CaS[O.sub.4] and cationic polyelectrolyte as possible pectin precipitants in sugar beet juice clarification/CaS[O.sub.4] i katjonski polielektroliti kao moguci precipitanti pektina pri preciscavanju soka secerne repe

• Published in: Hemijska industrija 2015-11, p.617
• Main Authors: Kuljanin, Tatjana, Loncar, Biljana, Pezo, Lato, Nicetin, Milica, Knezevic, Violeta, Jevtic-Mucibabic, Rada
• Format: Article
• Language: English
• Subjects: Chemical properties; Composition; Fruit juices; Identification and classification; Observations; Pectin; Polyelectrolytes; Precipitation (Chemistry); Sugar beet
• ISSN: 0367-598X
• DOI: 10.2298/HEMIND141015085K

Three pectin preparations were isolated from fresh sugar beet pulp during the 150 min of extraction, at pH values of 1, 3.5 and 8.5. CaS[O.sub.4] precipitant was added to 100 [cm.sup.3] of 0.1 wt.% solution of pectin. Studies were performed with 9 different concentrations of CaS[O.sub.4] solution (50-450 mg [dm.sup.-3]) with the addition of a cationic polyelectrolyte (cationic PAM) in concentrations of 3 and 5 mg [dm.sup.-3]. The efficiency of pectin precipitation was monitored by measuring the zeta potential of pectin preparations. Optimal amounts of precipitant CaS[O.sub.4], without the use of a cationic polyelectrolyte, were as follows: 490-678 mg CaS[O.sub.4]/g pectin. After the use of a cationic polyelectrolyte, the optimal amounts of CaS[O.sub.4] were smaller (353-512 mg/g pectin). These quantities are significantly lower than the average amount of CaO used in the conventional clarification process of sugar beet juice (about 9 g/g pectin of sugar beet juice). Keywords: clarification, pectin, sugar beet juice, CaS[O.sub.4], cationic polyelectrolyte, zeta potential. U toku industrijske obrade secerne repe, jedna od najvaznijih faza je ciscenje soka secerne repe. U tu svrhu, najcesce se koristi CaO u obliku Ca[(OH).sub.2]. Posto kalcijumovi joni iz ovih jedinjenja imaju relativno mali afinitet vezivanja sa pektinima soka secerne repe, potrebne su vrlo velike kolicine kreca (oko 15 g CaO/100 g soka). Zbog toga je razmatrana mogucnost izdvajanja pektina procesom razelektrisanja cestica dodavanjem jedinjenja sa dvo- i trovalentnim katjonima kao i katjonskog polielektrolita. U ovom radu, izneta su istrazivanja i date su teorijske osnove nove metode ciscenja soka secerne repe koja se bazira na primeni CaS[O.sub.4] i katjonskog polielektrolita. U toku trajanja ekstrakcije od 150 min, na pH vrednostima od 1, 3.5 i 8.5, iz rezanaca sveze secerne repe izolovana su tri pektinska preparata. Precipitant CaS[O.sub.4] u vidu vodenog rastvora, dodavan je u 100 [cm.sup.3] 0.1% (mas) rastvora pektina. Ispitivanja su vrsena sa 9 razlicitih koncentracija rastvora CaS[O.sub.4] (u intervalu 50-450 g/[dm.sup.3]) bez dodavanja katjonskog polielektrolita i uz dodatak katjonskog polielektrolita koncentracije 3 i 5 mg/[dm.sup.3] (cationic PAM). Efikasnost talozenja pektina pracena je merenjem zeta potencijala modelrastvora pektinskih preparata. Izmerene vrednosti zeta potencijala za razlicite procesne parametre uporedivane su statisticki, primenom RSM analize. Optimalne kolicine