Alcoholic beverage from cheese whey: identification of volatile compounds

A spirit was produced from cheese whey continuous fermentation by Kluyveromyces marxianus, and the volatile compounds present in this alcoholic drink were identified. Fermentation was performed in a 1000 L reactor at 30 ºC, with initial lactose concentration and hydraulic residence time of 50 g/L and 5 h (dilution rate 0.2 h-1), respectively. The raw spirit (35.4% v/v ethanol) was obtained by distilling the fermentation broth in a pot still. Volatile compounds were quantified by gas chromatography, either by direct injection (with flame ionization detector) or after dichloromethane extraction (coupled with mass spectrometry). Higher alcohols were quantitatively the most abundant group of volatile compounds in this drink, with isoamyl alcohol, isobutanol, and 1-propanol being the most abundant (886.6 mg/L, 542.1 mg/L and 266 mg/L, respectively). Among the total esters, ethyl acetate showed the highest concentration (138.2 mg/L). Other components, such as the terpenes linalool, α-terpineol and geraniol were also identified. Considering that the quality of an alcoholic drink can be evaluated by the ratio between isoamyl alcohol/2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it can be concluded that a novel spirit of acceptable organoleptic character could be produced by whey fermentation with K. marxianus

Total reuse of brewer’s spent grain in chemical and biotechnological processes for the production of added-value compounds

Brewer’s spent grain was fractionated by means of three different procedures: dilute acid hydrolysis, for the hemicellulose recovery; alkaline hydrolysis, for the lignin solubilization, and enzymatic hydrolysis, for the cellulose conversion into glucose. The best hydrolysis conditions were optimized to each case. The cellulosic and hemicellulosic hydrolysates produced under these conditions were used as fermentation medium for the production of lactic acid and xylitol, respectively. The efficiency of hemicellulose acid hydrolysis was >85% for all the evaluated conditions, but xylitol production was highest (0.70 g/g xylose) when the hydrolysate was obtained at 120 ºC, 17 min, using 1:8 g:g solid:liquid ratio, and 100 mg H2SO4/g dry matter. The best alkaline hydrolysis condition (120 ºC, 90 min, 2% w/v NaOH, 1:20 g:g solid:liquid ratio) gave a pulp constituted by 90.4% (w/w) cellulose, and a liquor containing several phenolic acids, mainly ferulic and p-coumaric. In the optimum condition of cellulose enzymatic hydrolysis (45 FPU/g dry matter, 100 rpm, 2% w/v substrate, 45 ºC, 96 h), cellulose was converted into glucose with 93.1% efficiency, and lactic acid was produced with high yield (0.98 g/g glucose) from this hydrolysate

Fructooligosaccharides production using immobilized cells of Aspergillus japonicus

The fructooligosaccharides (FOS) production using immobilized cells of the fungus Aspergillus japonicus ATCC 20236 was evaluated. Polyurethane foam, stainless steel sponge, vegetal fiber sponge, pumice stones, zeolites and cork were tested as immobilization carrier during the fermentation under submerged conditions. Experiments were carried out in 500 ml Erlenmeyer flasks containing 1 g of carrier and 100 ml of sucrose medium (165 g/l) enriched with nutrient sources. The flasks were agitated in an orbital shaker at 160 rpm, 28°C, for 48 h. Samples were withdrawn during the fermentation to determine the consumption of sucrose, liberation of glucose and fructose to the medium, production of FOS (1-kestose (GF2), 1-nystose (GF3) and 1-β-fructofuranosyl nystose (GF4)) and enzymatic activity of β-fructofuranosidase. At the fermentation end, the cell mass adhered to the carrier was quantified. The microorganism adhesion to the carrier varied to each tested material. Consequently, the FOS production and enzymatic activity also varied to each medium, due to the differences in the amount of free and immobilized cells present. The highest values of immobilized cells, FOS production and enzymatic activity were achieved by using vegetal fiber sponge as immobilization carrier, while cork gave the worst results.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/38212/2007

Characterisation of volatile compounds in an alcoholic beverage produced by whey fermentation

An alcoholic beverage (35.4% v/v ethanol) was produced by distillation of the fermented broth obtained by continuous whey fermentation with a lactose-fermenting yeast Kluyveromyces marxianus. Forty volatile compounds were identified in this drink by gas chromatography. Higher alcohols were the most abundant group of volatile compounds present, with isoamyl, isobutyl, 1-propanol, and isopentyl alcohols being found in highest quantities (887, 542, 266, and 176 mg/l, respectively). Ethyl acetate had the highest concentration (138 mg/l) among the esters. Besides higher alcohols and esters, other components, including aldehydes, acids and terpenes were also identified in the whey spirit. Considering that the quality of an alcoholic beverage can be evaluated by the relation between isoamyl alcohol/2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it was concluded that a novel spirit of acceptable organoleptic characteristics can be produced by cheese whey continuous fermentation with K. marxianus

Influence of temperature on continuous high gravity brewing with yeasts immobilized on spent grains

Flavor compounds’ formation and fermentative parameters of continuous high gravity brewing with yeasts immobilized on spent grains were evaluated at three different temperatures (7, 10 and 15 °C). The assays were performed in a bubble column reactor at constant dilution rate (0.05 h−1) and total gas flow rate (240 ml/min of CO2 and 10 ml/min of air), with high-gravity all-malt wort (15°Plato). The results revealed that as the fermentation temperature was increased from 7 to 15 °C, the apparent and real degrees of fermentation, rate of extract consumption, ethanol volumetric productivity and consumption of free amino nitrogen (FAN) increased. In addition, beer produced at 15 °C presented a higher alcohols to esters ratio (2.2–2.4:1) similar to the optimum values described in the literature. It was thus concluded that primary high-gravity (15°Plato) all-malt wort fermentation by continuous process with yeasts immobilized on spent grains, can be carried out with a good performance at 15 °C.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Elaboration of distilled beverage from spent coffee ground

Spent coffee ground (SCG) is the solid residue obtained from the treatment of coffee powder with hot water to prepare instant coffee, and constitutes the main coffee industry residue. Finding alternatives for the reuse of this residue is of great interest from economical and environmental viewpoints. The goal of the present study was to use this residue as raw material for the production of a new distilled beverage. The process for elaboration of this beverage consisted in an initial extraction of the aromatic compounds from SCG with water, followed by the fermentation of this extract in a bench bioreactor and subsequently distillation of the fermented broth. The produced drink contained 40% v/v ethanol, and presented mild coffee flavor. Several volatile compounds were identified in this distillate among of which, higher alcohols were quantitatively the most abundant group. Isoamyl alcohol (3-methyl-1-butanol), isobutanol (2-methyl-1-propanol), and 2-methyl-1- butanol were the higher alcohols found in major quantities (810, 269, and 185 mg/l, respectively), contributing thus for the greatest proportion of the total aroma and essential character. Ethyl acetate and acetaldehyde, which are also volatile compounds of large influence on the flavor of alcoholic beverages, were found in SCG distillate in concentrations of 38 mg/l and 80 mg/l, respectively. On the other hand, methanol that is a compound harmful to the health was found at low level (11 mg/l). Considering the flavor, the volatile compounds present, and the ratio between isoamyl alcohol/2- methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which are indicative of the quality of alcoholic beverages and have to be higher than unity, it was concluded that a novel spirit of acceptable organoleptic character can be produced by fermentation using SCG as raw material.(undefined)info:eu-repo/semantics/publishedVersio

Optimal fermentation conditions for maximizing the ethanol production by Kluyveromyces fragilisfrom cheese whey powder

Cheese whey powder (CWP) is an attractive raw material for ethanol production since it is a dried and concentrated form of CW and contains lactose in addition to nitrogen, phosphate and other essential nutrients. In the present work, deproteinized CWP was utilized as fermentation medium for ethanol production by Kluyveromyces fragilis. The individual and combined effects of initial lactose concentration (50-150 kg m-3), temperature (25-35 ºC) and inoculum concentration (1-3 kg m-3) were investigated through a 23 full factorial central composite design, and the optimal conditions for maximizing the ethanol production were determined. According to the statistical analysis, in the studied range of values, only the initial lactose concentration had a significant effect on ethanol production, resulting in higher product formation as the initial substrate concentration was increased. Assays with initial lactose concentration varying from 150 to 250 kg m-3 were thus performed and revealed that the use of 200 kg m-3 initial lactose concentration, inoculum concentration of 1 kg m-3 and temperature of 35 ºC were the best conditions for maximizing the ethanol production from CWP solution. Under these conditions, 80.95 kg m-3 of ethanol was obtained after 44 h of fermentation.The authors acknowledge the financial support from "CAPES/Grices (BEX2150/07-7) and Lactogal for supplying cheese whey powder

Optimization of ethanol production from cheese whey powder by Kluyveromyces fragilis using factorial design and response surface methodology

The individual and combined effects of initial lactose concentration, temperature and inoculum concentration on ethanol production from cheese whey powder by Kluyveromyces fragilis were investigated. A 2 3 full-factorial central composite design (CCD) and response surface methodology (RSM) were employed in order to determine the optima conditions that maximize the ethanol production. Statistical analysis of results showed that, in the range studied, only the initial lactose concentration had a significant effect on ethanol production. Response surface data showed maximum ethanol production at inoculum concentration between 1 and 3 g/L and temperature between 25 and 35ºC when the initial lactose concentration was 150 g/L.CAPES/Grices - BEX2150/07-7