High shear rheology of paper coating colors – more than just viscosity

Capillary viscometry is used to characterize viscosity, entrance pressure loss and apparent wall slip of paper coating colors at high shear rates. Special emphasis is laid on the dependence of these phenomena on solids content in order to account for changes in the rheology due to the dewatering of the color during the coating process. Coating colors with substantially different runnability have been investigated. Differences in apparent wall slip and high shear viscoelasticity (manifesting itself in extremely high entrance pressure losses) are observed at increased concentration, even if these phenomena do not show up at the initial solids content. Poor runnability is observed when viscosity, entrance pressure loss and wall slip increase strongly with increasing solids content. But all rheological features change simultaneously with the coating color recipe and it is not possible to separate out the contribution of the particular rheological features on the runnability of the coating colors or to correlate the runnability to a single rheological prorameter. Future work will have to focus on a numerical analysis of the blade coating process taking into account all the rheological features described here. First simulations including slip at the color/blade interface indicate that wall slip may cause severe runnability problems, at least when the apparent slip velocity exceeds the web velocity.     

Biomimicry – An approach to engineering oils into solid fats

The ability to eliminate trans fats, without incorporating additional saturated fats, is limited by the physico‐chemical properties of the processed food and what role the lipids play in the food structure. To maintain the levels of cardio‐protective unsaturated fats alternative methods to structure them are desperately needed. One such strategy is to utilize oleogels or molecular gels comprised of small molecules. Herein, we illustrate the potential of biomimicking the assemblies formed by the intercellular lipids in stratum corneum using stearic acid, ceramide III and replacing cholesterol with β‐sitosterol.     

Fast analysis of fats,oils and biodiesel by FT‐IR

Historically, the determination of chemical information or traits which describe the quality of fats and oils required analysis using wet chemistry, chromatography, and spectroscopic methods. Unfortunately, each of these methods is time‐consuming and requires a well equipped laboratory staffed with trained chemists. In contrast, Fourier Transform Infrared (FT‐IR) Spectroscopy is a fast analytical technique, but requires expertise for method development and operation. To overcome these difficulties, we have successfully developed a FT‐IR system which utilizes remote/local FT‐IR data collection, Internet communication to a central database, FT‐IR based chemometric analysis, and re‐communication of the analysis results to the remote unit. This Internet‐enabled quality trait analysis (QTA®) FT‐IR system has been thoroughly field tested. It has been found to be a rugged, fast, and accurate technique for the analysis of fats and oils and biodiesel. In addition, the Internet‐enabled QTA® FT‐IR system requires minimal skills for operation. Examples using the Internet‐enabled QTA® FT‐IR system for the analysis of fats and oils and biodiesel are described in this article.     

Specialty fats – How food manufacturers can get more out of them

Specialty fats add market value to prepared foods through the sensory attributes they produce. While specialty fats may have been known to food manufacturers for decades, many have yet to realize the full potential of what these functional fats can do for their products and businesses. To achieve this, an adequate level of working knowledge on specialty fats is vital. The application of specialty fats in chocolate, chocolate confectionery, bakery products and ice cream are surveyed, to illustrate a variety of interesting ways food manufacturers can use specialty fats.     

γ‐ and δ‐tocopherols are more effective than α‐tocopherol on the autoxidation of a 10% rapeseed oil triacylglycerol‐in‐water emulsion with and without a radical initiator

The antioxidative effects of γ‐ and mainly δ‐tocopherol in a multiphase system were hardly considered up to now. The aim of this study was i) to assess the effects and ii) to follow the degradation of α‐, γ‐ and δ‐tocopherol in concentrations of 0.01%, 0.05%, 0.1% and 0.25% during the oxidation of a 10% purified rapeseed oil triacylglycerol‐in‐water emulsion at 40 °C in the dark for 15 wk in a system containing a low oxygen concentration. Oxidation experiments were performed weekly by assessing the formation of hydroperoxides and hexanal, and the stability of the tocopherols was determined using high‐performance liquid chromatography. Storage tests were conducted with and without the addition of 0.01% α, α′‐azoisobutyronitrile (AIBN), which is a known radical initiator. α‐Tocopherol increased the formation of hydroperoxides in both tests as well as the generation of hexanal when the radical initiator was added; furthermore it was the least stable. γ‐Tocopherol delayed the formation of hexanal and prolonged the stability of the emulsion in a dose‐dependant manner. δ‐Tocopherol was the most stable and also the most effective in delaying lipid oxidation in the emulsions. Each concentration that was tested reduced the rate of hydroperoxide and especially hexanal formation. Hexanal was only formed to a slight extent after 15 wk of oxidation in the test with AIBN and the lowest dose of 0.01% δ‐tocopherol. For all tocopherols, strong correlations were found between tocopherol stability and the extent of oxidation. Results suggest that i) mainly δ‐tocopherol, but also γ‐tocopherol even less pronounced, are very good antioxidants in order to stabilize and prolong the shelf life of oil‐in‐water emulsions, ii) the antioxidative effects were intensified with increasing amounts.     

Long‐chain omega‐3 oils: Current and future supplies,food and feed applications,and stability

Increasing recognition of the health benefits of omega‐3 long‐chain (⪈C₂₀) polyunsaturated fatty acids (omega‐3 LC‐PUFA or LC omega‐3 oils) continues. But new sources are needed, with recent developments with novel land plants showing promise. The value of existing and future sources LC omega‐3 oils occurs through aquaculture, livestock and other feeding. There is also a need toenhance the stability of oils containing LC omega‐3 oils. Challenges include increasing DHA levels in land plants, increasing oxidative stability in food products and product labeling. Consumers have difficulty recognizing and differentiating long‐chain and shorter‐chain (SC, C₁₈) omega‐3 PUFA, both of which are referred to as “omega‐3” fatty acids.     

Issues in fortification and analysis of omega‐3 fatty acids in foods

It is extensively documented that omega‐3 fatty acids play important roles in many bioactive processes. Omega‐3 can also influence the onset, prevention, and control of many illnesses, including prevention of cardiovascular disease. The main sources of omega‐3 fatty acids are currently from vegetable oils and cold water fish. New sources such as from microalgae and krill oils are quickly increasing their share in the supplement market. Challenges for the incorporation of omega‐3 into foods and supplements have been gradually overcome by the introduction of new, more effective, antioxidants and by the use of various types of encapsulation technologies. Also, the smaller, micronutrient level, amounts of omega‐3 fatty acids normally added to fortified foods and supplements present several challenges of sample extraction, preparation and analysis of bioactive omega‐3 ingredients.     

Synthesis and characterization of α‐butyl‐omega‐{3‐[2‐hydroxy‐3‐(N‐methyl‐N‐hydroxy‐ ethylamino)propoxy]propyl}polydimethylsiloxane

A novel synthesis path for the monotelechelic polydimethylsiloxane with a diol‐end group, α‐butyl‐omega‐{3‐[2‐hydroxy‐3‐(N‐methyl‐N‐hydroxyethylamino)propoxy]propyl}polydimethylsiloxane, is described in this article. The preparation included three steps, which were anionic ring‐opening polymerization, hydrosilylation, and epoxy addition. The structure and polydispersity index of the products were analyzed and confirmed by FTIR, ¹H NMR, ¹³C NMR, H? H, and C? H. Correlated Spectroscopy and gel permeation chromatography. The results demonstrated that each step was successfully carried out and the targeted products were accessed in all cases. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Enzymatic removal of 3‐monochloro‐1,2‐propanediol (3‐MCPD) and its esters from oils

3‐Monochloro‐1,2‐propanediol (3‐MCPD) is a contaminant in processed food well known for about 30 years. More recently, this compound has observed attendance due to its occurrence as fatty acid esters in edible oils and products derived from them. In this study, the first enzymatic approach to remove 3‐MCPD and its esters from aqueous and biphasic systems by converting it into glycerol is described. First, 3‐MCPD was converted in an aqueous system by an enzyme cascade consisting of a halohydrin dehalogenase from Arthrobacter sp. AD2 and an epoxide hydrolase from Agrobacterium radiobacter AD1 with complete conversion to glycerol. Next, it could also be shown, that the corresponding oleic acid monoester of 3‐monochloropropanediol‐1‐monooleic‐ester (3‐MCPD‐ester) was converted in a biphasic system in the presence of an edible oil by Candida antarctica lipase A to yield free 3‐MCPD and the corresponding fatty acid. Hence, also 3‐MCPD‐esters can be converted by an enzyme cascade into the harmless product glycerol. Practical applications: Since several reports have been recently published on the contamination of foods with 3‐MCPD and its fatty acid esters, there is a great demand to remove these compounds and an urgency to find useful methods for this. In this contribution, we present an easy enzymatic way to remove 3‐MCPD and its esters from the reaction media (i.e., plant oil) by converting it to the nontoxic glycerol. The method requires neither high temperature nor organic solvents.     

Synthesis and Surface Properties of a Novel Sodium 3‐(3‐Alkyloxy‐3‐oxopropoxy)‐3‐oxopropane‐1‐sulfonate at the Air–Water Interface

The present paper describes the synthesis and evaluation of surface properties of a novel series of anionic surfactant, namely sodium 3‐(3‐alkyloxy‐3‐oxopropoxy)‐3‐oxopropane‐1‐sulfonate with varying alkyl chain length (C8–C16). Synthesis involves initial formation of the 3‐alkyloxy‐3‐oxopropyl acrylate along with fatty acrylate during the direct esterification of fatty alcohol with acrylic acid in the presence of 0.5 % NaHSO₄ at 110 °C followed by sulfonation of the terminal double bond of the 3‐alkyloxy‐3‐oxopropyl acrylate. Synthesized compounds were evaluated for surface and thermodynamic properties such as critical micelle concentration (CMC), surface tension at CMC (γ_cmc), efficiency of surface adsorption (pC₂₀), surface excess (Γ_max), minimum area per molecule at the air–water interface (A_min), free energy of adsorption (?G°_ads), free energy of micellization (?G°_mic), wetting time, emulsifying properties, foaming power and calcium tolerance. Effect of chain length on CMC follows the classic trend, i.e. decrease in CMC with the increase in alkyl chain length. High pC₂₀ (>3) value indicates higher hydrophobic character of the surfactant. These surfactants showed very poor wetting time and calcium tolerance, but exhibited good emulsion stability and excellent foamability. Foaming power and foam stability of C14‐sulfonate were found to be the best among the studied compounds. Foam stability of C14‐sulfonate was also studied at different concentrations over time and excellent foam stability was obtained at a concentration of 0.075 %. Thus this novel class of surfactant may find applications as foam boosters in combination with other suitable surfactants.     

Shelf‐life prediction of edible fats and oils using Rancimat

Determining the shelf‐life of edible fats and oils under normal storage conditions is a tedious and time‐consuming task. Accelerated tests are therefore frequently used to determine the stability of the products at ambient conditions. However, the mechanisms of lipid oxidation at accelerated conditions may be different from those under normal storage conditions, leading to errors in the shelf‐life predictions. This article describes an automated accelerated method, namely Rancimat, for shelf‐life prediction of edible fats and oils under normal storage conditions, and the effect of its operational parameters on these predictions.