Simultaneous Determination of Total Vitamins B1, B2, B3, and B6 in Infant Formula and Related Nutritionals by Enzymatic Digestion and LC-MS/MS: Single-Laboratory Validation, First Action 2015.14

This method provides simultaneous determination of total vitamins B1, B2, B3, and B6 in infant formula and related nutritionals (adult and infant). The method was given First Action for vitamins B1, B2, and B6, but not B3, during the AOAC Annual Meeting in September 2015. The method uses acid phosphatase to dephosphorylate the phosphorylated vitamin forms. It then measures thiamine (vitamin B1); riboflavin (vitamin B2); nicotinamide and nicotinic acid (vitamin B3); and pyridoxine, pyridoxal, and pyridoxamine (vitamin B6) from digested sample extract by liquid chromatography-tandem mass spectrometry. A single-laboratory validation was performed on 14 matrixes provided by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) to demonstrate method effectiveness. The method met requirements of the AOAC SPIFAN Standard Method Performance Requirement for each of the three vitamins, including average over-spike recovery of 99.6 ± 3.5%, average repeatability of 1.5 ± 0.8% relative standard deviation, and average intermediate precision of 3.9 ± 1.3% relative standard deviation.

Is There a Difference in Metabolic Outcome Between Different Enteral Formulas?

BACKGROUND

Despite appropriate enteral nutrition, many elderly patients do not reach a good metabolic outcome. Two nutrition formulas are commonly used in Israel with no evidence-based medicine to indicate preference of one over the other.

METHODS

We describe a 2-month observational study of patients fed by 1 of the 2 formulas. The first (Osmolite, Abbott Company, Abbott Park, IL) is without fiber, and the second (Easy Fiber, Easyline Company Givataim, Israel) in addition to containing fiber is also richer in protein, vitamins, and minerals. The formula was selected by the primary care physician before enrollment in the study and was not influenced by the investigators. Routine blood tests as well as body weight were monitored at the start of enteral feeding and during the 2 months following as part of the regular follow-up.

RESULTS

Fifty-seven patients were fed with the regular formula and 77 with the enriched one. No statistically significant differences were noted between the groups during the follow-up period, in body weight, cholesterol levels, total lymphocyte count, renal function tests, or electrolyte balance. However, in the enriched formula group there was a significant decrease in glucose (p < .05), and increase in albumin (p < .05) and hemoglobin (p = .01) levels.

CONCLUSIONS

Enteral feeding with enriched formula appears to improve albumin and hemoglobin levels as well as diabetic control, thus it may be more appropriate than the nonfiber diet for use in long-term care patients.

An Anthology of Advances in Enteral Tube Feeding Formulations

This article summarizes several major advances in tube feeding formulas marketed in the United States. It traces the progress in tube feeding formulas, starting with blenderized formulas to commercially available intact-nutrient formulas and culminating in the introduction of the concept of immunonutrition. The impact of packaging is also described.

Gastric Residual Volume (GRV) and Gastric Contents Measurement by Refractometry

BACKGROUND

Traditional use of gastric residual volumes (GRVs), obtained by aspiration from a nasogastric tube, is inaccurate and cannot differentiate components of the gastric contents (gastric secretion vs delivered formula). The use of refractometry and 3 mathematical equations has been proposed as a method to calculate the formula concentration, GRV, and formula volume. In this paper, we have validated these mathematical equations so that they can be implemented in clinical practice.

METHODS

Each of 16 patients receiving a nasogastric tube had 50 mL of water followed by 100 mL of dietary formula (Osmolite HN, Abbott Laboratories, Columbus, OH) infused into the stomach. After mixing, gastric content was aspirated for the first Brix value (BV) measurement by refractometry. Then, 50 mL of water was infused into the stomach and a second BV was measured. The procedure of infusion of dietary formula (100 mL) and then water (50 mL) was repeated and followed by subsequent BV measurement. The same procedure was performed in an in vitro experiment. Formula concentration, GRV, and formula volume were calculated from the derived mathematical equations.

RESULTS

The formula concentrations, GRVs, and formula volumes calculated by using refractometry and the mathematical equations were close to the true values obtained from both in vivo and in vitro validation experiments.

CONCLUSIONS

Using this method, measurement of the BV of gastric contents is simple, reproducible, and inexpensive. Refractometry and the derived mathematical equations may be used to measure formula concentration, GRV, and formula volume, and also to serve as a tool for monitoring the gastric contents of patients receiving nasogastric feeding.

Determinants of Insulin Availability in Parenteral Nutrition Solutions

BACKGROUND

Management of hyperglycemia in patients receiving parenteral nutrition (PN) often includes the addition of regular insulin to the PN solution. A literature review has shown insulin availability in such solutions to range from 10% to 95%. This discrepancy in availability may be due to differences in the composition of the PN solution, the final concentration of insulin, or the assay method used to determine insulin concentrations. The purpose of this study was to evaluate insulin recovery from a standard PN solution used at our medical center.

METHODS

Solutions were manually prepared in our pharmacy according to standard practice. Multivitamins and trace elements were added to 1 of 2 L of solution each day. Each of 3 simulated patients received 2 L of solution per day for 3 consecutive days. Samples from each bottle were drawn at baseline, 1 hour after the start of infusion, and 1 hour before the end of infusion and were subsequently analyzed for immunoreactive insulin levels by radioimmunoassay.

RESULTS

Recovery of insulin from solutions containing multivitamins and trace elements was much greater (95%) than from those without (5%).

CONCLUSIONS

The presence of multivitamins and trace elements is a major determinant of insulin availability in PN solutions. Additional research is necessary to determine the mechanism mediating this effect and to assess its clinical significance.

Effects of multilayered bags vs ethylvinyl-acetate bags on oxidation of parenteral nutrition

BACKGROUND

We evaluate the effects of multilayered bags vs ethylvinyl-acetate bags on peroxidate formation of various emulsions for all-in-one total parenteral nutrition solutions (TPN) during storage.

METHODS

Twenty-four parenteral nutritions were prepared with 4 commercial i.v. lipid emulsions (Soyacal 20%, Grifols; Intralipid 20%, Fresenius-Kabi; Lipofundina 20%, Braun; and Clinoleic 20%, Clintex) and 2 different bags (multilayered [ML] bag, Miramed; and 1 ethylvinyl-acetate [EVA] bag, Miramed). Each kind of TPN was prepared in triplicate. Samples were taken at 3 different times: immediately after preparation (time 0), after 6 days at 4 degrees C and 48 hours at 37 degrees C (time 1), and finally after a total of 14 days at 37 degrees C (time 2). Oxidation of TPN was evaluated by analysis of hydroperoxides by ferrous oxidation-xylenol orange (FOX) reactive, lipoperoxides by thiobarbituric acid reactive species (TBARS), alpha-tocopherol by high-performance liquid chromatography (HPLC), and ascorbic acid and dehydroascorbic acid by HPLC.

RESULTS

TPN admixtures in ML bag showed less oxidation evaluated by peroxide determination using FOX than EVA bag. Lipoperoxides by TBARS did not show significant differences between 2 bags. Ascorbic acid and dehydroascorbic acid disappeared in EVA bags at time 1. No important differences were found in alpha-tocopherol content.

CONCLUSIONS

Multilayered bags minimize oxidation.

Sodium polystyrene sulfonate used to reduce the potassium content of a high-protein enteral formula: a quantitative analysis

BACKGROUND

Sodium polystyrene sulfonate (Kayexalate) commonly is used in treating hyperkalemia. As a cation exchange resin, it also can be used to reduce the potassium content of enteral nutrition formulas. This study evaluates the use of Kayexalate to reduce potassium in one high-protein enteral formula and describes the quantitative analysis of the product.

METHODS

Sodium polystyrene sulfonate and enteral formula were mixed into a slurry and allowed to settle, and then the supernatant was decanted off and tested as samples. Three sample concentrations were analyzed: a control not subjected to potassium reduction, 0.5 g of Kayexalate per mEq K+ sample, and a 1 g/mEq K+ sample. Of these samples, moisture, lipid, protein, carbohydrate, ash, and mineral content were obtained.

RESULTS

Compared with the control, the percentage decrease of potassium ranged from 25% to 36%, depending on the concentration of Kayexalate. A significant increase of 324% in sodium concentration was found in the 1.0 g/mEq K+ sample. Although there was no change in magnesium content, a slight increase in phosphorus, iron, and zinc was evident.

CONCLUSIONS

The treatment of an enteral formula with sodium polystyrene sulfonate significantly increases its sodium content, with a modest decrease in potassium content. Clinicians using this method in clinical practice should be aware of the increase in sodium content.

Analytical Method for Sugar Profile in Pet Food and Animal Feeds by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection

There is a need for a standardized, accurate, rugged, and consistent method to measure for sugars in pet foods and animal feeds. Many traditional standard sugar methods exist for other matrixes, but when applied in collaborative studies there was poor agreement and sources of error identified with those standard methods. The advancement in technology over the years has given us the ability to improve on these standard methods of analysis. A method is described here that addresses these common issues and was subjected to a single-laboratory validation to assess performance on a wide variety of pet foods and animal feeds. Of key importance to the method performance is the sample preparation before extraction, type of extraction solvent, postextraction cleanup, and, finally, optimized chromatography using high-performance anion exchange chromatography with pulsed amperometric detection. The results obtained from the validation demonstrate how typical issues seen with these matrixes can influence performance of sugar analysis. The results also demonstrate that this method is fit-for-purpose and can meet the challenges of sugar analysis in pet food and animal feeds to lay the foundation for a standardized method of analysis.

Determination of Labeled Fatty Acids Content in Milk Products, Infant Formula, and Adult/Pediatric Nutritional Formula by Capillary Gas Chromatography: Collaborative Study, Final Action 2012.13

A collaborative study was conducted on AOAC First Action Method 2012.13 "Determination of Labeled Fatty Acids Content in Milk Products and Infant Formula by Capillary Gas Chromatography," which is based on an initial International Organization for Standardization (ISO)-International Dairy Federation (IDF) New Work Item that has been moved forward to ISO 16958:2015|IDF 231:2015 in November 2015. It was decided to merge the two activities after the agreement signed between ISO and AOAC in June 2012 to develop common standards and to avoid duplicate work. The collaborative study was performed after having provided highly satisfactory single-laboratory validation results [Golay, P.A., & Dong, Y. (2015) J. AOAC Int. 98, 1679-1696] that exceeded the performance criteria defined in AOAC Standard Method Performance Requirement (SMPR(®)) 2012.011 (September 29, 2012) on 12 products selected by the AOAC Stakeholder Panel on Infant Formula (SPIFAN). After a qualification period of 1 month, 18 laboratories participated in the fatty acids analysis of 12 different samples in duplicate. Six samples were selected to meet AOAC SPIFAN requirements (i.e., infant formula and adult nutritionals in powder and liquid formats), and the other Six samples were selected to meet ISO-IDF requirements (i.e., dairy products such as milk powder, liquid milk, cream, butter, infant formula with milk, and cheese). The fatty acids were analyzed directly in all samples without preliminary fat extraction, except in one sample (cheese). Powdered samples were analyzed after dissolution (i.e., reconstitution) in water, whereas liquid samples (or extracted fat) were analyzed directly. After addition of the internal standards solution [C11:0 fatty acid methyl ester (FAME) and C13:0 triacylglycerols (TAG)] to the samples, fatty acids attached to lipids were transformed into FAMEs by direct transesterification using methanolic sodium methoxide. FAMEs were separated using highly polar capillary GLC and were identified by comparison with the retention times of pure analytical standards. Quantification of fatty acids was done relative to C11:0 FAME as internal standard and to instrument response factors (determined separately using calibration standards mixture). The performance of the method (i.e., transesterification) was monitored in all samples using the second internal standard, C13:0 TAG. RSDR values were summarized separately for labeled fatty acids in SPIFAN materials and ISO-IDF materials due to different expression of results. This method was applied to representative dairy, infant formula, and adult/pediatric nutritional products and demonstrated global acceptable reproducibility precision for all fatty acids analyzed (i.e., 46 individuals and/or groups) for these categories of products.

Determination of Free and Total Choline and Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): Single-Laboratory Validation, First Action 2015.10

Analytical methods for the analysis of both L-carnitine and choline are needed for reliable and accurate determination in infant formula and adult/pediatric nutritional formula. These compounds are different in how they are utilized by the human body, but are structurally similar. L-carnitine and choline are quaternary ammonium compounds, enabling both to be retained under acidic conditions with strong cation exchange (SCX) chromatography. This method analyzes both compounds simultaneously as either the free forms or as a total amount that includes bound sources such as phosphatidylcholine or acetylcarnitine. The free analysis consists of water extraction and analysis by LC/MS/MS, while the total analysis consists of extraction by acid assisted microwave hydrolysis and analysis by LC/MS/MS. Calibration standards used for calculations are extracted with all samples in the batch. A single laboratory validation (SLV) was performed following the guidelines of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) utilizing the kit of materials provided. The results achieved meet the requirements of SMPR 2012.010 and 2012.013 for L-carnitine and total choline, respectively.

Current Methods for the Analysis of Selected Novel Nutrients in Infant Formulas and Adult Nutritionals

Infant formula is designed to provide the human infant with a sole source of nutrition and it is intended to imitate breast milk. In recent years, advances in the science of infant nutrition have led to an increasing number of novel ingredients that are supplemented into infant formula. As the list of these nutritionally important nutrients is lengthy, this review summarizes contemporary analytical methods that have been applied to a representative selection (lutein, carnitine, choline, nucleotides, inositol, taurine, sialic acid, gangliosides, triacylglycerides, oligosaccharides, α-lactalbumin, and lactoferrin).

Modernization of AOAC Nutrient Methods by Stakeholder Panel on Infant Formula and Adult Nutritionals

Infant formula is one of the most highly regulated products in the world. To comply with global regulations and to ensure the products are manufactured within product specifications, accurate analytical testing is required. Most of the AOAC INTERNATIONAL legacy test methods for infant formula were developed and validated in the 1980s and 1990s. Although these methods performed very well for many years, infant formulas have been updated, and today's products contain many new and novel ingredients. There were a number of cases in which the legacy AOAC methods began to result in problems with the analysis of modern infant formulas, and the use of these methods caused some disputes with regulatory agencies. In 2010, AOAC reached an agreement with the International Formula Council, which has changed its name to the Infant Nutrition Council of America, regarding a project to modernize these AOAC infant-formula test methods. This agreement led to the development of Standard Method Performance Requirements (SMPRs(®)) for 28 nutrients. After SMPR approval, methods were collected, evaluated, validated, and approved through the AOAC Official Methods(SM) process. Forty-seven methods have been approved as AOAC First Action Methods, and eight have been approved as Final Action.

Descriptive and hedonic analyses of low-Phe food formulations containing corn (Zea mays) seedling roots: toward development of a dietary supplement for individuals with phenylketonuria

BACKGROUND

Seedling roots of anthocyanin-rich corn (Zea mays) cultivars contain high levels of phenylalanine ammonia lyase (PAL) activity. The development of a natural dietary supplement containing corn roots could provide the means to improve the restrictive diet of phenylketonuria (PKU) patients by increasing their tolerance to dietary phenylalanine (Phe). Therefore this research was undertaken to explore the sensory characteristics of roots of four corn cultivars as well as to develop and evaluate food products (cereal bar, beverage, jam-like spread) to which roots had been added.

RESULTS

Sensory profiles of corn roots were investigated using ten trained judges. Roots of Japanese Striped corn seedlings were more bitter, pungent and astringent than those of white and yellow cultivars, while roots from the Blue Jade cultivar had a more pronounced earthy/mushroom aroma. Consumer research using 24 untrained panelists provided hedonic (degree-of-liking) assessments for products with and without roots (controls). The former had lower mean scores than the controls; however, the cereal bar had scores above 5 on the nine-point scale for all hedonic assessments compared with the other treated products.

CONCLUSION

By evaluating low-Phe food products containing corn roots, this research ascertained that the root-containing low-Phe cereal bar was an acceptable 'natural' dietary supplement for PKU-affected individuals.

Determination of Vitamin B12 in Infant, Adult, and Pediatric Formulas by HPLC-UV and Column Switching: Collaborative Study, Final Action 2011.10

AOAC First Action Method 2011.10, Vitamin B12 in Infant and Pediatric Formulas and Adult Nutritionals, was collaboratively studied. This method uses a pH 4.5 sodium acetate buffer and potassium cyanide at 105°C to extract and convert all biologically active forms of vitamin B12 present to cyanocobalamin; octylsilyl (C8) or C18 SPE cartridges to purify and concentrate cyanocobalamin; a combination of size-exclusion and RPLC to isolate cyanocobalamin; and visible absorbance at 550 nm to detect and quantitate cyanocobalamin in infant, pediatric, and adult nutritionals with vitamin B12 concentrations greater than 0.025 μg/100 g ready-to-feed (RTF) liquid. During this collaborative study, nine to 11 laboratories from eight different countries analyzed blind duplicates of 12 infant, pediatric, and adult nutritional formulas. Per the AOAC Expert Review Panel (ERP) on Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Nutrient Methods the method demonstrated acceptable repeatability and reproducibility and met SPIFAN Standard Method Performance Requirements (SMPRs®) for the majority of product matrixes analyzed. Vitamin B12 SPIFAN SMPRs for repeatability were ≤15% RSD at vitamin B12 concentrations of 0.01 μg/100 g RTF liquid and ≤7% RSD at vitamin B12 concentrations of 0.2-5.0 μg/100 g RTF liquid. Vitamin B12 SPIFAN SMPRs for reproducibility were ≤11% RSD in products with vitamin B12 concentrations ranging from 0.3 to 5.0 μg/100 g RTF liquid. During this collaborative study, the RSDr ranged from 2.98 to 9.77%, and the RSDR ranged from 3.54 to 19.5%. During previous single-laboratory validation studies, the method LOQ was estimated to be 0.025 μg/100 g RTF liquid.

Pantothenic Acid (Vitamin B5) in Infant Formula and Adult/ Pediatric Nutritional Formula by Ultra-High Pressure Liquid Chromatography/Tandem Mass Spectrometry Method: Collaborative Study, Final Action 2012.16

In order to determine repeatability and reproducibility of AOAC First Action Method 2012.16 [Pantothenic Acid (Vitamin B5) in Infant Formula and Adult/Pediatric Nutritional Formula by Ultra-High Pressure Liquid Chromatography/Tandem Mass Spectrometry], a collaborative study was organized. The study was divided in two parts: method setup and qualification of participants (part 1) and collaborative study participation (part 2). For part 1, each participating laboratory was asked to analyze two practice samples using the aforementioned method. Laboratories that provided results within a range of expected levels were qualified for part 2, during which each laboratory received 10 samples in blind duplicates. Results have been compared to the Standard Method Performance Requirement (SMPR®) 2012.009 established for pantothenic acid. Precision results (repeatability and reproducibility) were within the limits stated in the SMPR. Repeatability ranged from 1.3 to 3.3%, and reproducibility ranged from 4.1 to 7.0%. Horwitz ratio (HorRat) values were all <1, ranging from 0.33 to 0.69. The AOAC Expert Review Panel on Stakeholder Panel on Infant Formula and Adult Nutritionals Nutrient Methods determined that the data presented met the SMPR and recommended the method for Final Action status, which was then granted by the AOAC Official Methods Board.

Determination of Myo-Inositol in Infant, Pediatric, and Adult Formulas by Liquid Chromatography-Pulsed Amperometric Detection with Column Switching: Collaborative Study, Final Action 2011.18

AOAC First Action Method 2011.18, Myo-Inositol (Free and Bound as Phosphatidylinositol) in Infant and Pediatric Formulas and Adult Nutritionals, was collaboratively studied. With this method free myo-inositol and phosphatidylinositol bound myo-inositol are extracted using two different sample preparation procedures, separated by ion chromatography using a combination of Dionex Carbo Pac PA1 and MA1 columns with column switching, and detected with pulsed amperometry using a gold electrode. Free myo-inositol is extracted from samples with dilute hydrochloric acid and water. Phosphatidylinositol is extracted from samples with chloroform and separated from other fats with silica SPE cartridges. Myo-inositol is then released from the glycerol backbone with concentrated acetic and hydrochloric acids at 120°C. During this collaborative study, nine laboratories from five different countries analyzed blind duplicates of nine infant and pediatric nutritional formulas for both free and phosphatidylinositol bound myo-inositol, and one additional laboratory only completed the free myo-inositol analyses. The method demonstrated acceptable repeatability and reproducibility and met the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Standard Method Performance Requirements (SMPRs®) for free myo-inositol plus phosphatidylinositol bound myo-inositol for all the matrixes analyzed. SMPRs for repeatability were ≤5% RSD at myo-inositol concentrations of 2-68 mg/100 g ready-to-feed (RTF) liquid. SMPRs for reproducibility were ≤8% RSD in products with myo-inositol concentrations ranging from 2 to 68 mg/100 g RTF liquid. During this collaborative study, repeatability RSDs ranged from 0.51 to 3.22%, and RSDs ranged from 2.66 to 7.55% for free myo-inositol plus phosphatidylinositol bound myo-inositol.

Determination of Free and Total Carnitine and Choline in Infant Formulas and Adult Nutritional Products by UPLC/MS/MS: Single-Laboratory Validation, First Action 2014.04

A single-laboratory validation (SLV) has been performed for a method that simultaneously determines choline and carnitine in nutritional products by ultra performance LC (UPLC)/MS/MS. All 11 matrixes from the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) were tested. Depending on the sample preparation, either the added (free, with a water dilution and filtering) or total (after microwave digestion at 120°C in nitric acid and subsequent neutralization with ammonia) species can be detected. For nonmilk containing products, the total carnitine is almost always equal to the free carnitine. A substantial difference was noted between free and total choline in all products. All Standard Method Performance Requirements for carnitine and choline have been met. This report summarizes the material sent to the AOAC Expert Review Panel for SPIFAN nutrient methods for the review of this method, as well as some additional data from an internal validation. The method was granted AOAC First Action status for carnitine in 2014 (2014.04), but the choline data are also being presented. A comparison of choline results to those from other AOAC methods is given.

Assessment of anti-factor Xa activity of heparin in binary parenteral nutrition admixtures for premature neonates

An in vitro study was carried out to determine the anti-Xa activity of heparin in binary parenteral nutrition (BPN) admixtures for premature neonates in our neonatal intensive care unit (NICU) after a 24-hour infusion, as well as to assess drug interaction with a 50% glucose solution. Two types of bags were prepared: (1) BPN admixtures (composition defined in the NICU) including sodium heparin at 77 UI/mL and (2) bags containing only G50% with sodium heparin at 193 UI/mL. The anti-Xa activity of heparin was measured in bags at T0, after the 24-hour infusion and in eluates at the outlet of the infusion line after 24hours, using a validated chromogenic anti-Xa method. Comparisons of the mean concentration observed with the theoretical value for anti-Xa activity were performed with the Student t-test. Mean values of anti-Xa activity do not differ significantly from the values expected for all conditions. We found a slight variation in anti-Xa activity when infused over 24hours for both types of bags, with and without in-line filtration, showing that heparin remains stable during this infusion period in both BPN admixtures and G50%.

Chemically defined diet alters the protective properties of fructo-oligosaccharides and isomalto-oligosaccharides in HLA-B27 transgenic rats

Non-digestible oligosaccharides (NDO) were shown to reduce inflammation in experimental colitis, but it remains unclear whether microbiota changes mediate their colitis-modulating effects. This study assessed intestinal microbiota and intestinal inflammation after feeding chemically defined AIN-76A or rat chow diets, with or without supplementation with 8 g/kg body weight of fructo-oligosaccharides (FOS) or isomalto-oligosaccharides (IMO). The study used HLA-B27 transgenic rats, a validated model of inflammatory bowel disease (IBD), in a factorial design with 6 treatment groups. Intestinal inflammation and intestinal microbiota were analysed after 12 weeks of treatment. FOS and IMO reduced colitis in animals fed rat chow, but exhibited no anti-inflammatory effect when added to AIN-76A diets. Both NDO induced specific but divergent microbiota changes. Bifidobacteria and Enterobacteriaceae were stimulated by FOS, whereas copy numbers of Clostridium cluster IV were decreased. In addition, higher concentrations of total short-chain fatty acids (SCFA) were observed in cecal contents of rats on rat chow compared to the chemically defined diet. AIN-76A increased the relative proportions of propionate, iso-butyrate, valerate and iso-valerate irrespective of the oligosaccharide treatment. The SCFA composition, particularly the relative concentration of iso-butyrate, valerate and iso-valerate, was associated (P ≤ 0.004 and r ≥ 0.4) with increased colitis and IL-1 β concentration of the cecal mucosa. This study demonstrated that the protective effects of fibres on colitis development depend on the diet. Although diets modified specific cecal microbiota, our study indicates that these changes were not associated with colitis reduction. Intestinal inflammation was positively correlated to protein fermentation and negatively correlated with carbohydrate fermentation in the large intestine.

Aquatic animal nutrition for the exotic animal practitioner

Fish are the most popular pets in the United States based on numbers and high-quality medical care is coming to be expected by owners. Increasing numbers of veterinarians are responding to this need and providing veterinary care for aquatic animals. Part of good medical care for exotic animals is advice on husbandry, including nutrition. However, there are numerous missing areas of research for the nutritional needs of many ornamental fish species. What is known for food species can be combined with what is known for ornamental species to give nutritional advice to owners to maximize health in these animals.

Simultaneous determination of vitamins D2 and D3 by electrospray ionization LC/MS/MS in infant formula and adult nutritionals: First Action 2012.11

A method was developed for the analysis of vitamins D2 and D3 in a variety of nutritional products. To extract vitamins D2 and D3 from products containing substantial amounts of fat, a saponification with alcoholic potassium hydroxide is required to release the vitamin D. Trideuterium-labeled vitamin D is added to the sample prior to saponification, and quantitation is achieved using linear regression of the ratio of peak response for 2H3-D and vitamin D. Acceptable linearity was achieved between 0.6 and 27 microg/100 g with a correlation requirement of >0.999. The method detection limit of 0.02 microg/100 g was verified by spiking placebo products carried through the saponification and extraction steps of the method. At the quantitation limit (0.12 microg/100 g), the signal was easily distinguished from the background. Vitamin D3 spike recoveries ranged from 107 to 119% at the low level and 104 to 116% at the high-level spike. Vitamin D2 recoveries were 105 to 116% and 91 to 110% for the low- and high-level spikes, respectively. SRM 1849a has a certified concentration of 11.1 +/- 1.7 microg/100 g; using this standard reference material, the range of 9.4 to 12.8 microg/100 g was met on each of the 6 days. Method repeatability, determined in 12 vitamin D3 product matrixes over 6 days, ranged from 3.9 to 48%. The adult nutrition-milk protein sample was the most notable; it failed within-day, as well as day-to-day, precision requirements. There was no attempt to optimize the sample preparation to accommodate any problem matrix.

Determination of vitamins A and E in infant formula and adult/pediatric nutritional formula by HPLC with UV and fluorescence detection: First Action 2012.09

The method presented is for quantification of alpha-tocopherol (vitamin E), vitamin E acetate, vitamin A acetate, and vitamin A palmitate in infant formula and adult/pediatric nutritionals. The entire lipid fraction, including vitamins A and E, is extracted from product with iso-octane after products are mixed with methanol, which precipitates proteins and disrupts micelles freeing lipids for extraction. Vitamin A palmitate, vitamin A acetate, and vitamin E acetate are separated from alpha-tocopherol on a 3 cm silica column with a 1% methylene chloride, 0.06% isopropanol in iso-octane mobile phase; eluted onto a 20 cm silica column; and, after a column switch, further separated on the 20 cm column before UV detection at 325 nm (vitamin A palmitate and vitamin A acetate) and 285 nm (vitamin E acetate). Alpha-Tocopherol is further separated from other extraneous compounds on the 3 cm silica column and detected by fluorescence at excitation and emission wavelengths of 295 and 330 nm, respectively. Quantification limits in ready-to-feed products were estimated to be 80 IU/L for vitamin A palmitate, 207 International Units (IU)/L for vitamin A acetate, 2.4 mg/L for vitamin E acetate, and < 0.15 mg/L for alpha-tocopherol. Over-spike recoveries and intermediate precision averaged 100.4 and 2.09% RSD for vitamin A palmitate, 100.4 and 1.52% RSD for vitamin E acetate, and 99.6 and 3.02% RSD for alpha-tocopherol. Vitamin A acetate spike recovery data averaged 96.6%, and the intermediate precision for the only product fortified with vitamin A acetate was 2.75% RSD.

[Use of the Six Sigma methodology for the preparation of parenteral nutrition mixtures]

OBJECTIVE

To use the tools of the Six Sigma methodology for the statistical control in the elaboration of parenteral nutrition mixtures at the critical checkpoint of specific density.

METHODS

Between August of 2010 and September of 2013, specific density analysis was performed to 100% of the samples, and the data were divided in two groups, adults and neonates. The percentage of acceptance, the trend graphs, and the sigma level were determined. A normality analysis was carried out by using the Shapiro Wilk test and the total percentage of mixtures within the specification limits was calculated.

RESULTS

The specific density data between August of 2010 and September of 2013 comply with the normality test (W = 0.94) and show improvement in sigma level through time, reaching 6/6 in adults and 3.8/6 in neonates. 100% of the mixtures comply with the specification limits for adults and neonates, always within the control limits during the process.

CONCLUSION

The improvement plans together with the Six Sigma methodology allow controlling the process, and warrant the agreement between the medical prescription and the content of the mixture.