Characterisation of a new exopolysaccharide obtained from of fermented kefir grains in soymilk.
Microbial exopolysaccharides (EPSs) have been widely studied in recent decades due to similarity to gums used in the food industry. Exopolysaccharides can be used in food processing as a thickener and/or stabiliser. This study aimed to investigate the physicochemical properties, thermal behaviour and structural composition of the lyophilised EPS obtained from the fermentation of kefir grains in soymilk. The EPS in concentration 18 mg/mL exhibited water activity of 0.204 and pH=6.20 at 25°C, reducing sugars content of 22.10% (v/v) and protein content of 2% (v/v). The thermogravimetric curve obtained was similar to those reported in the literature for other EPSs. The degradation temperature was 351.84°C and showed that the EPS in this study had a high thermal stability. Characteristic polysaccharide bands were observed in the infrared spectrum. The analysis by liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI-MS) showed that the EPS is only composed of glucose.
Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N, Dois Irmãos, Recife CEP: 52171-900, Brazil.
Priscilla S
PS
Botelho
Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N, Dois Irmãos, Recife CEP: 52171-900, Brazil. Electronic address: m.inesdcd@gmail.com.
Maria I S
MI
Maciel
Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N, Dois Irmãos, Recife CEP: 52171-900, Brazil.
Luciano A
LA
Bueno
BioLogicus-Ind. e Com. de Produtos Naturais S.A., Av. Prof. Luiz Freire, 700, Cidade Universitária, Recife CEP: 50740-540, Brazil.
Maria de Fátima F
Mde F
Marques
BioLogicus-Ind. e Com. de Produtos Naturais S.A., Av. Prof. Luiz Freire, 700, Cidade Universitária, Recife CEP: 50740-540, Brazil.
Djalma N
DN
Marques
Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, S/N, Dois Irmãos, Recife CEP: 52171-900, Brazil.
Tania M
TM
Sarmento Silva
D055598:Chemical Phenomena; D005285:Fermentation; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D041942:Soy Milk / Q000737:chemistry*
D011135:Polysaccharides, Bacterial
Microbial polysaccharides; Structural characterisation; Thermal analysis