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Rangkuman kuliah pewarna
YNT
FOOD COLOR• With 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.
ANTOSIANIN
• Antosianin merupakan golongan pigmen kemerahan yang bersifat larut dalam air
• Terdapat 20 jenis antosianin. 6 diantaranya merupakan pigmen pnting yang sering digunakan dalam produk pangan, antara lain: Pelargonidin, Cyanidin, Delphidin, Peonidin Petunidin, Malvidin
Struktur antosianin
Anthosianin
Merupakan kelompok pigmen kemerahan yang bersifat larut dalam air
Tersebar dalam tanaman: buah, sayur, bunga
Seluruh antosianin merupakan turunan dari struktur dasar kation flavilium
Ada 20 jenis antosianin, 6 yang penting adalah Pelargonidin, cyanidin, delphidin, peonidin, petunidin, dan malvidin
Lanjutan…
• Lima jenis gula yang terdapat dalam antosianin, yaitu: ~ Glukosa ~ Rhamnosa ~ Galaktosa ~ Xilosa ~ Arabinosa
meskipun ada lima gula yang dapat dimiliki oleh antosinin, namun dalam antosianin hanya dapat mengandung 3 tiga gula didalamnya.
Berdasarkan Jumlah Gulanya Dapat Bibedakan Menjadi 3• Monosida: 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
Flavonoid
Flavonoid berwarna kuning
Struktur kimia mirip antosianin
Lebih stabil terhadap panas dan oksidasi dibandingkan antosianin
Biasa berikatan dengan gula seperti glukosa, rhamnosa, galaktosa,arabinosa, xilosa, dan asam glukuronat
Ada sekitar 400 jenis flavonoid
Flavono
id
~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
Flavono
id
o Kaempferolo Quercetino Myricetino Apigenino Luteolino Tricetin
o Chalconeo Auroneo Flavanone
Jenis-
jenis
Flavonoid
Lanjutan . .
.
Sumber
Flavono
idFlavon pada jeruk disebut naringin, menyebabkan rasa pahit
Makanan yang berbahan kedelai, merupakan senyawa bioaktif
Buah Berry
Apel
TANIN
• Tanin disebut juga asam tanat dan asam galotanat
• Tanin 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 Tanin terdiri dari asam tanat, asam gallotanat.
Terdiri dari dua jenis: tanin terkondensasi (condensed tannin) dan tanin yang dapat dihidrolisis (hydrolyzable tannin)
Contoh hydrolyzable tannin: gallotanin dan elagitannin
Contoh tanin terkondensasi: katekin
Flavonoid
Flavonoid berwarna kuning
Struktur kimia mirip antosianin
Lebih stabil terhadap panas dan oksidasi dibandingkan antosianin
Biasa berikatan dengan gula seperti glukosa, rhamnosa, galaktosa,arabinosa, xilosa, dan asam glukuronat
Ada sekitar 400 jenis 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.
Karotenoid
Jenis-jenis Karotenoid
• Fucoxantin• Lutein• Violaxantin• Neoxantin• Beta Karoten• Zeaxantin
• Pigmen 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 Karotenoid
Carotenoids as NaturalColorants
• Lycopene• β-Carotene• α-Carotene• Lutein + zeaxanthin• β-Cryptoxanthin
Lycopene
• Tomato, watermelon, pink grapefruit, papaya, guava, rose hip
Lycopene• This 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, ψ,ψ-carotene) has maxima of absorption at 446, 472, and 505 nm (for the trans form).
Lycopene
• It is soluble in chloroform and benzene, and virtually insoluble in methanol and ethanol.
• The β-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.
Lycopene
• Lycopene 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.
β-Carotene
• Carrot, apricot, mango, red pepper, kale, spinach, broccoli
• It has vitamin A activity: 1 g of β-carotene corresponds to 1.67 million IU of vitamin A and the vitamin activity of 0.6 mg of β-carotene is almost equivalent to 0.3 mg of vitamin A.
• The antioxidant properties of β-carotene are currently the subjects of special attention because they may be involved in the mechanisms of preventing certain types of cancers.
β-Carotene
• This compound occurs in nature, usually associated with a number
• of chemically closely related pigments and extracts that have been used as food colorants for many years.
• β-Carotene is a carotenoid with the many conjugated double bonds seen in lycopene, forming a connected double ring structure.
β-Carotene
• Most β-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.
β-Carotene
• β-Carotene is found in the form of a crystalline powder (C40H56, mol wt 536.9,
• β,β-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. • β-Carotene is sensitive to oxygen (air), heat, light, and
humidity.• β-Carotene plays a crucial role in human health since it is the
major source of vitamin A for most people throughout the world.
α-Carotene
• Carrot, collard green, pumpkin, corn, yellow pepper, cloudberry
Lutein + zeaxanthinβ
• Kale, spinach, broccoli, pea, Brussels sprout, collard green, lettuce,
• corn, egg yolk
Lutein + zeaxanthinβ
• Lutein 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 β-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 β and one ε end group. Zeaxanthin is symmetric and has two β 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 ε ring.
Lutein + zeaxanthinβ
• The maximum spectrometric absorption of lutein (C40H56O2, mol wt 568.9, xanthophyll, (3R,3.S,6.R)-β,ε-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 β-carotene.
• It contributes yellow color.
Lutein + zeaxanthinβ
• Zeaxanthin (C40H56O2, mol wt 568.9, (3R,3R ) β,β-′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
β-Cryptoxanthin
• Avocado, orange, papaya, passion fruit, pepper, persimmon
Characteristics of Common FoodCarotenes and Xanthophylls
Name Characteristics
PhytoflueneLycopeneζ-Caroteneδ-Caroteneγ-Caroteneβ-Caroteneα-Caroteneβ-Cryptoxanthinα-CryptoxanthinZeaxanthin,LuteinViolaxanthinAstaxanthin
Acyclic, colorlessAcyclic, redAcyclic, light yellowMonocyclic (1β ring), red-orangeMonocyclic (1β ring), red-orangeBicyclic (2β rings), orangeBicyclic (1β ring, 1ε ring), yellowBicyclic (2β rings), orangeBicyclic (1β ring, 1ε ring), yellowBicyclic (2β rings), yellow-orangeBicyclic (1β ring, 1 ring), yellowBicyclic, yellowBicyclic (2β rings), red
CHLOROPHYL
Type of Chlorophyl
• chlorophyll 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 dipole–dipole interactions between the solvent–water 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 ORGANISMS
• Data 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 μ m) phytoplankton to macroalgae, the kelps ( Macrocystis spp.) reaching up to 30 m in length, can be found in salt and freshwater Ecosystems• However, 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 RIPENING
• Disappearance 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.
ANTOXANTIN
• Antoxantin 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.
Kurkumin
• Kurkumin (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
Kurkumin• Salah satu produk senyawa metabolit sekunder dari
tanaman kunyit dan temulawak• Dua lainnya curcuminoids yang
desmethoxycurcumin dan bis-desmethoxycurcumin• Polifenol yang bertanggung jawab untuk warna
kuning kunyit• Terdapat 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 rosocyanine• Berwarna kuning cerah dan dapat digunakan
sebagai pewarna makanan. Sebagai aditif makanan
Dampak POSITIF DAN NEGATIF KURKUMIN
Positif Negatif
sebagai 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 kanker
membutuhkan jumlah sumber yang banyak untuk mendapatkan ektrak warnanya
pengolahannya susah
Berdasarkan kelarutannya dikenal dua macam pewarna buatan, yaitu:
1. Dyes2. Lakes
Dyes• Umumnya bersifat larut dalam air,
propelin glikol, gliserin, atau alkohol• Tidak dapat larut dalam semua jenis
pelarut organik• Terdapat dalam bentuk bubuk,
granula, cairan, campuran warna, pasta, dan dispersi
• Stabil 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 logam
• Untuk mewarnai roti dan kue, produk susu, kulit sosis, kembang gula, minuman ringan, dll.
Lakes• Dibuat melalui proses pengendapan
dan absorpsi dyes pada radikal (Al atau Ca) yang dilapisi alumina
• Tidak larut pada hampir semua pelarut
• Stabil pada pH 3,5-9,5. lebih stabil terhadap cahaya, kimia, dan panas
• Kandungan dyes dalam lakes disebut pure dyes contents (pdc)
• Umumnya mengandung 10-40% dyes murni
•Digunakan 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 Indonesia
Pewarna Nomor Indeks Warna (C.I.No.)
Amaran 16185
Tartrazine (kuning) -
Hijau S 44090
Indigotin 73015
Kuning FCF -
Riboflavina 19140
Struktur Amaran
Struktur Tartrazine
Struktur Hijau S
Struktur Indigotin
Struktur Kuning FCF
Struktur Riboflavina
Contoh Bahan Pewarna Sintetis yang Dilarang di IndonesiaBahan Pewarna Nomor Indeks Warna (C.I.No.)
Citrus Red No. 2 12156
Rhodamine B 45170
Chrysoidine 11270
Magenta 42510
Butter Yellow 11020
Methanil Yellow 13065
Struktur Citrus Red No. 2
Struktur Rhodamine B
Struktur Chrysoidine
Struktur Magenta
Struktur Butter Yellow
Struktur Methanil Yellow
PEWARNA SINTETIK KUNING
• Metanil Yellow• Merupakan 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 KUNING
• Tartrazin• Pewarna kuning lemon sintetis yang umum
digunakan sebagai pewarna makanan. Tartrazin merupakan turunan dari coal tar, yang merupakan campuran dari senyawa fenol, hidrokarbon polisiklik dan heterosklik
TARTRAZIN
• Turunan dari coal tar, yang merupakan campuran dari senyawa fenol, hidrokarbon polisiklik dan heterosklik
• Larut dalam air• Absorbansi maksimal senyawa ini dalam air
jatuh pada panjang gelombang 427±2 nm
Efek Negatif TARTRAZIN• Tartrazin 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 TARTRAZIN
• Karena kelarutannya dalam air, tartrazin umum digunakan sebagai bahan pewarna minuman
• Juga terdapat pada minuman ringan, puding, keripik, sereal, kue, sup, saus, es krim, permen, selai, jeli, mustard, acar, yogurt, mie, dan jus
• Sedangkan dalam produk medis seperti vitamin, antasida, kapsul dan obat-obat preskripsi tertentu.
METHANYL YELLOW
• Kuning metanil merupakan zat warna sintetis berbentuk serbuk, padat, berwarna kuning kecoklatan
• Kuning metanil umumnya digunakan sebagai pewarna tekstil, dan cat
• Kuning metanil dilarang digunakan dalam obat, kosmetik, makanan dan minuman
• Kuning metanil seringkali disalahgunakan untuk pewarna makanan dan minuman, misalnya : krupuk, sirup, tahu dan mie
Bahaya Utama METHANYL YELLOW Terhadap Kesehatan
• Dalam 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 kulit
• Jika terkena mata akan menimbulkan gangguan penglihatan/kabur
• Jika terhirup akan menimbulkan iritasi pada saluran pernafasan,
dalam jumlah banyak bisa menimbulkan kerusakan jaringan dan
peradangan pada ginjal
