Purification, bioactivity and application of maltobionic acid in active films.

The objective of this study was to purify sodium maltobionate using Zymomonas mobilis cells immobilized in situ on flexible polyurethane (PU) and convert it into maltobionic acid for further evaluation of bioactivity (iron chelating ability, antibacterial potential and cytoprotection) and incorporation into films based on cassava starch, chitosan, and cellulose acetate. Sodium maltobionate exhibited a purity of 98.1% and demonstrated an iron chelating ability of approximately 50% at concentrations ranging from 15 to 20 mg mL-1. Maltobionic acid displayed minimal inhibitory concentrations (MIC) of 8.5, 10.5, 8.0, and 8.0 mg mL-1 for Salmonella enterica serovar Choleraesuis, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes, respectively. Maltobionic acid did not exhibit cytotoxicity in HEK-293 cells at concentrations up to 500 µg mL-1. Films incorporating 7.5% maltobionic acid into cassava starch and chitosan demonstrated inhibition of microbial growth, with halo sizes ranging from 15.67 to 22.33 mm. These films had a thickness of 0.17 and 0.13 mm, water solubility of 62.68% and 78.85%, and oil solubility of 6.23% and 11.91%, respectively. The cellulose acetate film exhibited a non-uniform visual appearance due to the low solubility of maltobionic acid in acetone. Mechanical and optical properties were enhanced with the addition of maltobionic acid to chitosan and cassava films. The chitosan film with 7.5% maltobionic acid demonstrated higher tensile strength (30.3 MPa) and elongation at break (9.0%). In contrast, the cassava starch film exhibited a high elastic modulus (1.7). Overall, maltobionic acid, with its antibacterial activity, holds promise for applications in active films suitable for food packaging. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03879-3.

Anthraquinone as emerging contaminant: technological, toxicological, regulatory and analytical aspects.

Anthraquinone (anthracene-9,10-dione) is a multifaceted chemical used in the paper industry, in the production of synthetic dyes, in crop protection against birds and is released from fossil fuels. Additionally, the anthraquinone scaffold, when substituted with sugars and hydroxyl groups is found in plants as metabolites. Because of these multiple applications, it is produced on a large scale worldwide. However, its toxicological aspects have gained interest, due to the low limits in the foods defined by legislation. Worrying levels of anthracene-9,10-dione have been detected in wastewater, atmospheric air, soil, food packaging and more recently, in actual foodstuffs. Recent investigations aiming to identify the anthracene-9,10-dione contamination sources in teas highlighted the packaging, leaves processing, anthracene metabolism, reactions between tea constituents and deposition from the environment. In this context, this review seeks to highlight the uses, sources, biological effects, analytical and regulatory aspects of anthracene-9,10-dione.

Malolactic fermentation of lactic acid bacteria isolated from southern Brazilian red wine.

The objective was to isolate lactic acid bacteria (LAB) from southern Brazil's wines and investigate their potential as starter cultures for malolactic fermentation (MLF) in Merlot (ME) and Cabernet Sauvignon (CS) wines through the fermentative capacity. The LAB were isolated from CS, ME, and Pinot Noir (PN) wines in the 2016 and 2017 harvests and evaluated for morphological (color and shape of the colonies), genetic, fermentative (increase in pH, acidity reduction, preservation of anthocyanins, decarboxylation of L-malic acid, yield of L-lactic acid, and content of reduced sugars), and sensory characteristics. Four strains were identified as Oenococcus oeni [CS(16)3B1, ME(16)1A1, ME(17)26, and PN(17)65], one as Lactiplantibacillus plantarum [PN(17)75], and one as Paucilactobacillus suebicus [CS(17)5]. Isolates were evaluated in the MLF and compared to a commercial strain (O. oeni), as well as a control (without inoculation and spontaneous MLF), and standard (without MLF). CS(16)3B1 and ME(17)26 isolates finished the MLF for CS and ME wines, respectively, after 35 days, similar to the commercial strain, and CS(17)5 and ME(16)1A1 isolates ended the MLF in 45 days. In the sensory analysis, ME wines with isolated strains received better scores for flavor and overall quality than the control. Compared to the commercial strain, CS(16)3B1 isolate obtained the highest scores for buttery flavor and taste persistence. CS(17)5 isolate received the higher scores for a fruity flavor and overall quality and the lowest for a buttery flavor. The native LAB displayed MLF potential, regardless of the year and grape species from which they were isolated.

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 Yarrowia lipolytica: cell viability and application in vitro ruminant diets.

Microencapsulation is an alternative to increase the survival capacity of microorganisms, including Yarrowia lipolytica, a widely studied yeast that produces high-value metabolites, such as lipids, aromatic compounds, biomass, lipases, and organic acids. Thus, the present study sought to investigate the effectiveness of different wall materials and the influence of the addition of salts on the microencapsulation of Y. lipolytica, evaluating yield, relationship with cell stability, ability to survive during storage, and in vitro application of ruminant diets. The spray drying process was performed via atomization, testing 11 different compositions using maltodextrin (MD), modified starch (MS) and whey protein concentrate (WPC), Y. lipolytica (Y. lipo) cells, tripolyphosphate (TPP), and sodium erythorbate (SE). The data show a reduction in the water activity value in all treatments. The highest encapsulation yield was found in treatments using MD + TPP + Y. lipo (84.0%) and WPC + TPP + Y. lipo (81.6%). Microencapsulated particles showed a survival rate ranging from 71.61 to 99.83% after 24 h. The treatments WPC + Y. lipo, WPC + SE + Y. lipo, WPC + TPP + Y. lipo, and MD + SE + Y. lipo remained stable for up to 105 days under storage conditions. The treatment WPC + SE + Y. lipo (microencapsulated yeast) was applied in the diet of ruminants due to the greater stability of cell survival. The comparison between the WPC + SE + Y. lipo treatment, wall materials, and the non-microencapsulated yeast showed that the microencapsulated yeast obtained a higher soluble fraction, degradability potential, and release of nutrients.

Active edible films based on green tea extract and gelatin for coating of fresh sausage.

The objective of this work was to develop, characterize and evaluate the application of active edible films based on gelatin and green tea extract in coating of fresh sausages. The green tea extract showed IC50 of 0.088 mg/mL and minimum inhibitory concentrations of 0.05 mg/mL for Listeria monocytogenes, 0.025 mg/mL for Staphylococcus aureus, 0.04 mg/mL for Escherichia coli, and >1.0 mg/mL for Salmonella enterica serovar Choleraesuis. The formulation with 15% (w/v) of gelatin and 30% (w/w) of glycerol showed better adhesion and appearance in the coating of the product. When using 1.0% of green tea extract, the lowest IC50, was obtained and the antioxidant activity was maintained for 35 days. There was a more accentuated decrease in pH and an increase in acidity and peroxide index in fresh sausages without film compared to those coated with the active film (1.0% of green tea extract) during storage. In addition, it was found that the use of active gelatin film (1.0% of green tea extract) kept the TBARS indexes of fresh sausage samples lower than the standard (without coating) and of films containing only gelatin, after 48 days of storage.

High-sodium maltobionate production by immobilized Zymomonas mobilis cells in polyurethane.

The purpose of this study was the production of maltobionic acid, in the form of sodium maltobionate, by Z. mobilis cells immobilized in polyurethane. The in situ immobilized system (0.125-0.35 mm) was composed of 7 g polyol, 3.5 g isocyanate, 0.02 g silicone, and 7 g Z. mobilis cell, at the concentration of 210 g/L. The bioconversion of maltose to sodium maltobionate was performed with different cell concentrations (7.0-9.0 gimobilized/Lreaction_medium), temperature (30.54-47.46 °C), pH (5.55-7.25), and substrate concentration (0.7-1.3 mol/L). The stability of the immobilized system was evaluated for 24 h bioconversion cycles and storage of 6 months. The maximum concentration of sodium maltobionate was 648.61 mmol/L in 34.34 h process (8.5 gdry_cell/Lreaction_medium) at 39 °C and pH 6.30. The immobilized system showed stability for 19 successive operational cycles of 24 h bioconversion and 6 months of storage, at 4 °C or 22 °C.

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.

Water absorption and dripping of chicken breast and carcasses during pre-cooling in an industrial system.

This study aimed to evaluate the parameters that influence the water absorption and drip of chicken carcasses due to the processing and pre-cooling of the meat in an industrial chiller. A total of 1,179 chickens were sampled during industrial processing to evaluate the influence of variables, validate the parameters, and conduct histological analysis. The best parameters for guaranteeing absorption levels and drip tests within acceptable limits on chicken carcasses were total residence time of 60 min (in the pre-chiller, chiller 1, and chiller 2); air pressure of chillers at 0.5 bar; the abdominal opening of carcasses at a maximum of 2 cm. These parameters did not influence the protein content, moisture/protein ratio, pH, or lipid content. The validation of the parameters and the histological analysis performed after each cooling stage showed that the most significant structural changes occurred in the pre-chiller, where the temperature of carcasses and water was higher, which contributes to greater absorption.