Transglutaminase-Induced Free-Fat Yogurt Gels Supplemented with Tarragon Essential Oil-Loaded Nanoemulsions: Development, Optimization, Characterization, Bioactivity, and Storability

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.

Impact of Storage Conditions of Yogurt Dry Ingredients on the Physicochemical Properties of the Final Product

“…The dynamic rheological properties, ultrasound viscosity as well as yogurt firmness increased for the yogurt dry ingredients stored at a lower temperature for a shorter period of time (Table 5). The highest values of yogurt firmness (0.209 N), ultrasound viscosity (369 mPas•gcm −3 ), and storage modulus (22.8 Pa), and the lowest value of tan delta (0.261) were observed in yogurt obtained from dry ingredients stored for 2 weeks at 5 • C. Interestingly, similar yogurt firmness values were observed by Gharibzahedi et al [39], applying the penetration test method. There was a strong correlation between the firmness of yogurt and ultrasonic viscosity (R 2 = 0.98) (Table 6).…”

Transglutaminase in Foods and Biotechnology

“…TGM was first isolated from S. mobaraensis in 1989, and later found in many other strains, listed in Table 3. Microbial TGM from S. mobaraensis is used widely in different food industries, where it is applied in the reconstruction and manufacturing of meat, texturization of dairy products (yoghurt [42,[89][90][91][92] and cheese [42,[93][94][95][96]), or in different materials sciences, where it is used for the stabilization of wool and leather [97,98]. Due to the various applications of TGM, different grades of enzyme are available commercially.…”

Recent Advances in Dietary Sources, Health Benefits, Emerging Encapsulation Methods, Food Fortification, and New Sensor-Based Monitoring of Vitamin B12: A Critical Review

“…These include heightened physical stability, exceptional optical clarity, heightened aqueous solubility, and notably improved bioavailability, both in vitro and in vivo, of bioactive compounds [111][112][113][114][115]. As such, NEs hold great promise as a vehicle for more effective delivery of functional ingredients and pharmaceuticals [116,117].…”