Cocoa fermentation: Microbial identification by MALDI-TOF MS, and sensory evaluation of produced chocolate

Dynamic microbial over the cocoa fermentation using starter culture and the effect sensory characteristics of chocolate produced were investigated. The cocoa fermentation inoculated with Saccharomyces cerevisiae CCMA0681 and Lactobacillus fermentum UFLA CHBB 8.12 as starter cultures were assessed, and compared with spontaneous fermentation. The microbial succession was identified using polyphasic approach including classical morphological and biochemical assays, and Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF). Overall 873 colonies were isolated, 445 (51%) strains were isolated from the spontaneous fermentation, while 428 (49%) strains were isolated from the inoculated fermentation. The dominant yeast in both fermentation processes were S. cerevisiae and Candida magnolia. L. fermentum and Pediococcus acidilactici were detected in both fermentations, whereas L. coryniformis, L. curvatus, L. mali, L. plantarum, and L. sakei were isolated from the spontaneous fermentation only. Acinetobacter sp., Gluconobacter oxydans, and Acetobacter pasteurianus were isolated from both the fermentation processes. Chocolate produced from the spontaneous fermentative process presented dominance of the bitter flavour, while obtained through inoculated fermentation process presented bitter, astringent and acid as dominant flavours. Cocoa inoculation with S. cerevisiae and L. fermentum affected the sensory quality of the produced chocolate. The microbial inoculation influenced on fermentation and therefore the final product.The authors thank the following Brazilian agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico of Brasil (CNPQ), Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for scholarships, and Fazendas Reunidas Vale do Juliana (Igrapiúna, Bahia, Brazil) for sample collection

Physico-chemical and microbiological characterization of corn and rice ‘calugi’ produced by Brazilian Amerindian people

Abstract‘Calugi’ is a fermented porridge that is produced from corn and rice by Javaé Amerindians. Samples of this porridge were chemically and microbiologically characterized. The microbial population was composed of yeasts, aerobic mesophilic bacteria (AMB), lactic acid bacteria (LAB), acetic acid bacteria (AAB) and some enterobacteria. The population of lactic acid bacteria (LAB), acetic acid bacteria (AAB) and yeasts increased slightly during ‘calugi’ fermentation. During the initial fermentation period (12 and 24h), counts of the bacterial population (LAB, AMB and enterobacteria) and yeast increased. After 48h of fermentation, the population of mesophilic bacteria was 5.06logCFU/mL; lactic acid bacteria (LAB), 4.69logCFU/mL; yeast, 4.37logCFU/mL; enterobacteria, 3.29logCFU/mL and acid acetic bacteria (AAB), 3.14logCFU/mL. During the fermentation process, Lactobacillus plantarum, Streptococcus salivarius, Streptococcus parasanguis, Weissella confusa, Enterobacter cloacae, Bacillus cereus and Bacillus sp. and the yeasts Saccharomyces cerevisiae, Pichia fermentans and Candida sp. were detected by PCR-DGGE. The LAB were dominant during the process and were likely most responsible for the reduction in pH value, which permitted yeast growth. Carbohydrates (70.48g/L — maltose), alcohols (1.70g/L — glycerol) and acids (4.56g/L — acid lactic) were identified by HPLC. Fifteen volatile compounds were identified and quantified by GC-FID. From the fermentation, acetaldehyde, 1-1-diethoxyethane, isobutyl acetate, ethyl acetate, furfuryl alcohol and nonanoic acid were identified, with maximum concentrations of 457.02μg/L, 73.96μg/L, 54.03μg/L, 24.82μg/L, 755.82μg/L, 61.85μg/L, respectively