Processing of spices and its by products

Pepper, onion, annatto, tumeric, bay leaf (laurel) cloves, cinnamon, nut meg (mace), capsicum, anise, dill, oregano, coriander and mint are among the spices which are found or cultivated in the country. There is a dearth of information on research studies on this very popular commodity. Very little information too, is available on their local processing and in- use application.

The antiquity and uses of spices has long been established and could be traced back to ancient times when it was not only used as condiment but was widely employed as essences, perfume, cosmetic and medicine. The increasing demand for spices dates as far back as 1492 when Columbus was not only looking for gold but for a short cut to the Indies in search for spices.

Spices are natural products widely accepted by consumers. It covers a multiplicity of plant parts such as root, bark, stem, bud, seed or fruit which have a variety of fragrance, aromaticity and pungency. They are largely valued for the contents of their secretory tissues giving rise to essential oils, oleoresins, and oleogum resins, most of which are highly aromatic and which bequeaths an aroma and flavor to food with an undeniable psychological as well as physiological effect. It exerts peristalsis in the digestive system so that food is more utilized by the body. Foodstuffs are therefore made more acceptable and easily digestible.


Most spice processing usually take place in the primary growing areas between harvesting and marketing. It involves two basic operations: drying and cleaning. Additional operation may include storage period to allow for fermentation or other biological processes to take place. In developed countries, the term spice processing refers to further series of operations in which the flavor and aromatic substances are removed from the dried matric and incorporated as essential oils or oleoresins ending with whatever products maybe demanded by the food processing industry.

These may be done by: a. dissolving the concentrate in alcohol, propylene glycol or some other appropriate solvent to make an essence. b. dispersing the concentrate onto a dry carrier such as salt, dextrose or starch as appropriate to make a dry dispersed spice. c. emulsifying the concentrate with gum arabic or one of the modified starches followed by spray drying to give an encapsulated spice.

Spice processors are actively engaged in reappraising their products and processing methods with growing concern on problems of quality control.

Producers aware usually careful to avoid loss of essential oil in the drying and preparation of spices for the market, particularly where the essential oil is contained in cells near or in the epidermis, as for example in leaf spices. The highest concentration of essential oil is believed to be reached at the time when the plants come to bloom. It is at this time that harvesting is carried on.

Spices are grown in many parts of the world. It may be dried indoors or outdoors according to climatic condition. Care is essential in drying. Over exposure to air and sunlight can cause loss of essential oil, and so do too much artificial heat and too rapid drying. When artificial heat is employed, it must be carefully controlled and effectively circulated, beginning with a moderate degree of heat and gradually increasing the temperature to the permissible maximum.

When the whole spices reach the spice merchant, some are set aside for sale as such. Some will be reduced to powder to meet the needs of consumer. Some spices require being brought to suitable size for milling as in the daze of barks. Among the machines which could be used for grinding spices are hammer mills, roller mills, attrition mills, and shifting but employ a combined grinding and shifting machine.

Some essential oils are volatile and also, since grinding creates a large area of exposure, ground spices must therefore be kept tightly capped in their containers when not in use; or else quality and flavor will soon be dissipated. Whole spices naturally are less prime to loss of their volatile constituents, nevertheless, they should also be kept in closed containers for the same reason.



Pepper contains a volatile oil, fixed oil, resin, alkaloids, proteins, cellulose, pentosans, starch, mineral elements, etc. It contains l to 3% of volatile oil which is colorless or yellowish liquid, not pungent, but with aromatic flavor of pepper. The pungent principle of pepper are contained in its oleoresin, and consists of piperine, charvicine and peperidine.

When the berries begin to turn red, the spikes are pick from the vines, then beaten lightly with sticks or rubbed by hand to separate the berries from the stalks, which are removed by winnowing. The berries are then prepared for the market. In Asia, the practice is to steep the berries in boiling water for about ten minutes, then are spread in mats to dry in the sun. Drying is carried out as rapidly as possible to prevent mold growth and with good sun, drying is complete in 3 to 4 days. The hot water treatment makes the skin turn black in an hour. The end product is dried black pepper.

White pepper is prepared by keeping ripe berries in moist heaps for 2 or 3 days, or by soaking the berries contained in gunny sacks, in running water for 7 to 8 days to soften the outer pericarp, or outer coating as is usually called. The process of removing the outer part of the pericarp begins with the trampling of the berries under foot, after which they are placed in rattan baskets, then rubbed and washed by hand to remove the pulpy covering and stalks. The berries are then spread out on mats in the sun for a day or two to dry. The resultant berry is light yellowish gray in color and consists of the seed coated with the inner part of the pericarp.

White pepper can also be prepared by mechanical abrasion of dried black peppercorns. This process permits the manufacture of various grades depending upon the length of time of attrition. Part of the peericarp of the black peppercorn or all of it can be removed. The resultant product is known as "decorticated white pepper". This pepper is preferred by food manufacturers in the production of such preparations as mayonnaise and salad dressings where black specks are undesirable.

In Brazil, black pepper is prepared by drying the berries in the sun (in case of small producers) or in driers (large producers). To obtain white pepper, the berries are soaked in water for 8 days to loosen the outer coat (small producers) or the outer coat is removed by mechanical means and washing in water (large producers). The berries are then dried in the sun or in driers.

Both black and white pepper berries are imported whole by spice merchants who mill them to the requirements of the food processing industry and the retail food trade.

Both black and white pepper enjoy almost universal use. They are available whole, cracked, coarsely ground or finely ground. Both have many culinary uses including the seasoning and flavoring of soups, meats, poultry, game, fish eggs, vegetables, salad dressings, mayonnaise and other foods.


Onion contains a volatile oil, fixed oil, protein, cellulose, sugars, mineral elements, etc. The volatile oil of onion is very small and little is known about its chemistry.

The spice consists of:

l. onion powder which is the ground product of dehydrated onion bulbs, and is a creamy white powder with an aroma and taste similar to that of the fresh onion.

2. onion salt, which is the ground dehydrated onion mixed with free running table salt and sometimes with a small quantity of edible starch to prevent caking. Flaked and minced dehydrated onion have been added to the spice shelf.

The above products maybe employed in place of onion in the culinary art. Onion powder is employed commercially in the processing of fancy meats and sausages.

Onion spice products are effective, labor-saving, and convenient for both kitchen and outdoor cooking. They readily absorb moisture and their containers should be tightly capped when not in use.


The ripe seed contains by weight some l0% inner seed, 22% peel or test and 68% mark or outer covering. The mark contains 4 to 5.5% pigment, 40-45% cellulose, 3.5-5.2% sugars and 0.25- .85% essential oils. The only useful known material obtainable from Bixa orellana is the pigment in the mark which is the annatto of commerce.

Annato or Bixin is widely used by the natives as a dye. It is used as an artificial coloring for food stuffs like butter, margarine, cheese, chocolate and the like.

The coloring pigment is best extracted by leaching with alkali followed by subsequent washings with water, the combined extracts are then precipitated with a mineral acid, then washed again with water until acid-free, drying at 60oC followed by pulverizing of the extract.


Turmeric contains a volatile oil, fixed oil, resin, a coloring matter, protein, cellulose, pentosans, starch, mineral elements, etc.

On distillation, turmeric yields from about l.3 to 5.5% of volatile oil, orange yellow in color, slightly fluorescent and aromatic. It is reported that the main fraction of the volatile oil consists of turmerone, a ketone. The coloring matter is curcumin.

Methods of curing the rhizome varies somewhat in the different countries of production. It is the practice to split the stout tuberous portions (mother sets) lengthwise in four pieces. The prepared rhizomes are then placed in an earthen or metal vessel and just enough water added to cover the rhizomee. The remaining space is packed with dry tumeric laves and the mouth of the vessel is covered with jute material and sealed with mud plaster. The vessel is placed over a slow fire for about three hours and then allowed to cool. Following the boiling process the rhizomes are removed from the vessel and spread in the sun to dry for 5 to 7 days.

The process of preparing the spice is completed by rubbing the rhizomes by hand in a serrated earthen vessel or by rotating them for about l0 minutes in a cylindrical metal container fitted with handles at either end and mounted horizontally. The product is then ready for market. It takes 5 lbs. of fresh rhizomes to produce l lb. of cured turmeric.

The quality, appearance, and color of whole turmeric varies according to its source. Ground turmeric of good quality is orange-yellow in color and has a characteristic pepper-like odor and slightly aromatic somewhat bitter taste.

Turmeric is available whole or ground. It is used to flavor meat and egg dishes and to add flavor to pickles, relishes and prepared mustard. It is an indispensable constituent of curry powder.

Laurel (Bay Leaves)

Laurel leaves contain a volatile oil, fixed oil, protein cellulose, pentosans, pigments, mineral elements, etc. The principal constituents is its volatile oil, present in amounts of about 2%. The chief constituent of the oil is cineol (about 45-500%), a colorless liquid with a strong aromatic, camphoraceous odor and cooling taste.

Only the dried leaves are employed as a spice. It has an agreeable odor and when bruised or crushed yield a very fragrant and aromatic aroma. The taste is bitter and aromatic. Laurel leaves are employed to flavor meat, game, poultry and fish dishes, soups and sauces. Crushed laurel leaves are an ingredient of whole pickling spice.


Cloves contain a volatile oil, fixed oil, resin, tannin, proteins, cellulose, pentosans, mineral elements, etc. The volatile oil of cloves contain from 70 to 90% of eugenol. Eugenol is a colorless, or faintly yellow, optically inactive liquid with the aromatic odor and pungent taste of cloves.

When the base of the buds turns reddish in color, they are ready for harvesting. Pickers climb the trees and remove the clusters by hand. The buds are later separated from the stems and spread on grass mats or cement drying floors for 4 to 5 days to dry. Drying is an important part of the preparation of the spice. Too rapid drying can cause the cloves to become shriveled and brittle. Under bad drying and storage conditions the color becomes darker and the cloves turn musty. Finally, the epidermis becomes pale and wrinkled. Cloves must bee handled with care, especially when dry, since the heads or crowns are easily broken off.

Good quality cloves are large, bold and not too wrinkled. Cloves are graded on appearances and allowances for maximum impurities. Clove stems are largely used for distilling oil of cloves.

This widely used spice is employed whole or ground. Its use include the studding of hams and roast pork and the flavoring of meat dishes, gravies, pickles, preserves, desserts, cakes, pudding, etc. It is an ingredient of many spice mixtures including curry powder, mincemeat spice, pastry spice, sausage seasoning, and others.


Ceylon cinnamon bark contains a volatile oil, fixed oil, tannin, resin, proteins, cellulose, pentosans, micilage, starch, calcium oxalate, mineral elements, etc. On distillation the bark yields from 0.5 to l% of volatile oil, the chief constituent of which is cinnamic alddehyde. It is an aromatic pungent, sweet- tasting and yellowish, oily liquid. Cinnamon oil is distilled from the chips and trimmings of the quills; and this is known as "Barl Oil". Before distillation the chips are macerated in sea water or strong solution of brine for 2 to 3 days. The active constituent of bark oil is cinnamic aldehyde whereas that of the leaf oil is eugenol. Leaf oil is sometimes designated "clove oil".

After cutting, the shoots are bundled and taken to sheds for peeling. The shoots are first trimmed of twigs and leaves, then two longitudinal slits are made on the bark, which is gradually loosened with the knife and removed. The sections of bark are then carefully put one into the other, the outerside of one piece against the inner side of another. These are then collected and firmly bound together in bundles and set aside for 24 hours to "ferment". Following the process, each section of bark is placed on a cylindrical piece of wood about two feet long, one end of which is supported by a low tripod of sticks, the other resting on the ground. The peeler sitting on the ground opposite the tripod, hold lathe section firmly with his food and using a small curved knife scrapes off the outer layers of the bark.

After a few hours, the smaller sections of scrapped bark are introduced into the larger and pieced together to a length of about 36 inches. As the bark dries, it contracts and gradually acquires the form of "pipe"" or "quill".

Ground cinnamon is employed to flavor breads, buns, cakes, cookies and pies. It is used with apples, stewed fruits, and in confectionaries. It is used commercially by bakers, confectioners and other food processors.

Nutmeg (Mace)

Nutmeg or mace contains a volatile oil, fixed oil, proteins, cellulose, pentosans, starch, mineral elements, etc. The volatile oil is obtained by distilling; the fixed or expressed oil by pressure accompanied by heat. The volatile oil of nutmeg (oil of myristica) is a colorless or pale yellow liquid with the odor and taste of nutmeg. Nutmeg yields from about 24 to 30% of fixed oil expressed oil of nutmeg, also known as nutmeg butter, or oil of mace.

Nutmeg and mace are products of the same tree. Nutmeg is the seed and mace is the aril of the fruit.

As soon as the fruits split, they are collected by hand. The nutmegs are taken to curing houses where the mace is carefully removed. The nutmegs and mace are dried separately. The drying of nutmeg is a slow process involving exposure to the sun for limited daily periods and turning them twice daily over a period of 6 to 8 weeks. When dry, the shell is removed by breaking with the aid of a wooden truncheon or by mechanical means.

The mace is flattened by hand or between boards. It is then dried by exposure to the sun for varying daily periods. In drying, the color changes from the natural crimson to a pale yellow or buff color, and the spice becomes horny and brittle.

Nutmeg has a characteristic aromatic odor and an aromatic, warm, gently bitter taste, Mace has fragrant nutmeg-like odor and an aromatic, slightly warm taste.

Nutmegs are available whole or ground. The culinary uses for nutmeg include the flavoring of sweet dishes, pies, pudding toppings, and some meat and vegetables dishes and beverages. It is an ingredient of a number prepared ground spice mixtures including mince-meat, poultry dressing, sausage, bologna and frankfurter seasonings.

Mace is available whole, broken or ground. It is used to flavor cakes, biscuits, preserves, sauces, pickles, meat and fish dishes. It is employed in the commercial manufacture of a number of feeds including relishes, sauces and some fancy meats. It is an ingredient of mincemeat spice, poultry dressing, pork sausage spice and other ground spice flavorings and seasonings.


Capsicum fruits contain a fixed oil, resin, coloring matter, a pungent principle, protein, cellulose, pentosans, mineral elements, etc. Thee principal coloring principle of capsicum fruits is the carotenoid pigment capsanthin. The pungent principle of capsicum is capsaisin. The quantity of capsaicin in capsicum varies, being greatest in the hot peppers, and slight or almost nil in the mild or sweet fruits.

Capsicum spices are prepared from the dried fruits of plants of the Genus Capsicum, belonging to the Solanaceae family. From capsicum fruits we get paprika, cayenne pepper, red pepper, chili powder and chilies.

Paprika is manufactured from the large fruits of C. annum, and may be sweet, semi sweet, mildly pungent, or pungent. It ranges in color from a bright rich red to brick-red depending upon the selection, quality and preparation of the pods for grinding. The better the quality, the better the color.

The fruit maybe sundried or dried artificially. After drying, the fruits are sorted into the different grades to be manufactured. Grinding involves the use of roller mills and shifting apparatus. Usually a series of mills with iron rollers and one mill with emery roller are employed. Several grindings and shifting are required to bring the paprika to the required fineness. Finally, the screened paprika is conveyed to a mechanical batcher to be thoroughly mixed and homogenized. It is then packed and labeled for the market.

Paprika has many culinary uses. It is employed for flavoring and garnishing meat and fish dishes, poached and deviled eggs, salads, canap├ęs, etc. It is used by the food manufacturing industry in the preparation of fancy meats, catsup, sauces and other prepared foods.

Cayenne pepper is obtained from the dried fruits of C. frutescence or some other small fruited species of capsicum. The dried chilies are mechanically ground and then sifted through a fine screen to produce the pepper.

Red pepper is the ground product derived from the above chilies and also from the large long peppers to the cayenne group such as the long red cayenne.

Cayenne and red peppers, used with discretion, add flavor to meat, fish, egg dishes, sauces, etc.

Chili powder is prepared from the mild or pungent capsicums including the large Mexican chili pods with the addition of other spices such as cumin, oregano, garlic powder and onion powder. Chili powder is used in the preparation of chili con carne, fish and oyster cocktail sauces, and with eggs, omelets, stews, etc.


Anise fruit contains a volatile oil, fixed oil, proteins, cellulose, sugar, pentosans, calcium oxalate, mineral elements, etc. The volatile oil, which is colorless or pale yellow liquid and is the most important constituents of anise is about l.5 to 3.5%/. Of this, 80 to 90% is anethole which possess the aromatic odor and sweet taste of anise.

The fruit is harvested when they begin to ripen. They are piled into stacks and left in the field until ripening of the fruit is complete. The fruits are then separated by threshing.

Dried anise fruit, commonly called aniseed, has a pleasing aroma and taste. It is used to flavor rolls, cakes, cookies, biscuits, licorice and confections.


Dill fruit contains a volatile oil, fixed oil, protein, cellulose, calcium oxalate, mineral elements, etc. The volatile oil, about 2 to 4%, is colorless pale yellow and with the odor of the spice. The chief constituent of the oil is carvonee (about 40-50%). Its presence permits the use of dill as a substitute for caraway.

Dill seed is available whole or ground. It is used to flavor soups, meat dishes, meat and fish sauces, salads and pickles. It is employed commercially in the preparation of pickles, and to flavor processed meats, fancy sausages and bologna.


Oreganum or Oregano contains a volatile oil, fixed oil, proteins, cellulose, pigment, mineral elements, etc. It consists of the dried leaves and flowering tops of a variety of oreganum vulgare of the mint family.

Dried oreganum has a strong aromatic odor, and a warm pungent, bitter taste. It is used to flavor soups, meat, fish and egg dishes, meat sauces, chili con carne and other dishes.


Coriander fruit contains a volatile oil, fixed oil, tannin, protein, cellulose, pentosans, calcium oxalate, mineral elements, etc. The volatile oil (about 0.l to %) is a colorless or pale yellow liquid with the odor and flavor of spice. The chief constituent of the oil is coriandrol di- linalool).

Coriander seed is available whole or ground. It is used to flavor pastries, cookies, buns and cakes. It is employed commercially to add flavor to some processed meats. Whole coriander seed is an ingredient of whole mixed pickling spice. Ground coriander seed is a constituent of curry powder, and of seasonings for pork sausages, bologna and frankfurters.


Peppermint and spearmint constitute the dried mint of the spice merchant. Peppermint contains a volatile oil, fixed oil, resin, tannin, cellulose, pentosans, pigment, mineral elements, etc. The chief constituent of peppermint oil is l-menthol with a strong peppermint-like odor and cooling taste and l-menthone, ketone with an odor reminiscent of peppermint, and a bitter taste less than that of menthol. Spearmint contain a volatile oil, fixed oil, resin, tannin, cellulose, pentosans, pigment, mineral elements, etc. The volatile oil of spearmint is a colorless, yellow or greenish-yellow liquid with the characteristic spearmint odor and taste. The coil contains l-carvone (50% or more), l-limonene, etc.

The plants are harvested when in bloom. Generally, they are allowed to partially dry in the open for a short period of time and the drying completed indoors by a process of carefully controlled, circulating warm air, avoiding overheating and too slow drying. When the leaves have attained the desired degree of brittleness they are stripped from the stems, allowed to dry out completely, and then rubbed through a wire sieve or fragmented mechanically.

Dried peppermint has a characteristic sweetish, strong aroma and aromatic warm, pungent taste, with a cooling after taste; spearmint to a lesser degree with no cooling after taste.

Mint is used to flavor soups, stews, meat and fish sauces, salads, mint sauce, mint drinks and confections.


The physical form of spice is normally a fine powder, although some may be obtained in a rather coarse "rubbed" form. With modern technological approaches to food seasoning aimed at consistent products of high quality, the many disadvantages associated with the use of good spice is now unquestionably accepted. Flavor is an important factor in salability which in turn is independent upon appearance and keeping qualities of the meat products. Since spices can actually detract from fresh appearance and shorten shelf-life, this has been a subject of considerable research abroad.

Bacterial Contamination

Ground spices are carriers of considerable levels of bacteria. This results from low standards of hygiene associated with harvesting, open-air drying, storage and so on. Cleaning consists mainly of screening to remove larger foreign bodies (stones, wood, earth) followed by either airblowing or water washing to remove dust. When the spices are introduced into a meat product, high bacterial count can result in its rapid deterioration, especially in a fresh product such as sausage. The high bacterial and spore content of many pure and mixed spices is a technological and hygienic problem for food manufacturers.

Sterilization methods are often employed to reduce bacterial loading. The most effective method is exposure to ethylene oxide which denaturates the bacterial cell wall. Alternatives such as irradiation are not acceptable. Besides, at effective levels to achieve sterilization, the spice flavor is altered and other factors may lead to development of off-notes. If the technique of gas sterilization is correctly handled, then ethylene oxide residues are minimal and no change in the flavor of lathe spice can be observe.

Lypolytic Activity

Certain spices have been shown to contain lipases, which are enzymes capable of splitting fat molecules. These enzymes remain inactive which the cell structure within the spice is intact. The grinding process however, destroys much of the structure, thereby releasing the enzymes. When the spices are added to fat containing foods such as meat, the lipases react to form fatty acids giving a rancid odor and flavor to the product.

Quality Variations and Speckling

Being natural products, spices are subject to variations in flavor strength and quality. Factors such as climatic differences, methods of cultivation and drying methods make the task of minimizing variations difficult. Certain variations inherent in this materials must be accepted and this requires consideration in the establishing of a consistent finished product.

Ground spices present themselves as dark specks in the melat product which produces a dulling effect on the natural color.

Spice Extracts

Some of the problems associated with ground spices have resulted in the currently widespread use of preparations based on solvent extracted oleoresins. In concentrated form, these oleoresins maybe either dispersed or "dry-soluble" spices or more recently encapsulated spices. These are standardized as to their flavoring effect and are very hygienically acceptable. The compositions of such products vary among suppliers and find advantage in large scale manufacturing of processed foods. The food manufacturer has now a wide range of processed spices for soups and meat products. In spite of this, the food manufacturer is constantly in search for the best flavoring product to improve his current lines or for development of new products.

A number of papers concerned with various aspects of spice extraction were presented at the International Conferences on Spices in April l972 organized by the TPI.

Current World Trends in Spices

In l970, the USA imported some 265 m lbs of all spices valued at about $l06M. Of these, l4% were processed into essential oils and oleoresins. About 90% of the spics handled by only a few companies involved the processing of pepper, paprika, capsicum, celery, ginger, turmeric, cinnamon and clove. On the American Spice Market in l972, about $l50 lM of spices were imported to the USA each year. In the USA, there is now an import and domestic inspection program, the analysis being run by competent laboratories recognized by the ASTA and FDA.

The exports of spices in Ceylon formed l% of its total export value in 1950 to 1960 and has increased to about 2 to 3% during 1965-1970. Its major spice crop is cinnamon and provides about 60% of the world's supply of these spices. agricultural diversification has been directed at replacing rubber and tea, and Ceylon now has several private producers of cardamom, nutmeg, pepper, ginger and turmeric. Essential oil production is expected to increase with the attention given now to the growing of these spices. Improved distillation techniques and methods of quality control are now being developed at CISIR and attempts are being made to use instrumental methods for this program. The chemistry of the constituents of the main spices are being studied as a prerequisite to their proper quality assessment. The Ceylon Bureau of Standards is formulating specifications for all essential oils and spices produced in their country. Particular attention is being paid to the cultivation of chilies as this spice is at present being imported. Effects are also being made to improve the growing aspect, distillation technique and assessment of quality of cardamom, cinnamon and pepper.

Source: SPICE CROPS PROCESSING OF ITS PRODUCTS AND BY-PRODUCTS By Violeta P. Arida, as published in DOST website; photo courtesy of

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