Study on plant gums and their new development in application: with focus on tragacanth, guar and Arabic gum; a short review

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There are many challenges in way of production of functional beverages. The main target is supplying health claims and permanent developments of flavor profile and desire mouth feel throughout their shelf life.

Formulating a functional component is an obligation and fulfillment of functional properties is one of the controversial issues in production of any functional foods. All these challenges increase in terms of final product. It must be noted that compounds are final and critical items in ensuring the quality and safety of final products (Pimenov N., 2015). Before formulating, it is important that final functionality must define base on all the food ingredients (Pimenov N., 2016).

Texture definitions and beverages stabilization

Texture is a wide term which covers many rheological and sensorial qualities. Texture covers appearance and mouth feel of beverage when drink: appearance when poring, glassing on bottle, mouth feel, precipitation of taste.

The importance of rheological behavior, in particular flow properties of hydrocolloids can be related to mouth feel and textural properties of Gum (Glykex Mann, 1982). Stabilizing, a term relating to bio-physiochemical mechanism is complicated and different. Each parameter needs to be categorized correctly and overall, a stabilized beverage is homogenous and flow. A homogenous beverage defines as a beverage with no gelling status, no viscosity, lack of layer forming, lack of phase separation, lack of clarification,

with no flocculation (Pimenov N., 2013). Each parameter has different parts and depends on formulation and process of beverage.

Mainly, hydrocolloids create the following proerpties in different formulation of food stuffs:

─ Viscosity enhancing or thickening properties

─ Gelling properties

─ Surface activity and emulsifying properties

─ Hydrocolloids as edible films and coatings

─ Fat replacers

Hydrocolloids can modify organoleptic properties and consider as one of food additives. Due to the property of having conformationally disorder chains, hydrocolloids are good alternatives for creating thickening agent. In regards to create thickening properties polymer solvent interaction is needed (Philips et al., 1986).

There are several factors affecting aforesaid property such as the type of used hydrocolloid, its concentration and food system .

From the viewpoint of functionality hydrocolloids categorize in two groups as follows:

• 1)    Thickening agent: creating beverage texture but unable to make it suspension, they slow down precipitation of oil droplet with no possibility of prevention of separation.

• 2)    Gelling agent: make connections and bond among molecules along with 3 dimensional matrixes. It leads to stabilize oil droplets in matrix and thus density of created droplets will be less than the amount of efficacy in matrix.

Since Gums have solid soft matrix, they can widely use in food applications. Some correlated phenomenon is affecting emulsifier properties of Gums

which include retarding of precipitation, diminishing of oil droplet and so forth. It must be noted that Gums will adsorb very slowly onto liquid surface.

Gums or Hydrocolloids are main compounds which create stability of emulsion via entering into water phase. The importance of these compounds is on viscosity and electrostatic reactions to stabilize nonalcoholic emulsion with below properties; 1) easily soluble in cold water, 2) the lowest amount of viscosity in water, 3) having maximum level of emulsifier amount, 4) no creation of gelling.

Introduce of some Gums

• 1.1    Guar

Guar Gum and Locust Bean Gum: they are galactomanam extracted from endosperm of Cy-amopsistertragonobola and Ceratoniasiliqua respectively. Endosperm parts degrade to fine particles. Both Gums compose of glycoside bonds (β 1,4) and a bond on branch which connects Galactose.

• 1.2    Arabic Gum

  Acacia Gum or so-called Arabic Gum is used since thousand years ago is an exudate Gum and today known as an additive (Imenson, 2010). The structure of Gum Arabic is relatively complex. The main chain of this polysaccharide is built from (1→3) and (1→6) – linked β-D-galactopyranosyl.

Figure 1. Arabic Gum

• 1.3    Tragacanth Gum

This kind of Gum exudate from Astragalus Gummifer Labillardiere and other special species of Astragalus from western Asia (mostly in Iran, some in Turkey). This type includes a water soluble part which is соntаinеd30–40% of Gum Structure which is a highly branched neutral polysaccharide composed of 1→6-linked D-galactosyl backbones with L-arabinose side chains joined by 1→2, 1→3 – and/or 1→5-linkages.

Table 1.

Summary of the recent finding on Arabic, Guar and Tragacanth Gums