Selection of starter cultures for the production of sour cassava starch in a pilot-scale fermentation process

ABSTRACT Sour cassava starch (Polvilho azedo) is obtained from a spontaneous fermentation conducted by microorganisms from raw materials and fermentation tanks. This product is traditionally used in the baking industry for the manufacture of biscuits and Brazilian cheese breads. However, the end of fermentation is evaluated empirically, and the process occurs without standardization, which results in products of inconsistent quality. Predominant microbiota from a cassava flour manufacturer was isolated in order to select starter cultures for the production of sour cassava starch in a pilot-scale fermentation process. Lactic acid bacteria and yeasts were isolated, enumerated and grouped by Restriction Fragment Length Polymorphism, and PCR fingerprinting, respectively. One isolate of each molecular profile was identified by sequencing of the rRNA gene. LAB were prevalent throughout the entire process. Lactobacillus brevis (21.5%), which produced the highest values of acidity, and Lactobacillus plantarum (13.9%) were among the most frequent species. Pichia scutulata (52.2%) was the prevalent yeast and showed amylolytic activity. The aforementioned species were tested as single and mixed starter cultures in a pilot-scale fermentation process for 28 days. L. plantarum exhibited better performance as a starter culture, which suggests its potential for the production of sour cassava starch.

Selection of starter cultures for the production of sour cassava starch in a pilot-scale fermentation process.

Sour cassava starch (Polvilho azedo) is obtained from a spontaneous fermentation conducted by microorganisms from raw materials and fermentation tanks. This product is traditionally used in the baking industry for the manufacture of biscuits and Brazilian cheese breads. However, the end of fermentation is evaluated empirically, and the process occurs without standardization, which results in products of inconsistent quality. Predominant microbiota from a cassava flour manufacturer was isolated in order to select starter cultures for the production of sour cassava starch in a pilot-scale fermentation process. Lactic acid bacteria and yeasts were isolated, enumerated and grouped by Restriction Fragment Length Polymorphism, and PCR fingerprinting, respectively. One isolate of each molecular profile was identified by sequencing of the rRNA gene. LAB were prevalent throughout the entire process. Lactobacillus brevis (21.5%), which produced the highest values of acidity, and Lactobacillus plantarum (13.9%) were among the most frequent species. Pichia scutulata (52.2%) was the prevalent yeast and showed amylolytic activity. The aforementioned species were tested as single and mixed starter cultures in a pilot-scale fermentation process for 28 days. L. plantarum exhibited better performance as a starter culture, which suggests its potential for the production of sour cassava starch.

Identification of aroma-active volatiles in banana Terra spirit using multidimensional gas chromatography with simultaneous mass spectrometry and olfactometry detection.

Fruit spirits have been produced and consumed throughout the world for centuries. However, the aroma composition of banana spirits is still poorly characterised. We have investigated the aroma-impact compounds of the banana Terra spirit for the first time, using multidimensional gas chromatography (MDGC and GC × GC) in a multi-hyphenated system - i.e., coupled to flame ionisation detection (FID), mass spectrometry (MS), and olfactometry (O). Solid-phase microextraction (SPME) was used to isolate the headspace aroma compounds of the banana spirit. The detection frequency (DF) technique was applied and aroma regions, detected in the first column separation at >60% Nasal Impact Frequency (NIF), were screened as target potent odour regions in the sample. Using a polar/non-polar phase column set, the potent odour regions were further subjected to MDGC separation with simultaneous O and MS detection for correlation of the aroma perception with MS data for individual resolved aroma-impact compounds. GC-O analysis enabled 18 aroma-impact regions to be located as providing volatiles of interest for further study; for example, those comprising perceptions of flower, whisky, green, amongst others. Compounds were tentatively identified through MS data matching and retention indices in both first and second dimensions. The principal volatile compounds identified in this work, which are responsible for the characteristic aroma of the banana spirit, are 3-methylbutan-1-ol, 3-methylbutan-1-ol acetate, 2-phenylethyl acetate and phenylethyl alcohol. This is the first such study to reveal the major aroma compounds that contribute to banana spirit aroma.

Efeitos sensoriais da adição de extratos de diferentes madeiras à cachaça / Sensorial effects of the addition of different wood extracts to sugar cane spirit

Para avaliar o impacto sensorial da adição de extratos de madeira à cachaça foram produzidos extratos de oito diferentes madeiras: amburana (Amburana cearensis), bálsamo (Miroxylom peruiferum), carvalho brasileiro (Panopsis organensis), carvalho europeu (Quercus alba), ipê amarelo (Tabebuia chrysostrichae), ipê roxo (Tabebuia impetiginosa), jequitibá rosa (Cariniana estrellensis) e louro-canela (Aniba parviflora). Utilizou-se cachaça diluída com água a 8 por cento v/v de etanol como solvente e 30 g de madeira. Os extratos obtidos foram diluídos 20 vezes com cachaça não-envelhicida e submetidos ao teste de aceitação com escala hedônica não-estruturada. Obtiveram destaque positivo e cachaça com extrato de bálsamo e a cachaça comercial envelhecida em ipê amarelo. As amostras com extratos de louro-canela e jequitibá rosa apresentaram destaque negativo. Tais resultados indicaram a possibilidade da utilização de extratos de madeira no aprimoramento do porcesso de envelhecimento da cachaça

Propriedades físicas do sorvete de baunilha elaborado com substitutos de gordura e sacarose / Physical properties of vanilla ice cream prepared with fat and sucrose substitutes

Sorvetes de baunilha preparados com substitutos de gordura (3-5 por cento) e de sacarose (6-10 por cento) foram comparados, mediante análises físicas e calóricas, com sorvete convencional. A combinaçäo de 4 por cento de "Simplesse" e 8 por cento de "Litesse" evidenciaram efeito sinergístico para retardar a velocidade de fusäo. Menores valores de densidade aparente e maior reduçäo calórica foram obtidos com concentraçöes próximas a 3 e 6 por cento (p/p) de "Simplesse" e "Litesse", respectivamente. Baixas concentraçöes de "Litesse" (6 por cento, p/p) e altas de "SIMPLESSE" (5 por cento p/p) resultaram em maior tempo de início de fusäo. A utilizaçäo desses substitutos permitiu a obtençäo de produtos com baixos teores calórico e de gordura e características físicas semelhantes às de sorvete convencional

Biotransformation of lapachol by Penicillium citreonigrum dierckx: characterization of Lomatiol

Testou-se a biotransformaçäo do lapachol [2-hidroxi-3-(3-metil-2-butenil)-1,4-naftoquinona] por 63 cepas de microorganismos. Com um fungo filamentoso, isolado do solo e identificado como Penicillium citreonigrum Dierckx, observou-se a formaçäo de um metabólito majoritário. Este fungo foi avaliado mais intensamente como biocatalisador para a obtençäo de quantidades suficientes de produtos tranformados para elucidaçäo estrutural. Um produto foi isolado e caracterizado como lomatiol [2-hidroxi-3-(4-hidroxi-3-metil-2-butenil)-1,4-naftoquinona], por análises espectrofotométricas(UV, IV, RMN1H e massa)