Emerging Natural Hydrocolloids

14 Brea Tree (Cercidium praecox) Exudate Gum

María A. Bertuzzi and Aníbal M. Slavutsky

Instituto de Investigaciones para la Industria Química, Facultad de Ingeniería, Universidad Nacional de Salta, CP: A4408FVY Salta, Argentina

14.1 Introduction

Brea gum is an exudate gum from the brea tree, also known as “palo verde” or “chañar brea.” The accepted name of this species is Parkinsonia praecox (Ruiz & Pav.) Hawkins or Cercidium praecox (Ruiz & Pav.) Harm, as a synonym. This species belongs to the Fabaceae family and grows from northern Patagonia to the southern United States of America, mainly in tropical and subtropical arid habitats. The scientific name Cercidium, from the Greek “kerkidion,” refers to the similarity between the fruit and a weaving shuttle, and praecox means “precocious” [1]. The small trees or large shrubs reach up to 8 m tall (Figure 14.1). The leaves develop after the first rains and shed shortly afterward. Thus, the tree depends on the photosynthetic activity of the light green bark of the stem and twigs. Generally, at each knot, there are solitary thorns up to 2 cm in length. The leaves are small, composed, and characterized by sprouting after the beginning of flowering. The flowers appear in spring and summer, and the tree fructifies in late summer and early autumn [2,3].

Figure 14.1 Brea tree and branch with exudate.

This species has ...