Reduction Of Acidity Research Articles

English

Soil degradation and desertification pose a major threat to agricultural production in sub-Saharan Africa. The influence of cropping systems which had been established on selected physical and chemical properties of soil were investigated in Akinyode-Okinni community in Egbedore Local Government Area (LGA) of Osun State, Nigeria. The cropping systems included agri-silviculture (SCM), silvi-pasture (SPC), agri-horti-silviculture (PAH) and agroforestry (AFT) selected from existing farms in the community. The selected plots had cocoa (Theobroma cacao), oil palm (Elais guineensis) and kola-nut (Kola nitida) as permanent crops; coco-yam (Coco nucifera), guinea grass (Panicum maximum), plantain (Musa spp), maize (Zea mays), and cassava (Manihot utilissima) were the annual crops. The experiment was carried out for two cropping seasons. Results showed that in the AFT system bulk density (BD) decreased slightly from 1.22 to 1.16 g/cm3 in the top soil and from 1.18 to 1.09 g/cm3 in the subsoil after two seasons of crop growth. The pH varied between 6.40 and 7.05 in the first season and between 7.05 and 7.29 after two seasons. On average, the topsoil contained more organic carbon (OC) in the SPC (38 g kg-1) and SCM (36 g kg-1) systems than in the PAH and AFT systems. Similarly, the total phosphorus content was higher in the topsoil of SPC and SCM systems than in the other systems. There was a slight reduction in soil acidity and no significant changes occurred in the concentrations of exchangeable bases after two cropping seasons. Conclusively, these cropping systems have the potential to reduce soil deterioration and thus, further studies to develop appropriate management strategies are necessary. Key words: Cropping systems, exchangeable bases, organic carbon, silviculture, soil degradation. &nbsp

Assessment of relevant and exchange acidity of cespitose-podsolic sandy loamy soil when the Hotynetsky field zeolite is used

The following paper considers influence extent of zeolite breed of the Hotynetsky field on indicators of relevant and exchange acidity of the cespitose-podsolic sandy loamy soil in the Nizhny Novgorod Region. A three-year experiment, representing microfield experiment, was started in 2014 in the Borsky District Elitkhoz. Zeolite was brought in the plough-layer once in high doses 3, 6 and 12 t/hectare. During the research (20152017) on allotments the main crops of the region were grown up. The acidity of the soil was estimated on рН indicators, defined from water and salt extracts which were selected during the autumn period after cultural plants harvesting. As a result of the conducted researches positive action of all doses of the studied zeolite on indicators of the acid and main mode of the cespitose-podsolic soil was established. The essential effect was traced already at the minimum dose of material: 12,0% increase of рНwater indicator and 6,3% increase of рНsalt indicator on average during the research time. Application of 6 t/hectare of zeolite breed in the greatest measure promoted reduction of the relevant acidity of the soil by 20%, exchange acidity for 13% and also for 60% to increase in an ionic exchanging of the soil solution system with preservation of the action force during the research time.

Fish Oil Enzymatic Esterification for Acidity Reduction

The reduction of the fish oil acidity is a significant problem in the rendering industry, as the oil’s range of applications and market value strongly depend on this parameter. In particular, the lower the acidity, the larger the oil’s market value. This work aims to study the potential of enzymatic esterification for reducing the fish oil acidity, by converting the free fatty acids into esters. Thus, four commercial lipases were used and a parametric study was performed to identify the best operating conditions, varying the reaction temperature, enzyme/oil mass ratio and alcohol/FFA mass ratio. All experiments were performed in duplicate with a very good reproducibility of results. Results showed that Lipozyme TL 100L contributed to greater acidity reduction (75% from an initial acid value of 10–14 mg KOH/g oil) for esterification at 40 °C, using ethanol 96% v/v, enzyme/oil and alcohol/FFA mass ratios of 0.01 and 3.24 w/w, respectively, reaching 3.13 mg KOH/g oil of final acid value or 1.57% FFA content. The reaction kinetics were also studied and it was found that a second order rate law as a function of the alcohol and oil concentrations is more adequate, with 35.44 kJ/mol of activation energy and 1.94 × 103 L mol− 1 min− 1 of pre-exponential factor. In conclusion, this work shows that the enzymatic esterification to reduce the fish oil acidity is technically feasible, increasing its market value.

Quantifying Enhancement of Metal-Supported Zeolites Due to Hydrogen Spillover

As bifunctional catalysts, metal-supported zeolites play an important role in refining and petrochemical processes, e.g. isomerisation, alkylation, etc. Reduction in acidity and acid strength of zeolites upon their impregnation with metals have been widely reported. Also hydrogen spillover vis-a-vis the closeness of two catalyst functions (acid and metal) has been discussed at length. Hydrogen spillover has been claimed to give rise to formation of additional acid sites on supports. Here quantification of acid sites for two zeolites, zeolite Y and ZSM-5, impregnated with different metals in various proportions after exposing them to hydrogen, has been attempted using ammonia temperature programmed desorption. The observed acidity values have been explained on the basis of metal cluster size.

Comparative transcriptome analysis reveals distinct ethylene\u2013independent regulation of ripening in response to low temperature in kiwifruit

BackgroundKiwifruit are classified as climacteric since exogenous ethylene (or its analogue propylene) induces rapid ripening accompanied by ethylene production under positive feedback regulation. However, most of the ripening–associated changes (Phase 1 ripening) in kiwifruit during storage and on–vine occur largely in the absence of any detectable ethylene. This ripening behavior is often attributed to basal levels of system I ethylene, although it is suggested to be modulated by low temperature.ResultsTo elucidate the mechanisms regulating Phase 1 ripening in kiwifruit, a comparative transcriptome analysis using fruit continuously exposed to propylene (at 20 °C), and during storage at 5 °C and 20 °C was conducted. Propylene exposure induced kiwifruit softening, reduction of titratable acidity (TA), increase in soluble solids content (SSC) and ethylene production within 5 days. During storage, softening and reduction of TA occurred faster in fruit at 5 °C compared to 20 °C although no endogenous ethylene production was detected. Transcriptome analysis revealed 3761 ripening–related differentially expressed genes (DEGs), of which 2742 were up–regulated by propylene while 1058 were up–regulated by low temperature. Propylene exclusively up–regulated 2112 DEGs including those associated with ethylene biosynthesis and ripening such as AcACS1, AcACO2, AcPL1, AcXET1, Acβ–GAL, AcAAT, AcERF6 and AcNAC7. Similarly, low temperature exclusively up–regulated 467 DEGS including AcACO3, AcPL2, AcPMEi, AcADH, Acβ–AMY2, AcGA2ox2, AcNAC5 and AcbZIP2 among others. A considerable number of DEGs such as AcPG, AcEXP1, AcXET2, Acβ–AMY1, AcGA2ox1, AcNAC6, AcMADS1 and AcbZIP1 were up–regulated by either propylene or low temperature. Frequent 1–MCP treatments failed to inhibit the accelerated ripening and up–regulation of associated DEGs by low temperature indicating that the changes were independent of ethylene. On–vine kiwifruit ripening proceeded in the absence of any detectable endogenous ethylene production, and coincided with increased expression of low temperature–responsive DEGs as well as the decrease in environmental temperature.ConclusionsThese results indicate that kiwifruit possess both ethylene−dependent and low temperature–modulated ripening mechanisms that are distinct and independent of each other. The current work provides a foundation for elaborating the control of these two ripening mechanisms in kiwifruit.

Caracterização físico-química de polpas de manga ‘Rosa’ liofilizadas

Objetivou-se neste estudo realizar a caracterização físico-química de polpa de manga ‘Rosa’ em pó, obtida por liofilização. Utilizou-se polpa integral e uma formulação contendo 30% de maltodextrina (agente de secagem). As amostras foram homogeneizadas e congeladas a -18ºC para posterior liofilização por um período de 72 horas. Realizou-se análises das polpas (integral e formulada) e dos pós obtidos quanto aos parâmetros de umidade, atividade de água, sólidos solúveis totais, pH, acidez total titulável, ácido ascórbico e cor instrumental. Verificou-se que a adição do agente carreador alterou as características da polpa com diminuição da umidade, atividade de água, acidez total titulável e ácido ascórbico, elevando o teor de sólidos solúveis totais. Na polpa formulada observou-se aumento de 34% dos sólidos solúveis totais, enquanto que a redução da atividade de água foi de quase 80%. Em relação ao pó, o produto com maltodextrina apresentou redução nos teores de umidade, atividade de água e acidez total titulável quando comparado ao pó de fruta integral. Quanto à cor, houve aumento da luminosidade (L*), de 72,45 para 78,85 e decréscimo da intensidade de amarelo (b*), de 62,72 para 35,33, do pó formulado quando comparado ao pó sem adição de coadjuvante. Foi possível verificar que a inclusão de maltodextrina alterou os parâmetros físico-químicos estudados, tanto nas polpas quanto no pó liofilizado, sendo os parâmetros de umidade, atividade de água e luminosidade os mais afetados.

Economic and environmental analysis of animal fats acidity reduction by enzymatic esterification

Abstract This study examines the economic potential of reducing the acidity of animal fats (fish oil, poultry and mammalian fats) by enzymatic esterification, when applied at industrial scale in a Portuguese company, and determines its carbon and water footprints as a measure of its potential environmental impact. Cost and revenue data were obtained from real industrial and commercial sources, complemented with literature and life cycle inventory data for the environmental impact calculations. Based on esterification experiments, for optimizing operating conditions and enzymes selection, two scenarios are analyzed in this work, using ethanol 96% (v/v) as reagent, and the following enzymes commercialized by Novozymes as catalyst: (1) Lipozyme® CALB L for fish oil and mammalian fat and Novozym® 435 for poultry fat; (2) Lipozyme® TL 100L for fish oil and Lecitase® Ultra for mammalian fat. Results show that under current conditions the new process for the fats acidity reduction is not economically viable. To be feasible the cost of enzymes should decrease to at least 9.75 €/kg and 1 €/kg for treating, respectively, the fish oil and the mammalian fat. Alternatively, the sale price of fish oil alone and of fish oil and mammalian fat together, should increase at least 3 and 4% respectively, to ensure that the process is cost effective. For the process operating conditions defined in this work, it is estimated a carbon and water footprints of, respectively, 1.3 t CO2 eq/t fat and 574 m3 water/t fat for the new esterification process, corresponding to minor increases in the footprints of the current company processes.

Comparison of NO conversion over Cu/M (M = TiO2, Al2O3, ZSM-5, carbon nanotubes, activated carbon) catalysts assisted by plasma

NO conversion using dielectric barrier discharge (DBD) plasma with different catalysts was investigated. Cu/TiO2, Cu/Al2O3, Cu/ZSM-5, Cu/CNTs and Cu/AC catalysts were prepared by incipient wetness impregnation with 4 wt% Cu loaded. BET, SEM, XRD, XPS, H2-TPR, NH3-TPD were used to measure and evaluate various catalysts. Compared with the plasma only process, the combination of plasma with different catalysts significant improved the NO conversion rate. The highest NO conversion rate of 76% could be achieved with Cu/ZSM-5 catalyst at the energy density of 184 J/L. The results indicate that Cu species over the support ZSM-5 can produce high concentrations of CuO, largest specific surface area, largest amounts of acidity and lowest reduction temperature (209 °C), these factors conducive to plasma-catalyst reaction. Besides, Cu/TiO2 and Cu/Al2O3 catalysts exhibited excellent NO conversion at the low energy density because of the low thermal stability. After plasma-catalyst reaction, the reducibility of CuO and Cu2O over supports decreased and the peak position of acid sites shifted to lower temperature.

Evaluation of different adsorbents for acidity reduction in residual oils

ABSTRACTThis work aims to evaluate the adsorption potential of bentonite and sugarcane bagasse clay for the reduction of free fatty acids in cooking oil through batch technique, experimental planning with different operating conditions (temperature, adsorbent mass and agitation). After were carried out kinetic studies and thermodynamic studies. Thus, both adsorbents were characterized by nitrogen dispersion, scanning electron microscopy with coupled energy dispersion spectroscopy. The sugarcane bagasse provided higher reductions compared to the bentonite clay, 58 and 50%, respectively. In the kinetic studies, it was observed that the pseudo-secunda model for both materials. Among the isotherms studied, the Langmuir model was better adjusted for sugarcane bagasse and Freundlich for bentonite clay. Thermodynamic parameters indicated spontaneous and endothermic adsorption at temperatures of 18°C, 20°C and 25°C. Both materials showed an advantageous result with the reduction to the adsorption of free fatty acids in the residual oil, considering that they are low-cost materials, their pre-treatment is simple from the operational point of view and their physical and chemical characteristics are favorable to the adsorption process, sugarcane bagasse contains about 42% hemicellulose, which is a hydroxyl-rich material that attracts the H+ ions from the medium.

Protective effect of obestatin on indomethacin-induced acute gastric ulcer in rats: role of VEGF and TNF-α

Background Gastric ulcer (GU) is one of the most common disorders that affect the gastrointestinal tract. Obestatin, a ghrelin-related peptide, has been shown to exhibit some protective and therapeutic effects in the gut. Aim This study aimed at investigating the protective effect of obestatin on acute indomethacin (IND)-induced GU, clarifying the role of vascular endothelial growth factor (VEGF) and tumor necrosis factor-α (TNF-α). Materials and methods A total of 32 adult Wistar albino male rats were divided into four main groups: control group, obestatin group, GU group, and obestatin+GU group. Obestatin was given by a single intraperotineal injection (30 µg/kg) 1 h before induction of GU by a single oral dose of IND (40 mg/kg). Pyloric ligation was carried out in all animals before IND or distilled water administration. Four hours later after IND treatment, gastric ulcer index, preventive index, gastric juice volume, and free and total acidity were assessed. Nitric oxide, VEGF mRNA, and TNF-α mRNA were measured in gastric tissue, as well as histopathological study of gastric injury. Results IND caused a significant increase in ulcer index, gastric juice volume, free and total acidity, and TNF-α mRNA, with a significant decrease in nitric oxide and VEGF mRNA. Pretreatment with obestatin reversed these effects. Conclusion Obestatin pretreatment showed a gastroprotective effect against the IND-induced GU that can be explained by the anti-inflammatory and angiogenic effects of obestatin treatment and reduction of gastric juice volume, free acidity, and total acidity.

Effect of sulfur and NPK treatments on some quantitative and qualitative properties of Pears ( Pyrus communis l.) Cv. Le-cont

An experiment was conducted at private orchard in AL-Musaiab region / Provence of Babylon during the growing seasons of 2011 and 2012 to investigate the effect of sulfur at two levels (0 , 500) g/tree and NPK 0, 0.5 and 1 % as foliar spray and 1000g / tree in soil on some quantitative and qualitative properties of yield of Pears Cv. Le-conte using R.C.B.D design with three replicates. Results showed a significant effect of agricultural sulfur , NPK treatments and their interactions. The interaction of 500 g agricultural sulfur x 1000 g of NPK gave the highest average of fruits number (420.33 , 442.67) fruit, fruit weight (150.11 , 156.84) g, yield (63.10 , 69.43) kg/tree for two seasons respectively, while control treatment recorded the lowest average of these characteristics. Also there were a significant increase of percentage of (TSS) and reduction in Total Acidity in fruits.

Gastro Protective effect of Standardized Ethanolic leaf extract of Indigofera tinctoriao on experimental Gastric Ulcers in Rats

Objective:The anti-ulcer activity of ethanolic extract of Indigofera tinctoria (Fabaceae) leaf (EEIT) was investigated in Indomethacin and ethanol induced ulcer models in wistar rats. Methods: The preliminary Phytochemical evaluation was carried out by standard methods. Indomethacin and ethanol induced ulcer models the common parameter determined was ulcer index. Animals are divided in to four groups. First groups serves as control, second group treated with standard drug third and fourth group treated with EEIT at doses of 200 and 400 mg/kg p.o produced significant inhibition of the gastric lesions induced by Indomethocin induced ulcer and Ethanol induced gastric ulcer. Results: Phytochemical evaluation shows that alkaloids and flavonoids are present in extract.The extract (200 mg/kg and 400 mg/kg) showed significant (P<0.01) reduction in gastric volume, free acidity and ulcer index as compared to control. This present study indicates that Indigofera tinctoria extract have potential anti ulcer activity in the both models.Cellular level changes was reveled with histopathological studies. Conclusion:These results may further suggest that ethanolic extract was found to possess antiulcerogenic as well as ulcer healing properties, which might be due to its antisecretory activity.

Nitrate Reductase, Micronutrients and Upland Rice Development as Influenced by Soil pH and Nitrogen Sources

ABSTRACTThe average yield of upland rice under no-tillage system (NTS), a sustainable soil management, is lower than in conventional tillage (one plowing and two disking). One of the reasons given for this drop in crop grain yield would be the low-nitrate assimilation capacity of rice seedlings, due to the low activity of the nitrate reductase (NR) enzyme in the early development phase. A greenhouse experiment was conducted to evaluate the effects of the soil acidic and nitrogen source in the micronutrient concentrations, NR activity and grain yield of upland rice growing under NTS. The soil used in the experiment was an Oxisol. The experimental design was completely randomized in a factorial 3 × 4. Treatments consisted of three levels of soil acidity (high, medium, and low) combined with four nitrogen sources (nitrate, ammonium, ammonium + nitrification inhibitor, and control – without N fertilization). The reduction of soil acidity reduced the concentration of zinc and manganese in rice plants. Generally, the activity of the NR enzyme was higher in plants grown in soils with low acidity and fertilized with calcium nitrate. There was a greater response in growth and yield in rice plants grown in soils with high acidity. Under medium acidity, rice plants grown with ammonium sulfate were more productive (no differences were detected with the addition of the nitrification inhibitor).

Drying kinetics and physical and chemical characterization of white-fleshed ‘pitaya’ peels

ABSTRACT The objective of this work was to obtain the drying kinetic curves of white-fleshed ‘pitaya’ peels and characterize the obtained powder regarding physical and chemical parameters. Different mathematical models were fitted to the experimental data of drying kinetics, considering the coefficient of determination (R2), mean square deviation (MSD) and residual distribution as fit criteria. The peels had an initial moisture content of 93.38% (w.b.) and final moisture contents of 5.39% at temperature of 50 °C, 5.27% at 60 °C and 4.40% at 70 °C. After drying, the peels were disintegrated to obtain the powders and characterized for moisture content, reducing sugars, total titratable acidity, ascorbic acid, betacyanins, betaxanthins, water activity and color, in order to evaluate the influence of temperature on the quality of powders. The Page model was the one that best fitted to the experimental data, presenting coefficient of determination higher than 0.998, mean square deviation lower than 0.02 and random distribution of residuals. Increment in drying air temperature promoted increase of pH, ascorbic acid, luminosity and yellowness, and reduction of moisture content, reducing sugars, acidity, betacyanins, betaxanthins, water activity and redness. Considering the retention of betalains, the drying temperature of 50 °C is the most suitable for the production and use of ‘pitaya’ peel powder.

Use of rice husk in waste cooking oil pretreatment

ABSTRACTSince industrial wastes are increasing, the development of studies to find ways for their use is urgent. Waste cooking oil is an important source for the production of biodiesel, one of the main biofuels in Brazil. However, during cooking, the oil undergoes conditions that change its properties and decrease its quality, such as its acidity value. Current research treats waste cooking oil by the adsorption process using rice husk, an agro-industrial waste, and activated carbon to compare results. The potential of the adsorbents to remove free fatty acids in waste cooking oil has been investigated by the batch technique, evaluating different operating conditions of temperature, adsorbent mass and agitation. Adsorbents were characterized by nitrogen physisorption, scanning electron microscope, energy-dispersive spectroscopy and X-ray diffraction. The maximum result obtained for activated carbon at acidity reduction was 63%, using 22.4°C, 169.64 rpm and 3.39 g of adsorbent mass. Already, using the rice husk the percentage of removal was the same, 63% using 22.4°C, 80.36 rpm and 1.61 g of adsorbent, however in shorter times. The results prove that the application of the rice husk for this purpose is advantageous, for being a low-cost material, available on a large scale and that provide results similar to activated carbon.

Changes in flavonoid biosynthesis and in the berry whole transcriptome of ‘Sangiovese’ under moderate air temperature increase

Among the environmental factors, temperature is the one that poses serious threats to viticulture in the present and future scenarios of global climate change. In this work, we evaluated the effects on berry ripening of two thermal regimes, imposed from veraison to harvest. Potted vines were grown in two air-conditioned greenhouses with high temperature (HT) and low temperature (LT) regimes characterized respectively by 26 and 21°C as average and 41.7 and 35°C as maximum air daily temperature. We carried out analyses of the main berry compositional parameters and of berry skin phenolics on HT and LT berries sampled at six phases during ripening. In the same sampling dates, the berry skin transcriptome under the two temperature regimes was analyzed. The two thermal conditions strongly differentiated HT and LT berries. The HT regime did not increase sugar accumulation at harvest but contributed to a total acidity reduction and to a pH increase. Conversely, changes in growing temperatures greatly impacted on grape phenolic composition as the anthocyanin and flavonol concentrations resulted strongly reduced. Whole transcriptome analysis identified genes with a different expression profile when berries were ripened under HT or LT. Focusing on phenylpropanoid-related genes, we found many differential transcripts involved in stilbene biosynthesis. Nevertheless, the effect observed on genes involved in flavonoid biosynthesis was only marginally in line with the berry biochemical parameters, suggesting a possible post-transcriptional response of this pathway to moderate increments of temperature in 'Sangiovese'.

Pre-harvest spray application of abscisic acid (S-ABA) regulates fruit colour development and quality in early maturing M7 Navel orange

Abstract Poor fruit colour development at harvest in early maturing M7 sweet orange cultivar causes economic losses to the growers. The responses of different concentrations (50, 100, 200, 300 or 500 mgL−1) of abscisic acid (S-ABA) and its biosynthesis inhibitor nordihydroguaiaretic acid (NDGA) (0.01, 0.02, 0.04 mM) at pre-harvest stage (6 or 3 weeks before anticipated harvest) on peel colour development particularly from yellow to deep orange and on the fruit quality of M7 were studied during 2015 and 2016 in Western Australia. S-ABA treatments during both years irrespective of the concentrations applied exhibited significantly lower hue angle (h°) with enhanced citrus colour index (CCI) and higher levels of total carotenoids in the flavedo during 2015 and 2016. Spray application of S-ABA (300 and 500 mg L−1) resulted in higher level of total carotenoids (35.0 and 71.5 mg kg−1) in the flavedo during 2015 and 2016. A single spray application of S-ABA applied at 6 weeks before anticipated harvest (WBAH) showed higher mean CCI (10.1) and level of total carotenoids (37.6 mg kg−1) as compared to its single application at 3 WBAH and double spray at 6 WBAH followed by 3 WBAH in 2015. However, nordihydroguaiaretic acid (NDGA) restricted colour development indicated by higher h° and reduced CCI with lower levels of total carotenoids in the flavedo during 2015. S-ABA treatments exhibited significantly reduced total organic acids in the juice, whilst total sugars were not affected by any of the treatments. S-ABA treatments (200 and 300 mg L−1) showed increased SSC/TA ratio (12.8%) as a result of reduction in total acidity (TA) (0.96%). In conclusion, pre-harvest spray application of S-ABA promoted fruit colour development from yellow to deep orange, indicated by reduced h° and increased CCI as well as the levels of total carotenoids in the flavedo of M7 Navel orange. Promotion of fruit colour development (yellow to deep orange) with the pre-harvest application of S-ABA and its down regulation with the application of ABA biosynthesis inhibitor (NDGA) suggested the involvement of S-ABA in flavedo colour development in M7 Navel orange fruit.

Biological Demalication and Deacetification of Musts and Wines: Can Wine Yeasts Make the Wine Taste Better?

Grape musts sometimes reveal excess acidity. An excessive amount of organic acids negatively affect wine yeasts and yeast fermentation, and the obtained wines are characterized by an inappropriate balance between sweetness, acidity or sourness, and flavor/aroma components. An appropriate acidity, pleasant to the palate is more difficult to achieve in wines that have high acidity due to an excess of malic acid, because the Saccharomyces species in general, cannot effectively degrade malic acid during alcoholic fermentation. One approach to solving this problem is biological deacidification by lactic acid bacteria or non-Saccharomyces yeasts, like Schizosaccharomyces pombe that show the ability to degrade L-malic acid. Excessive volatile acidity in wine is also a problem in the wine industry. The use of free or immobilized Saccharomyces cells has been studied to solve both these problems since these yeasts are wine yeasts that show a good balance between taste/flavor and aromatic compounds during alcoholic fermentation. The aim of this review is to give some insights into the use of Saccharomyces cerevisiae strains to perform biological demalication (malic acid degradation) and deacetification (reduction of volatile acidity) of wine in an attempt to better understand their biochemistry and enological features.

Acidity reduction of mammalian fat by enzymatic esterification

This work studies the mammalian fat acidity reduction, through enzymatic esterification with ethanol for converting FFA into esters. The fat samples collected in a Portuguese company were characterized for their acid value, iodine value, density, kinematic viscosity and moisture content. Four commercial enzymes were tested as catalyst. Lipozyme CALB L contributed to highest acidity reduction. It was selected for the parametric study of the best operating conditions: 45 ºC of temperature, enzyme/fat and ethanol/FFA mass ratios of respectively0.0060 and 3.25wt/wt, which reduced 67 % the acidity in just one reaction step, after 3 h of reaction time.

Fish oil acidity reduction by enzymatic esterification

This work studies the enzymatic esterification for fish oil acidity reduction. Lipozyme TL 100L showed greater acidity reduction (75 %) for esterification at 40 °C, with ethanol 96 %, with enzyme/oil and alcohol/FFA mass ratios of respectively 0.01 and 3.24 w/w, reaching 3.13 mg KOH/g oil of final acid value or 1.57 % FFA content. Lipozyme CALB L showed greater acidity reduction (76 %) for esterification at 45 °C, with ethanol 99.8 %, with enzyme/oil and alcohol/ FFA mass ratios of respectively 0.0045 and 4.92 w/w, reaching 3.33 mg KOH/g oil of final acid value or 1.67 % FFA content.