Evaluation of chemical changes during Myrciaria cauliflora (jabuticaba fruit) fermentation by ¹H NMR spectroscopy and chemometric analyses

Abstract

Ácidos orgânicos, açúcares, álcoois, compostos fenólicos, propriedades de cor, pH e acidez titulável foram monitorados durante fermentação comercial de jabuticaba (Myrciaria cauliflora) através da espectroscopia de ressonância magnética nuclear (NMR) de 1 H, ensaios espectrofotométricos e métodos usuais de análise. Os dados coletados foram analisados por meio de análise de componentes principais (PCA), agrupamentos (HCA) e correlação canônica (CCA). Dois grupos de amostras foram reconhecidos, e as variáveis responsáveis pela separação foram açúcares, antocianinas, álcoois, tonalidade e ácidos acéticos e succínico. A análise de correlação canônica confirmou a influência dos álcoois (etanol, metanol e glicerol), ácidos orgânicos (ácidos cítrico, acético e succínico), pH e acidez titulável na extração e estabilidade das antocianinas e copigmentos. Consequentemente, as propriedades de cor também foram afetadas pelas variações nos níveis de compostos fenólicos durante o processo de fermentação.Organic acids, sugars, alcohols, phenolic compounds, color properties, pH and titratable acidity were monitored during the commercial fermentation of jabuticaba (Myrciaria cauliflora) by 1 H nuclear magnetic resonance (NMR) spectroscopy, spectrophotometric assays and standard methods of analysis. Data collected was analyzed by principal component (PCA), hierarchical cluster (HCA) and canonical correlation (CCA) analyses. Two sample groups were distinguished and the variables responsible for separation were sugars, anthocyanins, alcohols, hue and acetic and succinic acids. The canonical correlation analysis confirmed the influence of alcohols (ethanol, methanol and glycerol), organic acids (citric, succinic and acetic acids), pH and titratable acidity on the extraction and stability of anthocyanins and copigments. As a result, color properties were also affected by phenolic variation throughout the fermentative process.Keywords: jabuticaba, phenolic compounds, sugars, organic acids, NMR, chemometrics Introduction Jabuticaba (Myrciaria cauliflora Berg.) is a Brazilian fruit that bears an edible purplish-black sweet fruit. It has a slightly acid taste and is rich in phenolic compounds, such as anthocyanins, flavonoids, tannins and depsides, which are responsible for antioxidant and anti-inflammatory activities, as well as for colon cancer cell cytotoxicity. 1 High sugar content of jabuticaba makes it suitable for jam, juice, liqueur and wine production. 2 Wines made from jabuticaba have shown great acceptance in sensory analysis and a higher antioxidant activity than grape wines in a β-carotene/linoleic acid system. 3,4 Several fruit wines have been made from Brazilian tropical fruits such as cashew, 5 cacao, gabiroba, umbu and cupuaçu. 3 Such industrial processing is an alternative to prevent post-harvesting losses and to promote exotic fruit production, allowing a more rational use of Cerrado and Amazonian biomes (Brazil). Like most beverages, fruit wines not only have to be in accordance with the current legislation but also ac...

Vinegar rice (Oryza sativa L.) produced by a submerged fermentation process from alcoholic fermented rice

“…Bortolini et al (2001) obtained an oxidation time for ethanol from kiwi acetic acid of 12 h in a submerged process and 24 h for a generator process. Nanba et al (1985) optimized the fermentation should not exceed 0.2 g/100 mL, and methanol should not be present at levels greater than 0.035 g/100 mL (Fortes et al, 2012;Reddy et al, 2008). These compounds have an inhibitory effect on acetic acid fermentation.…”

Fermentation Kinetics of Rice Syrup, with High Content of Dextrose Equivalent, bySaccharomyces cerevisiaeand Characterization of Volatile Compounds from Wine

“…Rice wine showed a glycerol concentration of 6.50 g/L. Low values for glycerol in the range of 3.27-3.88 g/kg for fermented jabuticaba were also reported by Fortes et al (2012).…”

“…Low values for glycerol in the range of 3.27–3.88 g/kg for fermented jabuticaba were also reported by Fortes et al . ().…”

“…Fortes et al . () report glycerol is among one of the major volatile compounds of wine responsible for the soft and sweet taste characteristic of the drink, and it must be present in limits between 7.0 and 9.0 g/L. Rice wine showed a glycerol concentration of 6.50 g/L.…”

“…Total concentration of the superior alcohols (n-propanol, n-butanol, iso-amylic alcohols, iso-butanol and glycerol) were 6.877 g/ L, being glycerol responsible for 94.5% of the superior alcohols. Fortes et al (2012) report glycerol is among one of the major volatile compounds of wine responsible for the soft and sweet taste characteristic of the drink, and it must be present in limits between 7.0 and 9.0 g/L. Rice wine showed a glycerol concentration of 6.50 g/L.…”