Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Effect of Substrate Concentration and Scale Up on the Polygalacturonase Production(Gıda Teknolojisi Derneği, 2019) Göğüş, Nihan; Tarı, CananPectinases have been used for many industrial applications since long time ago. The largest industrial application of these enzymes is in fruit juice and wine production for the extraction, filtration and clarification and for the maceration of fruits and vegetables. They work by enzymatic breaking down of the cell wall.In this study it was aimed to use the previously optimized shake flask media formulation in batch mode 1 L scale serial bioreactor system and 5 L scale in order to investigate the effects of substrate concentration and scale on PG activity and biomass production. In conclusion it was observed that average PG activity (101.29 U/ml) obtained in 5L scale bioreactor experiments was higher than the maximum PG activity (88.55 U/ml) at 40 g/L orange peel (OP) concentration obtained in the 1 L scale substrate concentration experiment. Furthermore,PG activity increased with an increase in substrate concentration except for 60 g/L orange peel concentration.Article Citation - WoS: 12Citation - Scopus: 16Utilization of Orange Peel, a Food Industrial Waste, in the Production of Exo-Polygalacturonase by Pellet Forming Aspergillus Sojae(Springer Verlag, 2015) Büyükkileci, Ali Oğuz; Lahore, Marcelo Fernandez; Tarı, CananThe production of exo-polygalacturonase (exo-PG) from orange peel (OP), a food industrial waste, using Aspergillus sojae was studied in submerged culture. A simple, low-cost, industrially significant medium formulation, composed of only OP and (NH4)2SO4 (AS) was developed. At an inoculum size of 2.8 × 103 spores/mL, growth was in the form of pellets, which provided better mixing of the culture broth and higher exo-PG activity. These pellets were successfully used as an inoculum for bioreactors and 173.0 U/mL exo-PG was produced. Fed-batch cultivation further enhanced the exo-PG activity to 244.0 U/mL in 127.5 h. The final morphology in the form of pellets is significant to industrial fermentation easing the subsequent downstream processing. Furthermore, the low pH trend obtained during this fermentation serves an advantage to fungal fermentations prone to contamination problems. As a result, an economical exo-PG production process was defined utilizing a food industrial by-product and producing high amount of enzyme.Article Citation - WoS: 3Citation - Scopus: 4Evaluation of Agro-Industrial Wastes, Their State, and Mixing Ratio for Maximum Polygalacturonase and Biomass Production in Submerged Fermentation(Taylor and Francis Ltd., 2015) Göğüş, Nihan; Evcan, Ezgi; Tarı, Canan; Cavalitto, Sebastian F.The potential of important agro-industrial wastes, apple pomace (AP) and orange peel (OP) as C sources, was investigated in the maximization of polygalacturonase (PG), an industrially significant enzyme, using an industrially important microorganism Aspergillus sojae. Factors such as various hydrolysis forms of the C sources (hydrolysed-AP, non-hydrolysed-AP, hydrolysed-AP + OP, non-hydrolysed-AP + OP) and N sources (ammonium sulphate and urea), and incubation time (4, 6, and 8 days) were screened. It was observed that maximum PG activity was achieved at a combination of non-hydrolysed-AP + OP and ammonium sulphate with eight days of incubation. For the pre-optimization study, ammonium sulphate concentration and the mixing ratios of AP + OP at different total C concentrations (9, 15, 21 g-1) were evaluated. The optimum conditions for the maximum PG production (144.96 ml-1) was found as 21 g-1 total carbohydrate concentration totally coming from OP at 15 g-1 ammonium sulphate concentration. On the other hand, 3:1 mixing ratio of OP + AP at 11.50 g-1 ammonium sulphate concentration also resulted in a considerable PG activity (115.73 ml-1). These results demonstrated that AP can be evaluated as an additional C source to OP for PG production, which in turn both can be alternative solutions for the elimination of the waste accumulation in the food industry with economical returns.Article Citation - WoS: 13Citation - Scopus: 14Evaluation of Orange Peel, an Industrial Waste, for the Production of Aspergillus Sojae Polygalacturonase Considering Both Morphology and Rheology Effects(TUBITAK, 2014) Gögüş, Nihan; Hakgüder Taze, Bengi; Demir, Hande; Tarı, Canan; Ünlütürk, Sevcan; Lahore, Marcelo FernandezOrange peel is an agroindustrial waste rich in pectin and known to be an inducer for pectinase production. The use of this low-cost substrate for the production of an industrially important enzyme, polygalacturonase (PG), can be an alternative way to turn this waste into a value-added product, contributing to the reduction of environmental waste disposal problems. Enzyme productions by fungal microorganisms are affected by environmental and nutritional factors, demanding the determination of optimum conditions for maximum enzyme production with the desired fungal morphology and broth rheology. Therefore, complex and additional carbon sources were optimized with respect to PG production by Aspergillus sojae using statistical approaches. Effect of pH, another significant parameter affecting the rheology and morphology of the strain, was investigated in the serial bioreactor system using the optimized medium composition. Highest PG enzyme yield and productivity together with the maximum PG enzyme production (93.48 U/mL) were obtained under uncontrolled pH conditions. Under these conditions, morphologically, pellet sizes exhibited a normal distribution ranging between 0.5-1.0 mm and 1.0-1.5 mm, and rheological measurements revealed that fermentation broths showed non-Newtonian flow. The low pH trend observed during the course of the fermentation was another important positive outcome for industrial fermentations, prone to contamination problems.Article Citation - WoS: 28Citation - Scopus: 32Optimization of the Process Parameters for the Utilization of Orange Peel To Produce Polygalacturonase by Solid-State Fermentation From an Aspergillus Sojae Mutant Strain(TUBITAK, 2012) Demir, Hande; Göğüş, Nihan; Tarı, Canan; Heerd, Doreen; Lahore, Marcelo FernandezThe effect of orange peel concentration, HCl concentration, incubation time and temperature, and inoculum size on the spore count and activity of polygalacturonase (PG) enzyme produced from Aspergillus sojae M3 by solidstate fermentation was screened using 2k factorial design. Orange peel and HCl concentrations and incubation time were significant factors affecting the responses. Optimum conditions favoring both PG and spore production from Aspergillus sojae M3 were determined as 2% orange peel and 50 mM HCl concentrations at 22 °C and 4.3 days of incubation. An overlay plot was constructed for use as a practical chart for production of high enzyme activity (>35.0 U/g substrate) and spore count (9.0 × 108 to 2.0 × 109 spore/mL) by superimposing the contours of PG activity and spore count responses. The accuracy and reliability of the constructed models on the responses was validated with the maximum calculated error rate between the predicted and actual activities at 14.1% and 22.4%, respectively. © TÜBİTAK.Article Citation - WoS: 8Citation - Scopus: 7Commercially Suitable Pectin Methylesterase From Valencia Orange Peels(Türkiye Klinikleri Journal of Medical Sciences, 2010) Şimşek, Şebnem; Yemenicioğlu, AhmetA simple and effective procedure was developed to extract pectin methylesterase (PME) from Valencia orange peels. Orange peels contain 25-34 μmol of COOH min-1 g-1 of peel PME activity. The enzyme was ionically bound to cell walls and could not be extracted with water. This enables removal of water soluble pectic substances and oils from peels via homogenization and washing with water before enzyme extraction. Enzyme extraction can be conducted simply by addition of suitable amounts of NaCl (optimum: 10 g of NaCl 100 g-1 of extraction mixture) to peel homogenate and stirring (optimum: 30 min at 200 rpm). The PME extracted from orange peels contains almost the same amount of heat-stable and heat-labile fraction, and the enzymes cannot be activated by mild heating. A slight activation of enzyme (almost 20%) was achieved by adding 1 mM CaCl2 to enzyme extracts, but this agent was inhibitory at higher concentrations. The extracts stabilized by Na-benzoate and K-sorbate maintained more than 90% of their PME activity at 4 °C for at least 5 months. The obtained PME was successfully used to prepare low-methoxyl citrus pectin used in edible film formation in the presence of CaCl2. This study shows the potential of using Valencia orange peels as a source of commercial PME. © TÜBİTAK.