Analysis of Vitamin E Compounds in Colored-Grain Wheat, Tritordeum, and Barley using HPLC

Analysis of Vitamin E Compounds in Colored-Grain Wheat, Tritordeum, and Barley using HPLC

Vitamin E is a group of compounds that include tocopherols and tocotrienols. The structure of each compound in this family include a chromane double ring with a hydroxyl group and a hydrophobic side chain. The chromane double ring with the hydroxyl group can donate an H+ ion to reduce free radicals (antioxidant properties) and the hydrophobic chain allows to pass through phospholipid membranes. Vitamin E is present in a variety of foods including wheat. Lachman et. al was able to assess the Vitamin E content in color-grained wheat, tritordeum, and barley.

In their analysis, Lachman et. al obtained their samples from Agricultural Research Institute Kroměříž, Ltd., Czech Republic. Their samples were harvested in 2014 and 2015. The samples were prepared using a modification to a method presented in Sánchez-Machado, López-Cervantes, and Ríos Vázquez (2006). Steps in the sample preparation included, but not limited to, homogenization, rapid cooling, and evaporation steps. After sample preparation, the samples were analyzed using HPLC with fluorescence detection. The analytical conditions included using a Develosil RPAQUEOUS, 5 µm (4.5 mm x 250 mm) as the analytical column, and a mobile phase comprising of H2O and methanol at 3 to 97 ratio (v:v).[1][2]

Analysis of Vitamin E in the tested samples revealed some evidence of seasonal effects in addition to genomic differences. It was revealed that: (1) there was higher amounts of Vitamin E in the spring wheats compared to the fall wheats (2) higher amounts of Vitamin E in blue- and purple- gained spring wheat and (3) barley had more quantifiable amounts of than the tested tritordeum and wheat (6-8 Vitamin E compounds compared to 4).[1]

References:

1. Jaromír Lachman, Alena Hejtmánková, Matyáš Orsák, Marek Popov, Petr Martinek, Tocotrienols and tocopherols in colored-grain wheat, tritordeum and barley, Food Chemistry, Volume 240, 2018, Pages 725-735, ISSN 0308-8146, https://doi.org/10.1016/j.foodchem.2017.07.123.

2. D.I. Sánchez-Machado, J. López-Cervantes, N.J. Ríos Vázquez, High-performance liquid chromatography method to measure α- and γ-tocopherol in leaves, flowers and fresh beans from Moringa oleifera, Journal of Chromatography A, Volume 1105, Issues 1–2, 2006,Pages 111-114, ISSN 0021-9673, https://doi.org/10.1016/j.chroma.2005.07.048.

 

How should you cook your eggs?

How should you cook your eggs?

Eggs have been known to be a rich protein source as well as great source of various nutrients such as antioxidants. They are considered one of the most important sources of xanthophylls.[1] Xanthophylls, one of the major groups of carotenoids, have a potential protective role in eye health and prevention of heart disease and stroke.[2] Cooking and intestinal conditions affect the nutritional value of the eggs due to the changes in protein and lipid digestibility.[1]

Asencio-Grau et. al explores the effects of various cooking methods and intestinal conditions on the different levels of digestibility of macronutrients and micronutrients in eggs. Their matrix of tests included boiled eggs, poached eggs, and omelets in two main sets of experiments. One set was fixing the pH and bile salt concentration while changing the enzyme concentration. Another set of experiments was fixing the enzyme concentration while varying the pH and bile salt concentration.[1]

To analyze the bioavailability of the xanthophylls, Asencio-Grau et. al uses a method to obtain a fine powder from the raw and cooked egg samples before and after digestion. The method consists of homogenization and freeze-drying steps.[1] The xanthophylls are subsequently extracted using a combination of solvents and analyzed using HPLC-DAD with a gradient mobile phase consisting of methanol, tert-methyl-butyl-ether, and water and a Develosil C30, 5 µm column (4.6 x 250 mm).[1]

Overall, their findings indicated that there are massive differences in the bioaccessibility of xanthophylls in their array of tests. For exocrine pancreatic insufficiency (EPI) conditions (pH 6 – 1 mM) and healthy intestinal conditions (pH 7 – 10 mM), boiling eggs seem to be only cooking that negatively affected in terms of lipid digestibility.[1] Based on the data from the study, it can be suggested that:

-If you suffer from EPI, then poaching your eggs would be the most advisable due to their fat and protein digestibility.
-If you have healthy intestines, then boiling your eggs would be the most advisable due to their fat and protein digestibility.

Works Cited:

1. Andrea Asensio-Grau, Irene Peinado, Ana Heredia, Ana Andrés, Effect of cooking methods and intestinal conditions on lipolysis, proteolysis and xanthophylls bioaccessibility of eggs, Journal of Functional Foods, Volume 46, 2018, Pages 579-586, ISSN 1756-4646, https://doi.org/10.1016/j.jff.2018.05.025.

2. Ribaya-Mercado JD, Blumberg JB. Lutein and zeaxanthin and their potential
roles in disease prevention. J Am Coll Nutr. 2004 Dec;23(6 Suppl):567S-587S.
Review. PubMed PMID: 15640510.

A novel analytical procedure for assaying lysozymes

A novel analytical procedure for assaying lysozymes

Lysozymes (EC. 3.2.1.17) are widely recognized for their contribution to the antibacterial defense in many animals and their use as a preservative in foods and pharmaceuticals. [1] The key characteristic for all lysozymes is their ability to hydrolyze the ß-(1-4)-glycosidic bond between the alternating residues of peptidoglycan, a unique bacterial cell wall polymer.[1] There are many approaches to study the lysozyme activity such as using chitooligosaccharides, but these approaches often require study for overall kinetic rates to later dissect into individual rates.[2] Ogata, et. al. were able to create a novel analytical procedure for studying lysozyme activity undergoing a single cleavage reaction, which simplifies the kinetic measurements.[3]

The research group was able to synthesize ß-D-galactosyl-chitotetraose derivative [Ga(GlCN)3D] from chitin tetrasaccharide [(GlcN)4] using chemical and enzymatic modifications. Subsequently, the hydrolytic action of lysozyme on Ga(GlCN)3D was then analyzed.[3] Overall, they were able to synthesize a novel compound that can serve as a basis for studying enzyme kinetics as well as develop a new assay method for quantifying lysozymes.[3]

Ogata, et. al. used quantitative HPLC-UV to aid this development of this novel analytical procedure. They used HPLC-UV to study the enzymatic-transglycosylation reaction for the synthesis of Gal(GlCN)3D, to measure the reaction products of chitin oligosaccharide derivatives, and to verify a portion of the lysozyme assay system using Gal(GlN3)D as the substrate.[3] The HPLC -UV system consisted of a Develosil ANIDIUS column and detection at 210 nm.[3]

Works cited:

  1. Callewaert, L. & Michiels, C.W. J Biosci (2010) 35: 127. https://doi.org/10.1007/s12038-010-0015-5
  2. Tamo Fukamizo, Takeya Minematsu, Yugi Yanase, Katsuya Hayashi, Sachio Goto, Substrate size dependence of lysozyme-catalyzed reaction, Archives of Biochemistry and Biophysics, Volume 250, Issue 2, 1986, Pages 312-321, ISSN 0003-9861, https://doi.org/10.1016/0003-9861(86)90732-0.
  3. Makoto Ogata, Megumi Matsui, Haruka Kono, Yuka Matsuzaki, Yuna Kato, Taichi Usui, A novel analytical procedure for assaying lysozyme activity using an end-blocked chitotetraose derivative as substrate, Analytical Biochemistry, Volume 538, 2017, Pages 64-70, ISSN 0003-2697, https://doi.org/10.1016/j.ab.2017.09.015
Impact of Canning and Storage of Cartotenoids and Polyphenols in Apricots

Impact of Canning and Storage of Cartotenoids and Polyphenols in Apricots

Carotenoids are often studied in the food industry due to their nutritional value and may contribute to reduced risks of degenerative diseases like cancer [1, 2] and Parkinson’s disease. [3]

Reverse phase HPLC (RP-HPLC) is a common way to identify and quantify carotenoids since there is a strong interaction between the nonpolar stationary phase and the long alkyl structure of the carotenoids. C30 stationary phases are popular for analyzing these compounds since they are able to separate carotenoids and their isomers at greater selectivity when compared to their ODS counterparts. [4]

Dr. Le Bourvellec, et. al. studied the impact of canning and storage on polyphenol and carotenoid levels in apricots after industrial and domestic cooking, and after 2 months of storage for industrial processing. [5] They were able to identify and quantify carotenoids using RP-HPLC with a Develosil C30 column.

The research group identified 4 different carotenoids in fresh and cooked apricots: phytoene, phytofluene, trans-β-carotene, and cis- β-carotene.[5] They found there was a limited effect of the heat processing of apricots. However, during storage, they saw a significant decrease in the concentrations of carotenoids over the 2 months of storage. The research group described that there is a discrepancy of the data with the amount of degradation of carotenes in food; they attributed this to the differences in the food matrices.[5] Overall, the research group concluded that the content of carotenoids is a “net result of a combined increase in phytonutrients extractability, and a loss of degradation and leaching.” [5] They noted that “processing preserved a good part of the potential of the fruit, which is of interest to the consumer.” [5]

Works Cited

  1. Vieira, AR; et al. (Jan 2016). “Fruits, vegetables and lung cancer risk: a systematic review and meta-analysis”. Ann Oncol. 27 (1): 81–96. doi:10.1093/annonc/mdv381.
  2.  Leoncini; Sources, Natural; Head; Cancer, Neck; et al. (Jul 2015). “A Systematic Review and Meta-analysis of Epidemiological Studies”. Cancer Epidemiol Biomarkers Prev. 24 (7): 1003–11. doi: 10.1158/1055-9965.EPI-15-0053.
  3.  Takeda, A; et al. (2014). “Vitamin A and carotenoids and the risk of Parkinson’s disease: a systematic review and meta-analysis”. Neuroepidemiology. 42 (1): 25–38. doi:10.1159/000355849.
  4. Sebastiaan Bijttebier, Els D’Hondt, Bart Noten, Nina Hermans, Sandra Apers, Stefan Voorspoels, Ultra high performance liquid chromatography versus high performance liquid chromatography: Stationary phase selectivity for generic carotenoid screening, Journal of Chromatography A, Volume 1332, 2014, Pages 46-56, ISSN 0021-9673, doi: 10.1016/j.chroma.2014.01.042.
  5. Carine Le Bourvellec, Barbara Gouble, Sylvie Bureau, Patrice Reling, Romain Bott, Albert Ribas-Agusti, Jean-Marc Audergon, Catherine M.G.C. Renard, Impact of canning and storage on apricot carotenoids and polyphenols, Food Chemistry, Volume 240, 2018, Pages 615-625, ISSN 0308-8146, doi: 10.1016/j.foodchem.2017.07.147.