Production of high FFA Jatropa curcas oil biodiesel using oscillatory flow reactor

Jatropa Curcas is one of the most feasible sources for biodiesel feedstock. Some advantages of Jatropa curcas oil are non edible, growing in arid soil, and high oil yield from their seed, while it’s disadvantage is tend to oxidized and form high Free Fatty Acid (FFA) due to the oil composition. Oscillatory Flow Reactor is useful when reaction should performed for a long time in a turbulence flow, the other advantage is OFR have a compact size because substantially smaller length to diameter ratios than conventional tubular reactor. Two step reaction was performed for biodiesel production from High FFA Oil, first reducing FFA by esterification process catalized by H2SO4 and the second is transesterification process catalized by KOH. Initial FFA on Jatropa Curcas Oil is 47%, the first step was performed in Stirred Tank Reactor for 90 minute, 60oC, etanol 50% v/v and H2SO4 1,5% v/v stirring on a speed 500 rpm 99% of the FFA was converted on this step while the second step was performed in Oscillatory Flow Reactor for 60 minute at 600C, ethanol 25% v/v, Sodium Metoxide 1% v/v, 91% of the oil was converted on this step. It is concluded that OFR is sufficient enough for biodiesel production using High FFA Jatropa Curcas Oil as feedstock

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

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

Determination of sulfur compounds in fermented raspberry beverages by GC-PFPD

Volatile sulfur compounds are known to have very powerful and characteristic odours, and can contribute to pleasant or unpleasant aromas of a wine, according to their nature and concentration. Their concentration has a great influence on sensory properties, often being strongly dependent on threshold values, normally low. The determination of sulfur compounds, eluted in a chromatographic column, has been performed using mainly flame photometric detection (FPD), sulfur chemiluminescence detection (SCD), atomic emission detection (AED) and more recently, pulsed flame photometric detection (PFPD). The objective of this study was to determine the sulfur compounds in a fermented raspberry beverage using GC-PFPD. The analyses were made on a Varian CP-3800 gas chromatography equipped with a PFPD detector operating in sulfur mode. Aromatic extracts, obtained by liquid-liquid extraction with dichloromethane, were injected into a 1079 split/splitless injector (splitless for 30 s). The separation was performed with a CP-Wax 52 CB column (50 m x 0.25 mm i.d., 0.2 m film thickness; Chrompack). The oven temperature was programmed from 60 oC (5 min) to 200 oC, at 20 oC/min (final hold for 5 min). The carrier gas was helium with a constant flow rate of 1.2 mL/min. The temperature of the injector and detector was set to 250 oC. The detector voltage was 570 V, the gate delay for sulfur compounds was 6 ms and the gate width was 20 ms. All sulfur compounds were identified by comparing their retention times with those of the pure standards. Raspberry pulp was diluted with water (1:1), sucrose was added to adjust the initial sugar concentration to 160 g/L (sucrose + glucose + fructose) and the pH was corrected to 4 with CaCO3. Batch fermentations (3 L of raspberry must) were carried out at 22 ºC in a bioreactor, after inoculation with 1 g/L of Saccharomyces cerevisiae CAT-1 previously grown in YPD medium. In fermented raspberry beverage were identified and quantified 7 sulfur volatile compounds: furfuryl mercaptan (16.9 g/L), 2-mercaptoethanol (4.7 g/L), 2-(methylthio)ethanol (158.1 g/L), 3-mercapto-3-methylbut-1-ol (4.0 g/L), 3-methylthio-1-propanol (128.9 g/L), 4-mercapto-1-hexanol (1.5 g/L) and benzothialoze (5.7 g/L). The highest concentrations were found for 2-(methylthio)ethanol and methionol (3-methylthio-1-propanol). Methionol, with cauliflower and cabbage descriptors, can be related to the metabolism of yeasts, when methionine is metabolized. It was concluded that liquid-liquid microextraction with dichloromethane followed by GC-PFPD analysis is effective to quantify volatile sulfur compounds produced in fermented raspberry beverages. As expected, the PFPD detector exhibited a quadratic behavior for these compounds

Kinetics of fermentation of different Saccharomyces cerevisiae in raspberry must

In modern viniculture selected yeast has been used preferably to ensure a final product with desired quality. These yeasts are selected based on certain desirable characteristics such as resistance to high concentrations of sugars. Yeasts strains used for fruit wine production have to adapt to different sugar composition and concentrations, presence of organic acids, pectin and other components present in the fruit pulp. The objective of this study was to evaluate the performance of different Saccharomyces cerevisiae strains during alcoholic fermentation of raspberry (Rubus idaeus) must. Fermentation parameters such as ethanol yield, productivity and maximum specific rate of cell growth are considered to be essential for good performance in a fermentation process. Raspberry pulp was diluted with a sucrose solution to adjust the sugar concentration to 16° Brix. CaCO3 was added to increase the pH value to 4.0. Batch fermentations were carried out at 22ºC in Erlenmeyer flasks containing 100 ml of raspberry must. The max (h-1) found were 0.08, 0.09 and 0.12 for yeast UFLA CA1162, UFLACA11 and UFLACA15, respectively. The higher yield of ethanol (Yp/s) was 0.48 g/g for yeast UFLA CA15, while the other yeasts showed a an Yp/s of 0.41 g/g. The values found for the biomass yield (Yx/s) were 0.06, 0.07 and 0.08 g/g for yeasts UFLA CA11, UFLA CA1162 and UFLA CA15, respectively. The highest ethanol productivity was found 1.45 g/l.h for yeast UFLA CA15. It was concluded that raspberry must can be fermented by the different S. cerevisiae strains used in this study and based on the kinetic parameters, the yeast UFLA CA15 showed the best fermentation performance in comparison with yeasts UFLA CA11 and UFLA CA1162 in the fermentation of the raspberry pulp

Profile of higher alcohols in fruit wines produced by different Saccharomyces cerevisiae

Higher alcohols are secondary yeast metabolites, and can have both positive and negative impacts on the aroma and flavour of wine. Concentrations lower than 300 mg/l of higher alcohols contribute to the aroma, while concentrations above 400 mg/l negatively influence the wine quality. The formation of these compounds is influenced by several factors like temperature, presence of nitrogen compounds and the type of yeasts used for the fermentation. The aim of this study was to evaluate the profile of higher alcohols in alcoholic beverage produced from the fermentation of raspberry must by different yeast. The pH of the must was adjusted to 4.0 by the addition of CaCO3 and the initial sugar concentration to 16 Brix (adjusted with sucrose syrup). Batch fermentations were carried out at 22º C. Higher alcohols were determined by gas chromatography (GC­FID). Five higher alcohols (1­propanol, 2­methyl­1­propanol, 2­methyl­1­butano, 3­methyl­1­butanol and 2­phenylethanol) were identified and quantified. 3­methyl­1­butanol was the alcohol found in highest quantity. The highest concentrations were 140.9 and 149.4 mg/l for the yeast UFLA CA1162 and UFLA CA15, respctively. The beverage produced by the yeast UFLA CA155 showed the highest concentration of 2­phenylethanol (29.1 mg/l). 1­propanol was found in similar values (21 mg/l) in raspberry wine fermented by the yeast UFLA CA11 and UFLA CA1174. The highest and lowest total concentrations of higher alcohols were 284.5 and 161.8 mg/l for the beverage produced by the yeast UFLA CA1162 and UFLA CA11, respectively. It can be concluded that raspberry wine with a total higher alcohol concentration similar to that considered desirable (300 mg/l) in alcoholic beverages can be produced by using the yeast UFLA CA1162

Comparative analyze of the kefir fermentation process and microbiota, using milk and cheese whey as substrates

Kefir, a mixed culture that ferments lactose, is known for the production of a refreshing fermented beverage popular in EasternEuropean countries by inoculating milk with kefir grains. Kefir grains are gelatinous white or creamcoloured, water insoluble, irregular granules with diameter ranging 0,33,5 cm. They are composed mostly of proteins and polysaccharides in which the complex microbiota is enclosed. The beverage consists of a microbial diversity that includes lactic acid bacteria, yeasts and their metabolites. The aim of this work was to compare the fermentation and the microbiota of kefir , using milk and cheese whey as substrates. The grains were added in the proportion of 5% in 250ml of each substrate. Assays were performed at 25 °C for 48h. The concentrations of lactose, ethanol, lactic acid and acetic acid were quantified by HPLC. To determinate the composition of microbiota in Kefir of fermentation, PCRDGGE analysis was used.The fermentation of milk and cheese whey by kefir grains are observed in this study. It can be observed that the lactose concentration at the end of the milk fermentation was lower in comparison with that obtained at 48 h for cheese whey fermentation. Despite the higher lactose consumption during the fermentation of milk by kefir grains, the concentrations of ethanol, acetic acid and lactic acid did not show significant differences with those obtained during the cheese whey fermentation. No changes in the DGGE profiles in all fermentations were observed to fungal and bacterial communities. It was thus concluded that lactose from cheese whey is converted to products with higher yields than lactose from milk, in addition to showing the same group of microorganisms for both fermentation process

Avaliação do perfil de metabolitos produzidos por diferentes leveduras utilizadas na produção de vinho de frutas

O aroma das bebidas alcoólicas fermentadas resulta da interação de compostos químicos como alcoóis,ésteres, ácidos, aldeídos e cetonas. Estes compostos são produzidos durante a fermentação,principalmente pelas leveduras e bactérias, ou podem estar presentes em pequenas quantidades nas frutas. Os compostos voláteis orgânicos são responsáveis pelo chamado bouquet, aroma e características gerais das bebidas. Durante a fermentação as leveduras podem produzir vários compostos em quantidades diferenciadas, podendo em algumas situações ocorrer a produção de compostos indesejáveis ou a produção de compostos desejáveis em quantidade excessiva. O objetivo deste trabalho foi avaliar a produção de metabolitos (alcoóis, aldeídos, ésteres e ácidos orgânicos) por diferentes leveduras utilizadas na produção de vinhos de frutas. Foi utilizado mosto de framboesa com 16º Brix e pH 4,0. A fermentação foi realizada em frascos contendo 100 mL, nos quais foram inoculados 1 g/L de diferentes leveduras Saccharomyces. Após o término da fermentação os compostos presentes nas bebidas foram analisados por cromatografia gasosa (GC) e cromatografia líquida (HPLC). As leveduras com melhores resultados para produção de compostos voláteis foram a UFLA CA 15, S. bayanus CBS 1505 e CAT-1. Para alcoóis superiores (1-propanol, 2-metil-1- propanol, 2-metil-1-butanol, 3-metil-1-butanol e 2-feniletanol), as concentrações encontradas foram 260, 4 mg/L, 277,6 mg/L e 282,8 mg/L para as leveduras S. bayanus CBS 1505, UFLA CA 15 e CAT-1, respectivamente. Para a levedura VR-1, apesar da alta concentração de alcoóis superiores, foram encontradas elevadas concentrações de ácido acético (2,2 g/L) e metanol (83 mg/L). A presença de elevadas concentrações destes dois compostos é indesejada, pois o ácido acético está diretamente relacionado com a acidez da bebida e o metanol é um composto tóxico. Além do teor desejável de alcoóis superiores, as bebidas produzidas com as leveduras UFLA CA 15, S. bayanus CBS 1505 e CAT-1 apresentaram baixas concentrações de ácido acético e metanol

Profile of sugars comsumption in fruit wines produced by different Saccharomyces cerevisiae

In wine fermentation, the two main soluble sugars present in must (glucose and fructose) are fermented to ethanol, CO2 and other compounds. Wine yeasts have a slight preference for glucose compared to fructose resulting in a difference between glucose and fructose consumption. Fructose is approximately twice as sweet as glucose and its presence as a residual sugar has a much stronger effect on the final sweetness of wine. The objective of this study was to evaluate the profile of sugars consumption by different yeasts during fruit wines production. Different Saccharomyces cerevisiae were used in the fermentation of raspberry must with 16 ºBrix and pH adjusted to 4.0. Batch fermentations were carried out at 22ºC. The concentrations of sucrose, glucose and fructose were determined by HPLC. The total conversion of sucrose into glucose and fructose by yeast UFLA CA11 was the fastest, within the first 8 h of fermentation, while for the yeast UFLA CA1174 the total hydrolysis of sucrose occurred after 32 h of fermentation. For the yeasts UFLA CA15 and UFLA EU 60.1, the sucrose hydrolysis occurred after 12 and 16 h, respectively. As expected, for all yeasts, was confirmed a preferential and fast consumption of glucose in comparison to the consumption of fructose. The highest residual concentrations of glucose and fructose were respectively, 300 and 920 mg/l for yeast UFLA CA11 and 400 and 2100 mg/l for yeast UFLA CA1174. Based on the concentrations of ethanol and residual sugar, the best efficiency of conversion was 93.88% for the yeast UFLA CA15. The other yeasts showed an efficiency of 75.56% (UFLA EU 60.1), 82.08% (UFLA CA11) and 83.69% (UFLA CA1174). It can be concluded that the evaluated yeasts were able to ferment the main sugars present in raspberry must. The yeast UFLA CA15 showed the best performance with higher conversion efficiency, rapid hydrolysis of sucrose and low concentration of residual sugars at the end of fermentation