@Article{macau_mods_00003024, author = {Gharibzahedi, Seyed Mohammad Taghi and Altintas, Zeynep}, title = {Transglutaminase-Induced Free-Fat Yogurt Gels Supplemented with Tarragon Essential Oil-Loaded Nanoemulsions: Development, Optimization, Characterization, Bioactivity, and Storability}, journal = {Gels}, year = {2020}, publisher = {MDPI AG}, address = {Basel}, volume = {8}, number = {9}, keywords = {yogurt gel; tarragon oil; transglutaminase; ultrasound-assisted emulsification; nanoemulsion; rheology; microstructure; sensory; antioxidant; antimicrobial}, abstract = {There is a high demand for designing healthy-functional dairy gels with a newly structured protein network in the food industry. Non-fat yogurt gels enriched with stable tarragon essential oil-nanoemulsions (TEO-NEs) using crosslinking of microbial transglutaminase (MTGase) were developed. The gas chromatography-mass spectrometry analysis showed that methyl chavicol (85.66{\%}) was the major component in TEO extracted by the hydrodistillation process. The storage-dependent droplet size and physicochemical stability data of samples at room temperature for 30 days revealed that the TEO-NE containing 0.5{\%} tween-80 and 1:2 TEO/sunflower oil had the lowest peroxide value and droplet growth ratio. The response surface methodology-based formulation optimization of free-fat yogurt gels using MTGase (0.15--0.85 U/g) and the best TEO-NE (0.5--3.02{\%}) using the fitted second-order polynomial models proved that the combination of 0.87{\%} TEO-NE and 0.70 U/g MTGase led to the desired pH (4.569) and acidity (88.3{\%} lactic acid), minimum syneresis (27.03 mL/100 g), and maximum viscosity (6.93 Pa s) and firmness (0.207 N) responses. Scanning electron microscopy images visualized that the MTGase-induced crosslinks improved the gel structure to increase the firmness and viscosity with a reduction in the syneresis rate. The optimal yogurt gel as a nutritious diet not only provided the highest organoleptic scores but also maintained its storage-related quality with the lowest mold/yeast growth and free-radical oxidation changes}, issn = {2310-2861}, doi = {10.3390/gels8090551}, url = {https://macau.uni-kiel.de/receive/macau_mods_00003024}, url = {https://doi.org/10.3390/gels8090551}, file = {:https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/macau_derivate_00004171/gels-08-00551-v2.pdf:PDF}, language = {en} }