Use of Selected Lactic Acid Bacteria and Quinoa Flour for Manufacturing Novel Yogurt-Like Beverages

Abstract

This study aimed at investigating the suitability of quinoa for making yogurt-like beverages. After the selection of the adequate technological parameters, the fermentation was carried out by using different lactic acid bacteria strains: a probiotic (Lactobacillus rhamnosus SP1), an exopolysaccharides (EPS)-producing (Weissella confusa DSM 20194), and one isolated from quinoa (Lactobacillus plantarum T6B10). During the 20 h of fermentation, W. confusa caused the highest viscosity increase. All the strains had improved concentration of free amino acids and γ-Aminobutyric acid (GABA), polyphenols availability, antioxidant activity (up to 54%), and protein digestibility. The nutritional index (NI) was the highest when L. rhamnosus SP1 was used. The starch hydrolysis index in vitro ranged from 52 to 60. During storage at 4 °C, viscosity and water holding capacity decreased with the exception of the beverage fermented with W. confusa, while all the nutritional characteristics remained stable or slightly increased. Sensory analyses showed that beverages had good textural and organoleptic profiles. Besides the well-known positive properties of the raw matrix, fermentation allowed the obtainment of beverages with different features. Due to the nutritional and functional characteristics conferred to the quinoa beverages, the use of the probiotic and EPS-producing strains showed adequate potential for the industrial application.

Keywords: Lactobacillus plantarum; Lactobacillus rhamnosus; beverage; fermentation; lactic acid bacteria; quinoa; yogurt-like.

Figure 1

Concentration of free amino acids and their derivatives (mg/kg) of the quinoa beverages B-SP1 and B-T6B10 (containing 35%, wt/wt of quinoa flour in water), inoculated respectively with L. rhamnosus SP1 and L. plantarum T6B10, and B-20194 (containing 25% wt/wt of quinoa flour and 10% wt/wt of sucrose), inoculated with W. confusa DSM 20194, fermented at 30 °C for 20 h, before (A), and after storage at 4 °C for 20 days (B). Data are the means of three independent analyses. Three-letters amino acid code (IUPAC) is used. ^a–c Values with different superscript letters within the same amino acid, differ significantly. The error bars indicate standard deviation.

Figure 2

pH (A), viscosity (B), and water holding capacity (C) of the quinoa beverages B-SP1 and B-T6B10 (containing 35%, wt/wt of quinoa flour in water), inoculated respectively with L. rhamnosus SP1 and L. plantarum T6B10, and B-20194 (containing 25% wt/wt of quinoa flour and 10% wt/wt of sucrose), inoculated with W. confusa DSM 20194 determined before (Ti) and after fermentation at 30 °C for 20 h (Tf), and after 20 days of storage at 4 °C (T20). ^a–c Values with different superscript letters, differ significantly. The error bars indicate standard deviation.

Figure 3

Sensory analysis of the quinoa beverages B-SP1 and B-T6B10 (containing 35%, wt/wt of quinoa flour in water), inoculated respectively with L. rhamnosus SP1 and L. plantarum T6B10, and B-20194 (containing 25% wt/wt of quinoa flour and 10% wt/wt of sucrose), inoculated with W. confusa DSM 20194, fermented at 30 °C for 20 h, before (A), and after storage at 4 °C for 20 days (B). The abbreviations used for sensory attributes are reported in Table 1.

Figure 3

Sensory analysis of the quinoa beverages B-SP1 and B-T6B10 (containing 35%, wt/wt of quinoa flour in water), inoculated respectively with L. rhamnosus SP1 and L. plantarum T6B10, and B-20194 (containing 25% wt/wt of quinoa flour and 10% wt/wt of sucrose), inoculated with W. confusa DSM 20194, fermented at 30 °C for 20 h, before (A), and after storage at 4 °C for 20 days (B). The abbreviations used for sensory attributes are reported in Table 1.