Antioxidant activity of rosemary extract, acerola extract and a mixture of tocopherols in sausage during storage at 8 °C.

Sausage is an emulsified meat product that, due to its composition, undergoes physicochemical changes during its shelf life, which makes the use of additives for its conservation necessary. The goal of the present study was to evaluate the antioxidant capacity of rosemary extract, acerola extract, and a mixture of tocopherols applied to industrialized sausages during storage at 8 °C. The antioxidant activity (IC50) in vitro showed values of 0.043, 0.489, 0.494, and 0.509 mg/mL for sodium erythorbate, rosemary extract, acerola extract, and a mixture of tocopherols, respectively. Formulations of sausage obtained in industrial installations were evaluated in terms of physicochemical, microbiological, and sensorial analyses. The pH and acidity values were stable during 23 days of storage. Treatments 1 and 3 with acerola extract and a mixture of tocopherols associated with sodium erythorbate showed the best results against lipid oxidation (TBARs), respectively. The hydroperoxides were only found after the 12th day of storage, consequently reducing the formation of malondialdehyde. The treatments with natural antioxidants showed an antimicrobial effect for the group of mesophilic bacteria; their results did not exceed 4 log10 CFU/g, while the control reached 5 log10 CFU/g on the 23rd day of storage. In regard to other microorganisms evaluated, no significant differences were found between treatments with natural antioxidants. Thus, the natural extracts evaluated in association with sodium erythorbate contributed to the antioxidant action for the application on an industrial scale, as they improved the sausage characteristics after 23 days of storage at 8 °C. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05815-y.

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.

Ultrasound as an alternative method to increase the extraction yield from chicken mecanically separated meatresidue collagen.

The residue from chicken mechanically separated meat (MSM) is a potential source for the extraction of collagen. However, this process requires the removal of many covalent crosslinks, which makes it quite complex. Ultrasound has been successfully used to extract collagen; it reduces the process time and increases the yield. However, information regarding the effects of this treatment on the structural and functional properties of proteins is still very limited. Therefore, the aims of the present study were to obtain collagen from chicken MSM residue and to test the effects of pre-treatment with ultrasonic probe and enzymatic extraction with pepsin in its yield, as well as to evaluate the properties of extracted collagen using gel electrophoresis, Fourier-transform infrared spectroscopy, solubility, and differential scanning calorimetry. Both the ultrasound and the enzymatic extraction had a positive effect on the extraction yield of collagen from chicken MSM residue without affecting its integrity. Using ultrasound led to an increase of up to 40% in yield when compared to treatments without ultrasound application. Five extraction treatments were considered. The extracted collagen exhibited high thermal stability (43.9-47.0 °C) and mainly type I structure. The use of ultrasound as pre-treatment, together with enzymatic extraction with pepsin, were effective in increasing the extraction yield of collagen from chicken MSM residue, as well as preserving the triple helical structure of the native collagen.

Molecular inferences about the genus Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae): a review.

This review compiles and discusses the use of genetic markers applied in the study of the fish genus Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae). The database comprises 51 peer-review articles that were published in the last 52 years (1968-2020) and that approach analysis based on different classes of genetic markers. The use of cytogenetic and enzymatic markers was predominantly especially in population studies with the genus Hypostomus, while mitochondrial markers were the majority in phylogenetic studies. Although significant methodological advances have occurred for molecular evaluation, they are still modestly applied to the study of neotropical fish genera, in which Hypostomus is included. New perspectives, especially on integrative approaches, are needed to improve our knowledge of the genetic functionality of fishes.

Light environment influences the flood tolerance in Cordia americana (L.) Gottschling & J.S.Mill.

The subtropical riverine forests present a variation in soil water availability throughout the year, following precipitation seasonality. The objective of this work was to evaluate the responses of Cordia americana to different light intensities combined with soil flooding. Seedlings were acclimated to light treatments, with full sun and shade conditions. Sun and shade plants were subjected to soil flooding during periods of 10 (short) and 30 (longer) days. After 10 days, flooded plants had a higher root dry mass accumulation and soluble sugars content, regardless of the light condition. Shade plants presented higher shoot soluble sugars content in relation to the sun plants. After 30 days, a higher shoot soluble sugar content was observed in sun and shade flooded plants. In addition, a higher root soluble sugar content was also observed in sun plants under flood. Periods of short flooding, characterized in subtropical forests as from 5 to 15 days, favor the growth of shade plants and the roots sugar accumulation, fact that can explain the species distribution. However, long periods of flooding may be associated with light environment plasticity, suggesting that the sun plants present a higher flooding tolerance, directly associated with the ability to maintain the sugar content.

Biotechnological potential of agro-industrial waste in the synthesis of pectin lyase from Aspergillus brasiliensis.

This study aims at investigating pectin lyase bioproduction in submerged fermentation with synthetic medium and agro-industrial residues, using the filamentous fungus Aspergillus brasiliensis. The maximum pectin lyase activity in a synthetic medium (42 g/l pectin, 40 g/l yeast extract, and 0.02 g/l iron sulfate) was 31 U/ml, and 46 U/ml in the agro-industrial medium (160 g/l orange peel, 150 g/l corn steep liquor, and 300 g/l parboiled rice water), obtained over 60 and 124 h of bioproduction, 180 r/min, 30 ℃, pHinitial 5.5, and 5·106 spores/ml, respectively. Partial characterization of pectin lyase crude enzyme extract obtained from the synthetic medium and the one made of agro-industrial residues showed optimum conditions at pH of 5.5 and 4.5 and temperatures of 37 and 55 ℃, respectively. The Ed obtained was 3.13 and 9.15 kJ/mol, and the half-life time (t1/2) was 5.71 and 80 h at 55 ℃ for pectin lyase produced in synthetic and agro-industrial medium, respectively.

Functional Carboxymethylcellulose/Zein Bionanocomposite Films Based on Neomycin Supported on Sepiolite or Montmorillonite Clays.

The present work introduces new functional bionanocomposite materials based on layered montmorillonite and fibrous sepiolite clays and two biopolymers (carboxymethylcellulose polysaccharide and zein protein) to produce drug-loaded bionanocomposite films for antibiotic topical delivery. Neomycin, an antibiotic indicated for wound infections, was employed as the model drug in this study. The physical properties and the antimicrobial activity of these materials were evaluated as a function of the type of hybrid and the amount of zein protein incorporated in the bionanocomposite films. In addition, the interfacial and physicochemical properties of these new clay-drug hybrids have been studied through a combination of experimental and computational methodologies, where the computational studies confirm the intercalation of neomycin into the montmorillonite layers and the possible penetration of the drug in the tunnels of sepiolite, as pointed out by N2 adsorption and X-ray diffraction techniques. The antimicrobial activity of these bionanocomposite materials show that the films based on montmorillonite-neomycin display a more pronounced inhibitory effect of the bacterial growth than those prepared with the sepiolite-neomycin hybrid. Such effect can be related to the difficult release of neomycin adsorbed on sepiolite due to a strong interaction between both components.

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.

Influence of the addition of natural antioxidant from mate leaves (Ilex paraguariensis St. Hill) on the chemical, microbiological and sensory characteristics of different formulations of Prato cheese.

The objective of this work is to evaluate the effects of the addition of dried extract from mate leaves and mesophilic cultures (Lactococcus lactis ssp. lactis and cremoris) on the chemical, microbiological and sensory characteristics of Prato cheese. The Prato cheese presented high moisture contents (49 to 53 %) and mean pH values of 5.15 for all tested formulations. The addition of mate leaves extract in the product did not influence the growth of the microbial cultures. During the maturation time, all formulations with the addition of adjunct cultures and mate leaves extract presented lower levels of lipid and protein oxidation compared to the control, proving the antioxidant effect of mate extract. The formulation of Prato cheese added of 0.1 wt.% of extract presented acceptability of about 80 % after 30 days of maturation. The sensory evaluation showed that only the formulation added by adjunct culture and 0.2 wt.% of mate extract presented lower values for the attributes global acceptance, texture and flavor, compared to the control. The formulations added of mate leaves extract presented residual bitter flavor after 45 days of storage.

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.

Comparative lethality kinetic curves and predictive models of F-value for Listeria monocytogenes using different sanitizers.

The objective of this work was to evaluate the kinetic of inactivation of Listeria monocytogenes using peracetic acid, chlorhexidine, and organic acids as active agent, determining the respective D-, Z-, and F-values. From our knowledge, these important results from an industrial view point are not available in the current literature, mainly for organic acids, pointing out the main contribution of the present work. Lower D-values were obtained for peracetic acid and chlorhexidine, compared with the organic acids. For the reduction of 6 log10 of L. monocytogenes using peracetic acid, at 0.2, 0.1, and 0.05% are necessary 7.08, 31.08, and 130.44 min of contact, respectively. The mathematical models of F-values showed that at concentrations lower than 0.15% one can verify an exponential increase in F-values, for both de chlorhexidine and peracetic acid. The organic acids presented a linear behavior, showing slight variation in F-values, is even more effective in under dosage. The results obtained are of fundamental importance in terms of industrial strategy for sanitization procedure, permitting to choose the best relation product concentration/exposure time, aiming at reducing costs without compromising the disinfectant efficiency.

Solvent-Free Production of Bioflavors by Enzymatic Esterification of Citronella (Cymbopogon winterianus) Essential Oil.

Enzymatic esterification of citronella essential oil towards the production of geranyl and citronellyl esters may present great scientific and technological interest due to the well-known drawbacks of the chemical-catalyzed route. In this context, this work reports the maximization of geranyl and citronellyl esters production by esterification of oleic and propionic acids in a solvent-free system using a commercial immobilized lipase as catalyst. Results of the reactions showed that the strategy adopted for the experimental design proved to be useful in evaluating the effects of the studied variables on the reaction conversion using Novozym 435 as catalyst. The operating conditions that maximized the production of each ester were determined, leading, in a general way, to conversions of about 90% for all systems. New experimental data on enzymatic esterification of crude citronella essential oil for geranyl and citronellyl esters production in solvent-free system are reported in this work.

Optimization of α-Terpineol production by the biotransformation of R-(+)-limonene and (-)-ß-pinene.

The main objective of this work is to present the optimization of the biotransformation of R-(+)-limonene and (-)-ß-pinene aiming at the production of α-terpineol by strains of fungal and yeasts previously isolated by our research group using the methodology of experimental design. New optimized experimental data on α-terpineol production by the biotransformation of R-(+)-limonene and (-)-ß-pinene using newly isolated microorganisms are reported in this work. Conversion of about 1,700 mg/L was achieved when R-(+)-limonene was used as substrate and the newly isolated strain 05.01.35 as microorganism at the central point of the experimental design, corresponding to a substrate concentration of 1.75%, mass of inoculum of 2 g, and substrate to ethanol volume ratio of 1:1. The same experimental condition led to higher conversions when (-)-ß-pinene was used as substrates and the strains coded as 04.05.08 and 01.04.03 as microorganism. Here, conversions of about 770 mg/L were achieved.

Solvent-free geranyl oleate production by enzymatic esterification.

This work reports the optimization of geranyl propionate production by esterification of geraniol and propionic acid in a solvent-free system using a commercial lipase as catalyst. For this purpose, a sequential strategy was performed applying two experimental designs. The operating conditions that optimized geranyl propionate production were determined to be 40 °C, geraniol to propionic acid molar ratio of 3:1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the optimum reaction parameters, a kinetic study was carried out evaluating the influence of substrates molar ratio, enzyme concentration and temperature on reaction conversion. Results obtained in this step allow to conclude that an excess of alcohol (acid to alcohol molar ratio of 1:6), relatively low enzyme concentration (5 wt%), temperature of 40 °C and substrates molar ratio of 1:1 afforded nearly complete reaction conversion after 30 min of reaction. New experimental data on enzymatic esterification of geraniol and propionic acid for geranyl propionate production are reported in this work, showing a promising perspective of the technique to overcome the well-known drawbacks of the chemical-catalyzed route.

Erratum to: Solvent-free geranyl oleate production by enzymatic esterification.

This study reports the maximization of geranyl oleate production by esterification of geraniol and oleic acid in a solvent-free system using a commercial lipase as catalyst. The operating conditions that maximized geranyl oleate production were determined to be 40 °C, geraniol to oleic acid molar ratio of 5:1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the best reaction parameters, a kinetic study was performed and the results obtained in this step allow to conclude that an excess of alcohol (alcohol to acid molar ratio of 5:1), relatively low enzyme concentration (5 wt%) and temperature of 50 °C afforded nearly complete reaction conversion after 1 h of reaction. New experimental data on enzymatic esterification of geraniol and oleic acid for geranyl oleate production are reported in this work, showing a promising perspective of the technique to overcome the inconvenience of the chemical-catalyzed route.

Screening of pectinase-producing microorganisms with polygalacturonase activity.

The aim of this work was to perform the screening of microorganisms, previously isolated from samples of agro-industrial waste and belonging to the culture collection of our laboratory, able to produce polygalacturonases (PG). A total of 107 microorganisms, 92 newly isolated and 15 pre-identified, were selected as potential producers of enzymes with PG activity. From these microorganisms, 20 strains were able to synthesize PG with activities above 3 U mL(-1). After the kinetic study, the enzyme activity was increased up to 13 times and the microorganism identified as Aspergillus niger ATCC 9642 and the newly isolated W23, W43, and D2 (Penicillium sp.) after 24 h of fermentation led to PG activities of 30, 41, 43, and 45 U mL(-1), respectively. The RAPD analysis demonstrated that the selected strains differs genetically, indicating that no duplication of strains among them in the experiments for polygalacturonases production was verified.

Microbial oxidation of (-)-α-pinene to verbenol production by newly isolated strains.

Verbenol is a bicyclicbicycle secondary allylic alcohol, with pronounced camphor and mint flavor notes, mainly used as food flavoring. This compound is also used to control harmful insects, and hence has potential for using in agriculture, and is an intermediate in the synthesis of valuable perfume and medicinal substances. This work is focused on the microbial oxidation of (-)-α-pinene to verbenol production. To carry out the present study, 405 microorganisms were tested for their ability to bioconvert the substrate. From the isolated microorganisms, 193 were selected in the pre-screening using mineral medium for limonene degradation. At the screening step, 31 strains were able to convert (-)-α-pinene in verbenol. The highest concentration in verbenol from (-)-α-pinene was about 125.6 mg/L for yeast isolated from orange juice industrial residue.

Isolation and screening of microorganisms for R-(+)-limonene and (-)-beta-pinene biotransformation.

This work is focused on the biotransformation of R-(+)-limonene and (-)-beta-pinene to bioflavor production. To carry out the present study, 405 microorganisms were tested for their ability to bioconvert the substrates. From the isolated microorganisms, 193 were selected in the prescreening using mineral medium for limonene degradation. At the screening step, eight strains were able to convert R-(+)-limonene and 15 to transform (-)-beta-pinene, both in alpha-terpineol. The highest concentration in alpha-terpineol from R-(+)-limonene was about 3,450 mg/L for Penicillium sp. isolated from eucalyptus steam. From (-)-beta-pinene, the highest product concentration of 675.5 mg/L was achieved using an Aspergillus sp. strain isolated from orange tree stem.

Enzymatic production of linalool esters in organic and solvent-free system.

This work investigated the influence of temperature, enzyme concentration, substrates molar ratio, in the absence and presence of organic solvent, at two molar ratios of the substrates on the enzymatic production of linalil esters using the immobilized lipase Novozym 435 as catalyst, different acids and linalool and Ho-Sho essential oil as substrates. The best reaction conversion was obtained at the highest temperature (70 degrees C), for both solvent free (3.81%) and with solvent addition (2.25%), for a solvent to substrates molar ratio of 2:1, enzyme concentration of 5 wt% and acid to alcohol molar ratio of 1:1. The reaction kinetics revealed that Ho-Sho essential oil afforded the greatest conversions when compared with pure linalool. Higher linalil esters production were achieved after 10 h reaction (5.58%) in 2:1 solvent to substrates molar ratio, with enzyme concentration of 5 wt%, at 70 degrees C and anhydride to alcohol molar ratio of 1:1 using Ho-Sho essential oil as substrate.

Optimization of extraction of lipase from wheat seeds (Triticum aestivum) by response surface methodology.

This work aimed to evaluate the effects of particle size, solid/solvent ratio (w/v), and reaction time on hydrolytic and esterification activities of a lipase extract from wheat seeds. The higher hydrolytic activity was 5.9 U/g with a particle size of 425 microm, solid/solvent ratio of 30:60 (w/v), and reaction time of 15 h, with maximum hydrolytic activity of 14.47 U/g after 24 h of precipitation. For esterification activity the best result was 57.88 U/g with a particle size of 425 microm and solid/solvent ratio of 30:120 (w/v) for 5 h, with a maximum value after 10 h of precipitation reaching 208.20 U/g. The partial characterization showed that the optimal pH and temperature were found to be 5.5 and 32-37 degrees C, respectively. The extract stability at low temperatures was kept after 48 h of storage in terms of esterification activity. The hydrolytic activity was kept constant at -10 degrees C during 72 h and diminished considerably after 24 h at 4 degrees C.