Differentiating True and False Cinnamon: Exploring Multiple Approaches for Discrimination.

This study presents a comprehensive literature review that investigates the distinctions between true and false cinnamon. Given the intricate compositions of essential oils (EOs), various discrimination approaches were explored to ensure quality, safety, and authenticity, thereby establishing consumer confidence. Through the utilization of physical-chemical and instrumental analyses, the purity of EOs was evaluated via qualitative and quantitative assessments, enabling the identification of constituents or compounds within the oils. Consequently, a diverse array of techniques has been documented, encompassing organoleptic, physical, chemical, and instrumental methodologies, such as spectroscopic and chromatographic methods. Electronic noses (e-noses) exhibit significant potential for identifying cinnamon adulteration, presenting a rapid, non-destructive, and cost-effective approach. Leveraging their capability to detect and analyze volatile organic compound (VOC) profiles, e-noses can contribute to ensuring authenticity and quality in the food and fragrance industries. Continued research and development efforts in this domain will assuredly augment the capacities of this promising avenue, which is the utilization of Artificial Intelligence (AI) and Machine Learning (ML) algorithms in conjunction with spectroscopic data to combat cinnamon adulteration.

Effect of Extraction Time on the Yield, Chemical Composition, and Antibacterial Activity of Hop Essential Oil Against Lactic Acid Bacteria (Lactobacillus brevis and Lactobacillus casei) Beer Spoilage.

Hop essential oil (EO) generates interest for its antioxidant and antimicrobial properties, in addition to the volatile compounds that are responsible for the hop aroma in beer. Thus, the objective of this study was to evaluate the chemical composition, EO yield, and antibacterial activity of hop essential oil from hops of the Chinook variety against lactic acid bacteria (Lactobacillus brevis and Lactobacillus casei) at different times of extraction. EO extraction was performed by hydrodistillation at different times. By analyzing the chemical composition by gas chromatography and mass spectrometry, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. The major compounds of hop EO were α-humulene, ß-myrcene, and ß-caryophyllene, and the extraction yields were 0.67, 0.78, and 0.85% mass of EO per mass of hops pelletized hops (m/m), for extractions of 90, 180, and 300 min, respectively. The EO obtained in 90 min was efficient against L. casei at 2.5 mg/mL (MIC) and 5.0 mg/mL (MBC), and the 300 min one against L. brevis at 2.5 mg/mL (MIC) and 25 mg/mL (MBC). The antibacterial activity was affected by the chemical makeup of the oil, revealing that the hop EO extracted in 300 min was the most efficient among the other extraction times.

Extraction of hops pelletized (Humulus lupulus) with subcritical CO2 and hydrodistillation: Chemical composition identification, kinetic model, and evaluation of antioxidant and antimicrobial activity.

Hop essential oil and hop extract using carbon dioxide (CO2) are products with high added value because they have bioactive and sensory properties. In this context, the objective of this study was to obtain and characterize essential oil and extracts from pelleted hops of El Dorado, Polaris, Hallertau Blanc and Callista varieties using hydrodistillation and subcritical CO2 extraction methods. Extraction yield ranged from 0.38 % to 1.97 % (m/m) for essential oils and from 8.76 % to 15.35 % (m/m) for extracts using subcritical CO2. The chemical compositions of the essential oils were mainly monoterpene (18.14 % to 29.91 %) and sesquiterpene (46.01 % to 59.03 %) hydrocarbons and for the extracts were sesquiterpene hydrocarbons (33.05 % to 71.90 %) and oxygenated sesquiterpenes (14.80 % to 34.89 %). The extracts showed better antioxidant activity than essential oils due to the presence of phenolic compounds and flavonoids. Hop extracts showed some antimicrobial activity, but essential oils did not demonstrate antimicrobial potential. Hop extracts obtained with subCO2 have the potential to be used in the brewing industry as a flavoring and as natural antioxidants.

Antifungal activity and aroma persistence of free and encapsulated Cinnamomum cassia essential oil in maize.

The objective of this study was to evaluate the chemical composition and antifungal activity of free and encapsulated Cinnamomum cassia essential oil (EO) against Penicillium crustosum, Alternaria alternata, and Aspergillus flavus, and the aroma persistence in maize flour. Trans-cinnamaldehyde (TC) was identified as the major compound (86 %) in the C. cassia EO. The EO was encapsulated by spray-dryer with 45.26 % efficiency using gum arabic (GA) and maltodextrin (MD) in a ratio of 1:1 (m/m). C. cassia EO showed antifungal activity against A. alternata, A. flavus, and P. crustosum, with a minimum inhibitory concentration (MIC) of 0.5 % for both free and standard TC, and 5 % for the encapsulated EO. Fungal growth inhibition was evaluated under exposition to vapors at different concentrations of C. cassia EO and TC standard, with MIC of 6 % and 8 % against P. crustosum, 4 % and 1 % A. alternata, and 4 % A. flavus, respectively. The sensory analysis results of the free and encapsulated C. cassia EO in maize flour showed a significant difference between the treated samples in relation to the standard sample (p < 0.05). The sample with free EO has high aroma intensity persistence, while the samples treated with encapsulated EO were evaluated as being closer to the standard sample. The results suggest that the encapsulated C. cassia EOs can be used as natural alternatives to control fungi in maize flour.

Microencapsulation of Brazilian Cherokee blackberry extract by freeze-drying using maltodextrin, gum Arabic, and pectin as carrier materials.

There are many blackberry cultivars in Brazil; however, the characteristics and applications of the Cherokee cultivar have not yet been widely studied. For this reason, this research investigated the behaviour of maltodextrin (MD), gum Arabic (GA), and pectin (PEC), as carriers combined in different proportions (20% MD, 15% MD + 5% GA, 15% MD + 5% PEC), on encapsulation of Cherokee blackberry pulp extract obtained by freeze-drying. The results of moisture content (2.73-3.36%), water activity (aw) (0.11-0.15), solubility (52.40-54.11%), hygroscopicity (17.59-21.11%), colour (hue 0.24-0.32), retention of anthocyanins (51.55-60.53%), total phenolic compounds (39.72-70.73 mg GAE/100g), antioxidant activity at 25 mg/mL (77.89-80.02%), IC50 (12.26-14.53), simulated in vitro digestion and morphology were discussed. Concerning morphology, blackberry powders had irregular structures and amorphous structures. Comparatively, the best results were obtained for MD-GA. MD-GA presented the highest content of phenolic compounds (70.73 ± 1.84 mg GAE/100g) and antioxidant activity (80.02%), as well as the lowest IC50 value (12.26). In general, all powders showed an increase in phenolic compounds during in vitro digestion, because of the pH conditions and digestive enzymes present in the simulated digestive fluid. This result shows that the wall material provides protection, since the blackberry rich extract (RE) showed degradation of phenolic compounds in in vitro digestion. In this sense, freeze-drying is a suitable technique for the encapsulation of Cherokee blackberry pulp extract.

Enzymatic synthesis of ascorbyl oleate and evaluation of biological activities.

Compounds that reduce or neutralize free radicals have been evaluated for use as nutraceutical or antioxidant additives in processed foods. This study aimed to enzymatically produce ascorbyl oleate and assess its biological properties. The synthesis was performed under previously maximized conditions (L-ascorbic acid/oleic acid 1:9 molar ratio, 70 °C, 1 h reaction). Immobilized commercial lipase from Candida antarctica (NS 88011) was used as biocatalyst. The reaction product was isolated, and its structure was confirmed by High-Performance Liquid Chromatography and Nuclear Magnetic Resonance. Ascorbyl oleate showed antioxidant and antimicrobial activity, besides no toxicity, did not influencing blood coagulation and also not presenting hemolytic profile. Better storage stability was achieved under refrigerated conditions, and the oxidative stability demonstrated free radicals fighting efficiency, increasing olive oil's shelf life. In vitro gastrointestinal simulation showed that ascorbyl oleate maintained antioxidant potential up to the duodenum stage during the digestive process. Therefore, the synthesized natural compound presented a high potential to be applied in the food and pharmaceutical industries.

Caracterização físico-química da farinha e dos extratos das sementes de abacate (Persea americana (Mill.) Lauraceae)

Introdução: as indústrias de processamento de frutas geram grande quantidade de biomassa residual que poderia ser reaproveitada. Considerando o elevado volume de resíduos produzidos pelo descarte das sementes do abacate e destacando o alto teor de compostos bioativos, é um produto interessante para ser avaliado. Objetivo: avaliar a composição centesimal da farinha das sementes de abacate e as propriedades antioxidantes e antimicrobianos dos seus extratos. Métodos: os extratos foram obtidos por maceração da farinha do caroço do abacate desidratada em diferentes temperaturas (4,25 e 60 °C) utilizando n-hexano e etanol como solventes. Resultados: verificou-se que a farinha é uma excelente fonte de carboidratos, com alto teor de fibras, proteínas e minerais (N, K, Mg e Ca, entre outros). A temperatura da extração influenciou tanto no rendimento como no conteúdo de fenóis totais, atividades antioxidantes e antimicrobianas dos extratos. Os extratos etanoicos obtidos à 60 °C apresentaram maior rendimento (18%) e teor de compostos fenólicos totais (~840 mgEAG/g). Também os extratos etanoicos apresentaram maior atividade antioxidante (IC50= 0,013 mg/mL e 0,018 mg/mL) em temperaturas mais baixas de extração, 4 °C e 25 °C, respectivamente. Já extrato hexanóico obtido à 4 °C apresentou maior atividade antimicrobiana para as quatro bactérias testadas (L. monocytogenes, S. aureus, S. choleraesuis e E. coli). Conclusão: a farinha obtida das sementes de abacate, apresentam alto valor biológico e podem ser usadas como suplementos na alimentação humana.

SUMMARY Introduction: The fruit processing industries generate a large amount of residual biomass that could be reused. Considering the high volume of residues produced by the disposal of avocado seeds and highlighting the high content of bioactive compounds. Aim: To evaluate the centesimal composition of avocado seed flour and the antioxidant and antimicrobial properties of its extracts. Methodology: The extracts were obtained by macerating the avocado seed flour dehydrated at different temperatures (4,25 and 60 °C) using n-hexane and ethanol as solvents. Results: The flour is an excellent source of carbohydrates, with a high content of fibers, proteins and minerals (N, K, Mg and Ca, among others). The extraction temperature has influence in the yield and the content of total phenols, antioxidant and antimicrobial activities of the extracts. The ethanolic extracts obtained at 60 °C showed high yield (18%) and content of total phenolic compounds (~840 mg GAE/g). In addition, ethanol extracts showed high antioxidant activity (IC50= 0.013 mg/mL and 0.018 mg/mL) at lower extraction temperatures, 4 °C and 25 °C, respectively. Hexanoic extract obtained at 4 °C, on the other hand, showed greater antimicrobial activity for the four tested bacteria (L. monocytogenes, S. aureus, S. choleraesuis and E. coli). Conclusion: The flour obtained from avocado seeds has a high biological value and can be used as supplements in human food.

Introducción: las industrias de procesamiento de frutas generan una gran cantidad de biomasa residual que podría reutilizarse. Considerando el alto volumen de residuos que produce la disposición de semillas de aguacate y destacando el alto contenido de compuestos bioactivos. Objetivo: evaluar la composición centesimal de la harina de semilla de aguacate y las propiedades antioxidantes y antimicrobianas de sus extractos. Metodología: los extractos se obtuvieron macerando la harina de semilla de aguacate deshidratada a diferentes temperaturas (4, 25 y 60 °C) utilizando n-hexano y etanol como solventes. Resultados: la harina es una excelente fuente de carbohidratos, con un alto contenido en fibras, proteínas y minerales (N, K, Mg y Ca, entre otros). La temperatura de extracción influye en el rendimiento y el contenido de fenoles totales, actividades antioxidantes y antimicrobianas de los extractos. Los extractos etanólicos obtenidos a 60 °C mostraron alto rendimiento (18%) y contenido de compuestos fenólicos totales (~ 840 mg GAE/g). Además, los extractos de etanol mostraron una alta actividad antioxidante (IC50 = 0,013 mg/mL y 0,018 mg/mL) a temperaturas de extracción más bajas, 4 °C y 25 °C, respectivamente. El extracto hexano obtenido a 4 °C, en cambio, mostró mayor actividad antimicrobiana para las cuatro bacterias ensayadas (L. monocytogenes, S. aureus, S. choleraesuis y E. coli). Conclusión: la harina obtenida a partir de semillas de aguacate tiene un alto valor biológico y puede ser utilizada como complemento en la alimentación humana.

Production of benzyl cinnamate by a low-cost immobilized lipase and evaluation of its antioxidant activity and toxicity.

In this work was optimized the production of benzyl cinnamate by enzymatic catalysis using the immobilized lipase NS88011 and to evaluate its biological properties. The optimized condition for this system was 1:3 (acid:alcohol) molar ratio, 59 °C, biocatalyst concentration 4.4 mg.mL-1 for 32 h, with a yield of 97.6 %. The enzyme stability study showed that the enzyme remains active and yields above 60 % until the 13th cycle (416 h), presenting a promising half-life. In the determination of the antioxidant activity of the ester, an inhibitory concentration necessary to inhibit 50 % of the free radical 2,2-diphenyl-1-picryl-hydrazyl DPPH (IC50) of 149.8 mg.mL-1 was observed. For acute toxicity against bioindicator Artemia salina, lethal doses (LD50) of 0.07 and 436.7 µg.mL-1 were obtained for the ester and cinnamic acid, showing that benzyl cinnamate had higher toxicity, indicating potential cytotoxic activity against human tumors.

Biological properties of functional flavoring produced by enzymatic esterification of citronellol and geraniol present in Cymbopogon winterianus essential oil.

The chemical composition and biological properties of citronella essential oil were modified by enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella (Cymbopogon winterianus) essential oil, into geranyl (99%) and citronellyl (98%) cinnamates was obtained after 48 hours of reaction using a molar ratio of 3:1 (cinnamic acid/alcohol), lipase concentration (Novozym 435) of 15% (w/w) and 70 °C. The esterified oil showed higher antimicrobial activity against Staphylococcus aureus bacteria resistant to oxacillin and penicillin and also greater larvicidal activity against Aedes aegypti larvae compared to unesterified oil. The results concerning the evaluation of toxicity against Artemia salina and cytotoxicity against monkey kidney epithelial cells also showed the superiority of the esterified oil.

Electronic Nose Based on Carbon Nanocomposite Sensors for Clove Essential Oil Detection.

This work describes the development of an electronic nose (e-nose) based on carbon nanocomposites to detect clove essential oil (CEO), eugenol (EUG), and eugenyl acetate (EUG.ACET). Our e-nose system comprises an array of six sensing units modified with nanocomposites of poly(aniline), graphene oxide, and multiwalled carbon nanotubes doped with different acids, dodecyl benzene sulfonic acid, camphorsulfonic acid, and hydrochloric acid. The e-nose presented an excellent analytical performance to the detected analytes (CEO, EUG, and EUG.ACET) with high sensitivity and reversibility. The limit of detection was lower than 1.045 ppb, with response time (<13.26 s) and recovery time (<106.29 s) and low hysteresis. Information visualization methods (PCA and IDMAP) demonstrated that the e-nose was efficient to discriminate the different concentrations of analyte volatile oil compounds. PM-IRRAS measurements suggest that the doping mechanism of molecular architectures is composed of a change in the oscillation energy of the characteristic dipoles and changes in the molecular orientation dipoles C═C and C═O at 1615 and 1740 cm-1, respectively. The experimental results indicate that our e-nose system is promising for a rapid analysis method to monitor the quality of essential oils.

(3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one attenuates hyperglycemia, increased hepatic glycogen content and hepatic damage induced by malathion acute exposure in rats.

BACKGROUND: Organophosphorus pesticides (OP's) are heavily constituted in agriculture, gardens, home and veterinary and although it is useful, there are concerns about the environment, safety and health of human and animals. In this study, we investigated the effects of a new oxime, (3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one (OXIME) against the alterations induced by malathion, an OP insecticide, acute exposure on markers of hepatic damage, glucose homeostasis, oxidative stress in rats cholinesterase (ChE) activity in rats. METHODS: Adult male Wistar rats were divided into four groups: Control; Malathion; OXIME; and Malathion+OXIME. Twelve hours after co-treatment with malathion (250 mg/kg, i.p.) and/or OXIME (50 mg/kg, i.g.), the plasma and liver samples were collected for biochemical analyses. RESULTS: The OXIME blocked the increase of plasma markers of hepatic function (AST and ALP) and the enzymatic inhibition of catalase and glutathione reductase in the liver of malathion-treated rats. Moreover, the hepatic cholinesterases inhibition induced by malathion acute exposure was suppressed by OXIME treatment. As assessed, a single dose of OXIME lowered the glycemia levels and hepatic glycogen content enhanced by malathion. CONCLUSIONS: This study suggests promise effects of (3Z)-5-Chloro-3-(Hydroxyimino) indolin-2-one against the hyperglycemia and the hepatic damage induced by malathion acute exposure, as well as its use as a ChE activity reactivator.

7-Chloro-4-(Phenylselanyl) Quinoline with Memory Enhancer Action in Aging Rats: Modulation of Neuroplasticity, Acetylcholinesterase Activity, and Cholesterol Levels.

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) to restore the cognitive impairment caused by aging in male Wistar rats. Moreover, modulation of neuroplasticity markers, acetylcholinesterase (AChE) activity, and cholesterol levels was performed. Aged rats were intragastrically treated with 4-PSQ (5 mg/kg) for 7 days. Animals were tested in behavioral tasks, and then plasma (to determine cholesterol levels), hippocampus, and cerebral cortex (to determine neural cell adhesion molecule (NCAM) and polysialyltransferase (PST) levels, and AChE activity) were removed. Our findings demonstrated that treatment of aged rats with 4-PSQ restored short-term and long-term memories in the object recognition tests. 4-PSQ treatment did not restore exploratory activity (rearings) but partially restored locomotor activity (crossings) reduced by aging in the open-field test. Moreover, the compound restored the reduction in the NCAM and PST levels, and AChE activity in cerebral structures, as well as the increase in the plasma cholesterol levels, caused by aging in rats. In conclusion, 4-PSQ restored cognitive impairment caused by aging in rats by modulating synaptic plasticity, cholinergic system, and cholesterol levels.

Linseed (Linum usitatissimum) Oil Extraction Using Different Solvents.

This work aims at characterizing linseed oil obtained using different extraction methods (hexane, subcritical propane and pressurized ethanol), and comparing the results with commercial linseed oil extracted by cold mechanical press method. An experimental design helped to evaluate temperature and pressure effects on the oil extraction using propane and ethanol. Gas chromatography assisted in evaluating the essential fatty acids. There were no significant differences among the ω-3, 6 and 9 fatty acids from linseed oil obtained using the different extraction methods. Only the acidity of linseed oil extracted by subcritical propane (0.956%) showed significant differences among the physicochemical parameters. Extraction using organic solvent (Soxhlet) gave a 36.12% yield. Extraction using subcritical propane at 107 Pa and 40 °C for 1.5 h gave a better yield (28.39%) than pressurized ethanol (8.05%) under similar conditions. Linseed oil extraction using subcritical propane was economically viable, resulting in a 124.58 US$/L product cost. The results present subcritical propane extraction as a promising alternative for obtaining linseed oil at mild temperature and pressure conditions, without losing quality and quantity of fatty acids such as ω-3, 6 and 9.

Protective role of chrysin on 6-hydroxydopamine-induced neurodegeneration a mouse model of Parkinson's disease: Involvement of neuroinflammation and neurotrophins.

Chrysin is a natural flavonoid which is found in bee propolis, honey and various plants, and neuroprotective effect of chrysin in mice was previously demonstrated by our group. Neuroinflammation, neurotrophic factors and neuronal recovery factors associated with the neuroprotective effect of this flavonoid require further investigations. Thus, now we investigated the possible involvement of inflammatory cytokines, neurotrophic factors and neuronal recovery in the effect of chrysin in 6-hydroxidopamine (6-OHDA), a well-established model of Parkinson's disease, in striatum of mice. The 6-OHDA microinjection induced behavioral alterations on the rotarod test and apomorphine-induced circling behavior in mice. 6-OHDA administration elevated levels of tumour necrosis factor-α, interferon-gamma, interleukin-1ß, interleukin-2, interleukin-6 and nuclear factor-kappa B and decreased the interleukin-10 levels, total reactive antioxidant potential and total antioxidant reactivity in striatum, as well as, modified the calcium-binding protein B (S100B), brain-derived neurotrophic factor, nerve growth factor and glial cell line-derived neurotrophic factor levels. The intrastriatal injection of 6-OHDA also induced an decrease of dopamine, 3,4-dihydroxyphenylacetic acid, homovanylic acid levels and tyrosine hydroxylase content. Oral treatment with chrysin (10 mg/kg, 28 days), culminated with the prevention of these alterations occasioned by 6-OHDA. These results corroborated with the neuroprotective effect of chrysin in the treatment of Parkinson's disease and, indicated the mechanism involved throught the inflammatory cytokines, neurotrophic factors and recovery of dopaminergic neurons in striatum.

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil.

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R2 = 0.99). A negative matrix effect (-28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2-105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.

Active starch biopolymeric packaging film for sausages embedded with essential oil of Syzygium aromaticum.

Starch polymer matrices were developed with the incorporation of 1% clove essential oil (EO) (Syzygium aromaticum) aiming for use as active packaging for sausages. At the concentration of 1% EO in the polymer matrix, it showed exponential behavior with respect to oil release over 30 days, with faster release in the beginning and a tendency towards a reduction in release velocity over time. The presence of OE in the biofilm led to significant differences versus the control in terms of aroma and flavor parameters. It was found that EO had an antioxidant effect in sausages with a significant difference between treatments with respect to TBA (thiobarbituric acid) values at the end of a 15 day period of refrigerated storage. There were no significant variations in pH and Aw among treatments during the evaluated period. A significant negative correlation (-0.78) between brightness (L*) and the lipid oxidation of the products was observed.

Effect of Partial and Total Replacement of Inorganic by Organic Microminerals Sources on the Quality of Broiler Carcasses

ABSTRACT Among the nutrients involved in the chicken diet, the microminerals deserve attention as they exert essential functions in the organism. These compounds can be provided in inorganic (traditional) and organic (chelate) forms. In organic form, the micromimerals can attend a new concept related to a better bio-availability. In this sense, the objective of this work was to evaluate the effect of the partial and total substitution of inorganic by organic sources of microminerals on the animal diet, assessing its concentration in the blood and liver after 21 and 40 days and also in the bones after 40 days. Moreover, the effect on the physical-chemical and sensory characteristics of the muscle after 15 days of storage at 4°C was also evaluated. The animals were divided into five treatments: 100% inorganic, 70% inorganic and 30% organic, 50% inorganic and 50% organic, 30% inorganic and 70% organic and 100% organic-chelate. It is shown that the use of organic sources of microminerals in the diet of poultry induced to an increase of its concentrations in the blood and liver, with no significant alterations in the compositions of bones, compared to the use of inorganic sources. Feed formulated using 50% of organic minerals and 50% of inorganic minerals led to similar results. The diet with organic minerals or mixture with inorganic sources results in a low lipid oxidation in the drumsticks stored at 4°C for 15 days, in comparison with those using only inorganic minerals. No sensory alterations were observed for all different treatments.

Biomimetic Mineralization of the Alginate/Gelatin/Calcium Oxalate Matrix for Immobilization of Pectinase: Influence of Matrix on the Pectinolytic Activity.

Pectinases catalyze the degradation of pectic substances and are used in several processes, mainly in food and textile industries. In this study, a biomimetic matrix of alginate/gelatin/calcium oxalate (AGOCa) was synthesized for the in situ immobilization via encapsulation of crude pectinase from Aspergillus niger ATCC 9642, obtaining an immobilization efficiency of about 61.7 %. To determine the performance of AGOCa matrix, this was compared to control matrices of alginate/calcium oxalate (AOxal) and alginate/water (ACa). By the evaluation of pH and temperature effects on the enzyme activity, it was observed an increase on pectinolytic activity for both three tested matrices with an increase on pH and temperature. The kinetic parameters for pectinase immobilized in the three matrices were determined using citric pectin as substrate. Values of K m of 0.003, 0.0013, and 0.0022 g mL(-1) and V max of 3.85, 4.32, and 3.17 µmol min(-1) g(-1) for AGOCa, AOxal, and ACa matrices were obtained, respectively. After 33 days of storage, the pectinase immobilized in the three different matrices kept its initial activity, but that immobilized in AGOCa presented high stability to the storage with a relative activity of about 160 %. The enzyme immobilized in AGOCa, AOxal, and ACa could be used in 10, 8, and 7 cycles, respectively, keeping 40 % of its initial activity.

Antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced by enzymatic esterification.

This work reports the maximization of eugenyl acetate production by esterification of essential oil of clove in a solvent-free system using Novozym 435 as catalyst. The antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced were determined. The conditions that maximized eugenyl acetate production were 60 °C, essential oil of clove to acetic anhydride ratio of 1:5, 150 rpm, and 10 wt% of enzyme, with a conversion of 99.87 %. A kinetic study was performed to assess the influence of substrates' molar ratio, enzyme concentration, and temperature on product yield. Results show that an excess of anhydride, enzyme concentration of 5.5 wt%, 50 °C, and essential oil of clove to acetic anhydride ratio of 1:5 afforded nearly a complete conversion after 2 h of reaction. Comparing the antibacterial activity of the essential oil of clove before and after esterification, we observed a decrease in the antimicrobial activity of eugenyl acetate, particularly with regard to minimum inhibitory concentration (MIC). Both eugenyl acetate and clove essential oil were most effective to the gram-negative than gram-positive bacteria group. The results showed a high antioxidant potential for essential oil before and particularly after the esterification reaction thus becoming an option for the formulation of new antioxidant products.

Concentration, characterization and application of lipases from Sporidiobolus pararoseus strain.

Lipases produced by a newly isolated Sporidiobolus pararoseus strain have potential catalytic ability for esterification reactions. After production, the enzymatic extracts (conventional crude and precipitated, 'CC' and 'CP', and industrial crude and precipitated, 'IC' e 'IP') were partially characterized. The enzymes presented, in general, higher specificity for short chain alcohols and fatty acids. The precipitated extract showed a good thermal stability, higher than that for crude enzymatic extracts. The 'CC' and 'CP' enzymes presented high activities after exposure to pH 6.5 and 40 °C. On the other hand, the 'IC' and 'IP' extracts kept their activities in a wide range of pH memory but presented preference for higher reaction temperatures. Preliminary studies of application of the crude lipase extract in the enzymatic production of geranyl propionate using geraniol and propionic acid as substrates in solvent-free system led to a reaction conversion of 42 ± 1.5%.