Effect of casein and inulin addition on physico-chemical characteristics of low fat camel dairy cream

Stabilizing emulsions by ultrasound-treated pea protein isolate - tannic acid complexes: Impact of ultrasonic power and concentration of complexes on emulsion characteristics

This work aimed to investigate the feasibility of stabilizing oil-in-water (O/W) emulsions by ultrasound-treated pea protein isolate-tannic acid (UPPI-TA) complex. The stability and microstructure of the O/W emulsions were evaluated at different ultrasonic powers (0-1000 W) and UPPI-TA complex concentrations (0.25-2.0 wt%). The contact angle (θ) of UPPI-TA was 59.6°, which was suitable for stabilizing O/W emulsions. At an ultrasonic power of 800 W, the droplet size and creaming index (CI) of emulsions decreased, and the apparent viscosity and interfacial protein adsorption content increased with increasing UPPI-TA concentration. In particular, emulsions with 1.5 % UPPI-TA showed the lowest CI, the highest interfacial protein adsorption content and viscoelasticity, as well as the best storage and thermal stability. These results showed that the suitable modifications of ultrasonic emulsification power and particle concentrations were a new potential approach to stabilize the O/W emulsions by ultrasound-treated pea protein isolated-tannic acid complex.

Freeze-thaw stability of Pickering emulsion stabilized by modified soy protein particles and its application in plant-based ice cream

Pickering emulsions are of great interest to the food industry and their freeze-thaw stability important when used in frozen foods. Particles of soybean isolate (SPI) were heat treated and then crosslinked with transglutaminase (TG) enzyme to produce Pickering emulsions. The protein particles produced using unheated and uncrosslinked SPI (NSPI) was used as the benchmark. The mean particle size, absolute zeta potential, and surface hydrophobicity of protein particles produced using heat treatment and TG crosslinking (at 40 U/g) SPI (HSPI-TG-40) were the highest and substantially higher than those produced using NSPI. The thermal treatment of protein particles followed by crosslinking with TG enzyme improved the freeze-thaw stability of Pickering emulsions stabilized by them. The Pickering emulsions produced using HSPI-TG-40 had the lowest temperature for ice crystal formation and they had better freeze-thaw stability. The plant-based ice cream prepared by HSPI-TG-40 particle-stabilized Pickering emulsions had suitable texture and freeze-thaw stability compared to the ice cream produced using NSPI. The Pickering particles produced using heat treatment of SPI followed by crosslinking with TG (at 40 U/g) produced the most freeze-thaw stable Pickering emulsions. These Pickering particles and Pickering emulsions could be used in frozen foods such as ice cream.

Nano casein-pectin complex: exploring physicochemical, organoleptic properties, and LAB viability in skimmed milk and low-fat yoghurt

Protein complexes with a nutritional value, heat stability, and gelling properties with no negative impact on culture viability have promising application prospects in the fermentation industry. The aim of the study was to investigate the possibility of applying physical modification seeking high-protein-fortified yoghurt production using the nano casein-pectin NCP complex as an active colloidal system with enhanced structural and thermal properties and monitor the quality properties of the physicochemical, heat stability, rheological, starter culture viability and sensory evaluation of fortified products comparing with the plain control throughout the cold storage. High-energy ball milling (HEBM) technique was used to produce nanoparticles of casein powder and smaller particles of pectin individually, and particle size and zeta potential was assessed. Deferent Nano casein-pectin (NCP) complex formulations were prepared, their physicochemical properties were assessed including protein quality via Amino Acid Analyzer (AAA), viscosity, thermogravimetric analysis (TGA), and then used in fortification of skimmed milk and low-fat yoghurt to monitor the fortification effects. The particle sizes showed to be ≈166 nm and 602.6 nm for nano-casein and pectin, respectively. Milk fortification with the NCP complex has significantly increased the nutritional value represented in increased protein content (7.19 g/100 g in NCP5); Ca, P, and S content (2,193.11, 481.21, and 313.77 ppm); and amino acid content with first limiting amino acids; histidine (0.89 mg/g), methionine (0.89 mg/g), and low content of hydrophobic amino acids (HAAs) may cause aggregation. NPC fortification enhanced physicochemical properties announced in enhanced viscosity (62. mP.s in NCP5) and heat stability (up to 200°C) compared with control skimmed milk (SM). NCP yoghurt fortification significantly increased protein content to 11 mg/100 g in T5, enhanced viscosity to 48.44 mP.s in T3, decreased syneresis to 16% in T5, and enhanced LAB viability which was translated in preferable sensorial properties. Applying fortification with nanoparticles of the casein-pectin (NCP) complex balanced the amino acid content and improved physicochemical, rheological, nutritional, and sensorial properties and LAB viability, which can be recommended further in functional food applications.

Thickening mechanism of recombined dairy cream stored at 4 °C: Changes in the composition and structure of milk protein under different sterilization intensities

This work elucidates the mechanism involved in the effect of varying sterilization intensities on RDC thickening via comparative analysis of the changes in the composition and structure of RDC interfacial protein after storage at 4 °C and at 25 °C. The results showed that pasteurized RDCs (75 °C for 16 s, 90 °C for 5 min) and high-temperature sterilized RDCs (105 °C for 3 min, 115 °C for 7 min and 121 °C for 7 min) did not thicken during storage at 25 °C, and had lower viscosities and higher Ca²⁺ concentrations than those stored at 4 °C. Whey protein (WP) aggregates were found to have been adsorbed at the interface of high-temperature treated RDCs stored at 4 °C, leading to the aggregation of fat globules and, consequently, reversible thickening. However, high-temperature sterilized RDCs underwent into irreversible thickening at 10 d, 7 d and 3 d. This phenomenon was attributed to the large amount of heat-induced whey protein and κ-casein complex that was absorbed on the oil-water interface, with Ca²⁺ bonded to form bridging flocculation, which altered the secondary structure of the interfacial protein to one with increased β-sheet content and decreased random coil content.

Ultrasound-modified interfacial properties and crystallization behavior of aerated emulsions fabricated with pH-shifting treated pea protein

The interfacial properties of pea protein isolate (NPP) were modified by pH12-shifting (BPP) and ultrasound treatment as a substitute for skimmed milk powder (SMP) in ice cream. The physicochemical properties and fat crystallization in emulsions before and after whipping were analyzed. Compared with SMP, the BPP emulsion displayed superior stability with small particle size and high viscosity. Fat clusters were observed in both SMP and BPP emulsions, which may promote the puncture and protrusion of fat crystals within droplets and lead to partial coalescence to allow air bubble entrapment. Aeration activity of BPP in cream was 1.5-fold that of NPP. Although the overrun value was smaller than SMP cream, the BPP cream retained the stable shape and had a slow melting rate due to its interactive dimensional network of fat. Ultrasound treatment was found to promote fat crystallization of emulsions, leading to the improved stability of final products.