Download 17.FIZIKALNO - Centar za transfer znanja

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
FIZIKALNO-HEMIJSKA SVOJSTVA I PRIMJENA PČELINJEG VOSKA
1
Amra Bratovčić1, Midhat Jašić1, Amra Odobašić1, Indira Šestan1
Univerzitet u Tuzli, Tehnološki fakultet, Univerzitetska 8, 75000 Tuzla
[email protected]
Sažetak
Uvod: Pčelinji vosak (Cera alba) je proizvod pčela radilica iz roda Apis kojeg one
sintetiziraju u žlijezdama smještenenim od 4 do 7 trbušnog segmenta. Pčele ga koriste za
formiranje satnih ćelija. U pčelarstvu se reciklira, pa je danas vrlo čest problem patvorenja
dodavanjem parafina, loji, biljnog voska i sl.
Cilj i metod rada: U radu su prikazane najznačajnije fizikalno-hemijske karakteristike
pčelinjeg voska. Opsežnim pregledom najnovije literature iz ove oblasti na jedan
sistematiziran način će se ukazati na važnost studije fizikalno-hemijskih karakteristika
pčelinjeg voska kao i raznovrsnost njegove primjene.
Rezultati: Pčelinji vosak se sastoji uglavnom od estera masnih kiselina i različitih
dugolančanih alkohola. Približan hemijski sastav čine: 35% monoestera , 14 % diestera, 3 %
triestera, 4% hidroksimonoestera, 8% hidroksipoliestera, 1% kiselih estera, 2% kiselih
poliestera. Ukupno je oko 67% poliestera, zatim 14% ugljikovodika, 12% slobodnih kiselina,
1% alkohola i 6%ostalih sastojaka.
Tačka topljenja se nalazi u temperaturnom rasponu od 61 do 65 °C, dok specifična težina od
0,950 do 0,965, a indeks refrakcije na 75 °C se kreće od 1,440 do 1,445. Pčelinji vosak
karakteriziraju: kiselinski broj u rasponu od 18 do 23, estarski od 70 do 80 te saponifikacijski
od 89 do 100. Peroksidni broj iznosi najmanje 8.
Boja voska je bijela, a u prksi se kreće od žute do smeđe. Presjek može biti fino granuliran i
nekristaliziran, a nakon rezanja nije ljepljiv. Miris je poput meda. Prirodni vosak pri
zagrijevanju u vodi ispliva na površinu, dok se primjese talože na dno suda. Pri gnječenju pod
prstima postaje elastičan ali ne i klizav, ne razmazuje se i pri razvlačenju se ne kida. Pri
žvakanju se ne lijepi za zube, a pri struganju stvara spiralne listiće (šuške, trake).
U praksi se najčešće koristi za izradu voštanih satnih osnova, zatim u proizvodnji svijeća, u
industriji kablova, tkanina, kože, hartije, aviona, automobila, u hemijskoj, staklarskoj i
optičkoj indsutriji, u vajarstvu i slikarstvu itd. Korisiti se za spravljanje ljekovitih masti,
flastera, kremova, voštano-mliječnih bonbona, izradu kozmetičkih preparata. U medicini se
koristi kod opekotina, sportskih povreda i u plastičnoj hirurgiji. Općenito vosak se koristi za
sljedeće svrhe: kozmetika 25-30, ljekovi 25-30%, svijeće 20% i druge namjene 10-20%.
Vosak nije probavljiv pa se malo koristi u prehrani. Ima zanemarljivu toksičnost, a kao aditiv
odobren je za upotrebu u hrani u Evropskoj uniji pod E broj E901. Monoesteri u pčelinjeg
voska se slabo hidroliziraju u crijevima ljudi, tako da imaju neznatnu nutritivnu vrijednost.
Zaključak: Vosak je po svom hemijskom sastavu lipid karakterističnih fizikalno-hemijskih
svojstava. Poznavanje hemije pčelinjeg voska je osnova da se unaprijedi kvalitet njegove
primjene kao i sprečavanje patvorenja.
Ključne riječi: pčelinji vosak, fizikalno-hemijske karakteristike.
PHYSICAL-CHEMICAL PROPERTIES AND APPLICATION OF BEESWAX
Amra Bratovčić1, Midhat Jašić1, Amra Odobašić1, Indira Šestan1
1
University of Tuzla, Faculty of Technology, Univerzitetska 8, 75000 Tuzla
[email protected]
Abstract
Introduction: Beeswax (Cera alba) is a natural wax produced by worker bees of the genus
Apis which they sinthetised in glands posted in the abdominal segments from 4 through 7.
Bees use it to form comb cells. In beekeeping it is recycled, and is now a very common
problem of adulteration by adding paraffin, tallow, vegetable wax, etc.
Objective and Methods: In this paper the most important physical-chemical characteristics
of beeswax are presented. An extensive review of the latest literature in this field in a
systematic manner will demonstrate the importance of the study of physical-chemical
properties of beeswax and variety of its application.
Results: Beeswax consists mainly of fatty acid esters and various long-chain alcohols. The
approximate chemical composition is: 35% monoester, 14% diester, 3% triester, 4%
hydroxymonoester, 8% hydroksypolyesters, 1% acid ester, 2% of the acidic polyester. Overall
is about 67% polyester, then 14% hydrocarbons, 12% of the free acids, 1% alcohols and 6%
of other ingredients. Melting point is in the temperature range of 61 to 65 ° C, while the
specific weight from 0.950 to 0.965, and a refractive index at 75 ° C ranging from 1.440 to
1.445. Beeswax is characterized by acid number in the range 18 to 23, ester number from 70
to 80 and a saponification number from 89 to 100. Peroxide number is at least eighth.
Wax color is white, and in practice ranging from yellow to brown. Section can be finely
granulated and non crystallined, and after cutting is not sticky. The smell is like honey.
Natural wax during warming in the water comes to the surface, while the impurities settle to
the bottom of the court. When kneading under the fingers becomes elastic but not slick,
without smudging and in rolling out the does not break. When chewing does not stick to your
teeth, and during griding creates spiral leaves (chippings, tape).
In practice, it is most commonly used for making honey comb, then in the candle production,
in the cable industry, textiles, leather, paper, plane, car, in chemical, glass and optical
industry, in sculpture and painting, and so on. It is used for the preparation of healing fat,
sticking plaster, creams, wax-milk candy and cosmetic products. In medicine is used for
burns, sports injuries and in plastic surgery. General wax is used for the following purposes:
25-30 % cosmetics, 25-30% drugs, 20% of candles and 10-20% other uses. The wax is not
digestible, and so is little used in the diet. It has negligible toxicity, and as an additive is
approved for use in food in the European Union under the E number E901. Monoesters in
beeswax are poorly hydrolyzed in the intestines of people, so they have little nutritional value.
Conclusion: Wax is by its chemical composition lipid with specific physical and chemical
properties. Knowledge of chemistry beeswax is the base to improve the quality of its
implementation and to prevent adulteration.
Keywords: beeswax, physical-chemical characteristics.