Dehydrated Onion

Dehydrated Onion
The domestic onion is one of the world’s oldest crops. The many advances in the formulation and manufacture of dehydrated meals have created a demand for onion in a powder form and considerable tonnages are now dehydrated annually to satisfy this need.

There is some loss in the fresh odor and flavor character during the processing but, in spite of this, the dehydrated form has the advantage that it saves valuable preparation time on the factory floor, there is little or no waste or spoilage and, within acceptable limits, it gives a consistent flavor to the end product.

The nature of this flavor is different from that of fresh onions so that a direct equivalence cannot be established. However, allowance is made for this during product formulation and an acceptable usage level established by trial and error. For guidance, initial usage levels assume an 8:1 fortification of the flavor in the dehydrated form and the missing top-notes may be added in the form of a liquid flavor made from onion oil.

Onions grown for dehydration are not generally the same as those used domestically. The prime consideration is, of course, that of high dry solids content with a good level of flavor and pungency.

Although care is taken during all stages of manufacture, onion powder is still hygienically suspect, and unless special handling techniques are adopted the product may show very high total bacterial and spore counts. However, these counts are of far less significance to the food processor than is presence of pathogens and Salmonella which clearly indicates faulty processing. Most specification for onion powder define limit for total count but this is relatively meaningless. Of far greater significance is a limit of Coliform organisms and a requirement that pathogens and Salmonella be completely absent.
Dehydrated Onion

Tamarind

Tamarind
Ornamental
Botanically name Tamarindus indica. The fruit has been used medicinally for at least 3000 years. The ripe pulp is widely used as a laxative, diuretic, antiscorbutic and to treat fevers. Other folk uses include the treatment of indigestion, bile disorders, sore throat, sunstroke, alcohol intoxication and the restoration of sensation after paralysis. The high vitamin C content of the pulp makes it an effective treatment for scurvy.

A tea prepared from the leaves has been used to treat worms, dysentery, diabetes, coughs as a diuretic and as an eyewash for infected or inflamed eyes. Strips of young bark have been pounded, cooked and eaten to cure diarrhea. A tea from roots has been uses to treat constipation and leprosy. The seed cut in two and rubbed on a scorpion sting is said to be a certain cure. Modern medicine has determined that the ripe fruit has antibiotic activity against gram positive and negative bacteria, yeast and fungi.


Edible
The young pods contain little of the sugar or acid present in the ripe fruit and may be used fresh as a seasoning in cooked dishes or preserved in syrup. The young leaves which are high in protein are used as an ingredient in soups and salads and some curries. The ripe fruit has several outstanding characteristics. It is the fruit with the lowest water content and is the most acidic with high cream of tartar content. It is equally in sugar content only by dates.

The pungent pulp of the ripe fruits often separated by hand and sold in compressed cakes. The fruit pulp is also easily separated as slurry by boiling for a few minutes with enough water to cover it. The resultant syrup may be made into various beverages or used as a sauce in meat. The pulp is used as s a flavoring agent in curries, chutney, and in worcestershire and proprietary sauces as well as being a traditional ingredient in some countries cooking.
Tamarind

The Flavor of Onion

The Flavor of Onion
In the natural products so far considered, the aromatic components exist per se in the plant material and can be recovered by simple distillation or extraction. The flavor of onions, on the other hand is an excellent example of the action of enzymes in flavor development as the characteristic notes are created spontaneously only when the onion is cut and the cells disrupted. The study has established that much of the odor and hence, flavor arise as a result of the conversion of odorless, nonvolatile, S-substituted cysteine sulfoxide derivatives, first to an unstable alkyl sulfenic acid intermediate by the action of an alliinase enzyme system.

The sulfenic acid moiety is very unstable and the reaction proceeds directly to a mixture of mercaptans, di-, tri-, and poly-sulfides as well as thiosulfonates. All possible combinations of methyl and prophyl derivatives have been isolated but little or no allyl compounds are present in onion. A similar system in garlic results in the formation of mainly allyl compounds, the difference being due to the nature of the precursor present.

Most onion flavor components are the result of the degradation of the thiosulfonates, resulting in a complex mixture of sulfides plus ammonia and pyruvic acid which is produced in the first stage of the reaction. A determination of pyruvic acid has been suggested as a measure of the flavoring strength of onion and onion products even though the acid itself does not contribute to the flavor profile.
The Flavor of Onion