The Tara plant (Caesalpinia spinosa or Tara spinosa) is a slow-growing, multipurpose legume native to the Andean regions of South America, with Peru being the largest global producer. It is commercially valued for two distinct components derived from its fruit. The seeds yield a refined gum used as a stabilizer in the food industry, while the pods are processed for their high content of industrial tannins. This duality of use underscores the plant’s economic significance across diverse global markets.
Identifying the Tara Plant and Habitat
The Tara spinosa is classified as a leguminous shrub or small tree, typically reaching a height of two to five meters. It is characterized by thorny branches and bipinnate, evergreen leaves. The plant produces showy, terminal racemes of bright yellow to orange flowers, which later develop into valuable pods.
The fruit is a flat, oblong legume pod, usually six to twelve centimeters long, that can be red or pale yellow when ripe. These pods contain four to seven round, black seeds, which are the source of the food gum. The plant thrives in the dry, high-altitude environments of the Andes mountains in Peru, Bolivia, and Ecuador, growing at elevations up to 3,000 meters. Its resilience to semi-arid conditions makes it a reliable commercial crop.
Tara Gum: Extraction and Role in Food Stabilization
Tara gum is a galactomannan, a polysaccharide extracted from the endosperm of the Tara seed. The industrial process involves milling the seeds to separate the endosperm from the hull and germ. The purified endosperm is then ground into a fine, white to yellowish powder, which is the commercial tara gum. This powder acts as a hydrocolloid, forming a viscous, gel-like solution when mixed with water.
In food production, the gum functions primarily as a thickener, stabilizer, and emulsifier, controlling texture and preventing ingredient separation. It is designated as E417 in the European food additive system. Tara gum is chemically similar to guar gum and locust bean gum, but its molecular structure gives it unique properties. It has a mannose-to-galactose ratio of approximately 3:1, positioning its viscosity between that of guar gum and locust bean gum. This characteristic allows it to be used in products like ice cream to control ice crystal formation, in sauces to maintain uniform consistency, and in baked goods to improve moisture retention.
Tannin Content: Uses in Dyeing and Leather Processing
The other major commercial product is tannin, concentrated in the thick, fleshy pod husks that surround the seeds. These husks contain a high concentration, typically ranging from 35 to 55 percent, of hydrolyzable tannins, primarily gallotannins. Gallic acid is a major constituent, often making up over 50 percent of the total tannin content.
Tara tannins are highly valued in the leather industry for producing light-colored, high-quality leathers with excellent lightfastness and heat resistance. The light color of the extract minimizes discoloration, making it suitable for pale shades and specialized applications like automotive upholstery. The tannins work by binding to the collagen proteins in animal hides, stabilizing the material and converting it into durable leather. The extract is also used in natural dyeing as a mordant, helping to fix colors to natural fibers and producing shades from light beige to brown.
Nutritional Components and Regulatory Status
The primary form of the Tara plant encountered by consumers is the highly refined tara gum additive, not the whole plant itself. While the whole seeds contain a notable amount of protein (around 14 to 16 percent), they must be cooked or roasted to remove potentially harmful substances before consumption. The commercial gum is a carbohydrate-based polysaccharide and is not consumed for its nutritional value.
The safety of tara gum as a food additive has been extensively reviewed by international bodies. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) have assigned tara gum (E417) an “acceptable daily intake (ADI) not specified.” This designation indicates the substance has very low toxicity and does not present a safety concern at typical usage levels. In the United States, purified tara gum is used under the Generally Recognized As Safe (GRAS) framework. This safe, refined gum should be distinguished from unapproved ingredients like “tara flour,” which is milled from the entire seed and does not meet scientific safety criteria for food use.