Effect of Catalyst on Transesterification of Waste Vegetable Oils from Food Processing Facility

Converting waste vegetable oils from food processing facilities, restaurants and households to biodiesel by the transestrification reaction with methanol has important advantages for human health and environment. The transesterification reaction of waste vegetable oils is affected by free fatty acids and water content of oils and fats, type of alcohol, type and quantities of catalyst, reaction temperature and reaction time. Basic aim of this paper is to explore effect of type and quantities of catalyst on transesterification process of different waste vegetable oils from food processing facilities with methanol. Comparison of basic characteristics between produced biodiesel, industrially produced biodiesel and values from European standards for biodiesel fuel (EN14214) was made

Monitoring of butter and animal fat oxidation stability by differential scanning calorimetry (DSC)

Oksidacija masti je jedna od osnovnih reakcija koja utječe na pad kvalitete maslaca i masla kako s gledišta proizvođača tako i s gledišta potrošača navedenih proizvoda, kao i proizvoda s njihovim sadržajem. Obzirom da je većina produkata reakcije oksidacije masti štetna po zdravlje potrošača, nedovoljno praćenje kvalitete jestivih masti i proizvoda koji ih sadrže dovelo bi do rizika po zdravlje potrošača, a i do financijskih gubitaka proizvođača. Pri procjeni oksidacione stabilnosti masti do danas su korištene standardne kemijske metode, odnosno određivanje karakterističnih brojeva (jodni, kiselinski, peroksidni, anisidni itd.) čiji proces zahtijeva upotrebukemikalija i dugo traje. Međutim analiza pomoću diferencijalne skenirajuće kalorimetrije (DSC) pokazuje da se jednostavnim načinom u vrlo kratkom vremenu, može utvrditi oksidaciona stabilnost maslaca i masla. Provedena su laboratorijska istraživanja mogućnosti primjene diferencijalne skenirajuće kalorimetrije (DSC) pri praćenju oksidacione stabilnosti maslaca i masla, kako u svježem stanju tako i već upotrijebljenom za prženje. Dobiveni rezultati komparirani su s promjenom jodnog broja određenog standardnom metodom. Postignuti rezultati potvrđuju opravdanost i mogućnost primjene diferencijalne skenirajuće kalorimetrije pri praćenju oksidacione stabilnosti maslaca i masla.Oxidation of fat is one of the basic reactions which causes the depletion of butter and animal fat quality as well as other products containing them. Since the most of reaction products of fat oxidation are harmful for consumers\u27 health, inadequate and scarce monitoring of edible fats and fat containing products quality, presents increased health risk as well as financial loss for the producers. In fat oxidation stability estimation, standard chemical methods were used (iodine number, acid number, peroxide number, anisidine number etc.), which require time and chemical usage. Differential scanning calorimetry (DSC) analysis presents the simple and efficient way for butter and animal fats oxidation stability estimation. Laboratory investigations were performed to monitor oxidation stability of butter and animal fat in fresh state, as well as in spent phase, used in frying process. The results obtained were compared to the results of standard chemical analysis, and they confirmed the reproducibility and applicability of differential scanning calorimetry in oxidation stability of butter and animal fats monitoring