Reduction Of Acidity Research Articles

Phenol oxidation by nitrous oxide: The role of zeolite catalyst acidity

Gas-phase phenol oxidation using nitrous oxide on zeolite catalysts is of great interest as an alternative method of dihydroxybenzene (DHB) synthesis. Catalysts for conducting this reaction with high selectivity in the sum of three isomers of DHB (85–90%) were discovered earlier. The aim of this work is to optimize these catalysts to regulate the regioselectivity of the reaction. The effect of thermal steam treatment (TST) on zeolite catalytic properties is studied. Using NMR and IR spectroscopy, an increase in the TST temperature in the range of 550–750°C is shown to be accompanied by 5-fold reduction in the concentration of Bronsted acidic sites in zeolite with a simultaneous 2to 3-fold increase in the number of a-sites responsible for the acidity in oxidation by nitrous oxide. Varying the TST temperature is found to be powerful tool for influencing the reaction selectivity in individual DHB isomers. The reduction in zeolite acidity changes the isomer ratio in favor of catechol. The reasons for this phenomenon and its relation to catalyst deactivation are discussed.

Physicochemical characteristics and oxidative stability of de-acidified lampante high acid olive oil

The aim of this investigation was to enhance the quality of high free fatty acid olive oil (HFFAO). Silica gel (SG) was used as adsorbent by applying filtration and stirring techniques. Alkali treatments with NaOH and Ca(OH)2 were also conducted to neutralize high acidity of HFFAO. The levels of linoleic acid (C18:2) in neutralized oils were lower than in reference olive oil. Untreated and treated HFFAO samples were stored under oxidative conditions for 30 days at 60 °C. The progress of oxidation was followed by measuring acid value (AV), the formation of oxidative products [i.e., peroxide value (PV) and p-anisidine value (AnV)], total phenolic compounds (TPC), radical scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and inhibition of β-carotene in a linoleate model system. The results indicated that SG and alkali treatments were effective in reducing the acidity of HFFAO. Alkali treatments reduced the AV of HFFAO, while treatments with SG induced variable degrees of reduction in HFFAO acidity. The percentage of reduction in the PV for HFFAO using SG was in the range of 10.5–47.3 %. Filtration with SG had a significant effect on AnV. Levels of TPC were reduced (ca. 70 %) with alkali treatments, while treatments with SG resulted in reduction of about 22–48 %. After 60 min incubation with DPPH, 78 % of DPPH radicals were quenched by control sample, while HFFAO treated with SG or alkali were able to quench from 48 to 56 %. SG and alkali treatments were not effective in inhibiting the oxidation of linoleic acid and the subsequent bleaching of β-carotene in comparison with control oil. During autoxidation experiments the same trends of results were noted for both control and treated oils. The results stated that SG with permitted high adsorbing capacity reduced free fatty acids levels in HFFAO and the effect was close to that induced with chemical treatments which are used commercially in a large scale to improve oil quality.

효모 종류와 발효조건에 따른 머루 첨가 복분자주의 품질 특성

본 연구의 목적은 효모균주와 발효조건 등을 달리하여 머루를 첨가하여 복분자 와인의 품질을 향상시키는데 있다. 효모별 복분자 와인 술덧 품질에 미치는 영향 연구에서는 Y1(Lalvin 71B)효모가 젖산, 퓨젤유 성분을 발효후에 타 효모에 비해 유의적으로 높게 생성하였으며, 술덧의 산도를 낮추고 복분자 와인의 아로마를 강화하는데 효과가 있는 것으로 분석되었다. 또한 발효온도가 복분자 와인 술덧에 미치는 영향 연구에서는 고온발효(<TEX>$25^{\circ}C$</TEX>)에서 Y1 효모를 이용하여 발효한 술덧에서 낮은 온도(<TEX>$15^{\circ}C$</TEX>)에서 발효한 술덧에서보다 아로마 성분(에틸 아세테이트 및 고급알코올)이 유의적으로 높게 생성되었다. 본 연구를 통해 머루를 첨가한 복분자 와인제조시 Y1 효모를 이용하고 고온에서 발효하는 것이 복분자 와인의 맛과 아로마를 강화하는데 효과가 있는 것으로 나타났다. The objective of this study was to improve the quality of black raspberry wine added with wild grape, based on selection of yeast strains and fermentation conditions. The Y1 yeast(Lalvin 71B) indicated significantly higher lactic acid, ester, fusel oil content after fermented mashing than other samples tested and had an effect on the reduction of acidity and enhanced aroma of black raspberry wine. In addition, the high fermentation temperature(<TEX>$25^{\circ}C$</TEX>) using Y1 yeast showed much higher tendency to retain components of aroma (ethyl acetate, higher alcohols) and the highest overall preference including sensory evaluation than that of low fermentation temperture(<TEX>$15^{\circ}C$</TEX>). Thus, the fermentation using Y1 yeast at <TEX>$25^{\circ}C$</TEX> can be applied to positively improve the taste and flavor of production of black raspberry wine added wild grape.

The evolution of podzolized and regraded chernozems in Eastern Upland Wooded Steppe of Ukraine and the ways of their development

It is indicated that podzolized and regarded chernozems in moderately humid and arid zones of Left-bank Wooded steppe with HTC 1,2–1,0 (within the valleys of the Sula and Oskil rivers) occur in high watersheds along right bedrock banks of the valleys, adjoining or being included into wooded refugiums. Being formed by the grove biogeocenosis, they have high rates of fertility. The morphological research of natural podzolized chernozems profiles showed, that the upper humus slightly-eluviated horizon, densely interweaved by roots, has coarse agronomically valuable structure, loose composition, dark-grey colour, that indicates high content of humus. It is mostly favoured by the biologically active, rich in calcium ground litter and the pristinity of soil texture. The general capacity of the humus profile is not less than 100 cm. While brining natural soils into tillage some changes of soil development conditions arise. They are: hydrothermic conditions, secondary carbonate enrichment (regradation), loosening of illuvial horizon. Under mechanical tillage the granular structure changes into a pulverescent and cloddy one, the topsoil becomes lighter because of humus loss, though the humus profile becomes 10–20 cm deeper. The analytical results indicate the sufficient differences in physicochemical and agrochemical characteristics between forest podzolized chernozems and their regradated analogs in tillage. Natural soils contain 5,7–6,5 % of humus in upper 0–35 cm layer, and up to 10,0 % in 0–15 cm layer. They also have considerable resources of hydrolyzable nitrogen. In agrogenic soils the humus content is up to 3,6 %. The humus is of a humate type both in podzolized and regarded soils. The smallest proportion of Сh.a./Сf.a is in the lower layer of humus eluviated horizon of forest soils. The level of humus loss by agrogenic soils in humus slightly-eluviated layer fluctuates from 37 % to 44 %. Dark-grey and grey forest soils lose more than half of humus content, typical chernozems – nearly 30 %, ordinary chernozems – 20 %. Regraded analogs are inferior according to the hydrolyzable nitrogen content. Positive evolutional changes in tillage, such as acidity reduction, bases saturation growth, illuvium destruction, didn’t yield expected results – resistance to degradation processes. For the development of agrogenic soils it is necessary to implement flexible complex systems of husbandry with minimal intensity of tillage, adapted to the landscape, bringing the culture of husbandry closer to natural conditions. Promising is the implementation of soil protection technologies with the maximum use of freak produce of plant growing. The integrity of soil composition and biologically active layer of mulch create the conditions, close to virgin ones, that lead to the transition of soil to natural non-degradation conditions without losing its productive functions.

AMDE-1 Is a Dual Function Chemical for Autophagy Activation and Inhibition

Autophagy is the process by which cytosolic components and organelles are delivered to the lysosome for degradation. Autophagy plays important roles in cellular homeostasis and disease pathogenesis. Small chemical molecules that can modulate autophagy activity may have pharmacological value for treating diseases. Using a GFP-LC3-based high content screening assay we identified a novel chemical that is able to modulate autophagy at both initiation and degradation levels. This molecule, termed as Autophagy Modulator with Dual Effect-1 (AMDE-1), triggered autophagy in an Atg5-dependent manner, recruiting Atg16 to the pre-autophagosomal site and causing LC3 lipidation. AMDE-1 induced autophagy through the activation of AMPK, which inactivated mTORC1 and activated ULK1. AMDE-1did not affect MAP kinase, JNK or oxidative stress signaling for autophagy induction. Surprisingly, treatment with AMDE-1 resulted in impairment in autophagic flux and inhibition of long-lived protein degradation. This inhibition was correlated with a reduction in lysosomal degradation capacity but not with autophagosome-lysosome fusion. Further analysis indicated that AMDE-1 caused a reduction in lysosome acidity and lysosomal proteolytic activity, suggesting that it suppressed general lysosome function. AMDE-1 thus also impaired endocytosis-mediated EGF receptor degradation. The dual effects of AMDE-1 on autophagy induction and lysosomal degradation suggested that its net effect would likely lead to autophagic stress and lysosome dysfunction, and therefore cell death. Indeed, AMDE-1 triggered necroptosis and was preferentially cytotoxic to cancer cells. In conclusion, this study identified a new class of autophagy modulators with dual effects, which can be explored for potential uses in cancer therapy.

Enhanced biological N2 fixation and yield of faba bean (Vicia faba L.) in an acid soil following biochar addition: dissection of causal mechanisms

Acid soils constrain legume growth and biochars have been shown to address these constraints and enhance biological N2 fixation in glasshouse studies. A dissection of causal mechanisms from multiple crop field studies is lacking. In a sub-tropical field study, faba bean (Vicia faba L.) was cultivated in rotation with corn (Zea mays) following amendment of two contrasting biochars, compost and lime in a rhodic ferralsol. Key soil parameters and plant nutrient uptake were investigated alongside stable 15 N isotope methodologies to elucidate the causal mechanisms for enhanced biological N2 fixation and crop productivity. Biological N2 fixation was associated with plant Mo uptake, which was driven by reductions in soil acidity following lime and papermill (PM) biochar amendment. In contrast, crop yield was associated with plant P and B uptake, and amelioration of soil pH constraints. These were most effectively ameliorated by PM biochar as it addressed both pH constraints and low soil nutrient status. While liming resulted in the highest biological N2 fixation, biochars provided greater benefits to faba bean yield by addressing P nutrition and ameliorating Al toxicity.

Changes in some biochemical qualities during drying of pulp pre-conditioned and fermented cocoa (Theobroma cacao) beans.

Fermentation and drying are critical to the development of flavour precursors that generate into distinctive chocolate flavour notes during industrial manufacture. These processes also lead to reduction in acidity and free fatty acids of nibs, which dictates the levels of bitterness and colour development in chocolates. This study investigated changes in nib acidity, flavour precursors (sugars concentration and proteins) and free fatty acids during drying of pulp pre-conditioned and fermented cocoa beans using a 4 x 3 full factorial experimental design with pod storage (0, 3, 7 and 10 days) and drying time (0, 3 and 6 days) as the principal factors. Non-volatile (titratable) acidity, pH, sugars (reducing, non-reducing and total sugars), changes in protein content and free fatty acids of the beans were studied using standard analytical methods. Increasing pod storage consistently increased pH of the fermented nibs at the end of drying with consequential decrease in titratable acidity. The pH increased from 4.92 for the freshly harvested pods to 6.00 for pods stored for 10 days at the end of the drying process. Similarly, pH of the fermented beans increased with increasing drying time for all pod storage treatment except for pods stored for 10 days. The pH of fermented beans whose pods were stored for 3 and 7 days were 5.26 and 5.56 respectively after drying for 7 days. Protein, reducing sugars, non-reducing sugars and total sugars decreased significantly (p&lt;0.05) with increasing duration of drying at all pod storage periods. Pod storage and drying significantly (p&lt;0.05) increased the free fatty acids content of the fermented nibs. The FFAs of the dried beans increased from 0.47% for the unstored (freshly harvested) pods to 0.55% for pods stored for 3 and 7 days and 0.58% for pods stored for 10 days. However, FFAs content of all the dried fermented beans were below the acceptable limits of 1.75% oleic acid equivalent in cocoa butter at all pod storage periods. Storage of cocoa pod between 3–7 days with 7 days of drying (after 6 days fermentation) led to considerable reductions in nib acidity, reducing sugars, nonreducing, total sugars and proteins and acceptable FFA levels.

TM9SF4 is a novel V-ATPase-interacting protein that modulates tumor pH alterations associated with drug resistance and invasiveness of colon cancer cells.

An inverted pH gradient across the cell membranes is a typical feature of malignant cancer cells that are characterized by extracellular acidosis and cytosol alkalization. These dysregulations are able to create a unique milieu that favors tumor progression, metastasis and chemo/immune-resistance traits of solid tumors. A key event mediating tumor cell pH alterations is an aberrant activation of ion channels and proton pumps such as (H+)-vacuolar-ATPase (V-ATPase). TM9SF4 is a poorly characterized transmembrane protein that we have recently shown to be related to cannibal behavior of metastatic melanoma cells. Here, we demonstrate that TM9SF4 represents a novel V-ATPase-associated protein involved in V-ATPase activation. We have observed in HCT116 and SW480 colon cancer cell lines that TM9SF4 interacts with the ATP6V1H subunit of the V-ATPase V1 sector. Suppression of TM9SF4 with small interfering RNAs strongly reduces assembly of V-ATPase V0/V1 sectors, thus reversing tumor pH gradient with a decrease of cytosolic pH, alkalization of intracellular vesicles and a reduction of extracellular acidity. Such effects are associated with a significant inhibition of the invasive behavior of colon cancer cells and with an increased sensitivity to the cytotoxic effects of 5-fluorouracil. Our study shows for the first time the important role of TM9SF4 in the aberrant constitutive activation of the V-ATPase, and the development of a malignant phenotype, supporting the potential use of TM9SF4 as a target for future anticancer therapies.

PHARMACOLOGICAL EVALUATION OF ANTI-ULCER ACTIVITY OF Cymbopogon flexuosus

Background: Peptic ulcer disease is a worldwide problem. Currently, there is no cost-effective treatment to relieve pain, heal the ulcer and prevent ulcer recurrence. Hence, there is a dire need to search and find a suitable treatment from natural sources. The present study was designed to investigate the anti-ulcer activity of ethanol extract of the leaves of Cymbopogon flexuosus. Methods: The ethanol extract of the leaves of Cymbopogon flexuosus was prepared by hot extraction method. Anti-ulcer activity was evaluated in rats and method employed was pylorus ligation. Animals were divided into four groups of six animals each. The animals of Group I served as normal control (vehicle) which received normal saline (5 ml/kg b.wt., p.o). Group II and III received 200 and 400 mg/kg b.wt. of ethanol extract, respectively. The animals of Group IV served as standard control which received ranitidine (15 mg/kg bd.wt.). At the end of study parameters like ulcer index, free acidity, total acidity, acid volume, and pH were determined. Results: The ethanol extract showed a significant reduction in the total acidity, free acidity, and acid volume. The efficacy of plant extract at high dose was comparable with the standard drug - ranitidine. Conclusion: Our study results support the ethnomedical use of leaves of C. flexuosus .

Gastroprotective effect of methanolic extract of Gomphrena celosioides on indomethacin induced gastric ulcer in Wistar albino rats.

Context:Gastric ulcer is one of the most prevalent gastrointestinal disorders. A number of studies have been carried out to determine the efficacy of herbal medicines in the treatment of gastric ulcer.Objectives:The present study was undertaken to evaluate the anti-ulcerogenic activity of methanol extract of Gomphrena celosioides (GC) in male Wistar rats.Materials and Methods:The rats were divided into eight groups, methanol extract of GC was administered orally, for seven consecutive to five groups. On the 7th day, indomethacin was administered to induce gastric ulceration. Gastric secretions were collected and analyzed.Results:Animals pretreated with GC extract showed a significant reduction in ulcer score, ulcer index, gastric volume, and gastric total acidity in indomethacin-induced ulcer models in a dose dependent manner when compared to the ulcerated control group.Conclusion:The study revealed gastroprotective activity of the extract in dose-dependent manner. Methanol extract of the leaves of GC was significantly effective in protecting the gastric mucosa against indomethacin-induced ulcers at all the dose level studied.

Evaluación de especies vegetales para el manejo de la acidez en suelos sulfatados ácidos de Paipa, Boyacá

Los suelos sulfatados ácidos se caracterizan por conteneraltas cantidades de hierro y azufre, que en presencia de aire se oxidan y forman horizontes sulfúricos extremadamente ácidos, los cuales generan alteraciones ambientales que van desde la contaminación hídrica hasta problemas asociados con su fertilidad y producción de cultivos, entre otros. Esta investigación se realizó con el fin de identificar especies vegetales adecuadas para el manejo de la acidez de estos suelos en el municipio de Paipa, Boyacá, Colombia. Se implementó bajo cubierta un diseño experimental completamente al azar con 6 tratamientos y 3 repeticiones, donde se evaluó la respuesta de Beta vulgaris L. (remolacha forrajera), Brassica rapa L. (nabo forrajero) y Raphanus sativus L. (rábano forrajero) sobre la acidez de un suelo sulfatado ácido, contrastado con uno no sulfatado, previa corrección con enmienda calcárea. Para estimar sus efectos, se midió pH y acidez intercambiable (H+ + Al+3 cmolc/kg) en los dos tipos de suelo, antes y después de la siembra; al finalizar el periodo vegetativo (120 días después de la siembra) se determinó la respuesta agronómica de las plantas en cada tratamiento. En el suelo sulfatado ácido, las especies B. rapa, R. sativus y B. vulgaris junto con el uso complementario de enmiendas calcáreas como correctivo indujeron una reducción en la acidez intercambiable; B. rapa y R. sativus presentaron mejor potencial de crecimiento y tolerancia, mientras que B. vulgaris se vio afectada en altura y diámetro de raíz.

Effects of surface application of calcium-magnesium silicate and gypsum on soil fertility and sugarcane yield

Lime application recommendations for amendment of soil acidity in sugarcane were developed with a burnt cane harvesting system in mind. Sugarcane is now harvested in most areas without burning, and lime application for amendment of soil acidity in this system in which the sugarcane crop residue remains on the ground has been carried out without a scientific basis. The aim of this study was to evaluate the changes in soil acidity and stalk and sugar yield with different rates of surface application of calcium, magnesium silicate, and gypsum in ratoon cane. The experiment was performed after the 3rd harvest of the variety SP 81-3250 in a commercial green sugarcane plantation of the São Luiz Sugar Mill (47º 25' 33" W; 21º 59' 46" S), located in Pirassununga, São Paulo, in southeast Brazil. A factorial arrangement of four Ca-Mg silicate rates (0, 850, 1700, and 3400 kg ha-1) and two gypsum rates (0 and 1700 kg ha-1) was used in the experiment. After 12 months, the experiment was harvested and technological measurements of stalk and sugar yield were made. After harvest, soil samples were taken at the depths of 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40, and 0.40-0.60 m in all plots, and the following determinations were made: soil pH in CaCl2, organic matter, P, S, K, Ca, Mg, H+Al, Al, Si, and base saturation. The results show that the application of gypsum reduced the exchangeable Al3+ content and Al saturation below 0.05 m, and increased the Ca2+ concentration in the whole profile, the Mg2+ content below 0.10 m, K+ below 0.4 m, and base saturation below 0.20 m. This contributed to the effect of surface application of silicate on amendment of soil acidity reaching deeper layers. From the results of this study, it may be concluded that the silicate rate recommended may be too low, since the greater rates used in this experiment showed greater reduction in soil acidity, higher levels of nutrients at greater depths and an increase in stalk and sugar yield.

Foliar 2,4-D Application after Physiological Fruit Drop Reduces Fruit Splitting of Mandarin

Various mandarin (Citrus reticulata) cultivars are prone to fruit splitting, a physiological disorder that entails cracking of the rind, starting from the stylar end of the fruit, with eventual splitting of the endocarp and abscission of the fruit. On two mandarin cultivars, Marisol and Mor, foliar applications of 2,4-dichlorophenoxyacetic acid (2,4-D), calcium (Ca), and potassium (K) were evaluated over two growing seasons for efficacy to reduce fruit splitting in Paarl, South Africa (lat. 33°69′S, long. 18°95′E). Foliar treatment of 10 mg·L−1 2,4-D directly after physiological fruit drop (APFD) compared with later dates in January and February, either alone or in combination with K, increased rind thickness and reduced fruit splitting of ‘Marisol’ and ‘Mor’ by up to 50%, without negatively affecting internal fruit quality. Treatments increased rind thickness and rind strength throughout fruit development in addition to fruit diameter, length, and growth rate, with no significant effect on rind coarseness. There was a slight reduction in juice content and titratable acidity (TA), but no effect on the total soluble solids (TSS). Application of 2,4-D APFD is thought to increase rind integrity due to a direct strengthening effect on the rind during early stages of fruit development.

Uso de ácido ascórbico e cloreto de cálcio na qualidade de repolho minimamente processado

O objetivo deste trabalho foi avaliar o efeito do ácido ascórbico (AA) e do cloreto de cálcio (CaCl2) aplicado em imersão nas temperaturas de 20 e 40ºC, sobre as características físico-químicas e sensoriais do repolho minimamente processado e mantido sob refrigeração. Os repolhos foram cortados em fatias com espessura de 3 mm. As fatias foram imersas em hipoclorito de sódio (50 ppm) por 5 minutos para higienização. Foram realizados os tratamentos T1= testemunha (imersão em água por 5 min a 20ºC); T2= imersão em solução contendo AA a 1%, por 5 min a 20ºC; T3= imersão em solução contendo AA a 2%, por 5 min a 20ºC; T4= imersão em solução contendo CaCl2 a 1%, por 5 min a 20oC; T5= imersão em solução contendo CaCl2 a 2%, por 5 min a 20oC; T6= imersão em solução contendo CaCl2 a 1%, por 5 min a 40oC; T7= imersão em solução contendo CaCl2 a 2%, por 5 min a 40oC, com quatro repetições cada. Os produtos foram centrifugados por 1 minuto, embalados em bandejas de poliestireno expandido, recobertos com policloreto de vinila de 20 µm e mantidos a 6±1oC e UR de 85-90%, por oito dias. Observou-se pequena elevação dos valores de pH e acidez titulável e diminuição nos teores de sólidos solúveis durante o período de conservação, independente do tratamento. O tratamento com AA não diferiu da testemunha quanto a cor e aparência geral, enquanto que o tratamento com CaCl2 2% a 20oC foi o que melhor manteve a qualidade, com menor escurecimento, as melhores notas para aparência geral e intenção de compra e menor odor estranho no final do período de conservação

Use of Alkaline Slag and Crop Residue Biochars to Promote Base Saturation and Reduce Acidity of an Acidic Ultisol

This investigation was conducted by using alkaline slag and crop straw biochars to reduce acidity of an acidic Ultisol through incubation and pot experiments with lime as a comparison. The soil was amended with different liming materials: lime (1 g kg−1), alkaline slag (2 and 4 g kg−1), peanut straw biochar (10 and 20 g kg−1), canola straw biochar (10 and 20 g kg−1) and combinations of alkaline slag (2 g kg−1) and biochars (10 g kg−1) in the incubation study. A pot experiment was also conducted to observe the soybean growth responses to the above treatments. The results showed that all the liming materials increased soil pH and decreased soil exchangeable acidity. The higher the rates of alkaline slag, biochars, and alkaline slag combined with biochars, the greater the increase in soil pH and the reduction in soil exchangeable acidity. All the amendments increased the levels of one or more soil exchangeable base cations. The lime treatment increased soil exchangeable Ca2+, the alkaline slag treatment increased exchangeable Ca2+ and Mg2+ levels, and the biochars and combined applications of alkaline slag with biochars increased soil exchangeable Ca2+, Mg2+ and K+ and soil available P. The amendments enhanced the uptake of one or more nutrients of N, P, K, Ca and Mg by soybean in the pot experiment. Of the different amendments, the combined application of alkaline slag with crop straw biochars was the best choice for increasing base saturation and reducing soil acidity of the acidic Ultisol. The combined application of alkaline slag with biochars led to the greatest reduction in soil acidity, increased soil Ca, Mg, K and P levels, and enhanced the uptake of Ca, Mg, K and P by soybean plants.

Gastro-protective, Anti-Helicobacter pylori and, Antioxidant Properties of Moroccan Zizyphus lotus L.

Strategies to evaluate antioxidant and cytotoxic activity of pet ether extract of Artocarpus chama Buch. seedTaksim Ahmed, Mohammad Nasir Uddin, Md. Kamal Hossain, Md. Imamul Islam, Nizam Uddin, Md. Ehsanul Haque Mazumder

Proximate Composition, Biochemical and Microbiological Changes Associated with Fermenting African Oil Bean (&lt;i&gt;Pentaclethra macrophylla &lt;/i&gt;Benth) Seeds&lt;i&gt; &lt;/i&gt;

The proximate composition, biochemical changes and microbiology of fermenting Pentaclethra macrophylla (Ugba) seeds were evaluated. Studies were carried out to screen for microorganisms associated with the natural fermentation of the oil bean seeds. Bacterial isolates obtained include species of Bacillus, Streptococcus, Salmonella, Micrococcus, Lactobacillus and Proteus. Fungal isolates include Yeast, species of Penicillium, Aspergillus, Fusarium and Rhizopus. Total aerobic counts (TAC) ranged from 1.5 x 106 to 2.5 x 106 cfu/g, while total coliform counts (TCC) ranged from 1.7 x 103 to 7.2 x 103 cfu/g. More so, total lactic acid bacterial counts ranged from 2.6 x 105 to 4.6 x 105 cfu/g. Among the various bacterial isolates obtained from the fermenting Ugba, Bacillus and lactic acid bacteria were dominant from the beginning to the end of the fermentation the oil bean seeds. The proximate composition of the fermenting seeds showed the presence of protein, fats, fibre, carbohydrates, and ash. Temperature variations in oil bean seed fermentation showed higher temperatures in the purchased Ugba compared to the laboratory Ugba after 72 hours fermentation. There were significant reduction in pH and titratable acidity as the fermentation time progressed, showing that temperature, pH and titratable acidity of fermenting African oil bean seeds were affected by the metabolic activities of resident microorganisms.

Optimization of biodiesel production from waste lard by a two-step transesterification process under mild conditions

The aim of this work is to investigate a two-step homogenous catalyzed waste lard transesterification reaction for low cost biodiesel production. For this purpose, two 23 full factorial design of experiments was applied. Six variables, namely esterification time (60–120min), H2SO4 concentration (20–40wt.%), MeOH:FFA (15:1–23:1), transesterification time (30–60min), KOH concentration (1–2wt.%), and MeOH:triglycerides (6:1–9:1), that typically affect the production process were studied. The esterification step is significantly affected mostly by the reaction time and the MeOH:FFA ratio value. Specifically, their increase brings a reduction of the FFA acidity. Likewise, the transesterification step is positively affected primarily by three independent variables, namely reaction time, KOH concentration and MeOH:triglyceride ratio. Furthermore two empirical models describing evolution of the two-step transesterification reaction were developed. They can become useful tools for further scaling-up the process by predicting its reaction yield within a 95% of confidence level.

Desenvolvimento, caracterização e estabilidade de geleia tradicional de umbu-cajá

Objetivou-se desenvolver geleia tradicional de umbu-cajá, caracterizá-la quanto a parâmetros físicos, químicos, microbiológicos e sensoriais, e avaliar sua estabilidade durante o armazenamento por seis meses em condições ambientais. Para processamento, foram utilizados 44% de polpa diluída de umbu-cajá, 1% de pectina de alto teor de metoxilação (ATM) e 55% de açúcar cristal. A formulação foi submetida à cocção em tacho aberto de aço inoxidável até teor de sólidos solúveis totais de cerca de 68 ªBrix. A geleia foi envasada em recipientes de vidros transparentes, caracterizada e estocada em temperatura e umidade relativa médias de 23,25 ºC e 81%, respectivamente, com acompanhamento por meio de análises físicas e químicas a cada 30 dias de armazenamento. Os resultados da caracterização química evidenciaram produto com elevado teor de carboidratos, baixos conteúdos de cinzas e proteínas e valor calórico de 256 kcal/100g. Não foi verificado contagem dos microorganismos pesquisados (bolores e leveduras, coliformes totais e termotolerantes, Staphylococcus, bactérias mesófilas e Salmonella). Constatou-se alta aceitabilidade, com índices de aceitação superiores a 70% para todos os atributos sensoriais investigados (cor, aparência, aroma, consistência, sabor, doçura e impressão global) e intenção de compra de 67,5%, indicando potencial para industrialização e comercialização. O armazenamento promoveu aumento significativo nos valores de pH, sólidos solúveis totais (SST), relação SST/ATT e firmeza e reduções significativas na acidez total titulável (ATT), atividade de água, luminosidade, intensidades de vermelho e amarelo, croma, ângulo de tonalidade, extrusão e adesividade. Constatou-se tendência à estabilidade dos valores de umidade e de sólidos totais. O processamento do umbu-cajá para elaboração de geleia mostrou-se viável, apresentando-se como mais uma opção de renda para pequenos produtores do semiárido brasileiro.

Improvement in Regeneration Properties and Multicycle Stability for K2CO3/Al2O3 Adsorbents for CO2 Removal from Flue Gas

A new adsorbent based on potassium carbonate (K2CO3) supported on modified γ-Al2O3 has been developed in this work. It has shown excellent multicycle stability with adsorption and regeneration at 55 and 130 °C, respectively. The support (γ-Al2O3) is stabilized by thermal treatment and alkali treatment with hydroxide, followed by calcination. The excellent regeneration characteristics are due to minimal interactions between the support and reactants during CO2 adsorption. This is due to acidity reduction of the support responsible for the formation of stable species, for example, KAl(CO3)2(OH)2. Various physicochemical characteristics have been studied to understand the adsorption and regeneration behavior of the adsorbents over multiple cycles. The effects of operating parameters, such as adsorption temperature, thermal dehydration of support material, and gas hourly space velocity (GHSV), during regeneration have also been studied. The CO2 adsorption capacities are found to be in the range of 2.3–2.6 mmol of CO2/g of adsorbent (10–11.4 wt % CO2), which also shows good stability after multicycle tests. The developed adsorbents also show high attrition resistance and, thus, can be effectively used in commercial application for CO2 capture.