Enrichment of Protein Content in Rice-Based Dried Distillers’ Grain from Food-Ethanol Factory by Chemical Method

Dried distillers’ grain (DDG) from rice-based alcohol factories contains relatively high protein (ca. 79% of dry matter). However, this vegetative protein source has only been used for animal feeding. To enhance the value of this by-product, i.e. toward application for the food industry, this study has applied different approaches for the enrichment of protein content in this by-products. These approaches were either using solvents to directly extract and precipitate protein or removing non-protein components in rice-based DDG. The results showed that the direct extraction and precipitation of protein was not effective as the removal of non-protein components. The use of NaOH 10 mM has increased protein content up to 87% of dry matter by washing out the non-protein components such as starch from DDG. Preliminary, the protein-enriched DDG was used up to 15% as an ingredient for cookies without negative effect on the taste or color of this product.

Pharmacokinetic Study of Deltaline in Mouse Blood Based on UPLCMS/ MS

Introduction: Deltaline, an aconitine-type alkaloid, was detected in mouse blood using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method, and the pharmacokinetics of deltaline following intravenous administration in mice was studied. </P><P> Materials and Methods: The gelsenicine was used as the internal standard (IS). Deltaline and IS were eluted at a flow rate of 0.4 ml/min and separated on a UPLC BEH C18 column by gradient elution using acetonitrile and 10 mmol/L ammonium acetate (0.1% formic acid) as a mobile phase. The following transitions were obtained at m/z 508.2→75.0 for deltaline and m/z 327.1→107.8 for gelsenicine in multiple reactions monitoring mode. Acetonitrile was used to precipitate protein. Six mice after intravenous administration of a single dose of deltaline (1 mg/kg), 20-µL blood samples from each mouse were collected from the tail vein. Results: The UPLC-MS/MS method was sensitive and linear (r>0.995) with a lower limit of quantitation (LLOQ) of 0.1 ng/mL over the range of 0.1-500 ng/mL. Intra- and inter-day precisions were below 13%, the accuracy range was between 88.0% and 108.2%, the recovery was higher than 90.1%, and the matrix effect was between 102.9% and 108.1%. Conclusion: The method was sensitive, fast, specific, and has been successfully applied to a pharmacokinetic study of deltaline after intravenous administration.

Simple and Robust Analysis of Cefuroxime in Human Plasma by LC-MS/MS: Application to a Bioequivalence Study

A simple, robust LC-MS/MS assay for quantifying cefuroxime in human plasma was developed. Cefuroxime and tazobactam, as internal standard (IS), were extracted from human plasma by methanol to precipitate protein. Separation was achieved on a Zorbax SB-Aq (4.6×250 mm, 5 μm) column under isocratic conditions. The calibration curve was linear in the concentration range of 0.0525–21.0 μg/mL (r=0.9998). The accuracy was higher than 90.92%, while the intra- and interday precision were less than 6.26%. The extraction procedure provides recovery ranged from 89.44% to 92.32%, for both analyte and IS. Finally, the method was successfully applied to a bioequivalence study of a single 500 mg dose of cefuroxime axetil in 22 healthy Chinese male subjects under fasting condition. Bioequivalence was determined by calculating 90% Cls for the ratios ofCmax, AUC0-t, and AUC0-∞values for the test and reference products, using logarithmic transformed data. The 90% Cls for the ratios ofCmax(91.4%~104.2%), AUC0-t(97.4%~110.9%), and AUC0-∞(97.6%~111.1%) values were within the predetermined range. It was concluded that the two formulations (test for capsule, reference for tablet) analyzed were bioequivalent in terms of rate and extent of absorption and the method met the principle of quick and easy clinical analysis.

Influence of low temperature acclimation on fate of metabolic fuels in rainbow trout (Oncorhynchus mykiss) hearts

Rainbow trout (Oncorhynchus mykiss) were acclimated to 5 and 20 °C. Oxygen consumption of isolated perfused hearts was measured at 5 or 15 °C with either glucose or palmitate as the exogenous fuel source. With glucose as the fuel there was no significant difference in oxygen consumption of hearts from either acclimation group at either temperature. With palmitate as the fuel source, hearts from fish acclimated to and tested at 5 °C had significantly higher oxygen consumption than hearts from fish acclimated to 20 °C and tested at either 5 or 15 °C. Hearts from fish both acclimated to and tested at 5 °C had a higher oxygen consumption with palmitate than when glucose was supplied. This reflects the preference for fatty acid fuels found in cold acclimated muscle tissue, and consequently the amount of oxygen required to utilize fats. Under all experimental conditions, 14CO2 production from either (6-14C)glucose or (1-14C)palmitate could account for less than 0.5% of oxygen consumption. Tissue chemical analysis showed that most of the label from (6-14C)glucose appeared in acid-soluble (glycolytic intermediates, citric acid cycle intermediates, amino acids, etc.) and lipid fractions while most of the label from (1-14C)palmitate appeared in lipid- or acid-soluble or acid precipitate (protein material) fractions. This indicates considerable dilution of exogenous fuels in endogenous pools, which could account for the discrepancy in measured O2 consumption and 14CO2 production. Glucose catabolism was little affected by either acute or chronic changes in temperature other than an increase in glucose incorporation into the glycogen pool. Hearts from fish both acclimated to and tested at 5 °C showed an increased handling of exogenous fatty acids as reflected by elevated rates of catabolism and incorporation into intracellular lipids.

Fast and Simple Liquid Chromatographic Determination of Nonphosphorylated Thiamine in Infant Formula, Milk, and Other Foods

A very fast and simple method for determination of nonphosphorylated thiamine In Infant formula products, milk, and other nonfortlfled foods using reverse-phase ion-pairing liquid chromatography (LC) has been developed. Sample preparation consists of merely acid treatment to precipitate protein, followed by gravity filtration. No concentration, extraction, derlvatlzatlon, or preliminary column cleanup is necessary. The chromatography Is done on /tBondapack C18 with an aqueous mobile phase containing 0.15% sodium hexane sulfonate, 20% MeOH, 1.5% HOAc, and 0.1 % EDTA at a flow rate of 2.5 mL/mln. Ultraviolet detection at 248 nm Is used. A typical run takes 7 mln, and 60 samples can be processed In 4 h. Results average from 96 to 104% of theory for the Infant formula products analyzed. A 99 to 103% recovery of spike has been demonstrated. Method precision Is good (2 to 4% RSD, short-term, and 2 to 5% RSD, longterm, depending on sample type). Peak separation from thiamine phosphate esters Is achieved. Specificity Is demonstrated by UV spectral scan and absorbance ratios. Equivalency to a microbial method (validated against the official AOAC fluorometrlc method) was established. The method Is used for high-volume quality control testing of milk-based Infant formula products In the ready-to-use, concentrate, or powder form

A comparison of methods for determining the concentration of extracellular peptides in rumen fluid of sheep

SUMMARYSamples of rumen fluid were removed from pairs of sheep on four grass-hay-based diets 7 h after feeding. Micro-organisms were sedimented by centrifugation and the cell-free supernatant was treated with perchloric acid (PCA) to precipitate protein. The remaining fluid was analysed for peptides by several methods to determine how much peptide escaped degradation. Ammonia interfered with analysis by amino group reagents, especially ninhydrin. In this respect,o-phthalaldehyde and trinitrobenzene sulphonic acid were more specific and more useful than ninhydrin. Use of all these reagents showed that significant quantities of amino groups (equivalent to up to 153 mg amino acid N/1 of rumen fluid) were released by hydrolysis of the PCA extract with 6 M-HCI for 24 h. However, fluorescamine analysis indicated that the peptide content of the unhydrolysed PCA extract was < 3 mg N/1. The true amino acid content of different extracts was resolved by chromatographic amino acid analysis: the sum of individual amino acid concentrations in acid-hydrolysed PCA extracts of extracellular rumen fluid ranged from 7·8 to 14·5 mg N/1. Thus most of the free amino N released by hydrolysis of the PCA extract was not from amino acids, and most of the amino acids that were released were originally present in a form that did not react with fluorescamine. Although none of the methods gave a reliable estimate of peptide concentrations, amino acid analysis provided an upper limit. It was therefore concluded that peptide concentrations in extracellular rumen fluid are much lower than indicated by previous ninhydrin estimations, and that little dietary peptide escapes degradation for a prolonged period in the rumen.