[2] CARBOHYDRATES (oligosaccharides)

OLIGOSACCHARIDES

usually 3-9 monosaccharide units (some books consider 2-9 units)

MALTOSE

Chemical Nature

2 units of glucose on α-1,4 glycosidic bond

A reducing sugar

MALTOSE

Source/s

From diastatic fermentation of barley (Hordeum vulgare) and other grains

MALTOSE

Use

Sweetener

Tonicity adjuster

Component of beers (fruity flavor)

Malt or barley is fermented by the process of

alcoholic fermentation, then ethanol is extracted (beer)

ABV (Alcohol by volume) of beer:

3-8%

Bitter taste does not come from malt but from __

Hops (Humulus lupulus)

SUCROSE

Synonyms

Table sugar, saccharum

Sucrose is also known as Saccharum because

the official source is Tubo / Sugar Cane (Saccharum officinarum) from the Poaceae or Grass Family

SUCROSE

Chemical Nature

Glucose + fructose on a α-(1→2)-β glycosidic bond

SUCROSE

Non-reducing sugar (negative on Benedict's, Fehling's, Barfoed's, or Tollen's tests)

This is due to no free aldehyde and it is a ketone; these 2 groups are involved in glycosidic bond formation

SUCROSE

Upon hydrolysis, yields

a mix of glu and fru called INVERT SUGAR

INVERT SUGAR

Sweeter than the actual sucrose dahil na-free na ang fructose; fructose is the sweetest monosaccharide

SUCROSE

Source

sugar beet

sugar cane

sugar maple

Sugar Beet

(Beta vulgaris) through limp slivers called cosettes

Family: Amaranthaceae

Root, color purple

Sugarcane

(Saccharum officinarum)

Family: Poaceae

Is a stem

Sugar Maple

(Acer saccharum)

Family: Sapindaceae

Soapberry / Lychee Family

Maple syrup

Formation of Sucrose

Sugarcane/ sugar beet is boiled with lime (CaO) to invert the sugar and coagulate albumin, and is decolorized with sulfur dioxide;

-Albumin gloats as a layer and is removed

-Sugar crystallizes and is removed from solution, and

-Some sugar will not anymore crystallize, and the resulting thick mixture is known as (molasses or panutsa)

SUCROSE

use

Demulcent (relieves irritation, inflammation and pain), coating agent, sweetening agent, syrups, preservative (85% concentration), anti-oxidant

TREHALOSE

Chemical Nature

Glucose + glucose via α-1,1 glycosidic bond

Just like sucrose, is nonreducing

TREHALOSE

Source

Found in brown seaweed, widely distributed in fungi

Lactose

Synonyms

Milk Sugar

Lactose

Chemical Nature

Galactose + Glucose on a β(1→4) glycosidic bond

Lactose

Source

milk of cow (Bos taurus)

From the crystallization of whey

Whey:

byproduct of cheese production, skimmed milk w/out coagulated protein

Lactose

Use

Tablet Diluent (increases volume, size & improve consistency of tablet)

lactose intolerance

Absence of lactase or β-galactosidase

→ diarrhea, GI disturbance

LACTOSE EXAMPLES

butter

buttermilk

coagulum

whey

Butter

fat globules united by churning (after standing for hours, fat accumulates above because it is immiscible)

Yellow due to Vit. A; Popcorn butter

Buttermilk

Liquid after globules unite (fluid below, used to make ice cream)

Coagulum (coagulated casein)

Skimmed milk treated with rennin/rennet

→ Further treated/fermented to become Cheese (coagulum that is solid)

Whey

Skimmed milk w/out coagulated protein (without the cheese)

Inorganic salts + lactose = WHEY

VARIATIONS OF MILK

condensed

malted

kumyss

Condensed Milk

Partially evaporated, sweetened milk

Very viscous due to addition of a lot of sugar

"Evaporated milk" is similar, but is unsweetened

Malted Milk

Milk evaporated with malt extract

Kumyss

Alcoholic beverage

Made from fermented mare's milk

Made originally by Central Asia Nomads

Laxative & Aphrodisiac for nomads

Lactulose

Chemical Nature

Product from alkaline rearrangement (tautomerization) of lactose

Tautomerization:

alkaline rearrangement of ketone to an enol of the lactose

*Take note of the components

Lactulose

Source

Semi-synthetic

Lactulose

Use

Laxative (Ex. Duphalac®, Lilac®, Laxac®)

Lactulose MOA

Poorly absorbed; bacteria in colon convert it to acetic acid & lactic acid

-Both acids are GI irritants → increased peristalsis

-Decreases blood ammonia concentration in PORTAL-SYSTEMIC ENCEPHALOPATHY

-Acidified stools trap ammonia as NH4 +

OTHER OLIGOSACCHARIDES

maltotriose

dextrins (limit, a-glucosidase)

gentianose

raffinose

stachyose

Maltotriose

Hydrolyzed by Maltase Glucoamylase complex

Trisaccharide, 3 glucose linked by a(1→4) glycosidic bonds

Limit Dextrins

Products of partial hydrolysis of STARCH

Limit Dextrins

Ex. Amylase, glucosidase

α-glucosidase inhibitors

Inhibit intestinal absorption of sugars

Inhibit sugar spike for diabetic px

Oral hypoglycemic agent (for postprandial sugar)

Ex. Acarbose (standard)

Gentianose

Glu + Glu + Fru

Gentianose

gentiana spp.

Gentianeae

Non-reducing trisaccharide

Raffinose

Glu + Gal + Fru

Raffinose

From many seeds (ex. Cottonseed, Gossypium)

Raffinose

Non-reducing trisaccharide found in beans, cabbage, broccoli

Stachyose

Non-reducing tetrasaccharide found in beans, peas, vegetables (like raffinose)

Stachyose

Stachys japonica

Distinct flavor for pork & beans

Stachyose

Glu + Gal + Gal + Fru