Functionality and characterization of modified starch films with pineapple leaf fibers.

The objective of this work was to modify banana starch with pineapple leaf fibers (PALF) and its production of biodegradable films. The reaction conditions of the starch modification were a Starch/PALF mass ratio of 50, a time of 1 h and a temperature of 140 °C, to obtain a yield of 41.18 %. Characterization by FTIR and NMR confirmed that the chemical reaction was carried out. XRD and TGA analysis showed that the crystalline zones of the starch were affected during the modification and the product obtained is thermally less stable compared to unmodified starch. The modified starch showed a lower pasting profile compared to the native starch; however, the modified starch showed the ability to form a film. The starch-PALF films were obtained by the casting method and partially characterized. These films presented better mechanical properties compared to the unmodified films. Also, these films could compete with conventional non-biodegradable plastics.

AmyJ33, a truncated amylase with improved catalytic properties.

Biochemical and kinetic properties are of special interest for the specific applications of α-amylases in industrial sectors such as textile industries, detergents, biofuels and food among others. Therefore, protein engineering is currently directed towards a continuous demand to improve the properties of amylases and thus meet the specific characteristics for various industrial sectors. In the present work, modular protein engineering was performed to improve the biochemical and kinetic properties of AmyJ33r an α-amylase isolated from Bacillus siamensis JJC33M consisting of five domains, A, B, C, D and E (SBD) (Montor-Antonio et al. in 3 Biotech 7:336, 2017. https://doi.org/10.1007/s13205-017-0954-8 ). AmyJ33r is not active on native starch, only showing activity on gelatinized starch. At the C-terminal, AmyJ33r has a starch binding domain (SBD, domain E) belonging to the CBM26 family. In this study, four truncated versions were constructed and expressed in E. coli (AmyJ33-AB, AmyJ33-ABC, AmyJ33-ABCD, and SBD) to determine the role of the A, B, C, D, and E domains in the biochemical behavior of AmyJ33r on starch. Biochemical and kinetic characterization of the truncated versions showed that domain C is essential for catalysis; domain D improved enzyme activity at alkaline pH values, is also involved negatively in thermostability at 40, 50, and 60 °C and its presence favored the production of maltooligosaccharides with a higher degree of polymerization (DP4). E domain have interaction with raw starch, also the deletion of E domain (SBD) favors the affinity for the substrate while the deletion of D domain increased enzyme kcat at the time of product release. In conclusion, AmyJ33-ABC has better kinetic parameters than AmyJ33-ABCD and AmyJ33r, but is less stable than these two enzymes.

Use of Cardiac Injury Markers in the Postmortem Diagnosis of Sudden Cardiac Death.

In the daily practice of forensic pathology, sudden cardiac death (SCD) is a diagnostic challenge. Our aim was to determine the usefulness of blood biomarkers [creatine kinase CK-MB, myoglobin, troponins I and T (cTn-I and T), and lactate dehydrogenase] measured by immunoassay technique, in the postmortem diagnosis of SCD. Two groups were compared, 20 corpses with SCD and 8 controls. Statistical significance was determined by variance analysis procedures, with a post hoc Tukey multiple range test for comparison of means (p < 0.05). SCD cases showed significantly higher levels (p < 0.05) of cTn-T and cTn-I compared to the control group. Although only cases within the first 8 h of postmortem interval were included, and the control group consisted mainly of violent death cases, our results suggest that blood troponin levels may be useful to support a diagnosis of SCD.

Effect of dietary intake of avocado oil and olive oil on biochemical markers of liver function in sucrose-fed rats.

Metabolic changes, along with cardiovascular and hepatic factors, are associated with the development of diseases such as diabetes, dyslipidemia, and obesity. We evaluated the effect of avocado oil supplementation (centrifuged and solvent extracted), compared with olive oil, upon the hepatic function in sucrose-fed rats. Twenty-five rats were divided into five groups: control (basal diet), a sucrose-fed group (basal diet plus 30% sucrose solution), and three other groups (S-OO, S-AOC, and S-AOS, indicating basal diet plus 30% sucrose solution plus olive oil OO, avocado oil extracted by centrifugation AOC or using solvent AOS, resp.). Glucose, total cholesterol, triglycerides, total protein, albumin, globulin, direct bilirubin, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, alkaline phosphatase, cholinesterase, and α -amylase concentrations were determined and avocado oil effect on them was studied. In some cases the induced metabolic alteration significantly affected total protein and bilirubin levels and also had a highly significant effect on α -amylase levels. AOC and AOS exhibited effects similar to those of olive oil, according to the nonsignificant difference in fatty acid profile observed by other authors. Avocado oil consumption could be beneficial in the control of altered metabolic profile illnesses as it presents effects on hepatic function biochemical markers similar to olive oil.

Avocado oil supplementation modifies cardiovascular risk profile markers in a rat model of sucrose-induced metabolic changes.

The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome.

Hibiscus sabdariffa L., roselle calyx, from ethnobotany to pharmacology.

Using MEDLINE and SCOPUS databases, a review of the literature from the pioneering study of 1991 until 2010 was performed on the effects on biological models of Hibiscus sabdariffa L. roselle calyx, its extracts mainly in polar solvents, or pure components found in extracts, as well as their possible relationship to these effects. Three relevant effects on lipid metabolism, antihypertensive activity, and apoptosis were observed. Our chronological review of the studies mentioned in the literature provides another opportunity to see how humans compile scientific knowledge of a chemical structure-physiological activity relationship starting from an ethnobotanical-ethnopharmagognosy contribution. The chemical components that are the main active principles in the physiological activities of Hibiscus sabdariffa L. calyx are anthocyanins and polyphenols (protocatechuic acid and quercetin). Advances have also been made in the elucidation of action mechanisms. Additionally, it has become clear that the lack of standardization in terms of chemical components of the material arising from Hibiscus sabdariffa L. used in testing on biological models imposes limits on the possibility of carrying out comparative analyses between studies. Fortunately, more recent studies are overcoming this obstacle by reporting component concentrations of assumed active principles; however, complete analysis of the extract, if this is to be considered as a therapeutic agent, is not commonly reported in the aforesaid studies. If one of the eventual scenarios for Hibiscus sabdariffa L. calyx is as a therapeutic agent in communities with economic limitations, then studies of a pharmacological nature should guarantee the effectiveness, safety, and tolerability of this material, which is widely accepted to be associated with chemical complexity, thus making this knowledge necessary.

Treatment of vinasse from tequila production using polyglutamic acid.

Vinasse, the wastewater from ethanol distillation, is characterised by high levels of organic and inorganic matter, high exit process temperature (ca. 90°C) and low pH (3.0-4.5). In this study, the treatment of tequila vinasse was achieved by a flocculation-coagulation process using poly-γ-glutamic acid (PGA). Results showed that the use of PGA (250-300 ppm) combined with sodium hypochlorite and sand filtration managed to remove about 70% of the turbidity and reduced chemical oxygen demand (COD) by 79.5% with the extra benefit of colour removal. PGA showed its best flocculating activity at pH 2.5-3.5 and a temperature of 30-55°C. Such a treatment may be a solution for small tequila companies for which other solutions to deal with their vinasse may not be economically affordable.

Production of nisin Z using Lactococcus lactis IO-1 from hydrolyzed sago starch.

A membrane bioreactor for production of nisin Z was constructed using Lactococcus lactis IO-1 in continuous culture using hydrolyzed sago starch as carbon source. A strategy used to enhance the productivity of nisin Z was to maintain the cells in a continuous growth at high cell concentration. This resulted in a volumetric productivity of nisin Z, as 50,000 IU l(-1) h(-1) using a cell concentration of 15 g l(-1), 30( degrees )C, pH 5.5 and a dilution rate of 1.24 h(-1). Adding 10 g l(-1) YE and 2 g l(-1) polypeptone, other inducers were unnecessary to maintain production of nisin. The operating conditions of the reactor removed nisin and lactate, thus minimizing their effects which allowed the maintenance of cells in continuous exponential growth phase mode with high metabolic activity.

The consumption of Hibiscus sabdariffa dried calyx ethanolic extract reduced lipid profile in rats.

The scientific basis for the statement that plants and their active constituents play an important role in the prevention of chronic and degenerative diseases is continously advancing. The object of the present study was to evaluate the effect of Hibiscus sabdariffa L. dried calyx ethanolic extract on the serum lipid profile of Sprague-Dawley rats. The rats were fed during 4 weeks with either a basal diet, containing high cholesterol (1%), cholic acid (0.25%), lard oil (10%), or a supplemental diet with H. sabdariffa extract at 5%, 10%, and 15% levels (SD(5), SD(10), SD(15)). Weight gain and faeces dry weight were both very significantly less (p