Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 3Citation - Scopus: 3Shelf-Life Extension of Traditional Licorice Root “sherbet” With a Novel Pulsed Electric Field Processing(Frontiers Media S.A., 2023) Akdemir Evrendilek, Gulsun; Demir, Irem; Uzuner, SibelPulsed electric field (PEF) processing of licorice root "sherbet" (LRS) by various electric field strengths (7.00, 15.50, and 24.10 kV/cm), treatment times (108, 432, and 756 mu sec), and processing temperatures (6, 18, and 30 degrees C) according to the Box-Behnken design were performed. The samples were analyzed for pH, titratable acidity, conductivity, turbidity, total reducing sugar, color (L*, a*, and b*), hue, chroma, total color difference, color intensity, color tone (yellow, red, and blue color tones), total antioxidant capacity, total phenolic substance content, and sensory properties. Results revealed that PEF processing did not adversely affect most of the physical, chemical, and sensory properties of LRS, with a maximum of 2.48, 4.04, 1.78, and 1.20 log reductions on the initial total mesophilic aerobic bacteria, total mold and yeast, Bacillus circulans, and Candida tropicalis. The response variable modeled for the PEF was found to be conductivity, with the optimum processing conditions of 6.90 kV/cm, 756.00 mu s, and 7.48 degrees C. After that, the samples were stored at 4 degrees C and 22 degrees C for shelf-life studies. Control samples at 4 degrees C and 22 degrees C were spoiled on the fifth and second days, whereas PEF-treated samples stored at 4 degrees C began to deteriorate after the 40th day and the samples stored at 22 degrees C after the 30th day, respectively. It was revealed that PEF is a suitable process to extend the shelf-life of licorice "sherbet" with preservation of physicochemical and sensory properties.Article Production of Microalgae-Derived Exo-Polygalacturonase for Fruit Juice Clarification(Frontiers Media S.A., 2022) Uzuner, Sibel; Evrendilek, Gulsun Akdemir; Kurhan, SebnemDue to the growing demand for commercial enzymes derived from renewable and sustainable resources with higher efficacy, algal biomass has gained more attention. Thus, the production of exo-polygalacturonase (PGase) from Bacillus subtilis under submerged fermentation (SmF) using algal feedstocks as a carbon source in fermentation medium and its potential use for the clarification of apple and carrot juices with the optimization of the enzyme loading, pH, and time using Box-Behnken response surface methodology (RSM) were prompted. The maximum PGase activity of 510.61 +/- 7.86 U/L was achieved at pH 5.0 after 48 h at 40 degrees C using 0.5% (w/v) pectin, 0.1% (w/v) yeast extract, 0.02% (w/v) MgSO47H2O, 0.02% (w/v) K2HPO4, 0.3% (w/v) glucose, and 0.583% (w/v) microalgae hydrolysate as a fermentation medium. PGase production without glucose was favored by SmF with a shake flask working volume of 100 ml (248.90 +/- 4.58 U/L) as compared to a bioreactor with a working volume of 1 L (192.99 +/- 0.84) for 48 h. Both carrot and apple juices were treated with the crude PGase (248.9 U/L) at different concentrations (0.1-0.5%), temperature (30-50 degrees C), and time (30-120 min), and the maximal clarification conditions were obtained as 0.3% (w/v) enzyme concentration at 50 degrees C for 30 min exposure time. This study revealed that microalgae-derived PGase in crude form could be effectively used for clarification of the juices.