Composition, antioxidant activity and rheological characteristics of spreadable pastes with blackberry pulp (Rubus fruticosus)

Fecha de publicación: 01/04/2022
Fuente: Broccoli Byproducts Extraction
Abstract
The aim of this study was to determine the composition, antioxidant activity and rheological characteristics of spreadable pastes with blackberry pulp (BP) containing cream (C) or cream cheese (CC). Spreadable pastes were prepared in different ratios (1:3, 1:1, and 3:1, w/w). When the amount of blackberry pulp is greater in spreadable pastes containing cheese or cream cheese, the contents of dry matter, lipids, protein, and ash are minor, due to the composition of the blackberry pulp. The antioxidant activity was determined by ABTS [2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] and DPPH (2,2-diphenil-1-picrylhydrazyl) assays. The results indicate that when the proportion of blackberry pulp is greater in spreadable pastes, the antioxidant activity increases in a range of 43.51–44.50%, using the Trolox equivalent antioxidant capacity (TEAC) method. Spreadable pastes presented pseudoplastic non-Newtonian behavior, with n < 1. In general, the apparent viscosity was greater in spreadable pastes BP-CC than in BP-C. Spreadable pastes showed a predominance of the elastic component G′ > G″. The creep curves presented a recovery between 56.0 and 86.2% for BP-C and between 66.3 and 85.0% for BP-CC, indicating viscoelastic solid behavior. The viscoelastic behavior of pastes was adjusted by the Burgers model with a Kelvin-Voigt element. The rheological properties and antioxidant activity of spreadable pastes can increase interest in characterizing them as functional and health foods.