food chemistry - -food component and reactions - -analytical food chemistry - -- food -...

Food chemistry-Food component and reactions-Analytical Food Chemistry-- Food -Palatability, Energetic, functional

Water in food -The importance of water-Water content in different food articles-Milk, Meat, Bread, Honey, Butter, oilTransportation/ stabilization of the body temperature/ reactant/ solvent-The Importance of water in foodTechnological aspectsShelf life ( Hydrolytic reactions)/ textureEconomic aspects

►Chemical structure of Chemical structure of waterwater

►Water as a polar solventWater as a polar solvent►Affinity to sugar s ,Ions Affinity to sugar s ,Ions and polar groupsand polar groups►Hydrogenic boundHydrogenic bound►Ionic interactionIonic interaction

Solute/SolventSolute/Solvent ُ ُ nm)nm) 1<1<))SolutionsSolutionscolloids (1-100nm)colloids (1-100nm)

Dispersion/ Continues Dispersion/ Continues HydrocolloidsHydrocolloids100<nm)100<nm) ) )SuspensionSuspension

Moisture,Moisture, water activity,water activity,

Relative humidityRelative humidity

►aw= Pf/Paw= Pf/P00

►Rh= Pa/PRh= Pa/P00

ERh= Rh=aW × 100ERh= Rh=aW × 100

Moisture and awMoisture and aw

Moisture and awMoisture and aw

The effect of water activity The effect of water activity in shelf life of foodsin shelf life of foods

MineralsMinerals macro element/microelementmacro element/microelementessential (essential (macronutrient & micronutrientmacronutrient & micronutrient)/ possibly )/ possibly essential/ essential/ nontoxic –non essential/ toxicnontoxic –non essential/ toxic

Different parameters affects mineral content Different parameters affects mineral content of food of food

componentcomponent

Pre-harvest processingPre-harvest processing

Post-harvest processingPost-harvest processing fortification fortification

(enrichment(enrichment))►RestorationRestoration►SupplementationSupplementation►StandardizationStandardization

Chemical statues of minerals in foodChemical statues of minerals in food

►SolubleSoluble►Non-soluble Non-soluble

Chelatets ( chlorophyll, hemoglobin/ Chelatets ( chlorophyll, hemoglobin/ cyanocobalamin), calcium caseinate cyanocobalamin), calcium caseinate

ChlorophyllChlorophyll

Phytic acidPhytic acid

Minerals in food processingMinerals in food processing

OxidationOxidation

TasteTaste

Catalists in Hydrogenation ( with special Catalists in Hydrogenation ( with special reference to nickel)reference to nickel)

ColorColor

texturetexture

Salting in /salting outSalting in /salting out

CarbohydrateCarbohydrate

►Human derive their energy mainly Human derive their energy mainly from carbohydrate (55%-65%)from carbohydrate (55%-65%)

►MonosaccharideMonosaccharide►OligosaccharidesOligosaccharides►PolysaccharidesPolysaccharides

MonosaccharideMonosaccharide

►StereoisomerStereoisomer► epimer epimer DiasteromerDiasteromer ►EnantiomerEnantiomer

EnantiomerEnantiomer

L- (+)-Tartaric acid D(-)-Tartaric L- (+)-Tartaric acid D(-)-Tartaric acidacid

Anomer,EpimerAnomer,Epimer

Hemiacetal formation in Hemiacetal formation in glucoseglucose

Hemiketal formation in Hemiketal formation in fructosefructose

ReactionsReactions

11 - -Reduction to sugar alcoholsReduction to sugar alcohols

ReactionsReactions

►22))Oxidation to Aldlonic acids/ Aldaric Oxidation to Aldlonic acids/ Aldaric acids/ uronic acidsacids/ uronic acids

11))SugaraminSugaramin

Sugar derivativesSugar derivatives

22))GlycosidesGlycosides

AmygdalinAmygdalin

GlycosylaminGlycosylamin

►N-Glycosides/ S- GlyosidesN-Glycosides/ S- Glyosides

Maillard reactionMaillard reactionThe carbonyl group of the sugar reacts with the amino group of the amino acid, producing N-substituted glycosylamine and water

The unstable glycosylamine undergoes Amadori rearrangement, forming ketosamines

There are several ways for the ketosamines to react further:

Produce 2 water and reductones

short-chain hydrolytic fission products can be formed

Produce brown nitrogenous polymers and melanoidins

Factors affecting Maillard Factors affecting Maillard reactionreaction

High temperature, intermediate moisture levels, and alkaline conditions all promote the Maillard reaction.

In cooking, low moisture levels are necessary mainly because water boils into steam at (100 °C), whereas the Maillard reaction happens noticeably around (154 °C): significant browning of food does not occur until all surface water is vaporized.

The rate of Maillard reactions increases as the aw increases from 0.0 or as it decreases from 1.0, reaching a maximum at water activities in the range of 0.6 to 0.7. Since the Maillard reaction produces water, further increases in water activity may inhibit Maillard reactionsPentose reducing sugars react more than hexose, which react more than disaccharides . Different amino acids produce different amounts amounts of browningof browning..

Action of acids and alkaline Action of acids and alkaline on saccharineon saccharine

11 ) )Action of acid: Removal of water, Action of acid: Removal of water, Cyclyzation, Furfural from pentose andCyclyzation, Furfural from pentose and

hydroxy methyl furfural from hexosehydroxy methyl furfural from hexose

2) Action of Alkaline : Epimeration, 2) Action of Alkaline : Epimeration, Isomeration, Unstable IntermeIsomeration, Unstable Interme

Oligosaccharide formationOligosaccharide formation

ΒΒ-Lactose-Lactose

ΒΒ-Maltose -Maltose

IsomaltoseIsomaltose

SucroseSucrose

SucroseSucrose

Invert sugarInvert sugar

RaffinoseRaffinose

StacchioseStacchiose

CellobioseCellobiose

PolysaccharidesPolysaccharides

HomopolysacchridesHomopolysacchrides

Starch, Inolin, GlycogenStarch, Inolin, Glycogen

HeteropolysaccharidesHeteropolysaccharides

Hemicellulose, pectin, gumsHemicellulose, pectin, gums

StarchStarch

The basic structure of The basic structure of amyloseamylose

Starch degradationStarch degradation

Starch molecules are Starch molecules are HydrolyzedHydrolyzed by by

Enzyme or acidEnzyme or acid

Dextrose equivalentDextrose equivalent Dextrin ized starchDextrin ized starch

Starch gelatinizationStarch gelatinization

High Fructose Corn Syrup (HFCS), commonly used to sweeten soft drinks, is made by

treating corn syrup with enzymes to convert a portion of the glucose into fructose. Commercial HFCS contains from 42% to 55% fructose, with the remaining percentage being

mainly glucose.

GlycogenGlycogen

Inulin Inulins are present in many vegetables and fruits, including onions, garlic, bananas, asparagus/ artichokes. Inulins, also

called fructans, are polymers consisting of fructose units that typically have a terminal glucose.

Oligofructose has the same structure as inulin, but the chains consist of 10 or fewer fructose units. Oligofructose has approximately 30 to 50

percent of the sweetness of table sugar.

Inulin is less soluble than oligofructose and has a smooth creamy texture that provides a fat-like mouthfeel. Inulin and oligofructose are nondigestible by human intestinal enzymes,

but they are totally fermented by colonic microflora. The short-chain fatty acids and lactate produced by fermentation

contribute 1.5 kcal per gram of inulin or oligofructose. Inulin and oligofructose are used to replace fat or sugar and reduce the

calories of foods like ice cream, dairy products, confections and baked goods.

CelluloseCellulose

Cellulose

►1000 unitis of glocose►Intra & inter hydrogenic bounds is

stabilizing the unique structure as the amorphous or crystalline stricture

►Production of glucose syrup from cellulose

lignin should be acid hybridized prior to► enzymic hydrolyse

The difference between The difference between cellulose and hemi cellulosecellulose and hemi cellulose

►Number of units ►Variation in building block sugars ►Chains ►Xylose, mannose, galactose,

rhamnose, arabinose ►In acidic form

Hemicellulose (Hemicellulose (Xylan, Arabinogalactane))

Hemi cellulose and pentosans

PectinsPectins

Pectin

►Pectinic acid►Molecular w., methylasion D, Osmotic pressure, pH ►H.M.P 3.5=pH, high OP►M.M.P 3.5 <pH Medium OP ► L.M.P Ca Iones ►Pectic acid

GumsGums

Seed gums ( Carnob,Guar)Seed gums ( Carnob,Guar)

Exudate gums ( arabic, Tragacanta) Exudate gums ( arabic, Tragacanta)

AlgaAlga

Microbial gums (Dextan, Xanthan)Microbial gums (Dextan, Xanthan)

DextranDextranDextran is a polysaccharide similar to amylopectin, but the main Dextran is a polysaccharide similar to amylopectin, but the main

chains are formed by 1α→6 glycosidic linkages and the side chains are formed by 1α→6 glycosidic linkages and the side branches are attached by 1α→3 or 1α→4 linkages. Dextran is an branches are attached by 1α→3 or 1α→4 linkages. Dextran is an oral bacterial product that adheres to the teeth, creating a film oral bacterial product that adheres to the teeth, creating a film called plaque. It is also used commercially in confections,, as called plaque. It is also used commercially in confections,, as

food additivesfood additives , ,

Vitamins ( Chemical structure) Stability Functionality Fat soluble Water soluble

Fat soluble vitamins Fat soluble vitamins

Vitamin AVitamin A

Fat soluble vitamins Fat soluble vitamins vitamin D2 , D3 vitamin D2 , D3

Fat soluble vitamins Fat soluble vitamins vitamin E vitamin E

Fat soluble vitamins Fat soluble vitamins vitamin E vitamin E

Antioxidant activity of vitamin EAntioxidant activity of vitamin E

Fat soluble vitaminFat soluble vitaminVitamin KVitamin K

Water soluble vitaminWater soluble vitaminVitamin CVitamin C

11 ) )Anti oxidantAnti oxidant

22 ) )Chelating agentChelating agent

33 ) )UnstableUnstable

Water soluble vitaminWater soluble vitaminvitamin B1vitamin B1

Water soluble vitaminWater soluble vitaminvitamin B2vitamin B2

Water soluble vitaminWater soluble vitamin

Vitamin B3Vitamin B3

Water soluble vitamin, Water soluble vitamin, vitamin B5vitamin B5

Water soluble vitamin , vitaminB6Water soluble vitamin , vitaminB6

Vitamin B8Vitamin B8

Vitamin B9Vitamin B9

Vitamin B12

Food additivesFood additives

►Nutritive valueNutritive value Vitamins, Amino acids, MineralsVitamins, Amino acids, Minerals,,

Sensory valueSensory valueFlavor enhancersFlavor enhancers,, : :

Monosodium Glutamate, Nucleotides ,MaltolMonosodium Glutamate, Nucleotides ,Maltol

SweetenersSweeteners

Fructose, Sugar alcohols, SucraloseFructose, Sugar alcohols, Sucralose::Sugar derivativesSugar derivatives

Non sugar derivatives: Sachharin, Non sugar derivatives: Sachharin, Syclamate,AspartameSyclamate,Aspartame , , و و Miraculin, Miraculin,

Glyceyrrhizin,DihydrochalconesGlyceyrrhizin,DihydrochalconesووMonellin, AlitameMonellin, Alitame

MSG)MSG)) ) Monosodium Monosodium glutamateglutamate

IMP GMPIMP GMP

Food additivesFood additives

►Nutritive valueNutritive value Vitamins, Amino acids, MineralsVitamins, Amino acids, Minerals,,

Sensory valueSensory valueFlavor enhancersFlavor enhancers,, : :

Monosodium Glutamate, Nucleotides ,MaltolMonosodium Glutamate, Nucleotides ,Maltol

SweetenersSweeteners

Fructose, Sugar alcohols, SucraloseFructose, Sugar alcohols, Sucralose::Sugar derivativesSugar derivatives

Non sugar derivatives: Sachharin, Non sugar derivatives: Sachharin, Syclamate,AspartameSyclamate,Aspartame , , و و Miraculin, Miraculin,

Glyceyrrhizin,DihydrochalconesGlyceyrrhizin,DihydrochalconesووMonellin, AlitameMonellin, Alitame

SucraloseSucralose

SaccharinSaccharin

CyclamateCyclamate

Aspartame and AlitameAspartame and Alitame

MonellinMonellin

►Plant Protein, could be synthesized Plant Protein, could be synthesized duringduring

►yeast or bacterial fermentationyeast or bacterial fermentation

Flavonones Flavonones (Narinigin, neohespiridin)(Narinigin, neohespiridin)

H2H2

Naringin DihydrochalchoneNaringin Dihydrochalchone

Neohespiridin DihydrochalchoneNeohespiridin Dihydrochalchone

Colorant: Colorant:

Caroteoides, Caramels, Titanium oxide, Caroteoides, Caramels, Titanium oxide, Saffron, Annatto, CochinealSaffron, Annatto, Cochineal

Shelf life enhancementShelf life enhancement

Organic acids: pH reducing agents, Organic acids: pH reducing agents, Inhibition of browning reactions(Non Inhibition of browning reactions(Non Enzymatic and Oxidative), Flavouring, Enzymatic and Oxidative), Flavouring, hydrolytic reactions( sucrose hydrolytic reactions( sucrose inversion), Antibacterial propertiesinversion), Antibacterial properties

Sequestering agentSequestering agent

Succinic acid Malic acidSuccinic acid Malic acid

Tartaric acidTartaric acid Fumaric acidFumaric acid

Propionic acid citric acidPropionic acid citric acid

Mineral acidsMineral acids

22 ) )TextureTexture Phosphoric acid 1) WHC Phosphoric acid 1) WHC

::SOSO22

Weak preservative, Inhibition of BrowningWeak preservative, Inhibition of Browning

Propylene Oxide, Ethylene oxidePropylene Oxide, Ethylene oxide

BacteriocinsBacteriocins