New STABILIZER VS EMULSIFIER - Universitas Lampungstaff.unila.ac.id/sugiharto/files/2018/08/Koloid-Bagian... · 2020. 4. 25. · APLIKASI KOLOID •Tinta (Ink): Sifat paling penting

JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

STABILIZER VS EMULSIFIEREmulsifier: ➡ Golongan lipid dan/atau protein. ➡ Membentuk emulsi dengan menempatkan diri pada

permukaan antar muka (interface) air-minyak. ➡ Menuturkan energi antar muka (inface free energy),

mencegah penggabungan koloid.

Stabilizer: ➡ Golongan karbohidrat, kecuali gelatin (protein). ➡ Menstabilkan emulsi dengan membentuk matrik dalam

fase kontinyu. ➡ Meningkatkan viskositas fase kontinyu, mencegah

penggabungan koloid.1

JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

Fungsi Stabilizer: ➡ Menghasilkan tekstur halus/lembut. ➡ Kurangi laju meleleh (meltdown - ice cream). ➡ Mencegah penyusutan dan memperlambat migrasi air

selama penyimpanan. ➡ Menutupi (masker) rasa kristal es di mulut saat makan. ➡ Memungkinkan pemompaan yang lebih mudah dan

pengisian yang lebih akurat selama proses. ➡ Memfasilitasi penggabungan udara dalam emulsi

membantu menghasilkan emulsi yang stabil.

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Parkin: “dk9272_c005” — 2007/7/19 — 22:30 — page 271 — #55

Amino Acids, Peptides, and Proteins 271

No absorption

InterfaceAir or oil phase

Hydrophilicsurface

Nonpolar surface

Aqueous phaseHydrophobic core

Moderate probabilityof absorption

Strong probabilityof absorption

FIGURE 5.22 Schematic representation of the role of surface hydrophobic patches on the probability ofadsorption of proteins at the air–water interface. (From Damodaran, S. 1990. Adv. Food Nutr. Res. 34:1–79.)

Water

Water

Air or oil phase

Air or oil phase

Interface

Interface

FIGURE 5.23 Difference in the mode of adsorption of a small molecule surfactant and a protein at theair–water or oil–water interface.

flexibility of the molecule. Highly flexible molecules, such as caseins, can undergo rapid conforma-tional changes once they are adsorbed at the interface, enabling additional polypeptide segments tobind to the interface. On the other hand, rigid globular proteins such as lysozyme and soy proteincannot undergo extensive conformational changes at the interface.

At interfaces, polypeptide chains assume three distinct configurations: trains, loops, and tails(Figure 5.24) [26]. The trains are segments that are in direct contact with the interface, loops aresegments of the polypeptide that are suspended in the aqueous phase, and tails are N- and C-terminalsegments of the protein that are usually located in the aqueous phase. The relative distribution ofthese three configurations depends on the conformational characteristics of the protein. The greaterthe proportion of polypeptide segments in a train configuration, the stronger is the binding, and thelower is the interfacial tension.

Lipid

ProteinKarbohidrat

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Stabilizer

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

APLIKASI KOLOID• Detergen: ➡ Membuat kotoran menjadi

“larut” dalam air• Asam Empedu: ➡Membuat lemak/minyak pangan

“larut” dan dapat diurai oleh enzim lipase.

Amphiphiles possess the very important property of being able to span an oil-waterinterface. By doing so, they can stabilize emulsions of both the water-in-oil and oil-in-water types. Such molecules are essential components of the lipid bilayers thatsurround the cells and cellular organelles of living organisms.

Emulsions areinherentlyunstable; leftalone, they tend toseparate into "oil"and "water"phases. Think of asimple saladdressing made byshaking vegetableoil and vineger.When a detergent-

like molecule is employed to stabilize an emulsion, it is often referred to as an emulsifier. The resulting structure (left) isknown as a micelle.

Emulsifiers are essential components of many foods. They are widely employed in pharmaceuticals, consumer goods suchas lotions and other personal care products, paints and printing inks, and numerous industrial processes.

How detergents remove "dirt"

The "dirt" we are trying to remove consists of oily orgreasy materials whose hydrophobic nature makes themresistant to the action of pure water. If the water containsamphiphilic molecules such as soaps or cleaning detergentsthat can embed their hydrophobic ends in the particles, thelatter will present a hydrophilic interface to the water andwill thus become "solubilized".

Soaps and detergents can also disrupt the cell membranes of many types ofbacteria, for which they serve as disinfectants. However, they are generallyineffective against viruses, which do not possess cell membranes.

The microemulsion (right) istransparent, in contrast to theordinary macroemulsion on the left.

Bile: your body's own detergent

Oils and fats are important components of our diets, but being insoluble in water, they are unable to mix intimately with theaqueous fluid in the digestive tract in which the digestive enzymes are dissolved. In order to enable the lipase enzymes(produced by the pancreas) to break down these lipids into their component fatty acids, our livers produce a mixture ofsufactants known as bile. The great surface area of the micelles in the resulting emulsion enables efficient contact betweenthe lipase enzymes and the lipid materials.

The liver of the average adult produces about 500 mL of bile per day. Most ofthis is stored in the gall bladder, where it is concentrated five-fold by removal ofwater. As partially-digested material exits the stomach, the gall bladder squeezesbile into the top of the small intestine (the duodenum).

In addition to its action as adetergent (which also aids in thedestruction of bacteria that may havesurvived the high acicity of the gastricfluid), the alkaline nature of the bile saltsneutralizes the acidity of the stomachexudate.

The bile itself consists of of salts of avariety of bile acids, all of which arederived from cholesterol. The cholesterol-like part of the structure is

hydrophobic, while the charged end of the salt is hydrophilic. ↑

[WikiMedia]

Microemulsions

Ordinary emulsions are inherently unstable; they do not form spontaneously, andonce formed, the drop sizes are sufficiently large to scatter light, producing amilky appearance. As time passes, the average drop size tends to increase,eventually resulting in gravitational separation of the phases.

Microemulsions, in contrast, are thermodynamically stable and can formspontaneously. The drop radii are at the very low end of the colloidal scale, often100 nm or smaller. This is too small to appreciably scatter visible light, somicroemulsions appear visually to be homogenous systems.

Microemulsions require the presence of one or more surfactants which increasethe flexibility and stability of the boundary regions. This allows them to vary

form smaller micelles than surface tension forces would ordinarily allow; in some cases they can form sponge-likebicontinuous mixtures in which "oil" and "water" phases extend throughout the mixture, affording more contact areabetween the phases.

The uses of microemulsions are quite wide-ranging, with drug delivery, polymer synthesis, enzyme-assisted synthesis,coatings, and enhanced oil recovery being especially prominent.

The microemulsion (right) istransparent, in contrast to theordinary macroemulsion on the left.

Bile: your body's own detergent

Oils and fats are important components of our diets, but being insoluble in water, they are unable to mix intimately with theaqueous fluid in the digestive tract in which the digestive enzymes are dissolved. In order to enable the lipase enzymes(produced by the pancreas) to break down these lipids into their component fatty acids, our livers produce a mixture ofsufactants known as bile. The great surface area of the micelles in the resulting emulsion enables efficient contact betweenthe lipase enzymes and the lipid materials.

The liver of the average adult produces about 500 mL of bile per day. Most ofthis is stored in the gall bladder, where it is concentrated five-fold by removal ofwater. As partially-digested material exits the stomach, the gall bladder squeezesbile into the top of the small intestine (the duodenum).

In addition to its action as adetergent (which also aids in thedestruction of bacteria that may havesurvived the high acicity of the gastricfluid), the alkaline nature of the bile saltsneutralizes the acidity of the stomachexudate.

The bile itself consists of of salts of avariety of bile acids, all of which arederived from cholesterol. The cholesterol-like part of the structure is

hydrophobic, while the charged end of the salt is hydrophilic. ↑

[WikiMedia]

Microemulsions

Ordinary emulsions are inherently unstable; they do not form spontaneously, andonce formed, the drop sizes are sufficiently large to scatter light, producing amilky appearance. As time passes, the average drop size tends to increase,eventually resulting in gravitational separation of the phases.

Microemulsions, in contrast, are thermodynamically stable and can formspontaneously. The drop radii are at the very low end of the colloidal scale, often100 nm or smaller. This is too small to appreciably scatter visible light, somicroemulsions appear visually to be homogenous systems.

Microemulsions require the presence of one or more surfactants which increasethe flexibility and stability of the boundary regions. This allows them to vary

form smaller micelles than surface tension forces would ordinarily allow; in some cases they can form sponge-likebicontinuous mixtures in which "oil" and "water" phases extend throughout the mixture, affording more contact areabetween the phases.

The uses of microemulsions are quite wide-ranging, with drug delivery, polymer synthesis, enzyme-assisted synthesis,coatings, and enhanced oil recovery being especially prominent.

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

APLIKASI KOLOID

•Gel: ➡ Gel adalah jaringan tiga dimensi tersusun dari molekul

atau partikel yang saling terhubung yang menjebak fase kontinyu (air), sama seperti spons.

➡ Dalam produk makanan, jaringan gel terdiri dari molekul polimer (polisakarida dan/atau protein) tergabung oleh ikatan hidrogen, asosiasi hidrofobik (daya van der Waals), jembatan ionik, atau ikatan kovalen, yang membentuk perangkap.

➡ Fase kontinyu adalah air atau larutan dari molekul berbobot molekul rendah dan bagian rantai polimer.

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•Gel:

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APLIKASI KOLOID• Tinta (Ink): ➡ Sifat paling penting dari tinta berhubungan dengan

sifat-sifat pengeringan dan permukaan, harus dapat mengalir dengan baik dan menempel ke permukaan tanpa menembusnya.

➡ Banyak tinta terdiri dari pewarna organik yang dilarutkan dalam pelarut berbasis air.

➡ Tinta yang digunakan surat kabar menggunakan karbon hitam koloid dalam pelarut minyak.

➡ Tekanan yang diterapkan oleh mesin cetak memaksa kendaraan memasuki pori-pori kertas, menyisakan sebagian besar partikel pigmen di permukaan

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

• Tinta (Ink): ➡ Tinta yang digunakan dalam pena ball-point adalah

gel, diformulasikan sedemikian rupa sehingga tinta hanya akan mengalir di atas bola dan ke kertas ketika pena digeser (yang berputar ketika bergerak melintasi kertas).

➡ Saat bola berbutar, gel menjadi cairan; cairan yang dihasilkan melapisi bola dan ditransfer ke kertas.

➡ Seperti dalam pencetakan konvensional, partikel pigmen tetap berada di permukaan kertas, sementara cairan ditekan ke dalam pori-pori dan berangsur-angsur menguap.

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

Turbidities of 5, 50, and 500units. [WikiMedia]

The sulfates of aluminum (alum) andof iron(III) have long been widelyemployed for this purpose. Syntheticpolymers tailored specifically forthese applications have more recentlycome into use.

Paints and inks

Paints have been used since ancient times for both protective and decorative purposes. They consist basically ofpigment particles dispersed in vehicle — a liquid capable for forming a stable solid film as the paint "dries".

The earliest protective coatings were made by dissolving plant-derived natural polymers (resins) in an oil such as that oflinseed. The double-bonds in these oils tends to oxidize when exposed to air, causing it to polymerize into an imperviousfilm. The colloidal pigments were stabilized with naturally-occuring surfactants such as polysaccharide gums.

Present-day paints are highly-engineered products specialized for particular industrial or architectural coatings and formarine or domestic use. For environmental reasons, water-based ("latex") vehicles are now preferred.

Inks

The most critical properties of inks relate to their drying and surface properties; they must be able to flow properly andattach to the surface without penetrating it — the latter is especially critical when printing on a porous material such aspaper.

Many inks consist of organic dyes dissolved in a water-based solvent, and are not colloidal at all. The ink used in printingnewspapers employs colloidal carbon black dispersed in an oil vehicle. The pressure applied by the printing press forces thevehicle into the pores of the paper, leaving most of the pigment particles on the surface.

The inks employed in ball-point pens are gels, formulated in such a way that the ink will onlyflow over the ball and onto the paper when the shearing action of the ball (which rotates as itmoves across the paper) "breaks" the gel into a liquid; the resulting liquid coats the ball and istransferred to the paper. As in conventional printing, the pigment particles remain on the papersurface, while the liquid is pressed into the pores and gradually evaporates.

Colloids in water and wastewater treatment

Water, whether intended specifically for drinking, orwastewaters such as sewage or from industrial operationssuch as from pulp-and-paper manufacture (most of which are

likely to end up being re-used elsewhere) usually contains colloidal matter that cannot beremoved by ordinary sand filters, as evidenced by its turbidity. Even "pristine" surfacewaters often contain suspended soil sediments that can harbor infectious organisms andmay provide them with partial protection from standard disinfection treatments.

The usual method of removing turbidity is toadd a flocculating agent (flocculant). These aremost often metallic salts that can form gel-likehydroxide precipitates, often with the aid of added calcium hydroxide(quicklime) if pH of the water must be raised.

The flocculant salts neutralize the surface chargesof the colloids, thus enabling them to coagulate; these are engulfed and trapped by fragments ofgelatinous precipitate, which are drawn together into larger aggregates by gentle agitation untilthey become sufficiently large to form flocs which can be separated by settling or filtration.

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

APLIKASI KOLOID• Penjernihan Air: ➡ Air limbah seperti limbah biasanya mengandung zat

koloid yang tidak dapat pisahkan oleh metode penyartingan.

➡ Bahkan permukaan air yang "bersih" sering mengandung sedimen tanah tersuspensi yang dapat menampung organisme infeksi.

➡ Metode untuk menghilangkan kekeruhan adalah dengan menambahkan agen flokulasi (flokulan).

➡ Garam sulfat dari aluminium (tawas) dan besi (III) (dan ditambahkan Ca(OH)2 (kapur), jika pH perlu dinaikan) telah lama digunakan dan membentuk endapan hidroksida seperti gel, seringkali dengan bantuan air harus ditingkatkan.

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JURUSAN TEKNOLOGI HASIL PERTANIAN Fakultas Pertanian Universitas Lampung

Turbidities of 5, 50, and 500units. [WikiMedia]

The sulfates of aluminum (alum) andof iron(III) have long been widelyemployed for this purpose. Syntheticpolymers tailored specifically forthese applications have more recentlycome into use.

Paints and inks

Paints have been used since ancient times for both protective and decorative purposes. They consist basically ofpigment particles dispersed in vehicle — a liquid capable for forming a stable solid film as the paint "dries".

The earliest protective coatings were made by dissolving plant-derived natural polymers (resins) in an oil such as that oflinseed. The double-bonds in these oils tends to oxidize when exposed to air, causing it to polymerize into an imperviousfilm. The colloidal pigments were stabilized with naturally-occuring surfactants such as polysaccharide gums.

Present-day paints are highly-engineered products specialized for particular industrial or architectural coatings and formarine or domestic use. For environmental reasons, water-based ("latex") vehicles are now preferred.

Inks

The most critical properties of inks relate to their drying and surface properties; they must be able to flow properly andattach to the surface without penetrating it — the latter is especially critical when printing on a porous material such aspaper.

Many inks consist of organic dyes dissolved in a water-based solvent, and are not colloidal at all. The ink used in printingnewspapers employs colloidal carbon black dispersed in an oil vehicle. The pressure applied by the printing press forces thevehicle into the pores of the paper, leaving most of the pigment particles on the surface.

The inks employed in ball-point pens are gels, formulated in such a way that the ink will onlyflow over the ball and onto the paper when the shearing action of the ball (which rotates as itmoves across the paper) "breaks" the gel into a liquid; the resulting liquid coats the ball and istransferred to the paper. As in conventional printing, the pigment particles remain on the papersurface, while the liquid is pressed into the pores and gradually evaporates.

Colloids in water and wastewater treatment

Water, whether intended specifically for drinking, orwastewaters such as sewage or from industrial operationssuch as from pulp-and-paper manufacture (most of which are

likely to end up being re-used elsewhere) usually contains colloidal matter that cannot beremoved by ordinary sand filters, as evidenced by its turbidity. Even "pristine" surfacewaters often contain suspended soil sediments that can harbor infectious organisms andmay provide them with partial protection from standard disinfection treatments.

The usual method of removing turbidity is toadd a flocculating agent (flocculant). These aremost often metallic salts that can form gel-likehydroxide precipitates, often with the aid of added calcium hydroxide(quicklime) if pH of the water must be raised.

The flocculant salts neutralize the surface chargesof the colloids, thus enabling them to coagulate; these are engulfed and trapped by fragments ofgelatinous precipitate, which are drawn together into larger aggregates by gentle agitation untilthey become sufficiently large to form flocs which can be separated by settling or filtration.

Turbidities of 5, 50, and 500units. [WikiMedia]

The sulfates of aluminum (alum) andof iron(III) have long been widelyemployed for this purpose. Syntheticpolymers tailored specifically forthese applications have more recentlycome into use.

Paints and inks

Paints have been used since ancient times for both protective and decorative purposes. They consist basically ofpigment particles dispersed in vehicle — a liquid capable for forming a stable solid film as the paint "dries".

The earliest protective coatings were made by dissolving plant-derived natural polymers (resins) in an oil such as that oflinseed. The double-bonds in these oils tends to oxidize when exposed to air, causing it to polymerize into an imperviousfilm. The colloidal pigments were stabilized with naturally-occuring surfactants such as polysaccharide gums.

Present-day paints are highly-engineered products specialized for particular industrial or architectural coatings and formarine or domestic use. For environmental reasons, water-based ("latex") vehicles are now preferred.

Inks

The most critical properties of inks relate to their drying and surface properties; they must be able to flow properly andattach to the surface without penetrating it — the latter is especially critical when printing on a porous material such aspaper.

Many inks consist of organic dyes dissolved in a water-based solvent, and are not colloidal at all. The ink used in printingnewspapers employs colloidal carbon black dispersed in an oil vehicle. The pressure applied by the printing press forces thevehicle into the pores of the paper, leaving most of the pigment particles on the surface.

The inks employed in ball-point pens are gels, formulated in such a way that the ink will onlyflow over the ball and onto the paper when the shearing action of the ball (which rotates as itmoves across the paper) "breaks" the gel into a liquid; the resulting liquid coats the ball and istransferred to the paper. As in conventional printing, the pigment particles remain on the papersurface, while the liquid is pressed into the pores and gradually evaporates.

Colloids in water and wastewater treatment

Water, whether intended specifically for drinking, orwastewaters such as sewage or from industrial operationssuch as from pulp-and-paper manufacture (most of which are

likely to end up being re-used elsewhere) usually contains colloidal matter that cannot beremoved by ordinary sand filters, as evidenced by its turbidity. Even "pristine" surfacewaters often contain suspended soil sediments that can harbor infectious organisms andmay provide them with partial protection from standard disinfection treatments.

The usual method of removing turbidity is toadd a flocculating agent (flocculant). These aremost often metallic salts that can form gel-likehydroxide precipitates, often with the aid of added calcium hydroxide(quicklime) if pH of the water must be raised.

The flocculant salts neutralize the surface chargesof the colloids, thus enabling them to coagulate; these are engulfed and trapped by fragments ofgelatinous precipitate, which are drawn together into larger aggregates by gentle agitation untilthey become sufficiently large to form flocs which can be separated by settling or filtration.

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