The presence of fouling in evaporators can increase energy consumption as well as capital and labor costs. During corn ethanol production, fouling occurs when thin stillage is concentrated in multiple effect evaporators to form condensed distillers solubles. Limited studies have been conducted on fouling of corn ethanol processing. Process streams are biological in origin and have variable compositions. The objective of this study was to develop an improved understanding of components that accelerate fouling of thin stillage evaporators. An annular fouling probe was used to evaluate compositional variables on fouling behavior of thy grind corn thin stillage. Three experiments were performed with commercial processing streams. In the first experiment, the effects of carbohydrate materials in thin stillage on evaporator fouling were investigated by adding starch and sucrose. In the second experiment, commercial thin stillage samples were treated by adding wet cake. The third experiment was designed to observe if the age of thin stillage sample would affect fouling. The results indicate that fouling resistances increased with starch addition, as well as with wet cake addition, at equal total solids contents. Insoluble starch addition had larger effects than soluble sucrose addition. Sucrose alone did not cause increased rapid fouling. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Fouling is unwanted deposition of materials on surfaces of processing equipment, which leads to additional capital investment and lower processing efficiency. During fuel ethanol production, fouling occurs when thin stillage is concentrated into condensed distillers solubles. Investigations of protein impact on fouling are limited despite high protein concentration in thin stillage (17–33%db). Protein contributions to fouling have been verified in the dairy industry. Whey proteins and calcium phosphate interact with each other or other proteins and form aggregates on heated surfaces. Due to the complex biological composition of thin stillage, it is difficult to study a single effect on fouling without interference from other factors. The objective was to investigate fouling properties of nitrogenous substances (urea and yeast) using model fluids; effects of protease addition on fouling properties of model and commercial thin stillage fluids. Urea addition did not lead to fouling while glucose-yeast model fluids displayed fouling tendencies. Protease from pineapple stem (bromelain) incubation increased fouling in model and commercial fluids, which were indicative that hydrolyzed molecules such as peptides, amino acids or protease can be involved in deposit formation.

BACKGROUNDDeficiency and insufficiency of vitamin D (VD) afflicts populations worldwide. Fortification of foods with VD has been present for decades; however, its stability in foods is often compromised by its rapid degradation, low absorption and poor water solubility. In this study, soy protein isolate was conditioned using pH shifting and ultrasound treatment to create soy protein‐based nanoemulsions (SPNEs). The objective was to evaluate the stability, bioaccessibility and bioavailability of VD dispersed in SPNEs.METHODSSPNEs were prepared by mixing canola oil (1%, w/w) and soluble SPI (30 mg/mL) containing VD (100 μg/mL; cholecalciferol) and sonicating (20 kHz) 5 min. VD‐containing SPNEs were compared to controls including VD dispersed in water after sonication and in lecithin with canola oil after sonication. VD‐containing SPNEs were freeze dried and evaluated after resuspension. Particle size was measured using dynamic light scattering spectroscopy. VD stability was evaluated after UVB light exposure for 0, 30, 60 and 120 min followed by quantification using and reversed phase HPLC‐UV. Bioaccessibility was evaluated in a two‐compartment in vitro digestion model. Bioavailability was evaluated in adult Long‐Evans hooded rats. Rats were conditioned for a week under a AIN‐93M diet before receiving a gavage dose of: 1) VD‐containing SPNEs (2 mL, 150 μg/mL), 2) Oil with VD (0.5 mL, 300 μg/mL), and 3) Oil without VD (0.6 mL canola oil). After gavage, specific groups of animals (n=3–5) within each treatment were euthanized at 1, 9, 24, and 48 hours after oral dose. Serum 25(OH) VD levels in rats were measured post‐mortem using a colorimetric (450 nm) sandwich ELISA.RESULTSSoy nanoparticles (15–30 nm) were larger (p<0.05) than VD‐containing SPNEs (10–20 nm). VD‐containing SPNEs had higher particle size after freeze drying (50–70 nm; p<0.05). Recovery of VD after 60 min UV exposure was 52.3%, 12.8%, and 9.8% in SPNEs, emulsified in lecithin, or without emulsifier in water, respectively. VD bioaccessibility was higher (p<0.05) in SPNEs (96%) than emulsified in lecithin (69%), or without emulsifier in water (63%). Pharmacokinetic studies in rats showed that oral delivery of VD in SPNEs resulted in 8.1‐fold increase in the AUC (p<0.05) and reaching a Cmax at 24 hours compared to the Oil with VD control.These results revealed that dispersion of VD in SPNEs protects VD from UV exposure and increases its bioaccessibility and oral bioavailability. Future studies will evaluate the sensory properties of SPNEs in food products.Support or Funding InformationUniversity of Illinois at Urbana‐Champaign, King Saud University

The functional properties of soluble nano-sized soy protein aggregates produced by pH treatment followed by ultrasonication (US) were investigated. Commercial soy protein isolate (SPI) was subjected to pH treatment under acidic (pH 2-4) or alkaline (pH 9-12) conditions followed by US before neutralizing to pH 7. The pH treatment at pH 12 followed by sonication for 5 min (pH12 + US5) was the most effective in reducing the sizes and turbidity of soluble protein aggregates, enhancing protein solubility and surface hydrophobicity, and modifying protein subunits. The pH12 + US5 treated SPI increased protein solubility from 1.49% for the control to 82.73%, producing soluble protein aggregates with average size of 22 nm. SPI nanoemulsions prepared using pH12 + US5 treated protein and canola oil had particle sizes in the range of 70-117 nm. Nanoemulsions and nanocomplexes (no oil) prepared with the SPI nano-aggregates provided good protection of vitamin D-3 against UV exposure (180 min), with retention of 73.5 and 70.7%, respectively, compared to 5.2% in the control. This new treatment may offer an effective method to modify the functional properties of commercial SPI for use as building blocks for preparing nanoparticles and nano-structures to protect and deliver bioactive compounds. (C) 2015 Elsevier Ltd. All rights reserved.

Vegetable oils and animal fats are major components of food products and are used extensively for cooking. Recently, attention has been focused on their uses for making fuels for engines and heating. Vegetable oils and animal fats comprise mixtures of fatty acids in proportions that depend on the source materials. These fatty acids vary with respect to carbon chain length and degree of saturation. Fatty acid composition has been shown to have impacts on the properties of oils and fats and thus on both food and fuel quality. Some of these source materials also contain natural antioxidants that are beneficial for both food and fuel applications. The objectives of this article are to highlight the different requirements in the properties of vegetable oils and animal fats for health and for fuel, and to provide an assessment of the suitability of different materials as sources for food and/or fuel.

Arabidopsis plants were transformed with acyl carrier protein (ACP)-4 in antisense conformation driven by the cauliflower mosaic virus 35S promoter. It was hypothesized that reduction of ACP4 in leaf tissue would result in a reduction in lipid biosynthesis and, in addition, affect fatty acid composition and leaf physiology. Several transgenic lines have been generated with reduced ACP4 protein in leaf tissue. Dramatic reductions in ACP4 resulted in a reduction of leaf lipid content (22%-60%) based on fresh leaf weight and a bleached appearance and reduced photosynthetic efficiency. In addition, a decrease in 16:3 as a percentage of the total fatty acid composition was noted. There were no changes in leaf lipid class distribution; however, there was a decrease in the relative amount of 16:3 in monogalactosyldiacylglycerol. These results suggest that ACP4 plays a major role in the biosynthesis of fatty acids for chloroplast membrane development. Alterations in the ACP isoform profile of Arabidopsis leaf also appear to alter the flow of fatty acids between the prokaryotic and eukaryotic pathways for assembly of galactolipids. However, it has not yet been determined if the changes in fatty acid composition are due to changes in the profile of ACP isoforms, or if they are actually a reaction to a reduction in fatty acid precursors.

Honey has been known to exert significant in vitro antioxidant activity, in part due to its phenolic content. However, conclusions that the antioxidants in honey are or are not efficacious in the human body cannot be reached if its antioxidant action is not assessed as part of a human study. In the present study, the acute effect of consumption of 500 mL of water, water with buckwheat honey, black tea, black tea with sugar, or black tea with buckwheat honey on serum oxidative reactions was examined in 25 healthy men. Antioxidant capacity of human serum samples was measured using different methods: the oxygen radical absorbance capacity (ORAC) assay, ex vivo susceptibility of serum lipoprotein to Cu(2+)-induced oxidation, and the thiobarbituric acid reactive substances (TBARS) assay. The results showed that the serum antioxidant capacity determined by ORAC increased significantly (p < 0.05) by 7% following consumption of buckwheat honey in water. No significant changes in serum antioxidant capacity could be established after the consumption of any of the other beverages. Ex vivo serum lipoprotein oxidation and TBARS values were not significantly altered after consumption of any of the five beverages. This study provides primary evidence of the in vivo antioxidant activity of buckwheat honey. However, long-term studies and epidemiological data are necessary to investigate whether honey consumption can exert overall antioxidant-related health benefits.

Honeys from seven different floral sources were analyzed for in vitro antioxidant capacity and total phenolic content. Antioxidant capacity was measured by the oxygen radical absorbance capacity (ORAC) assay and by monitoring the formation of conjugated dienes as an index of the inhibition of copper-catalyzed serum lipoprotein oxidation. ORAC values ranged from 3.1 to 16.3 micromol Trolox equivalent/g honey. The darkest colored honeys, such as buckwheat honey, had the highest ORAC values. A linear correlation was observed between phenolic content and ORAC activity of the investigated honeys (p < 0.0001, R (2) = 0.9497). The relationship between the ORAC activity and inhibition of lipoprotein oxidation by the honeys yielded a correlation coefficient of 0.6653 (p = 0.0136). This work shows that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants.

Honey has been used since ancient times as a flavorful sweetener and for its therapeutic and medicinal effects. Consumers' demand for natural, healthy products has driven renewed interest in honey's health benefits. The commonly encountered food mutagen, Trp-p-1, has been demonstrated to be mutagenic in bacteria and carcinogenic in animals. Chemically, honey is quite complex. Honey is comprised primarily of sugars; however, it contains many other potentially biologically active components, such as antioxidants. Sugars have been reported to display both mutagenic and antimutagenic effects in different systems; antioxidants often display antimutagenic activity. Little information exists about potential antimutagenic effects of honey. Antimutagenicity of honeys from seven different floral sources against Trp-p-1 was tested via the Ames assay and compared to that of a sugar analogue and to individually tested simple sugars. All honeys exhibited significant inhibition of Trp-p-1 mutagenicity; most demonstrated a linear correlation between percentage inhibition and log transformed honey concentration from 10 microg/mL to 20 mg/mL. Each displayed significant degrees of inhibition of mutagenicity above concentrations of 1 mg/mL, with individual variations in degree of effectiveness. Buckwheat honey displayed the greatest inhibition at 1 mg/mL, with slightly less effectiveness at higher concentrations. A sugar analogue demonstrated a pattern of inhibition similar to that of the honeys, with enhanced antimutagenicity at concentrations greater than 1 mg/mL. Glucose and fructose were also similar to honeys and were more antimutagenic than maltose and sucrose.

Honeys from different floral sources were evaluated for their antioxidant content and for their ability to inhibit enzymatic browning in fruits and vegetables. Antioxidant contents of honeys vary widely from different floral sources, as do their abilities to protect against enzymatic browning. Polyphenol oxidase (PPO) activity was reduced over a range of approximately 2-45% in fruit and vegetable homogenates, corresponding to a reduction in browning index by 2.5-12 units. Soy honey was particularly effective when compared to clover honey, which had a similar antioxidant content. When compared to commercial inhibitors of browning, honeys were less effective; however, in combination they added to the effectiveness of metabisulfite and ascorbic acid. Honey has great potential to be used as a natural source of antioxidants to reduce the negative effects of PPO browning in fruit and vegetable processing.