers use 16 ounces of beans to make up
a gallon extract (approximately 12 g in l00 ml). The most economical concentrations are considered to be 2 pounds and 4 pounds of beans to a gallon, which provide extracts of just over 'two-fold' and 'four-fold' strength. These extracts are then diluted, if necessary, to the customers' specific requirements.

Glycerine and sugar are frequently included in the formulation as they lend smoothness and viscosity to the extract and also help to 'fix' the aromatic constituents, thereby extending the shelf-life. Inclusion of these additives in the initial extraction solvent, known as the menstruum, is believed to assist the extraction of the flavouring constituents and glycerine also increases the colour of the extract. One gallon (3.79 litres) of twofold extract would commonly have 1 pound (0.45 kg) of sugar and 0.06 gallon (i.e. 6 per cent v/v) of glycerine included in the initial menstruum.

　

The quality of a vanilla extract is dependent upon :

1. Careful handling and storage of the beans prior to extraction.
2. Appropriate selection and blending of beans.
3. The degree of comminution of the beans.
4. The method and conditions of extraction. Two extraction
methods are practiced : maceration and percolation.
5. Proper ageing of the extract to permit full flavour development.

Bean storage
Even after completion of curing, vanilla beans often continue to develop a desirable aroma and flavour if stored under suitable conditions, and it is usual for extract manufacturers to store beans for a period after importation. Experts recommend that vanilla beans should be stored in open containers at a temperature of about 10 °C and at a low humidity. Moisture contents of 25 to 30 per cent are preferred for extraction purposes, and storage temperatures may be raised to 15 to 21 °C without detriment to flavour quality if some moisture loss is desired in the beans.

Selection and blending of beans
The properties of vanilla beans can differ considerably according to their source and to the grade. Mexican vanilla is generally considered to possess the finest aroma but the 'body' of the flavour is relatively weak in comparison with other commercial sources of v. fragrans. Bourbon vanilla has a greater 'body' and fullness of flavour and the 'body' strength is even more pronounced in Java vanilla. The extractable colour is also variable and dry beans give a darker colour than moist ones. Consequently, extract manufacturers select and blend various types of beans, with due regard to the price and availability to obtain an end-product with the desired properties.

　

Merory (1968) has provided a number of examples of blends preferred in the United States. One of these is as follows :

50 per cent -Madagascan Firsts
15 per cent -Mexican Cuts
25 per cent -Madagascan Foxy Splits

If a stronger vanilla flavour is required, the proportion of Bourbon vanilla in the blend may be increased. Madagascan Foxy Splits and similar dry types are useful in enhancing the colour of the extract.

The menstruum
In addition to the aromatic constituents, the aqueous alcohol menstruum co-extracts some of the non -aromatic constituents of the beans : resins, sugars, waxes, gums, etc. Their presence in an extract assists in providing a certain depth of flavour and body. However, if present in too large a quantity, these compounds detract from the flavour by giving a woody, somewhat bitter taste, which masks the desired vanilla flavour. The relative proportion of non-aromatic constituents extracted is largely dependent upon the ethanol content of the menstruum.

With ethanol contents greater than 70 per cent, a considerable quantity of fixed oil is obtained which will precipitate in a fine cloud and cannot be removed when the extract is diluted to the normal 35 to 40 per cent ethanol content. Menstruums with ethanol contents below 35 per cent readily dissolve gum, and this causes difficulties in percolation and filtration operations.

The colour of the extract is dependent upon a number of factors, which include the quality of the bean, the duration of extraction and the presence of glycerine, but the ethanol content of the menstruum is also of importance. The colour of the extract progressively darkens as the ethanol-content of the menstruum is increased up to 60 per cent. With ethanol contents greater than 70 per cent, the colour lightens, and with 95 per cent ethanol very little colour is extracted. In the past, some manufacturers have added alkali to the water wash after the aqueous ethanol menstruum extraction in order to enhance colour and resin values, but this practice is considered detrimental to flavour quality.

Ethanol contents of 50 to 60 per cent in the menstruum yield extracts with a good flavour and colour and sufficient water-soluble extractives to provide 'body', but little, if any, of the undesirable oils and waxes. An ethanol content of 60 per cent in the menstruum is considered
optimal.

Comminution of the beans
Extraction is carried out on beans sliced into short lengths (about 1 to 2 cm) rather than with powdered vanilla, which is difficult to prepare and involves the risk of aroma loss by evaporation, or with pulped vanilla, which tends to yield an opaque extract. The comminution is generally done in a machine fitted with revolving blades (e.g. a Fitz Patrick comminuting machine). Prior to slicing, the beans are washed with a portion of the menstruum to dissolve any surface vanillin. During the cutting operation, a little of the menstruum is allowed to flow over the beans to prevent overheating and evaporation losses.

Extraction by maceration
This is the traditional method of preparing vanilla extract and involves placing the chopped beans in a vessel where they are allowed to steep in the menstruum for up to one year. In the past, wooden barrels and a 50 per cent ethanol content menstruum were used. This technique provided a product with a good flavour but of a non-standard quality owing to seepage, evaporation losses and to the variable moisture content of the beans. Modern macerators are airtight vessels, constructed from stainless steel, tin or lined with glass, which permit slow agitation by stirring, rocking or tumbling. With a menstruum containing about 60 per cent ethanol, modern maceration extractors provide a good-quality product in 1 to 3 months. The beans contain some moisture, which immediately dilutes the alcohol content of the menstruum, and the requisite initial ethanol content of the menstruum should be calculated according to the moisture content of the beans. As a guideline, a menstruum containing 60 per cent ethanol would be added to beans with a 30 per cent moisture content to provide a near-optimum extraction medium. After the requisite time has elapsed for extraction, the liquid is slowly drained off and filtered.

The maceration procedure is very lengthy when compared with the percolation method but it is considered by some to provide a superior-quality product.

Extraction by percolation
The bulk of vanilla extract is now prepared by this method. The equipment consists of a stainless steel or tin vessel fitted with a series of perforated trays to hold the chopped beans. The menstruum is sprayed on to the top tray, percolates down from tray-to-tray, collects in the base of the vessel and is then recirculated by a pump. The trays are designed so that the menstruum continually covers the beans and a slight positive pressure maintained by the pump aids percolation. Some vessels are fitted with hot-water jackets to permit extraction at a slightly elevated temperature of 38 to 49 °C as this is considered to assist extraction without detriment to flavour properties.
Merory (1956) has recommended three consecutive extractions, each for at least five days, using a menstruum with a 60 per cent ethanol content for the first extraction, 30 to 35 per cent ethanol in the second, and 15 per cent ethanol content in the third extraction. The beans are finally washed with water and this is done without circulation, to avoid extraction of gums.

Merory (1968) has described an operation to prepare l00 US gallons (379 litres) of twofold vanilla extract (26.7 ounces of beans per gallon or 20 g per l00 ml) with a 35 per cent ethanol content. The extraction vessel has a capacity of 200 gallons and is fitted with ten trays, each capable of holding about 18 1b (approx 8 kg) of cut beans. The initial menstruum (62 gallons at 65 per cent ethanol content) is made up by mixing 95 per cent ethanol (42 gallons), water (14 gallons) and glycerin (6 gallons). The beans (166.9 lb or 75.7 kg of 30 per cent moisture content) are first washed in a portion of the menstruum and are then comminuted. The cut beans and the menstruum are then loaded into the extractor and the menstruum is circulated twice daily for 8 to 10 days. After a few circulations, the moisture present in the beans dilutes the ethanol content to 60 per cent. The extractor is then drained slowly until 40 gallons (152 litres) of extract has been collected. The draining takes about two days.

For the second extraction, warm water (22 gallons or 83.4 litres) at
60 °C is poured into the extractor. The temperature drops to 45 °C after the first circulation. After three days, the temperature drops to 35 °C and the ethanol content of the menstruum is about 30 per cent. Draining is commenced on the fourth day and 20 gallons (76 litres) of extract are collected.

For the third extraction, warm water (20 gallons) is added and the process is repeated. The ethanol content of the menstruum is about 15 per cent and 20 gallons are drawn off.

Finally, the beans are washed with cold water (20 gallons) by adding 5 gallon portions at 30-minute intervals. The washes are collected in 5-gallon volumes until 20 gallons are obtained. This extract is then combined with those from the previous three extractions to provide 100 gallons of twofold extract of approximately 35 per cent ethanol content. After 'ageing' has been completed, the extract is filtered or centrifuged.

The exhausted beans are centrifuged or washed with water without circulation and the recovered dilute aqueous ethanol solution is used for a subsequent extraction operation.

Ageing of extracts
In order to permit a full development of the flavour, extracts should be ‘aged'. According to Broderick (1955), the greatest modification to the flavour occurs in the first 30 days after extraction but a definite improvement is discernible for at least 90 days. Three months is generally regarded, as the minimum time for ageing and six months is preferable. With extracts prepared by the lengthy maceration procedure, the product is usually well-aged when tapped off. However, this is not the case with the more rapid percolation process and a separate storage period is required to develop the full aroma/flavour. This is necessarily costly and material intended for the retail trade is often bottled immediately after preparation since ageing can occur during normal shelf-life.

Ethanol contents of 42 to 45 per cent are known to accelerate ageing of extracts and this fact can be applied to the problem of ageing percolated extracts. On combining the extracts from the percolator, all or a portion of the final water wash can be withheld to provide an extract with a near optimum ethanol content for ageing. The withheld wash water is set aside in cool storage until required to adjust the ethanol content of the aged extract (Merory, 1956).

Storage containers
Vanilla extracts are best stored in stainless-steel, tin or glass vessels. Wooden barrels are inferior owing to the risk of seepage and evaporation losses, and new wooden barrels are to be avoided as tannins and other undesirable flavours can be absorbed. Aluminium, nickel, copper and zinc are unsuitable for storage vessels and for extraction equipment.

　

VANILLA OLEORESIN

The preparation of vanilla oleoresin intended for flavouring purposes involves solvent extraction of chopped beans (usually 'cuts'), followed by removal of the solvent by distillation under vacuum. The oleoresin remaining after solvent stripping is a dark, viscous mass. Extraction is carried out either in a percolation vessel or in a sealed vessel in which the beans, placed in baskets, are continuously immersed in the solvent. The preferred solvents for extraction are warm, 50 per cent (v/v) aqueous ethanol or warm, 50 per cent aqueous isopropanol. These menstruums are considered to provide oleoresins with the optimum combination of flavour properties, yield and solubility in aqueous ethanol (Garros-Patin and Hahn, 1954; Merory, 1968; Cowley, 1973). Duty is payable with ethanol and there are cost-saving advantages in the use of isopropanol for the extraction.

For use in flavouring, the oleoresins are diluted to one, two or ten-fold strength as required. However, the flavour of vanilla oleoresins is not as full-bodied or well-rounded as those of vanilla extracts owing to
the loss of some aromatic constituents during the solvent stripping operation. Vanilla oleoresin 'best fulfils the role of a 'vanilla base' and is often used for compounding with synthetic vanillin.

Cowley (1973) prepared oleoresins from a number of types of vanilla beans by extraction with 50 per cent aqueous alcohol and obtained products with a specific gravity of approximately 1.3 in yields.

Merory (1968) has described a procedure for the preparation of vanilla oleoresin as follows: chopped vanilla beans (200 pounds; 91 kg) are placed in the baskets of an extractor and a menstruum of 50 per cent aqueous isopropanol (200 US gallons; 658 litres) is added, During the extraction, continuous heat of not higher than 46 °C is applied for 2 days. On the third day, extraction is continued without heat and on the fourth day the extract is drained off. For the second extraction, another menstruum of 50 per cent aqueous isopropanol (80 gallons; 304 litres) is used and the same procedure is followed. A third and final extraction is carried out with cold water (100 gallons; 379 litres) for one day and the extract is drained off on the second day. Residual menstruum is recovered by pressing the beans. The extracts from the three extraction steps are combined and the solvent is stripped off by distillation under vacuum. A viscous mass of vanilla oleoresin is obtained in a yield of about 100 pounds (45 kg).

VANILLA ABSOLUTE AND TINCTURE FOR PERFUMERY

For perfumery purposes, a very concentrated form of the vanilla aroma, known as an 'absolute', is required which is soluble in pure ethanol and perfume oils. Extraction of vanilla with hot 60 to 80 percent ethanol, followed by removal of the solvent, provides a semi-solid absolute in a yield of about 10 to 12per cent w/w. However, this type of absolute has limited applications in perfumery since it has high resin content and will not completely redissolve in pure ethanol. In order to minimise this solubility problem, some manufacturers have devised selective extraction techniques in which the vanilla is first extracted with a hydrocarbon or chlorinated hydrocarbon solvent to remove resinous material, and is then extracted with aqueous ethanol or acetone. An alternative approach involves first preparing an oleoresin by hot benzene extraction (yield: 6 to 9 per cent, w/w) and then washing the oleoresin with ethanol to obtain the aromatic constituents. On evaporation, this absolute is obtained in a yield of about 60 to 70 per cent (w/w) from the oleoresin in the form of a very dark-brown, highly viscous mass. The absolute prepared by direct ethanol extraction is the most concentrated form of the vanilla aroma but it lacks the full-rounded character of aqueous ethanol vanilla extracts owing to a loss of some of the constituents during solvent stripping. The absolute prepared from the benzene-extracted oleoresin is even less rich in aroma (Garros-Patin and Hahn, 1954; Arctander, 1960; Naves, 1974).

Vanilla tinctures used in perfumery differ from those employed in flavouring in that the ethanol content is much higher (approx. 90 per cent v/v) and they are prepared with perfume alcohol i.e. alcohol denatured with diethyl phthalate, etc. Perfumery tinctures are frequently made by maceration of vanilla beans (10 g) in 95 per cent ethanol (100 ml).

Finally it should be appreciated that the aroma character of perfumery vanilla absolutes and tinctures, is dependent upon the species, geographical source and grade of the vanilla extracted. The aroma can be modified by appropriate blending.

VANILLA POWDER

Owing to the high fat and moisture content of vanilla beans, they are difficult to powder alone and this operation is usually carried out in the presence of sugar or a similar suitable blending material. Consequently, 'vanilla powder' is normally a mixture of ground vanilla and a carrier. A minimum of 30 per cent sugar in the mixture is necessary during the powdering to obtain a satisfactory product. Care must be taken during the operation to avoid overheating which can result in the loss of volatile constituents by evaporation. An anti-caking agent, such as aluminium calcium silicate, may be incorporated in the ground mixture at a level of up to 2 per cent by weight.