Nanoteknoloji Mühendisliği Bölümü Makale Koleksiyonu
https://hdl.handle.net/20.500.12418/641
2024-03-28T14:21:09ZMicroencapsulated propolis in chewing gum production
https://hdl.handle.net/20.500.12418/15082
Microencapsulated propolis in chewing gum production
Gölge, Evren; Bostancı, Emre
Propolis is a resin with high antibacterial and antioxidant properties that honey bees (Apis mellifera L.) gather and then harmonize through their metabolic secretions. Propolis is beneficial to dental health because it contains antibacterial activity against the Streptococcus mutans, which causes tooth decay. The aim of this study is to use microencapculated propolis extract (MPE) in chewing gum formulation for the first time, in order to protect propolis from environmental effects during production and to ensure controlled release in mouth. Spray drying method was applied where maltodextrin acted as coating material. The particle structure of MPE was investigated by scanning electron microscope. The encapsulation efficiency was determined as 62.19%. The hygroscopicity and moisture content of the MPE particles was found as 31.50% and 7.98% respectively. The DPPH scavenging ability, total flavonoid and total phenolic content of the MPE appeared lower than propolis extract. The total flavonoid content of MPE was calculated as 29.06 mg/kg and total phenolic content as 89.17 mg/kg. In vitro antimicrobial activity against Streptococcus mutans of 9% MPE containing gum samples was measured highest with 4.20 mm zone diameter. Hunter b* value increased with increasing MPE concentration. The final MPE incorporated chewing gum appear to be highly functional.
2023-01-01T00:00:00ZRheology and sensory properties of microencapsulated propolis-enriched stirred-type yogurt
https://hdl.handle.net/20.500.12418/15081
Rheology and sensory properties of microencapsulated propolis-enriched stirred-type yogurt
Gölge, Evren; Taşdemir, Yasemin
In this study, the rheological, sensory and syneristic properties of yogurt enriched with 0.5%, 1% and 2% microencapsulated propolis (MP) was investigated. The viscosity measurements of stir-type yoghurt were performed with Brookfield DV-II viscometer. Shear rate varying between 0.02 s-1 and 100 s-1 flow models was obtained for rising and descending curves with the Rheocalc v3.3 software. Three flow models—Power Law, Herschel–Bulkley, and Casson models—were evaluated. All samples used in this analysis showed non-Newtonian and pseudoplastic properties. During the 21-day storage period, the Power Law flow model was optimal.
2023-01-01T00:00:00ZProduction of phenylalanine-reduced soymilk for phenylketonuria patients
https://hdl.handle.net/20.500.12418/15080
Production of phenylalanine-reduced soymilk for phenylketonuria patients
Gölge, Evren; Taşdemir, Yasemin
Phenylketonuria (PKU) is a hereditary disease caused by the deficiency of phenylalanine (Phe) hydroxylase enzyme or its cofactor tetrahydrobiopterin. Treatment involves a Phe-restricted diet, although food options are limited. Soymilk, derived from soybeans, is a functional food with nutritional benefits. In this study, soymilk was produced and hydrolyzed with protease of Aspergillus oryzae and papain, and then activated carbon was used to remove Phe for PKU patients. The second-derivative spectrophotometry method was used to determine Phe content in soymilk. The results showed no significant difference in dry matter, fat, and crude fiber between soymilk and Phe-extracted soymilk with respect to the control group (P < 0.05). Soymilk’s protein content was calculated as 2.74% (w/w) and that of Phe-reduced soymilk as 1.94% (w/w). Similarly, consecutive Phe content was 40.53 mg/L and 5.09 mg/L. After hydrolization, the calculated Phe removal rate was 87.44% (w/w), and the protein content was reduced by 29.19% (w/w). The study demonstrates that Phe-reduced soymilk is suitable for PKU patients, thus reducing the need for imported products and offering new market opportunities.
2023-01-01T00:00:00ZEffect of Si-doped and undoped inter-layer transition time on the strain-compensated InGaAs/InAlAs QCL active region grown with MOVPE
https://hdl.handle.net/20.500.12418/14693
Effect of Si-doped and undoped inter-layer transition time on the strain-compensated InGaAs/InAlAs QCL active region grown with MOVPE
Pertikel İzel; Demir İlkay
In this study, we report the effect of the combination of Si-doped and undoped inter-layer transition
time in the strain compensated In 0.67 Ga 0.33 As/In 0.36 Al 0.64 As quantum cascade laser (QCL) structure grown
on InP substrate by Metal Organic Vapor Phase Epitaxy (MOVPE). In situ reflectance spectroscopy and
high resolution X-ray diffraction (HRXRD) technique have been used for the analysis of growth steps and
crystalline quality of QCL structures, respectively. In addition, since thickness accuracy is very important
for QCLs, two different thickness calculation methods have been used in the Global Fit simulation program
for detailed thickness accuracy of structures. As a result, optimum values for thickness accuracy
have been obtained as 5 and 10 s between undoped and Si-doped layers, respectively, as verified by the
two methods.
0015-01-01T00:00:00Z