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.

Validation of a popsicle as a clear fluid to abbreviate preoperative fasting.

BACKGROUND & AIMS: This study is based on the development and validation of a popsicle to reduce preoperative fasting time. METHODS: The study was carried out in two stages, pre-clinical and clinical validation. The first stage consisted of producing a water-based, fat-free, high-calorie fruit-flavored popsicle, characterized by proximal composition and sensory analysis. In the second stage, clinical validation was performed in patients aged between 18 and 65 years before elective surgery, evaluating the incidence of aspiration during anesthesia and the patient's experience in relation to hunger, thirst, anxiety and palatability of the popsicle. RESULTS: The results of the study showed that the use of popsicle 2 h before the surgical procedure did not cause any adverse reaction in patients and in the anesthetic procedure. Furthermore, the full acceptability of the product by the participants and the control of thirst and satiety during the preoperative period were observed. CONCLUSIONS: The present study showed that with the use of popsicles it was possible to reduce safely the preoperative fasting time to up to 2 h before the surgical procedure.

Kinetic and stoichiometric parameters in the fed-batch bioreactor production of poly(3-hydroxybutyrate) by Bacillus megaterium using different carbon sources.

This study investigates the effects of different strategies on poly(3-hydroxybutyrate)-P(3HB) production in a fed-batch bioreactor by Bacillus megaterium using candy industry effluent (CIE), sucrose, and rice parboiled water (RPW) as carbon sources. In biosynthesis, kinetic and stoichiometric parameters of substrate conversion into products and/or cells, productivity, instantaneous, and specific conversion rates were evaluated. The maximum concentration of P(3HB) was 4.00 g.L-1 (77% of the total dry mass) in 42 h of cultivation in minimal medium/RPW added with a carbon source based on CIE, demonstrating that the fed-batch provided an increase of approximately 22% in the polymer concentration and 32% in the overall productivity in relation to medium based on commercial sucrose. Fed-batch cultivation also had the advantage of avoiding the extra time required for inoculum preparation and sterilization of the bioreactor during the batch, which thereby increased the overall industrial importance of the process. Effluents from the candy, confectionery, and/or rice parboiling industries can be used as alternative substrates for P(3HB) production at a low cost.

Technological characteristics of tofu from soybean coagulated with cardoon flower extract.

The objective of the present study was to develop tofu with soybean-water soluble extract coagulated with cardoon flower (F1) and magnesium chloride (MgCl2, F2). The produced tofu was characterized in terms of physical, chemical, microbiological, and sensory properties during 14 days of storage. The yield of F1 was higher (p < 0.05) (195 g/100 soybean seeds) than F2 (162 g/100 soybean seeds). F1 presented higher moisture, protein, acidity, syneresis, and lipids when compared with F2, and a reduction of these contents during the storage. F1 presented lower hardness, stickiness, springiness, and cohesiveness compared with F2. The acceptability of F1 showed a score of 6.00 and F2 of 4.68, and the purchase intention was 3.22 for F1 and 2.23 for F2. This study recommended the use of cardoon flower at 35% level as it has great potential as a coagulant for the elaboration of tofu with higher yield, and acceptability and reasonable purchasing intention.

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.

Production of Ethyl Esters by Direct Transesterification of Microalga Biomass Using Propane as Pressurized Fluid.

This work aimed to produce ethyl esters from Chlorella vulgaris microalgae biomass, using an immobilized enzymatic catalyst associated with pressurized fluid (propane) by direct transesterification. In order to optimize the ethyl conversion, different temperatures (46.7-68.1 °C) and pressures (59.5-200.5 bar) were applied a central composite design rotational (CCDR) obtaining the high conversion (74.39%) at 50 °C and 180 bar. The molar ratio also was investigated showing conversions ~ 90% using a molar ratio of 1:24 (oil:ethanol). From the best transesterification conditions, 50 °C, 180 bar, 20% enzymatic concentration, and 1:24 oil:ethanol molar ratio were obtained with success 98.9% conversion in 7 h of reaction. The enzyme reuse maintained its activity for three successive cycles. Thus, this simple process was effective to convert microalgal biomass into ethyl ester by direct transesterification and demonstrate high yields.

Development and Structural Behaviour of Soybean Gelato.

The aim of this study is to elaborate and evaluate structural characteristics of soybean gelato by varying the content of soybean protein concentrate (2.95 to 17.05%) and vegetable fat (7.95 to 22.05%) using experimental design. The replacement of milk by hydrosoluble extract and soybean protein concentrate presented itself as an alternative to gelato production with unique characteristics, especially in terms of protein, solubility, viscosity, melting point, overrun and acceptability. The addition of up to 5% (m/V) protein concentrate, 14% (by volume) soybean hydrosoluble extract, and 15% (by mass) vegetable fat to gelato formulations resulted in better structural characteristics, with viscosity ranging from 0.45-0.70 Pa∙s at 10 °C, a non-Newtonian behaviour and protein stability (total protein content 8.44% and solubility 41%). Soybean gelato structural analysis using X-ray diffraction revealed 15° and 35° diffraction angles at 2Θ, characterizing the crystalline part of the product. The thermal analyses showed four bands of mass loss in the temperature range of 40-600 °C, characterizing loss of moisture, decomposition of the soy protein and the fat/emulsifier of the formulations. Thus, the soybean gelato is an innovative product, lactose and milk protein-free with outstanding characteristics for the general public, mainly, for the populations with intolerance to such components.

Whey protein concentration by ultrafiltration and study of functional properties / Concentração de proteínas de soro por ultrafiltração e estudo das propriedades funcionais

ABSTRACT: This paper aim to evaluate the ultrafiltration (UF) process for constituents recovery from whey. Sequences of factorial designs were performed by varying temperature (5 to 40°C) and pressure (1 to 3 bar), to maximize the proteins concentration using membrane of 100kDa in dead end system. Based on the best result new experiments were performed with membrane of 50kDa and 10kDa. With the membrane of 50 the protein retention was about 3 times higher than the membrane of 100kDa. The concentrated obtained by UF membrane of 10kDa, 10°C and 2 bar in laboratory scale showed a mean protein retention of 80 %, greater protein solubility, emulsion stability and the identification of β-lactoglobulins (18.3 kDa) and α-lactalbumin fractions (14.2kDa). Therefore, the use of membrane of 100 and 50kDa are became a industrially recommendable alternatives to concentration of whey proteins, and/or as a previous step to the fractionation of whey constituents using membrane ≤10kDa, aiming at future applications in different areas (food, pharmaceutical, chemical, etc.).

RESUMO: O objetivo do estudo foi avaliar o processo de Ultrafiltração (UF) na recuperação dos constituintes do soro de leite. Planejamentos fatoriais sequenciais foram realizados, variando a temperatura (5 a 40°C), a pressão (1 a 3 bar) e visando maximizar a concentração de proteínas usando membrana de 100kDa em sistema dead end. Baseados nos melhores resultados, foram realizados experimentos com de 50kDa e 10kDa. Em relação a membrana de 50kDa, a retenção de proteínas foi cerca de três vezes maior em relação a membrana de 100kDa. O concentrado obtido por membrana UF de 10kDa, 10°C e 2 bar, em escala laboratorial, mostrou uma retenção média de proteína de 80%, maior solubilidade protéica, estabilidade da emulsão e a identificação das frações β-lactoglobulins (18.3kDa) e α-lactalbumin (14.2kDa). Portanto, o uso de membranas de 100 e 50kDa são alternativas recomendáveis industrialmente à concentração de proteínas de soro de leite, e/ou como etapa anterior ao fracionamento de constituintes do soro usando membrana ≤10kDa, visando aplicações futuras em difentes áreas (alimentícia, farmacêutica, química, etc).

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.