Biodegradable Food Packaging Films Using a Combination of Hemicellulose and Cellulose Derivatives.

This study aims to develop biodegradable films by combining hemicellulose B (HB) with methylcellulose (MC) and carboxymethyl cellulose (CMC) at two mass ratios, HB/MC 90/10 and HB/CMC 60/40. The effect of plasticizers, glycerol (GLY) and polyethylene glycol (PEG), on these films' mechanical and physicochemical properties was also investigated. Results showed that the film thickness increased with the addition of GLY and PEG.

BlpU is a broad-spectrum bacteriocin in .

strain B59671 naturally produces thermophilin 110, a broad-spectrum bacteriocin encoded within the bacteriocin-like peptide () gene cluster, and thermophilin 13 from a separate chromosomal locus. Analysis of the gene cluster revealed two genes, and , as potentially encoding bacteriocins. Deletion of from the B59671 chromosome did not result in a loss of antimicrobial activity against either ST113 or F.

Differential behavior of Lactobacillus helveticus B1929 and ATCC 15009 on the hydrolysis and angiotensin-I-converting enzyme inhibition activity of fermented ultra-high-temperature milk and nonfat dried milk powder.

Consumers' growing interest in fermented dairy foods necessitates research on a wide array of lactic acid bacterial strains to be explored and used. This study aimed to investigate the differences in the proteolytic capacity of Lactobacillus helveticus strains B1929 and ATCC 15009 on the fermentation of commercial ultra-pasteurized (UHT) skim milk and reconstituted nonfat dried milk powder (at a comparable protein concentration, 4%). The antihypertensive properties of the fermented milk, measured by angiotensin-I-converting enzyme inhibitory (ACE-I) activity, were compared.

Logistic modeling to predict the minimum inhibitory concentration (MIC) of olive leaf extract (OLE) against Listeria monocytogenes.

Olive leaf extract (OLE) has been increasingly recognized as a natural and effective antimicrobial against a host of foodborne pathogens. This study attempts to predict the minimum inhibitory concentration (MIC) of OLE against Listeria monocytogenes F2365 by utilizing the asymptotic deceleration point (PDA) in a logistic model (LM), namely MIC-PDA. The experimental data obtained from the inhibitory rate (IR) versus OLE concentration against L.

Characterization of an exopolysaccharide (EPS-3A) produced by Streptococcus thermophilus ZJUIDS-2-01 isolated from traditional yak yogurt.

Yak yogurt, one of the naturally fermented dairy products prepared by local herdsmen in the Qinghai-Tibet Plateau, contains a diverse array of microorganisms. We isolated and identified a novel Streptococcus thermophilus strain, ZJUIDS-2-01, from the traditional yak yogurt. We further purified and carried out detailed structural, physiochemical, and bioactivity studies of an exopolysaccharide (EPS-3A) produced by S.

Chemical composition as an indicator for evaluating heated whey protein isolate (WPI) and sugar beet pectin (SBP) systems to stabilize O/W emulsions.

We investigated changes in the chemical composition of WPI as a result of heating (60 °C, 72 h) with SBP in solution (pH 6.75). The concentration of WPI was kept at a constant (3%), whereas the level of SBP was varied at 1, 1.

Natural flagella-templated Au nanowires as a novel adjuvant against Listeria monocytogenes.

A simple method was developed for the extraction and purification of bacterial flagella with a yield of a concentration of 113.22 ± 5.64 mg mL.

Assessment of Antioxidant and Antimicrobial Properties of Lignin from Corn Stover Residue Pretreated with Low-Moisture Anhydrous Ammonia and Enzymatic Hydrolysis Process.

Lignin accounts for 15-35% of dry biomass materials. Therefore, developing value-added co-products from lignin residues is increasingly important to improve the economic viability of biofuel production from biomass resources. The main objective of this work was to study the lignin extracts from corn stover residue obtained from a new and improved process for bioethanol production.

Physical and chemical changes in whey protein concentrate stored at elevated temperature and humidity.

In a case study, we monitored the physical properties of 2 batches of whey protein concentrate (WPC) under adverse storage conditions to provide information on shelf life in hot, humid areas. Whey protein concentrates with 34.9 g of protein/100g (WPC34) and 76.

Effect of homogenization and pasteurization on the structure and stability of whey protein in milk.

The effect of homogenization alone or in combination with high-temperature, short-time (HTST) pasteurization or UHT processing on the whey fraction of milk was investigated using highly sensitive spectroscopic techniques. In pilot plant trials, 1-L quantities of whole milk were homogenized in a 2-stage homogenizer at 35°C (6.9 MPa/10.

Structural and thermal stability of β-lactoglobulin as a result of interacting with sugar beet pectin.

Changes in the structural and thermal stability of β-lactoglobulin (β-LG) induced by interacting with sugar beet pectin (SBP) have been studied by circular dichroism (CD), Fourier transform infrared, and steady-state as well as time-resolved fluorescence spectroscopic techniques. It has been demonstrated that SBP not only is capable of binding to native β-LG but also causes a significant loss in antiparallel β-sheet, ∼10%, accompanied by an increase in either random coil or turn structures. In addition, the interaction also disrupted the environments of all aromatic residues including Trp, Phe, and Tyr of β-LG as evidenced by near-UV CD and fluorescence.

Investigation of molecular interactions between β-lactoglobulin and sugar beet pectin by multi-detection HPSEC.

Molecular interactions between β-lactoglobulin (β-LG) and sugar beet pectin (SBP) were studied using online multi-detection high performance size exclusion chromatography (HPSEC) at neutral pH and 50mM ionic strength. The hydrodynamic properties of various interacting polymer fractions were characterized in detail and compared with those of β-LG and SBP. Results showed that ∼6.

Heavy metal and phenol adsorptive properties of biochars from pyrolyzed switchgrass and woody biomass in correlation with surface properties.

In this work, the surface structures of biochars, derived from three types of biomass, switchgrass (SG), hardwood (HW) and softwood (SW) through either fast pyrolysis (FP) in a fluidized-bed reactor (at 500 °C) or slow pyrolysis (at 500° and 700 °C), were studied in detail, and compared with that of the activated carbons obtained by steam activation of the slow pyrolyzed biochars (at 500 °C). The surface acidic functional groups were determined quantitatively by the Boehm Titration method. The adsorptive properties of heavy metals, Zn(2+) and Cu(2+) onto the biochars and the activated carbons were investigated by the adsorption isotherms and SEM images, and correlated with the surface properties.

Physico-chemical characterization of protein-associated polysaccharides extracted from sugar beet pulp.

We have solubilized and separated polysaccharides from sugar beet pulp (SBP) into three fractions with steam assisted flash extraction (SAFE). For pectin, recovery ranged from 8 to 14%, degree of methy-esterification 66-73%, crude protein 1.3-1.

Reactions between β-lactoglobulin and genipin: kinetics and characterization of the products.

In this paper, we present the first detailed study of the reaction kinetics and the characterization of the products from the endothermic reactions between β-lactoglobulin and genipin. The effects of the concentration, temperature, and pH were investigated. In the temperature range studied, the reaction was approximately a pseudo-first-order with respect to genipin and 0.

Extrusion texturized dairy proteins: processing and application.

The primary proteins in milk, casein and the whey proteins α-lactalbumin and β-lactoglobulin, have a number of health benefits and desirable functional properties. In a twin-screw extruder, mechanical shear forces, heat, and pressure cause considerable changes in the molecular structures of the dairy proteins, a process known as texturization. These changes further impart unique functional properties to dairy proteins, resulting in new protein-based food ingredients.

Physical properties, molecular structures, and protein quality of texturized whey protein isolate: effect of extrusion temperature.

Although extrusion technology has contributed much to increasing the effective utilization of whey, the effect of extrusion conditions on the functional properties of the proteins is not well understood. In this work, the impact of extrusion temperature on the physical and chemical properties, molecular structures, and protein quality of texturized whey protein isolate (WPI) was investigated at a constant moisture content and compared with WPI treated with simple heat only. The Bradford assay methods, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reversed-phase high-performance liquid chromatography techniques were used to determine protein solubility and to analyze compositional changes in the two major whey proteins, α-lactalbumin and β-lactoglobulin.

Implication of C-terminal deletion on the structure and stability of bovine beta-casein.

Bovine beta-casein (beta-CN) with its C-terminal truncated by chymosin digestion, beta-CN-(f1-192), was examined and characterized using circular dichroism (CD) under various temperature conditions. CONTIN/LL analysis of the CD data revealed significant secondary structure disruption in beta-CN-(f1-192) relative to its parent protein,beta-CN, in the temperature range (5 degrees to 70 degrees C) studied. Near-UV CD spectra indicated significant temperature dependent structural changes.

Thermal and alkaline denaturation of bovine beta-casein.

The secondary structure of bovine beta-casein was characterized using circular dichroism (CD) and FTIR spectroscopies under physiologically relevant conditions. Analytical ultracentrifugation technique was used to follow the highly temperature, pH and concentration dependent self-association behavior. CD measurements provide convincing evidence for short segments of polyproline II-like structures in beta-casein in addition to a wide range of secondary structure elements, such as 10-20% alpha-helix, approximately 30% turns, 32-35% extended sheet.

Structural determinants of the rate of protein folding.

To understand the mechanism of protein folding and to assist rational design of fast-folding, non-aggregating and stable artificial enzymes, it is essential to determine the structural parameters which govern the rate constants of folding, kf. It has been found that -logkf is a linear function of the so-called chain topology parameter (CTP) within the range of 10(-1)s(-1)< or = kf < or =10(8)s(-1). The correlation between -logkf and CTP is much improved than using previously published contact order (CO) method.