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David Peters Baran Group Meeting : An Organic Perspective 10/5/19 Food Chemistry: TODAY’S CASE STUDIES The study of the chemical processes, both biological and abiotic, that occur in food substances during processing, handling, and consumption. - What was in Pepsi Muscle ® Jelly Belly® Blue? Food : - What exacty does solve problems of the above processes with the use of change of food Phil drink after the components, their ratios, and conditions gym? - What is in those jelly beans?

Pepsi Blue®

Goup Meeting DOES NOT Include: - in-depth coverage of “food chemistry” - concepts of - discussion of WHY HAVE YOU EATEN THESE?! - any official health advice regarding H O O OH N O Goup Meeting Includes: S O - -related topics O H regarding food Na - major reactions during cooking - addititives O - additives - and minerals (brief) EtO ● largely in 3 categories: - other common additives & Me - EU #’s: - E100 to E199: color additives - fun & interactive chemical exploration - E200 to E299: preservatives Major references for this group meeting: Should there be more?! E300 to E399: antioxidants & - an ever-expanding variety of new pH reg. - Nursten, H. The Maillard Reaction 2005. Cambridge, UK. The Royal Society chemotypes in food E400 to E499: thickeners, stablizers of Chemistry. Food and Drug Administration (FDA): & emulsifiers - Baht, S.V., et. al. Chemistry of Natural Products 2005. New York, NY, Springer. - sets guidelines, allowances and E500 to E599: anti-caking - Ullman’s Encyclopedia of Industrial Chemistry 2002. Wiley-VCH. tollerances for food products E600 to E699: flavor enhancers - Porter, J. Cooking for Geeks 2010, Sebastapol, CA. O’Rielly Media. - nothing is ever permanently approved E700 to E799: antibiotics - www.FDA.gov - “Natural”= original source is natural E900 to E999: miscellaneous - www.thegoofscentscompany.com - “Artificial” = source is not food-based E1000 to E1599: additional chem. - www.femaflavor.org - GRAS = generally recognized as safe David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 The Maillard Reaction R R R OH OH O OH OH N OH OH HN OH OH HN HO R NH2 H HO HO HO − H2O OH OH OH OH OH OH OH O 1,2-enaminol Amadori product R OH N R OH O OH O OH O OH OH HN + H2O HO HO HO Me HO HO − H NR − H2O − H2NR 2 OH OH OH O OH O OH OH OH OH retro-aldol 2,3-enaminol − H2O

HMF O O OH OH OH OH OH OH OH O O H HO Me HO Me HO Me HO HO Me − H2O O reductone O O OH O O OH O Other Possible Ketone/Aldehyde Products R R R O O O OH H H + amino acid + H2O H Me HO HO H O HO H Me Me − H O O H 2 N CO2H − CO2 N O Strecker O O Me Me Me aldehyde O O O H N O HO HO HO OH 2 Protein H H Me intermediates N Protein Advanced above N NH2 N HO Glycation End O O HO HO CO2H NH Products Me HN N Protein N Protein H Me H Me H HO

O OH O acetic & Type I formic acid polymer Me CO2H Me H X X X Stage II NH X = O, NR Colored NH2 CO2H 2 Intermediates NH2 CO2H R CHO & Polymer O N O N Amines − CO O NH2 2 X X X NH2 R NH R 2 X X Type II O polymer Acrylamide − NH3 O NH2 David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 The Maillard Reaction Products: - term used for non-enzymatic browning of food products when amines and - produces heterogeneous polymers, volatile hydrocarbons, complex are involved heterocycles - First described by Louis-Camille Maillard in 1912 while he is trying to make - the colored polymeric structures are called melanoidins peptides w/ amino acids and reductants - molar mass of polymers increases w/ temperature NOT time - The “reaction” is a mind boggling complex mixture of hundreds of reactants, - those above 3 kDa are generally insoluble reactions, and products − hard to study - melanoidins are 25% of the dry mass of coffee - schematic pathway of reactions proposed in - numerous other products can be benificial or detrimental to taste 1953 by John E. Hodge - carcinogenic/mutagenic compounds are genereally product of very high - divided the process into three stages temperatures and long reaction times I. Initial Stage (colorless) - acrylamide is result of high temp. and high concentration of asparagine A. amine- condensation N O Me O O S HO B. Amadori rearrangement O Me Me O II. Intermediate Stage (light yellow) N H N O C. sugar dehydration O Me Me O Et D. sugar fragmentation S O HO O E. amino acid degradation N O Me III. Final Stage (highly colored) Me CO H F. aldol condensation O Me 2 G. adehyde-amine polymerization/ kahweofuran Cyclotene alapyridine heterocycle formation

CO H 13 Hodge, J. Agric. Food Chem. 1953, 1, 928. N O N O N 2 OH [1- C] Starting materials: O + - N-terminal amines, lysine side chain, or any other amine! proline - taste and smell mostly independent of sugars present O OH O OH OH - taste and smell dependent upon amino acids present - Strecker aldehydes maltoxazine - high levels of asparagine leads to high levels of acrylamide…(that’s bad) OH O OH O O O O O OH H2N H2N H2N O CHO O O OH = OH = / OH = floral N N crackers O HN O Me Me SH (2 eq.) O O HO Progress: OH OH indolizinium-6-olate - becomes noticable ~154 ºC (310 ºF); cooking below this = no browning derivative - extent of reaction is depended upon time, temperature, pH and pressure - kahweofuran is in coffee; gives a roasted/smoky aroma O - pH can change the dominant reaction pathway - cyclotene is an important caramel odorant H2N R - 1,2-enol @ low pH; 2,3-enol @ high pH - effects product distribution - alapyridine increases sensitivity to sweetness ~16x - maltoxazine is in dark malt (stouts/porters); 10 mg/kg CO H - progress inhibited by bisulfite (used in ) - indoliziniums are extremely bitter and are undesirable O OH 2 David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 acrylamide Caramelization Food Item (ng/g) NH2 N - term used for the non-enzymatic browning of sugars (alone) Potatoes (raw) n.d. - the process is a form of pyrolysis (irreversible thermal decomposition w/o Potatoes (boiled) n.d. Me N N Me combustion) Potato chips (fried) 3500 Potato chips (fried; overcooked) 13000 - products/reaction intermediates are very similar to those of Maillard Rection N Rye crackers 4000 - Begins ~150 ºC; Most noticable between 160-200 ºC (320-400 ºF) Breakfast cereal 1400 IQx - low temp. = light colors - most studied model is that of [highly mutagenic] Breakfast cereal (rice-based) 250 - high temp. = dark colors - medium temp. = rich Proteins in Food: Yang, Energy and Fuels 2017, 31, 8291. - where we get the majority of our amino acids to turn into our own proteins HO - denatured proteins are a staple of human food HO HO O O OH - heat and pH and mechanical aggitation are major the factors in destroying O HO O OH ∆ OH native proteins before consumption HO HO HO OH - denatured/coagulated proteins change in texture, solubility, color, solublizing OH O OH properties, etc. (nearly all physio-chemical properties) HO OH OH - the change in properties is often utilized to create food properties Sucrose OH Glucose - eg.− properly denatured egg whites are emulsifiers of air OH ∆ ∆ - temperatures of cooking are determined by this process 1,4:3,6-dianhydro - eg.− people prefer meat with actin but without myosin HO OH glucopyranose O OH (DGP) Coagulated O OH Native Denatured Temperatures of Denaturation: O O Egg whites: 61 ºC (122 ºF) OH O OH HO O O Myosin: 50 ºC (122 ºF) O HO OH ∆ O Actin: 65.5 ºC (150 ºC) OH O O O OH levoglucosan O O (LG) Emulsifiers/Emulsification: O OH HO OH - emulsifiers act as the border between oil and O OH HO HO O HO OH - help create and maintain the texture and from of food (eg. - ice cream) HO OH OH - Must be a ambiphillic to affect its purpose O OH HO2C CO H O - generally or esters O 2 O APP O Oleate O HO O O Me OH Common Emulsifiers: mO O O CMC O - soy/egg lecitin OH CO2H Me O O HO O Me - canola oil z OH HO HO − OH O O - carrageenan OSO3 O EtOAc O O x O O - polysorbates yOH polysorbate-80 O O HO O O - carboxymethylcellulose (CMC) HO O ∆ HO OH - guar gum (galactose/manose; branched) − OSO3 H AGF - (glucose/manose; branched) Carrageenan David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 Artificial Sweeteners: (and other “tames”) - delayed & lasting sweetness; slight bitterness - was the first (1884) - WWI and WWII helped its poularity - ~4 kcal/g - natural non-caloric sweeteners used throughout world previously - aspartame accidentaly discovered in 1965 O - originaly used mainly by diabetics and was taxed to protect sugar industry - solubility is highest at pH = 2.2 NHR - obesity & health affects of high-sugar diets has changed perspective/demand - maximum stability at pH = 4.0 MeO2C N H - sweetness is measured as a relative to dilute sucrose (~0.1g/L) - releases methanol and forms DKP - ADI: 50 mg/kg/day CO2H - all sweeteners have an asymtotic sweetness w/ concentration Aspartame: R = H Pb(OAc) -sweetness decreases after certain [conc.] OMe - many have “off tastes” - circumvented via blends of sweeteners 2 : R = t “Sugar of Lead” - other “tames” do not form DKP Bu - blended sweeteners are generally synergistic in sweetness - last two developed based on SAR Advantame: R = - may actually combat tooth decay OH Sweetness Intensity - most sweeteners are found by chance OMe : Cl sucrose 1 - very little sweetness-SAR is known - 1976 discovery after discovery that halogenation O 35 increases carbohydrate sweetness Cl O OH stevioside 160 - melts at 125 ºC w/ decomposition acesulfame K 200 - 283 g/L solubility in water HO aspartame 200 - slight delay (blends help); lasting effect; generally OH O OH Me O rebaudioside A 250 good neohesper. DHC 330 - made from sucrose through PG-heavy synthesis Cl Sucralose O ONa sodium saccharin 2500 Cl neotame 8000 Lactisole Steviol glycosides (stevia): [anti-sweetener] advantame 47800 OH HO - GMO leaves contain up to 20% steviol glycosides HO OH - just soluble enough for high sweetness (1.2 g/L) HO O Saccharin: O O O - stable at elevated temp. (acceptable for ) O - 1.0 kg/L solubility in H2O (Na-) − acidic in soln. HO O - metallic/bitter aftertaste - rebaudioside A is the sweetest/ best tasting H - fully excreted unmetabolized N Na / K - variety of extraction conditions = variety Me - used in concert w/ other sweeteners and sugar S of product qualities OH - used in weaning to feed and nickel elctroplating O - licorice-like aftertaste H O - ADI: 5 mg/kg/day - No ADI; has FDA GRAS O Saccharin HO O Stevioside HO H Me Cyclamate: OH H O O - accidentally discovered in 1937 N - Na salt decomposes at 260 ºC S Food Flavorings: O Na - generally used as 10:1 (cyclamate:saccharin) O - food flavorings can be both natural and artificial in nature - banned in US due to erroneous reports of toxicity - flavor chemistry is the field dedicated to crafting flavors wtih the available - used in most countries (Canadian Sweet N’Low) Cyclamate ingredients and analytical tools Acesulfame K - flavor chemists train in apprenticeships for 2-5 years; after bachelors - high temp stability; decomp. at 225 ºC O O - to create a desired artificial flavor there are generally upwards of 10 S - metalic taste at high concentrations O N K different additives - used in concert with numrous others - many artificial flavor additives are sold/used as the racemate - extremely soluble in water Me O - single compounds are usually present in ~5.0 to 0.1 ppm - highly absorbed and rapidly excreted unchanged - ADI: 16 mg/kg/day Acesulfame K - many compounds used as both scents (olfactory) and tastes (gustatory) David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 O SH O OH Me Me O O O Me MeO O (3S)-1-Methoxy-3-heptanethiol Me Me OEt Me O Me O Et O Me Me piperonyl isobutyrate ethyl ethyl maltol O O acetate isoamyl acetate Me O OHC Me S Me O 4-Methyl-2-propyl- Me Me HO 1,3-oxathiane O CHO O β-homocyclocitral O delta- O Me octalactoneEt norfuraneol Me Me EtO ● Me E-citral & citronellal Me O Ethyl 2-methyl- diacetyl OH 3,4-pentadienoate Me O Me O Me Me Me O octen-1-yl OEt cyclopentanone O HO O O Me strawbery aldehyde furaneol HO

O O Me O Me MeO O OEt Me ehtyl p-anisate Me Me (racemic) Me melon acetal Solanone O Me Me OH D-limonene O O Me EtO Me OAc Me Me O H OEt O Me Me Me Me O HO manzante hexyl acetate O ethyl vanilin O H Et N O O Hex Me SH H benzaldehyde NC !-decalactone Me Me OEt Me buchu mercaptan Et N Me ethyl butyrate Me hexanal hazelnut pyrazine Me Me Me Me Me Me O O O O HS Me (EtO)3CEt OEt Ph Me OEt O O EtO ● O O NC O HO Cl Me Me Me Me Me Me Me David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 O S O S Food Color Additives 3 N Me 3 N Me - FDA has two categories of colorants: Certified and Exempt 2 FD&C Green No. 3 - certified dyes are artificial; must be batch-certified - 16.5 million pounds were certified 2002 Na SO3 SO3 - exempt dyes are derived from natural sources (no certification required) O3S O3S - Lakes are dyes mixed with aluminum/ and precipitated - lakes color by dispersion; usually used in oily foods/coatings - dozens of additional color additives approved for drug, cosmetic, and N HO 2 Na N medical device use (both natural and artificial) FD&C Blue No. 1 - artificial food dyes originally from the dyestuff industry Me Me O H - food dyes make up a small fraction of the dyestuff industry O C Na 2 N O3S N - numerous suggestions that artificial dyes cause hyperactivity in children, 3 Na Na N SO cancer, mutagenicity − largely unproven for current set N 3 N N - Orange B only for use in hotdog/sausage casings SO3 OH H O - Citrus Red No. 2 only for use in orange peels SO3H SO3H O3S SO3 FD&C Blue No. 2 FD&C Yellow No. 5 FDA “Exempt” Food Color Additives HN O3S annatto extract FeII gluconate/lactate SO beet powder Fruit/vegetable NH2 O 3 OMe riboflavin OH canthaxanthin RO C N OH caramel carmine 2 CO R N N N 2 MeO N 2 Na N beta-carotenes cochineal extract 2 Na HO carrot oil paprika/paprika extract N HO NH2 RO2C A 2 Na N saffron N TiO2 1. Diazotization N O mica spirinula extract HO 2. pyrazole A SO3 Me Na Cu chlorophyllin lycopene 3. NaOH (aq.) FD&C EtO FD&C Yellow No. 6 SO toasted cottonseed tumeric Yellow No. 5 N 3 oxide tumeric oleoresin O N FD&C Red No. 40 SO3H Citrus Red No. 2 Orange B OH O OMe OMe O Me O OH HO OTMS 1. ∆ Cl MeO OH 2. Me2SO4, K2CO3 HO OH SO3 O CO2R 3. Na S O , NaOH, 2 2 4 OH TMSO Me2SO4 RO2C I I HO OH OH O Me Me OMe OMe O O Na O O O Carmine OMe OMe 2+ (cochineal 2H2O HO Al OH2 Ca BF •OEt MeO OBn 3 2 extract) O O Carminic OCOCF I I O 3 HO OH Acid OBn O CO2 OH RO C OBn 2 OBn Na O BnO HO OH Me OMe OMe BnO OBn OH J. Chem. Soc., Perkins Trans. 1 1999, 575. OBn FD&C Red No. 3 O Me O OH HO David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19

Vitamins B1 (thiamine): NH2 Vitamin B1 - organic that are essential micronutrients that humans (or other - first substance called a “vitamin” thiamine N N organisms) need for proper metabolic function - diphosphorylated to become active (cocarboxylase) S - diseases attributed to deficiency in each one - is a cofactor for carboxylases and trasnketolases Me N Me OH - often derived from natural sources in one’s diet - Not present in certain (rice) O + - supplementation and fortification provide full amounts where gaps may occur - oxidatively and reductively labile OH 1.H Me 2. H2O2 - RDA: 1.2 mg/day Cl NH Vitamin A (retinoids): NH2 NH2 2 S + - and light (E/Z) sensitive Me Me Me Me NC CN 1. H 1. CS2 NH 2. [H] N 2. -Cl ketone N N - most are interconvertable via " S OH - 90% stored in liver (as palmitate) Me NH NH Me N OH 2 2 Me N Me OH - generally cosidered as antioxidants Me Vitamin A1 retinol - important for epithelial growth O - sensitivity in isolation means current access is synthetic Vitamin B2 (riboflavin): Me N - RDA: 900 RAE/day (retinol activity equivalents) - resistant to oxidation, not reduction; easily re-oxidized NH Me 1. H , cat. Me Me 2 - central to oxidase enzymes (FAD- and FMN Me Me 2. Ac2O Me N N O 3. H+ dependent) OH - found in all plants/animals; high concentrations in Vitamin B2 β-carotene Me Me Me Me yeast, livers, and hearts riboflavin Me OH HO Me - numerous countries require fotification of grains w/ B2 HO - produced both chemically and by fermentation Me MeO C OH Me Me 2 - RDA: 1.5 mg/day Ph AcOH, BrMg Me N Cl N O Cl Me BrMgO Me 2 O 1. Me Ribose; Me Me N 2. −OH R H /cat. NH = R R CHO 2 Me OH O N O [from citral] Me NH2 Me NH Me NH H (ascorbic acid): Vitamin C Rib Rib - strongly reducing properties (reductone) HO H ascorbic acid O Vitamin B (niacin): - isolation done w/o light, oxygen, or O 3 Vitamin B HO - biologically active as nicotinamide 3 - cooking destroys most of it nicotinamide (Y = NH2) - becomes part of NAD/NADP-dependent eznymes niacin (Y = OH) - commercially syntehsized since 1930’s HO OH −H2O - RDA: 90-75 mg/day - body can convert tryptophan to niacin O CH OH CH OH - RDA: 15 mg/day CHO 2 2 CO2H Y=OH Y H OH H OH Arthro- O O - second process uses Ti/Sb/V or Ti/Sb/U 0 O , Pt0 HNO HO H H2, Ni HO H bacter HO H 2 HO H oxide heterogeneous catalyst 3 N Na CO 230−270 ºC H OH H OH H OH 2 3 H OH Me O Me 6−8 MPa aq. NH Me - dicarboxylate interm. H OH H OH H OH H OH 3 O O - neutralized with S.M. CH OH CH2OH CH2OH CH OH Me N - NO oxidized to NO2; 2 2 water to get HNO D-glucose L- Me 3 David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 OH Vitamin B5 (pantothenic acid): H (tocopherols): - coenzme A precursor N OH - vary in methylation of arene and olefins in tail (tocotrienols) HO - central to : fatty acid synthesis, citric - antioxidants: delay the oxidation of membrane lipids = increased integrity Me Me O O acid cycle, acetylation, porphyrin snyth, - high concentrations in plant oils Vitamin B5 degredation of and carbohydrates, etc. pantothenic acid - provided usually as all racemic & acetate (~67% activity of natural) - deficiency leads to a variety of symptoms - RDA: 15 mg/day NH2 - 80% of world production used in animal feed Me Me CO2Ca - RDA: 5 mg/day Me O Me Me OH [Rh(cod)Cl2], Me OH O O chiral Me HCHO Me bisphosphine Me Me Me HO Me OH Me HO Me O Vitamin E Me O Me OMe -tocopherol Me O O # L.A./B.A. O (previously via resolution) 1. H+, catalyst 2. vinyl-MgBr Me Me Me Me Me Me OH (iterative) OH Vitamin B6 (pyridoxine): Y 3. [H] - refers to 6 related compounds (those at OH Me Me EtO O 4. vinyl-MgBr right and their 5-phosphomethyl derivs.) HO O BF •OEt OAc ∆; H+; [H] [racemic 3 - active form as CHO bound in Me Vitamin K1 Me N route] - cofactor for transaminase, epimerase, Me Phylloquinone CO R Me N and decarboxylase enzymes 2 Me Vitamin B6 OH RO2C - obtained from eating plants pyridoxine (Y = OH) O Me Me Me Me (+2 steps) - Most stable form is pyridoxine HCl pyridoxal (Y = CHO) pyridoxamine (Y = NH ) Vitamin K (menaquinones): - RDA: 1.3 mg/day 2 - group of related compounds that vary in chain length and unsaturation - cofactor in glutamic acid carboxylase (Gla synthesis) 2+ Vitamin B9 (folic acid): - important for blood clotting (Gla binds Ca ) - Dihydro- and tetrahydrofolate are coenzymes for methyl and formyl transfer - phylloquinone (plant-based) is cleaved and geranylgeranyl moiety appended - RDA: 120 μg/day - central to methionine and purine synthesis (for DNA) O CO H O 2 NH - high concentrations in green-leaved plants 2 Vitamin K2 Me - lack of folate results in O N menaquinone (MK-4) H HO2C - metabolic link between N Me Vitamin B9 HN N HO C 2 HO C CO H vitamins B3, B9, and B12 folic acid H 2 2 Me Me Me Me O - RDA: 400 μg/day H N N N carboxyglutamic 2 acid (Gla) Note on Nomenclature H H - leters and numbers are O N O Me skipped due to reclassification N R’ O O CO H HO O HN N Cl Cl 2 N Me S CO2H - biotin and choline have flip H NH2 N HN N Me H H flopped (both vitamins now) H2N N N Cl H - B class are all water soluble & H Choline Biotin DHF H2N N NH2 H2N HO2C (Vitamin B4) (Vitamin B7) cofactors David Peters Baran Group Meeting Food Chemistry: An Organic Perspective 10/5/19 H NOC Vitamin B12 (cobalamins): 2 - the cobalamins are grouped; vary by Other Common Food Additives: Me Me Me Carbohydrate-based thickeners: Anticaking agents: axial ligands - corn starch - silicon dioxide - biosynthesized by H2NOC CN - tapioca starch - Na/Ca silicate - most comes from eating meat Me N N CONH2 - - stearic acid/stearates - methionine and Suc-CoA synthesis Me Co H - - calcium phosphate - humans have a specific mucoprotien N N - dextrin for absorbing Me Preservatives: H NOC - sodium alginate - produced by fermentation (P. 2 Me - nitrates Me pH regulators: - nitrites dentrificans - highly mutated strains) Me CONH2 - ascorbic acid - converted to cyanocbalamin w/ KCN; O - benzoates N - citric acid extracted w/ cresol & recrystalized - propionates NH - - for synthesis see: Classics in Total - sulfates N - Synthesis, Chapter 8 HO - ascorbates O - BHT - RDA: 2.4 μg/day Me O O P Vitamin B12 - gallic acid O cyanocobalamin Me HO OH Me H Vitamin D (calciferols): Me - central to maintaining calcium and phosphorous H Me homeostasis in body - converted to active form in body Vitamin D3 - In depth discussion of Vitamin D see: cholecalciferol Synthesis of Vitamin D, Gu, Baran Lab GM HO - RDA: 20 μg/day

Mineral RDA (mg) Minerals: K 4700 - nutritional minerals are essential dietary Cl 2300 Na 1500 components that are elemental Ca 1200 - does not include C, H, O, N P 700 Mg 420 - some of these fall under macrominerals Fe 18 (Ca, K Mg, Na, P) Zn 11 - the rest are minor (S, Fe, Cl, Zn, I, Cu, Mn 2.3 Cu 0.9 Mn, Mo, Se, Cr, Co) I 0.15 - others are recognized as important but Cr 0.035 the roles and levels necessary are Mo 0.045 Se 0.055 unestablished (Br, Li, Ni, F, etc.) Co N/A