1. Garlic Overview
1.1 Garlic species
Garlic(Allium sativum) is a species in the onion genus, Allium. It is native to central Asia, and has been used for both culinary and medicinal purposes. There are two subspecies of allium sativum: hardneck (Allium sativum ophioscorodon) and softneck (Allium sativum sativum).
1.11 Hardneck garlic
Hardneck garlic grow best in cold climates. Hardnecks have a hard central stalk and produce delicious curled scapes from the top. Removing the scapes encourages larger bulbs.
Hardneck garlics have fewer, larger cloves than the softnecks, and have little or no papery outer wrapper. Hardneck garlic has a rich and complex flavor. Porcelain, pocambole, and purple stripe types are hardnecks.
1.12 Softneck garlic
Softneck types grow best in mild climates. It is the type found most often in the grocery store. Softneck garlic has a white, papery skin. It doesn’t produce scapes, and has more cloves forming several layers surrounding the core. Softnecks mature faster than hardnecks and keep longer. The flexible stem makes it ideal for braiding.
Flavor of softneck garlic is generally mild. Most processed garlic foods, like garlic powder and seasoning, come from softneck garlic. Artichoke and Silverskin are two types of softneck garlic.
1.2 Health benefits and uses
1.21 Nutritional value
One raw clove(3g) contains 4 calories, 0.02g fat, no cholesterol, 1mg sodium, 1g carbohydrates, 0.2g protein. It is rich in potassium, calcium, manganese, phosphorus, selenium, vitamin B6, and vitamin C.
1.22 Medical and culinary uses
Garlic has been used to prevent or treat a variety of diseases including diabetes, high blood pressure, high cholesterol, atherosclerosis, cancer, and infections. Garlic is consumed fresh as well as used as a condiment in various food preparations like pickles, chutneys, curries powders, sauce, salad dressings, meat sausages, etc.
2. Garlic Deep Processing Technology and Processed Garlic Products
2.1 Garlic deodorization
Fresh garlic contains Alliin and an enzyme called Alliinase, each kept in separate cells. When garlic is chopped or crushed, the enzyme alliinase contacts with alliin and converts alliin into allicin. Allicin is very unstable and breaks down quickly producing allyl methyl sulfide. The chemical goes into our blood stream and gets expelled through skin’s pores when we sweat causing garlicky sweat. It also enters our lungs and comes out as we exhale causing garlic breath.
The odor of garlic poses negative influence on its application. Therefore, it’s important to choose a proper deodorizing method during garlic deep processing. Two methods are listed as follow:
1). Add 5kg water and 100g vinegar to every kilogram of garlic and mix evenly. Allow to boil for 15 minutes and then cool to ambient temperature. Clean the garlic with water.
2). Put the garlic in the solution made by 0.3% citric acid, 0.2% cyclodextrine, and 0.1% magnesium chloride, soak for 3 hours at 50℃, then rinse with clean water.
2.2 Garlic products in the industry
There are many types of garlic products in the market, including garlic flake, garlic powder, garlic oil, aged garlic extract, black garlic, etc.
2.21 Garlic flake
Working Process of Garlic Flake Production
garlic separating→garlic peeling→garlic washing→garlic slicing→garlic slice rinsing→garlic slice dehydration→garlic slice drying→garlic slice grading→garlic slice packing
Garlic flake production line mainly includes the following equipment:
(1).Garlic separating machine
Garlic bulbs are separated into cloves by passing between rubber rollers of garlic separating machine. With the built-in draught fan, garlic peels, garlic stem and cloves are separated automatically.
(2). Garlic peeling machine
By using pneumatic type garlic peeling machine, the outer skin of garlic cloves are removed off without water.
(3). Garlic washing machine
Garlic cloves are washed by washing machine to remove off foreign matters.
(4). Garlic slicing machine
With garlic slicing machine, clean garlic cloves are uniformly sliced to 1.5-2.2mm. The surface of garlic slice is smooth without damage.
(5). Garlic rinsing machine
Sliced garlic are washed again in the rinsing machine.
(6). Garlic dehydration machine
Garlic slices are processed by the centrifugal dewatering machine to remove surface water.
(7). Garlic drying machine
Dehydrated garlic flakes are spread uniformly on the drying tray and dried in the hot air drying oven at 65℃ for about 6 hours. The final moisture content should be less than 5%.
(8). Garlic grading machine
Dried garlic slices are graded by garlic grading machine. Unqualified products are removed.
(9). Garlic packing machine
Dried garlic slices are packed by garlic packing machine for safe storage.
2.22 Garlic powder
Garlic powder can be made by grinding dried garlic flakes in the garlic grinding machine into fine powder. If you make it coarser, it will be granulted garlic. Garlic powder can also be made in the following process:
garlic separating→garlic peeling→garlic grinding→garlic paste dehydration→garlic drying→garlic powder crushing→garlic powder packing
Garlic powder production line mainly includes the following equipments:
(1). Garlic separating machine
Garlic bulbs are separated into cloves by garlic separating machine.
(2). Garlic peeling machine
Garlic cloves are peeled by using garlic peeling machine.
(3). Garlic paste making machine
Peeled garlic cloves are put into the garlic grinding machine which grinds the cloves into paste.
(4). Garlic paste dehydration machine
Garlic paste are put into the centrifugal dewatering machine to remove water.
(5). Garlic drying machine
Dehydrated garlic powder are spread uniformly on the drying tray and dried in the hot air drying oven at 55℃ for about 6 hours. The final moisture content should be less than 5%.
(6). Garlic powder crushing machine
Garlic powder crushing machine grinds the dried powder into fine powder.
(7). Garlic powder packing machine
Garlic powder is packed by garlic packing machine automatically and store for sale.
2.23 Garlic oil
Garlic oil is mainly obtained by steam distillation from the crushed garlic. The working process is as follows:
Garlic separating→garlic peeling→garlic washing→garlic crushing→fermentation→steam distillation → separation → refining → packing
First the bulbs are separated into cloves, and then the cloves are peeled. After cleaning and crushing, 2-folds of water are added and the mixture are fermented at 55℃ for 3 hours. Then the mixture are subject to steam distillation. The distillate is separated by oil-water separator to get crude oil. The crude oil is refined and packed. This method has the advantages of simple equipment, low cost and good stability. Vegetable oil is usually added to refined oil to make capsules.
2.24 Aged garlic extract
Aged garlic extract is produced by extraction and aging of fresh garlic at room temperature for up to 20 months in stainless steel tanks. During this period, harsh unstable compounds, such as allicin in fresh garlic are converted into stable health-promoting substances.
2.25 Black garlic
Black garlic is produced through fermentation by heating whole bulbs of fresh garlic at high temperature under controlled humidity for several weeks. During fermentation, the cloves gradually darken to their final black appearance. Black garlic has soft, sweetish taste.