Characterization of vegetable cooking oil and its using on the biodiesel production

Thermomyces lanuginosus lipaz enzimi mikroporoz stiren-divinilbenzen- poliglutaraldehit (STR-DVB-PGA) polimerine kovalent olarak immobilize edilmiştir. Merkezi kompozit dizayn ile immobilizasyon üzerine enzim konsantrasyonunun (% 4-16 v/v), tampon pH'nın (6,0-8,0), tampon konsantrasyonunun (20-100 mM), immobilizasyon süresinin (8-40 saat) etkisi incelenmiş ve etkili faktörler optimize edilmiştir. Enzim konsantrasyonu, pH ve tampon konsantrasyonunun spesifik aktivite üzerinde etkili olan önemli faktörler olduğunu bulunmuştur. Optimum koşullardaki tahmini spesifik aktivite 8.78 ?mol pNP/mg enzim.dk olarak hesaplanmış, deneysel spesifik aktivite ise 8,41 ?mol pNP/mg enzim.dk olarak belirlenmiştir. Metanol ve t-bütonolün immobilize lipazın spresifik aktivitesi üzerine etkisi incelenmiştir. İmmobilize lipazın aktivitesi t-bütanolde hemen hemen değişmezken, metanolde büyük oranda azalmaktadır. Çalışmanın ikinci aşamasında çapraz bağlayıcı olarak glutaraldehit kullanılarak kitosan küreler hazırlanmıştır. Candida antarctica A lipaz enzimi kitosan küreler üzerine kovalent olarak immobilize edilmiştir. Bu küreler üzerine yapılan immobilizasyonda en yüksek spesifik aktivite, % 12 (v/v) enzim konsantrasyonunda ve 24 saat immobilizasyon süresinde elde edilmiştir. Optimum koşullarda enzim immobilize edilen STR-DVB-PGA polimeri ve kitosan küreleri kullanılarak ön işlem uygulanmamış atık kanola yağından biyodizel üretilmiştir. Her iki destek maddesi kullanılarak üretilen biyodizel verimleri sırası ile % 85,95 ve % 59,32 dir. STR-DVB-PGA destek maddesi ile daha yüksek oranda biyodizel elde edildiği görülmüştür.Lipase from Thermomyces lanuginosus was immobilized by covalent binding on a novel microporous styrene-divinylbenzene-polyglutaraldehyde copolymer (STY-DVB-PGA). The central composite design was employed to evaluate the effects of enzyme concentration (4-16 %v/v), buffer pH (6.0-8.0), buffer concentration (20-100 mM) and immobilization time (8-40 h) on the specific activity, and significant parameters were optimized. The results indicated that enzyme concentration, pH and buffer concentration were the significant factors on the specific activity of immobilized lipase. The predicted specific activity was 8.78 ?mol pNP/mg enzyme.min under the optimal conditions and the subsequent verification experiment with specific activity of 8.41 ?mol pNP/mg enzyme.min confirmed the validity of the predicted model. The effect of methanol and tert-butanol on the specific activity of immobilized lipase was investigated. The immobilized lipase was almost stable in tert-butanol whereas it lost most of its activity in methanol. In second part of study, chitosan beads were prepared by using a crosslinking agent as glutaraldehyde. Lipase from Candida antarctica A was immobilized by covalent binding on chitosan beads. The maximum specific activity was found as enzyme concentration of 12 % (v/v) and immobilization time of 24 hours. Production of biodiesel was performed with STY-DVB-PGA polymer and chitosan beads as support materials using waste canola oil. The yields of biodiesel were 85.95 % and 59.32 %, respectively. It was observed that STY-DVB-PGA support material provided higher biodiesel yield

Antioxidant properties of the anthocyanin-containing ultrasonic extract from blackberry cultivar "Cacanska Bestrna"

For the first time, an ultrasound-assisted extraction was used to investigate isolation of anthocyanin-containing extracts from the blackberry cultivar "Cacanska Bestrna" widely grown in Serbia. Sonication time and temperature influence on the yield, active substances content and antioxidant activity of the extracts isolated from blackberry fruit pur e was discussed. Ultrasound-assisted extraction with acidified ethanol at room and moderately high temperature (40 degrees C) enabled rapid isolation (15-30 min) of anthocyanin-containing blackberry extracts with the high yields (5.3-6.3%). Both increase of the sonication temperature and time within studied ranges had positive effect on the extraction yield. The HPLC analysis revealed the presence of the anthocyanins in the investigated samples. After hydrolysis of all the samples, aglycone-cyanidin was detected in the samples. Determined cyanidin content in the obtained blackberry extracts (0.7-1.0%) was up to 20 times higher than in the blackberry juice. Cyanidin content was positively affected by sonication time and temperature increase. The antioxidant properties of the extracts were analyzed by the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryihydrazyl (DPPH) radical scavenging capacity assays. Positive effect of increase of the sonication time and/or temperature on the scavenging activity of the extracts against free DPPH radicals and thus lower IC50 values was demonstrated. Strong linear correlation of DPPH radical scavenging capacities of the extracts with content of cyanidin and tannins was established. FRAP values significantly correlated with total tannin content in the extracts. The analyses of composition and antioxidant properties in this study revealed great potential of blackberry ultrasonic extracts of the cultivar "Cacanska Bestrna" for further use in food and pharmaceutical industries