Effects of edible coating containing nano-emulsion of Aloe vera and eugenol on the physicochemical properties of shrimp during cold storage.

BACKGROUND: Shrimp is nowadays recognized as a rich source of proteins and omega-3 fatty acids. Edible nano-emulsion coatings containing eugenol, as an antioxidant agent, and Aloe vera, as a functional compound, were prepared for the storage of pink shrimp over 7 days at 277 K. Samples of the nano-emulsion were prepared under ultrasonication using 0, 10 and 20 g L-1 of Aloe vera as well as 0, 15 and 30 mL L-1 of eugenol along with Tween 80. RESULTS: Results indicated that the low pH of Aloe vera reduced that of the nano-emulsions while the particle size and turbidity increased with increasing Aloe vera concentration. Moreover, both colour and antioxidant activity of the nano-emulsions were significantly affected by eugenol and Aloe vera concentrations (p < 0.05). Increasing eugenol concentration led to increased nano-emulsion pickup but to reduced lightness. Higher concentrations of Aloe vera significantly (p < 0.05) decreased drip loss, cooking loss, pH rise and oxidation rates but enhanced hardness in the shrimp samples. CONCLUSIONS: The best results were recorded for the nano-emulsion coating containing 30 mL L-1 of eugenol and 20 g L-1 of Aloe vera. The nano-emulsion was successfully able to upgrade shrimp quality over 7 days of cold storage. © 2019 Society of Chemical Industry.

Production of sesame oil oleogels based on beeswax and application as partial substitutes of animal fat in beef burger.

The effect of beeswax (BW) concentration (5, 7.5, 10%) and cooling temperature (4, 25 °C) on the properties of sesame oil oleogel was evaluated and compared with the extracted fats from beef flank and shank. Acid and peroxide values, fatty acid composition, color, texture, thermal properties and crystal morphology were studied. Then, 0, 25 and 50% of animal fat in beef burger were replaced by the oleogel (10% BW, cooled at 4 °C). Proximate composition, texture, color, fat absorption, cooking loss, shrinkage, microstructure, oxidative stability and sensory acceptance were determined for the burgers. Results indicated that acid value and thermal properties of the oleogels were affected by the BW concentration; however, peroxide value and fatty acid profile of the oleogels did not change as a function of the variables. The oleogels had less hardness than the animal fats which in turn decreased the hardness, gumminess and chewiness of the raw burgers to <50% of control sample. This is while cooked burger color did not significantly change. The 11% reduction of cooking loss and 1.6% reduction of fat absorption was considered as pros aspects of the oleogel incorporation to beef burger. However, cooking shrinkage and lipid oxidation increased significantly.

Investigation of stability, consistency, and oil oxidation of emulsion filled gel prepared by inulin and rice bran oil using ultrasonic radiation.

Inulin, rice bran oil and rosemary essential oil were used to produce high quality emulsion filled gel (EFG) using ultrasonic radiation. Response surface methodology was used to investigate the effects of oil content, inulin content and power of ultrasound on the stability and consistency of prepared EFG. The process conditions were optimized by conducting experiments at five different levels. Second order polynomial response surface equations were developed indicating the effect of variables on EFG stability and consistency. The oil content of 18%; inulin content of 44.6%; and power of ultrasound of 256 W were found to be the optimum conditions to achieve the best EFG stability and consistency. Microstructure and rheological properties of prepared EFG were investigated. Oil oxidation as a result of using ultrasonic radiation was also investigated. The increase of oxidation products and the decrease of total phenolic compounds as well as radical scavenging activity of antioxidant compounds showed the damaging effect of ultrasound on the oil quality of EFG.