Rangkuman kuliah pewarna
Rangkuman kuliah pewarnaYNT
FOOD COLORWith regard to choice and consumption of food, all
human sensory perceptions are involved. Among them, vision is the
most important one for selecting food and appreciating its quality.
Color is an intrinsic property of food. A color change of food
often is caused by a quality change.Consumers are attracted by the
color of a food product.
This implies three main consequences for food producers:1. Food
quality should be controlled by optical inspection.2. Food
processing steps may change food color.3. Colorants may be added to
food as preservatives or simply to attract consumers.Intrinsic food
colorants can be conserved more or less during food processing.The
pigments that color the original living biological material often
possess essential functional properties like anti-oxidative
effects, radical scavengers or are transmitters of signals or
energy. In this way, intrinsic food colorants are involved in
synergistic effects that they perform as components of molecular
complexes.These supramolecular structures may, at least partly, be
disturbed during food processing. Visual inspections cannot
evaluate those functional properties and rarely distinguish between
intrinsic and added food colorants. However, spectroscopic methods
allow qualitative examinations. Therefore, the evaluation of food
color is an essential topic in food technology.
ANTOSIANINAntosianin merupakan golongan pigmen kemerahan yang
bersifat larut dalam airTerdapat 20 jenis antosianin. 6 diantaranya
merupakan pigmen pnting yang sering digunakan dalam produk pangan,
antara lain: Pelargonidin, Cyanidin, Delphidin, Peonidin Petunidin,
Malvidin
6
Struktur antosianinAnthosianin
LanjutanLima jenis gula yang terdapat dalam antosianin, yaitu: ~
Glukosa ~ Rhamnosa ~ Galaktosa ~ Xilosa ~ Arabinosameskipun ada
lima gula yang dapat dimiliki oleh antosinin, namun dalam
antosianin hanya dapat mengandung 3 tiga gula
didalamnya.9Berdasarkan Jumlah Gulanya Dapat Bibedakan Menjadi
3Monosida: Mengandung satu gula, biasanya terletak pada posisi 3,
kadang-kadang pada posisi 5 dan 7
Biosida: Mengandung 2 gula dengan 3 kemungkinan penempatan gula
yaitu: kedua gulanya pada posisi 3 pada posisi 3 dan 5 pada posisi
3 dan 7
Triosida: Mengandung 3 gula, dengan 2 kemungkinan penempatan
gula yaitu: 2 pada posisi 3 dan satu pada posisi 5 Ketiga gula
terletak pada posisi 3
10
Flavonoid
Flavonoid
~Tidak Berwarna - berwarna kuning~Struktur kimianya mirip
antosianin~Ada sekitar 400 jenis flavonoid~Bisa berikatan dengan
gula seperti glukosa, rhamnosa, galaktosa, arabinosa, xilosa dan
asam glukoronat~Lebih tahan panas dan oksidasi daripada
antosianin
Struktur Flavonoid 15 Kaempferol Quercetin Myricetin Apigenin
Luteolin Tricetin
ChalconeAuroneFlavanone
Jenis-jenis Flavonoid
Lanjutan . . .
Sumber Flavonoid
Flavon pada jeruk disebut naringin, menyebabkan rasa pahit
Makanan yang berbahan kedelai, merupakan senyawa bioaktif
Buah Berry
Apel
TANINTanin disebut juga asam tanat dan asam galotanatTanin
terdiri dari katekin, leukoantosianin, dan asam hidroksi yang
masing-masing dapat menimbulkan warna bila bereaksi dengan ion
logam.Adanya tanin dalam bahan makanan dapat ikut menentukan cita
rasa bahan makanan tersebut
Tannin
Flavonoid
Karotenoid merupakan pigmen berwarna kuning, oranye, dan merah
oranye yang terlarut dalam lipida yang berasal dari hewan maupun
tanaman.Misalnya fukoxanthin yang terdapat pada lumut; lutein,
violaxanthin, dan neoxanthin pada dedaunan;likopen pada
tomat;kapsanthin pada cabe merah;caroten pada
wortel.KarotenoidJenis-jenis
KarotenoidFucoxantinLuteinViolaxantinNeoxantinBeta
KarotenZeaxantin
25Pigmen ini banyak terdapat dialam contohnya pada ~Fucoxantin
dalam alga~Lutein, violaxantin, neoxantin dalam sayuran hijau~Beta
karoten dan zeaxantin dalam wortel~Lycopene dalam tomat~Capsanthin
pada paprika dan cabe merah~Bixin pada annato
Sumber Karotenoid26Carotenoids as
NaturalColorantsLycopene-Carotene-CaroteneLutein +
zeaxanthin-Cryptoxanthin
Lycopene
Tomato, watermelon, pink grapefruit, papaya, guava, rose hip
LycopeneThis compound is the major pigment in tomatoes and is
one of the major carotenoids in the human diet.Lycopene is a long
hydrocarbon chain with 11 conjugated double bonds and it lacks the
characteristic ring structures. It is a long chain conjugated
hydrocarbon and its structure suggests that it would be easily
oxidized in the presence of oxygen and isomerized to cis compounds
by heat.Both of these reactions occur in purified solutions of
lycopene but in the presence of other compounds normally present in
tomatoes, lycopene is more stable.Lycopene (C40H56, mol wt 536.9,
,-carotene) has maxima of absorption at 446, 472, and 505 nm (for
the trans form). LycopeneIt is soluble in chloroform and benzene,
and virtually insoluble in methanol and ethanol. The
-apo-8-carotenal trans form is widespread in nature in citrus
fruits, vegetables, and grasses.Often a synthetic carotenoid in the
form of a fine purple crystalline powder, insoluble in water,
slightly soluble in ethanol and vegetable oils, and very soluble in
chloroform is used. This pigment is heat-sensitive.
LycopeneLycopene is a bright red pigment that colors several
ripe fruits, vegetables, and flowers.Tomato and tomato products are
the main dietary sources of this carotenoid, although it is also
found in watermelons, guavas, pink grapefruits, and in small
quantities in at least 40 plants.The absorption of lycopene in the
human gut is increased by heat treatment, probably because the
breakdown of the plant cells makes the pigment more accessible.
-Carotene
Carrot, apricot, mango, red pepper, kale, spinach, broccoliIt
has vitamin A activity: 1 g of -carotene corresponds to 1.67
million IU of vitamin A and the vitamin activity of 0.6 mg of
-carotene is almost equivalent to 0.3 mg of vitamin A. The
antioxidant properties of -carotene are currently the subjects of
special attention because they may be involved in the mechanisms of
preventing certain types of cancers.
-CaroteneThis compound occurs in nature, usually associated with
a numberof chemically closely related pigments and extracts that
have been used as food colorants for many years. -Carotene is a
carotenoid with the many conjugated double bonds seen in lycopene,
forming a connected double ring structure.-CaroteneMost -carotene
applied today is manufactured by synthesis, resulting in a molecule
equivalent to that found in nature. However, several natural
sources are available and are increasingly used to replace the
synthetic variant.It is derived from green leaves, where it
functions as a photoenergy transfer medium and as a photoprotectant
in the light-harvesting complexes of the chloroplasts.
-Carotene-Carotene is found in the form of a crystalline powder
(C40H56, mol wt 536.9,,-carotene). It is insoluble in water and
ethanol and not very soluble in vegetable fats. In chloroform, the
maximum spectrometric absorption is found between 466 and 496 nm.
-Carotene is sensitive to oxygen (air), heat, light, and
humidity.-Carotene plays a crucial role in human health since it is
the major source of vitamin A for most people throughout the
world.-Carotene
Carrot, collard green, pumpkin, corn, yellow pepper,
cloudberryLutein + zeaxanthinKale, spinach, broccoli, pea, Brussels
sprout, collard green, lettuce,corn, egg yolkLutein +
zeaxanthinLutein and Zeaxanthin Lutein is a major component of many
plants. It is a component of most of the carotenoid extracts
suggested as food colorants. Lutein is the dominant xanthophyll in
leafy green and yellow vegetables, which are the primary human
sources of carotenoids.Lutein has a structure similar to -carotene
with a hydroxyl group on the ionone ring at each end of the
molecule.As its name indicates, it is a dihydroxy carotenoid and
the presence of the polar groups alters its properties so that it
is easily separated from the hydrocarbon carotenoids. Lutein has
one end group and one end group. Zeaxanthin is symmetric and has
two end groups. Both lutein and zeaxanthin are dihydroxy
carotenoids with the hydroxyl groups located on the 3 and 3
carbons. In lutein, the hydroxyl group is allylic to the isolated
double bond in the ring.Lutein + zeaxanthinThe maximum
spectrometric absorption of lutein (C40H56O2, mol wt 568.9,
xanthophyll, (3R,3.S,6.R)-,-carotene-3,3.-diol) is found between
453 and 481nm. Its solubility in ethanol is greater than that of
the carotenoids.6 It is somewhat less sensitive to oxidation and
heat degradation than -carotene. It contributes yellow color.
Lutein + zeaxanthinZeaxanthin (C40H56O2, mol wt 568.9, (3R,3R)
,-carotene-3.3.-diol) is a constitutional isomer of lutein and it
differs from lutein structurally in subtle but important ways.This
dihydroxy carotenoid is mainly derived from maize as its name
suggests, although traces are found in many foods. It is
chromatographically difficult to separate from its isomer
lutein.Zeaxanthin is the abundant xanthophyll in only a small
number of food sources and is the dominant xanthophyll in orange
peppers and Gou Zi Qi or lycium mill (Lycium chinense) berries,
probably the richest sources.51,52
-Cryptoxanthin
Avocado, orange, papaya, passion fruit, pepper,
persimmonCharacteristics of Common FoodCarotenes and
XanthophyllsNameCharacteristicsPhytoflueneLycopene-Carotene-Carotene-Carotene-Carotene-Carotene-Cryptoxanthin-CryptoxanthinZeaxanthin,LuteinViolaxanthinAstaxanthinAcyclic,
colorlessAcyclic, redAcyclic, light yellowMonocyclic (1 ring),
red-orangeMonocyclic (1 ring), red-orangeBicyclic (2 rings),
orangeBicyclic (1 ring, 1 ring), yellowBicyclic (2 rings),
orangeBicyclic (1 ring, 1 ring), yellowBicyclic (2 rings),
yellow-orangeBicyclic (1 ring, 1 ring), yellowBicyclic,
yellowBicyclic (2 rings), redCHLOROPHYL
Type of Chlorophylchlorophyll a, b, c, d, and e, the latter
being merely a negligible and less studied derivative. All higher
plants, at the onset of the natural process of senescence in leaves
and ripening of fruits, contain only chlorophylls a, b, and their
respective breakdown derivatives: pheophytins, chlorophyllides, and
pheophorbides that are further metabolized into colorless
derivatives.Chlorophyll b differs from chlorophyll a by having an
aldehyde group (CHO) at C-7 in place of the methyl group.
SPECTROSCOPIC PROPERTIES ULTRAVIOLET(UV)VISIBLE(VIS) ABSORPTION
SPECTRA
Intact chlorophyll structures absorb strongly in the red and
blue regions of the visible spectrum due to the conjugated
double-bond system that imparts a green color to
chlorophyll-containing organisms, and molar extinction coefficients
vary between 104 and 10 5 M/cm. Chlorophylls and their green
derivatives are distinguishable from each other according to the
specific structural characteristics of the macrocycle, the
peripheral groups, and the nature of the central metal ion that may
have different effects on each resonance form and strongly
influence the profile of their UV-Vis absorption spectra.The
absorbance spectrum of chlorophyll a shows two dominant bands: the
Q-band in the 669 nm region and what is known as the Soret band at
432 nm. Although chlorophyll b is similar to chlorophyll a, except
for having an aldehyde group in place of the methyl group at C-7,
this small structural difference between both molecules generates
significant differences in absorption spectra. The absorption
maxima of chlorophyll b is shifted toward the green region of the
spectrum, showing two dominant bands: one around 644 nm and the
other near 455 nm, being responsible for the different green hues
of the pigments blue-green for chlorophyll a and yellow-green in
chlorophyll b. If the Soret band in the violet or near-violet
region is not detected, porphyrin structures have been
broken.Chlorophylls c have characteristic bands between 578 and 630
nm and between 443 and 450 nm that correspond to the Q-band and the
Soret band, respectively.The absorption maxima of chlorophyll d, as
expected, is very close to that of chlorophyll a, due to their
structural similarity: it has a formyl group instead of a vinyl
group at C-3 but is otherwise identical with chlorophyll a.
The spectral characteristics of bacteriochlorophylls differ from
each other, depending on their peripheral side chains, and the Q
band varies between 646 and 795 nm, while the Soret band ranges
between 365 and 456 nm. Bacteriochlorophylls absorb in the
infrared, in addition to the blue part of the spectrum.
The water-soluble phycobilin pigments, phycoerythrin and
phycocyanin, absorb strongly at 495, 540, and 565 nm, and in the
600 to 640 nm region, respectively, indicating that they absorb
wavelengths of visible light that are not efficiently absorbed by
chlorophylls and carotenoids. Photosynthetic rates are high at
these absorption maxima, indicating the unique role of phycobilins
as primary light absorbers.
Chlorophylls and related compounds are soluble in most organic
solvents like acetone, methanol, ethanol, petroleum ether, and
diethyl ether due to the hydrophobic character of the phytol chain
and of other alcohols, eventually present. Nevertheless, the
position of the absorption maxima and the shape of the spectrum can
vary by some nanometers depending on the surroundings of the
pigments (solvent, temperature, bond to protein, etc.). For
instance, the dielectric properties of the organic solvent alter
the spectral characteristics of chlorophylls due to hydrogen bonds
and dipoledipole interactions between the solventwater mixtures,
contributing to the formation of aggregates.Consequently, the
measurement of pigment concentration requires extraction with a
solvent for which specific or molar absorbance coefficients
DISTRIBUTION OF CHLOROPHYLLS INPHOTOSYNTHETIC ORGANISMSData
revealed that plants are descended from multicellular algae and
various green algae groups have been proposed to be the ancestors,
It is assumed that between 500 and 400 million years ago, some
algae became terrestrial by developing a series of adaptations to
help them survive on land.Estimates for annual chlorophyll
synthesis and degradation range up to 10 9 tons chlorophyll per
year on Earth, of which about one-third is from terrestrial and
two-thirds from aquatic (and mainly marine) environments In the
aquatic milieu, algae a wide variety of photosynthetic organisms
ranging from tiny bacteria-sized (1 to 5 m) phytoplankton to
macroalgae, the kelps ( Macrocystis spp.) reaching up to 30 m in
length, can be found in salt and freshwater EcosystemsHowever, the
microscopic marine plants called phytoplankton (primarily diatoms,
dinoflagellates, and Cyanobacteria) are the true bases of the
marine food chain due to their photodynamic properties: capturing
sunlight and transducing energy for the production of organic
compounds.Biosynthesis steps of porphyrins from protoporphyrin IX
to chlorophyll a.
CHLOROPHYLL DEGRADATION DURING PLANT SENESCENCEAND FRUIT
RIPENINGDisappearance of chlorophyll during fruit ripening and leaf
senescence or normal turnover in photosynthetic tissues indicates
programmed slowing of photosynthesis.The process was largely
unknown and only during the last 20 years has significant research
progress been made.ANTOXANTINAntoxantin termasuk dalam pigmen
flavonoid yang berwarna bening dan larut dalam air.Antoxantin juga
merupakan suatu glikosida dengan satu atau dua monosakarida
(ramnosa dan glukosa)Antosianin berbeda dengan pigmen kuning atau
jingga (karotenoid) karena sifatnya larut dalam air, sedangkan
karotenoid larut dalam lipida.KurkuminKurkumin (diferuloylmethane
adalah senyawa aktif yang ditemukan pada kunir, berupa polifenol
dengan rumus kimia C21H20O6. Kurkumin memiliki dua bentuk tautomer:
keton dan enol. Struktur keton lebih dominan dalam bentuk padat,
sedangkan struktur enol ditemukan dalam bentuk cairan. Senyawa
turunan kurkumin disebut kurkuminoid, yang hanya terdapat dua
macam, yaitu desmetoksikurkumin dan bisdesmetoksikurkumin
KurkuminSalah satu produk senyawa metabolit sekunder dari
tanaman kunyit dan temulawakDua lainnya curcuminoids yang
desmethoxycurcumin dan bis-desmethoxycurcuminPolifenol yang
bertanggung jawab untuk warna kuning kunyitTerdapat dua bentuk
tautomer, keto dan enol.Bentuk enol lebih stabil dari segi energi
dalam fase padat dan dalam larutan.Bereaksi dengan asam borat
membentuk senyawa berwarna merah, yang dikenal sebagai
rosocyanineBerwarna kuning cerah dan dapat digunakan sebagai
pewarna makanan. Sebagai aditif makanan
Dampak POSITIF DAN NEGATIF KURKUMINPositifNegatifsebagai pewarna
kuning alami makanan
berpotensi besar sebagai anti-inflamasi, antivirus,
anti-imunodefisiensi, antibakteri, antijamur, anti-oksidan,
antikarsinogenik, dan anti-infeksi
anti-oksidan kunyit dapat melindungi lemak, hemoglobin, dan DNA
dari serangan radikal bebas
memiliki zat anti kankermembutuhkan jumlah sumber yang banyak
untuk mendapatkan ektrak warnanya
pengolahannya susahBerdasarkan kelarutannya dikenal dua macam
pewarna buatan, yaitu: Dyes2. Lakes68DyesUmumnya bersifat larut
dalam air, propelin glikol, gliserin, atau alkoholTidak dapat larut
dalam semua jenis pelarut organikTerdapat dalam bentuk bubuk,
granula, cairan, campuran warna, pasta, dan dispersi69Stabil untuk
berbagai penggunaan dalam pangan dan dapat menjadi tidak stabil
bila dalam pangan tersebut terkandung bahan pereduksi atau
berprotein dan diproses dalam retort pada suhu tinggi, juga jika
kontak dengan logamUntuk mewarnai roti dan kue, produk susu, kulit
sosis, kembang gula, minuman ringan, dll.70LakesDibuat melalui
proses pengendapan dan absorpsi dyes pada radikal (Al atau Ca) yang
dilapisi aluminaTidak larut pada hampir semua pelarutStabil pada pH
3,5-9,5. lebih stabil terhadap cahaya, kimia, dan panasKandungan
dyes dalam lakes disebut pure dyes contents (pdc)Umumnya mengandung
10-40% dyes murni
71Digunakan untuk produk yang mengandung lemak dan produk yang
padat airnya rendah. Misalnya tablet yang diberi lapisan (coating),
icing, pelapis berminyak, campuran adonan kue dan donat, permen
karet, dll
Contoh Bahan Pewarna Sintetis yang Diijinkan di
IndonesiaPewarnaNomor Indeks Warna (C.I.No.)Amaran16185Tartrazine
(kuning)-Hijau S44090Indigotin73015Kuning
FCF-Riboflavina1914073Struktur Amaran
Struktur Tartrazine
Struktur Hijau S
Struktur Indigotin
Struktur Kuning FCF
Struktur Riboflavina
Contoh Bahan Pewarna Sintetis yang Dilarang di IndonesiaBahan
PewarnaNomor Indeks Warna (C.I.No.)Citrus Red No. 212156Rhodamine
B45170Chrysoidine11270Magenta42510Butter Yellow 11020Methanil
Yellow1306580Struktur Citrus Red No. 2
Struktur Rhodamine B
Struktur Chrysoidine
Struktur Magenta
Struktur Butter Yellow
Struktur Methanil Yellow
PEWARNA SINTETIK KUNINGMetanil YellowMerupakan salah satu zat
pewarna yang tidak diizinkan untuk ditambahkan ke dalam bahan
makanan. Metanil Yellow digunakan sebagai pewama untuk
produk-produk tekstil (pakaian), cat kayu, dan cat lukis. Metanil
juga biasa dijadikan indikator reaksi netralisasi asam basa.Pewarna
SINTETIK KUNINGTartrazinPewarna kuning lemon sintetis yang umum
digunakan sebagai pewarna makanan. Tartrazin merupakan turunan dari
coal tar, yang merupakan campuran dari senyawa fenol, hidrokarbon
polisiklik dan heterosklikTARTRAZINTurunan dari coal tar, yang
merupakan campuran dari senyawa fenol, hidrokarbon polisiklik dan
heterosklikLarut dalam airAbsorbansi maksimal senyawa ini dalam air
jatuh pada panjang gelombang 4272 nm
Efek Negatif TARTRAZINTartrazin dapat menyebabkan sejumlah
reaksi alergi dan intoleransi bagi orang-orang yang intoleransi
terhadap aspirin atau penderita asma.Aspirin atau asam
asetilsalisilat (asetosal) adalah sejenis obat turunan dari
salisilat yang sering digunakan sebagai senyawa analgesik (penahan
rasa sakit atau nyeri minor), antipiretik (terhadap demam), dan
anti-inflamasi (peradangan).Gejala alergi tartrazine dapat timbul
apabila senyawa ini terhirup (inhalasi) atau ditelan
(ingesti).Reaksi alergi yang timbul berupa sesak napas, pusing,
migrain, depresi, pandangan kabur, dan sulit tidur.Penggunaan
TARTRAZINKarena kelarutannya dalam air, tartrazin umum digunakan
sebagai bahan pewarna minumanJuga terdapat pada minuman ringan,
puding, keripik, sereal, kue, sup, saus, es krim, permen, selai,
jeli, mustard, acar, yogurt, mie, dan jusSedangkan dalam produk
medis seperti vitamin, antasida, kapsul dan obat-obat preskripsi
tertentu.METHANYL YELLOWKuning metanil merupakan zat warna sintetis
berbentuk serbuk, padat, berwarna kuning kecoklatanKuning metanil
umumnya digunakan sebagai pewarna tekstil, dan catKuning metanil
dilarang digunakan dalam obat, kosmetik, makanan dan minumanKuning
metanil seringkali disalahgunakan untuk pewarna makanan dan
minuman, misalnya : krupuk,sirup, tahu dan mie
Bahaya Utama METHANYL YELLOW Terhadap KesehatanDalam waktu lama
(kronis), dapat menyebabkan kanker pada saluran kemih dan kandungan
kemih.Gejala Akut Bila Terpapapar Kuning Metanil seperti jika
terkena kulit dalam jumlah banyak akan menimbulkan iritasi pada
kulitJika terkena mata akan menimbulkan gangguan
penglihatan/kaburJika terhirup akan menimbulkan iritasi pada
saluran pernafasan, dalam jumlah banyak bisa menimbulkan kerusakan
jaringan dan peradangan pada ginjal
