Effect of Interphase Properties on Isothermal and Non-isothermal Crystallization Behavior of Poly(lactic acid)/Acetylated Starch Blends.

The effect of interphase properties on the crystallization behavior of blends of poly(lactic acid) (PLA)/acetylated starch (AS) with different degrees of substitution (DSs) was investigated. Under isothermal crystallization conditions, the rate of crystallization was higher for PLA/DS0.5 and lower for PLA/DS1.

Poly(lactic acid)/acetylated starch blends: Effect of starch acetylation on the material properties.

This study investigated the acetylation of starch to improve its processability and compatibility with poly(lactic acid). The temperature at the maximum rate of degradation increased by 3.2% for poly(lactic acid) blends containing acetylated starch degree of substitution 2.

Fluorescence spectroscopy and principal component analysis of soy protein hydrolysate fractions and the potential to assess their antioxidant capacity characteristics.

The potential of intrinsic fluorescence and principal component analysis (PCA) to characterize the antioxidant capacity of soy protein hydrolysates (SPH) during sequential ultrafiltration (UF) and nanofiltration (NF) was evaluated. SPH was obtained by enzymatic hydrolysis of soy protein isolate. Antioxidant capacity was measured by Oxygen Radical Absorbance Capacity (ORAC) and Folin Ciocalteau Reagent (FCR) assays together with fluorescence excitation-emission matrices (EEM).

A Meta-Analysis of Enriched Pasta: What Are the Effects of Enrichment and Process Specifications on the Quality Attributes of Pasta?

Pasta products enriched with ingredients to improve their nutritional value or functionality have become increasingly popular, and substantial research efforts have been directed towards the development of new enriched pasta products. In this work, a meta-analysis was conducted to quantify the impact of enrichment and process specifications on the quality attributes of pasta. A literature search revealed 66 studies on enriched pasta.

Drying of Durum Wheat Pasta and Enriched Pasta: A Review of Modeling Approaches.

Models on drying of durum wheat pasta and enriched pasta were reviewed to identify avenues for improvement according to consumer needs, product formulation and processing conditions. This review first summarized the fundamental phenomena of pasta drying, mass transfer, heat transfer, momentum, chemical changes, shrinkage and crack formation. The basic equations of the current models were then presented, along with methods for the estimation of pasta transport and thermodynamic properties.

Fluorescence analysis of NOM degradation by photocatalytic oxidation and its potential to mitigate membrane fouling in drinking water treatment.

This study examined the photocatalytic oxidation of natural organic matter (NOM) as a method to mitigate membrane fouling in drinking water treatment. ZnO and TiO2 photocatalysts were tested in concentrations ranging from 0.05 g L(-1) to 0.

Flaxseed-Enriched Cereal-Based Products: A Review of the Impact of Processing Conditions.

The properties of cereals products, bread, pasta, muffins, cookies, cakes, and bars, enriched with flaxseed, were reviewed to highlight suitable processing conditions for the production of high-quality flaxseed-enriched products with the desired health attributes. The review highlights the contrasting effect of flaxseed enrichment on the mechanical and physical properties of cereal products according to product type, flaxseed enrichment level, and processing history. Flaxseed lipids remain stable for most processing and storage conditions, presumably due to the significant antioxidant properties of lignans, but information is lacking on the impact of home-handling, such as bread toasting, on lipid oxidation.

Characterizing natural colloidal/particulate-protein interactions using fluorescence-based techniques and principal component analysis.

Characterization of the interactions between natural colloidal/particulate- and protein-like matter is important for understanding their contribution to different physiochemical phenomena like membrane fouling, adsorption of bacteria onto surfaces and various applications of nanoparticles in nanomedicine and nanotoxicology. Precise interpretation of the extent of such interactions is however hindered due to the limitations of most characterization methods to allow rapid, sensitive and accurate measurements. Here we report on a fluorescence-based excitation-emission matrix (EEM) approach in combination with principal component analysis (PCA) to extract information related to the interaction between natural colloidal/particulate- and protein-like matter.

Reversible and irreversible low-pressure membrane foulants in drinking water treatment: Identification by principal component analysis of fluorescence EEM and mitigation by biofiltration pretreatment.

With the increased use of membranes in drinking water treatment, fouling--particularly the hydraulically irreversible type--remains the main operating issue that hinders performance and increases operational costs. The main challenge in assessing fouling potential of feed water is to accurately detect and quantify feed water constituents responsible for membrane fouling. Utilizing fluorescence excitation-emission matrices (EEM), protein-like substances, humic and fulvic acids, and particulate/colloidal matter can be detected with high sensitivity in surface waters.

Probing protein colloidal behavior in membrane-based separation processes using spectrofluorometric Rayleigh scattering data.

One of the primary problems in membrane-based protein separation is membrane fouling. In this study we explored the feasibility of employing Rayleigh light scattering data from fluorescence studies combined with chemometric techniques to determine whether a correlation could be established with membrane fouling phenomena. Membrane flux was measured in a dead-end UF filtration system and the effect of protein solution properties on the flux decline was systematically investigated.

Monitoring the fractionation of a whey protein isolate during dead-end membrane filtration using fluorescence and chemometric methods.

During membrane-based separation of proteins, changes in protein concentration of the permeate and retentate streams occurs over time. The current work proposes a new approach for monitoring the changes in concentrations of proteins in both permeate and retentate by making use of data collected using fluorescence spectroscopy and intrinsic protein fluorescence analyzed by multivariate statistical techniques. Whey protein isolate consists mainly of alpha-lactalbumin (alpha-LA), beta-lactoglobulin (beta-LG), and small proportion of bovine serum albumin (BSA) and was used as a model system in this study.

Identifying fouling events in a membrane-based drinking water treatment process using principal component analysis of fluorescence excitation-emission matrices.

The identification of key foulants and the provision of early warning of high fouling events for drinking water treatment membrane processes is crucial for the development of effective countermeasures to membrane fouling, such as pretreatment. Principal foulants include organic, colloidal and particulate matter present in the membrane feed water. In this research, principal component analysis (PCA) of fluorescence excitation-emission matrices (EEMs) was identified as a viable tool for monitoring the performance of pre-treatment stages (in this case biological filtration), as well as ultrafiltration (UF) and nanofiltration (NF) membrane systems.

Effect of pore size, shear rate, and harvest time during the constant permeate flux microfiltration of CHO cell culture supernatant.

The influence of the shear rate, the membrane pore size, and the age of the culture at time of harvest on transmembrane pressure (TMP) increase and membrane fouling during the microfiltration of a Chinese Hamster Ovary (CHO) cell culture supernatant was investigated. A hollow fiber microfiltration system operated at constant permeate flux was used. The highest TMP increase with filtration time was observed for the small membrane pore size (0.

Fluorescence-based soft-sensor for monitoring beta-lactoglobulin and alpha-lactalbumin solubility during thermal aggregation.

A soft-sensor for monitoring solubility of native-like alpha-lactalbumin (alpha-LA) and beta-lactoglobulin (beta-LG) and their aggregation behavior following heat treatment of mixtures under different treatment conditions was developed using fluorescence spectroscopy data regressed with a multivariate Partial Least Squares (PLS) regression algorithm. PLS regression was used to correlate the concentrations of alpha-LA and beta-LG to the fluorescence spectra obtained for their mixtures. Data for the calibration and validation of the soft sensor was derived from fluorescence spectra.

Carbohydrate and mineral removal during the production of low-phytate soy protein isolate by combined electroacidification and high shear tangential flow ultrafiltration.

In this work, soy protein isolates were produced by a combination of electroacidification and high shear tangential flow hollow fiber ultrafiltration with a 100 kDa membrane under constant pressure. The filtration performance was evaluated by comparing the filtration time and the final product composition for an electroacidified (pH 6) and a non-electroacidified (pH 9) soy protein extract. The removal of carbohydrates during the filtration was always consistent with the theoretical predictions (based on free permeability assumption) for both the electroacidified and the non-electroacidified feeds.

Fluorescence spectroscopy as a tool for monitoring solubility and aggregation behavior of beta-lactoglobulin after heat treatment.

Denaturation and aggregation of whey proteins are of interest to the food and pharmaceutical industry due to the importance of final structure in functionality, impact on food texture, and the chemical stability of the final product. In this study, we demonstrate the potential of fluorescence spectrometry combined with multivariate chemometric methods for quantifying solubility and aggregation behavior of beta-lactoglobulin (beta-LG); a major whey protein and a frequent food ingredient. Heat-induced aggregation of beta-LG was studied under different conditions including pH, temperature and heating durations.

Calcium interacts with antifreeze proteins and chitinase from cold-acclimated winter rye.

During cold acclimation, winter rye (Secale cereale) plants accumulate pathogenesis-related proteins that are also antifreeze proteins (AFPs) because they adsorb onto ice and inhibit its growth. Although they promote winter survival in planta, these dual-function AFPs proteins lose activity when stored at subzero temperatures in vitro, so we examined their stability in solutions containing CaCl2, MgCl2, or NaCl. Antifreeze activity was unaffected by salts before freezing, but decreased after freezing and thawing in CaCl2 and was recovered by adding a chelator.

Survey of bandage lens use in North America, October-December 2002.

Purpose: The purpose of this work was to report the findings of a survey of current modes of bandage lens (BL) use by optometrists and ophthalmologists in Canada and the United States in 2002.

Methods: Two thousand voluntary surveys were sent to ophthalmic practitioners across the United States and Canada. The survey contained a questionnaire with 15 questions about the practitioner's background and BL-prescribing trends and views.