To investigate the physicochemical, rheological and sensory characteristics of a new formulation proposed for low‐fat mayonnaise, nine mayonnaise samples containing different compositions of NFC (nanofibrillated cellulose), guar gum and CMC (carboxy methyl cellulose) were prepared and compared to commercial low‐fat mayonnaise (30% fat) as the control sample. The stability of emulsions containing NFC or NFC/CMC was observed to be lower than the commercial control sample where NFC/guar, due to its viscosifying effect, presented higher stability levels. Regarding to the diffraction behavior of particles, samples containing (0.5%/0.25%/0%), (0%/0.5%/0%) and (0%/0%/1%) NFC/guar/CMC were observed to have the smallest particle sizes and consequently lightest colors. No significant difference was recognized between the taste of treated mayonnaise samples and commercial control sample. The positive effect of NFC on the mouth‐feel features in organoleptic properties was also confirmed. As expected, firmness and cohesiveness in the emulsion samples with smaller droplet sizes and higher levels of monodispersity were observed to be higher. NFC/guar (0.5%/0.25%) sample presented higher elastic properties compared to NFC/CMC (0.5%/0.5%) which was ascribed to the neutral nature of guar adsorbed on NFC. Practical Applications Over the past few decades, along with the growing public awareness of the health risks associated with saturated fat (overweight, heart and blood vessel diseases or cancer), the accepted dietary wisdom has been shifted to low‐fat dieting through minimizing the intake of fat in particular. This has led to a dramatic increase in the demand for low‐fat food products. Physically Modified Cellulose, i.e., NFC and MCC, are conventionally used in reduced‐calorie food products to improve rheological and texture characteristics. This study investigates physicochemical, rheological and sensory characteristics of low fat mayonnaise by addition of NFC, guar gum and carboxy‐methyl cellulose.

In this research, simultaneous contribution of konjac-mannan (0.3%), xanthan (0.3%), and tragacanth (0.3%) gums in tomato ketchup was investigated comparing the physicochemical, rheological, texture, and sensory properties with the control sample containing 0.3% xanthan gum. Samples selected through viscosity and syneresis evaluation of the nine prepared samples were analyzed by color, flow behavior, frequency sweep, particle size, texture, and sensory experiments. Results indicated that increasing xanthan concentration did not have any significant effect on the apparent viscosity while considerable improvement was observed in the physical stability of ketchups containing konjac-mannan/xanthan ascribed to smaller particles with larger contact surfaces encouraging gel network formation. Highest a* and a*/b* was observed for konjac-mannan/xanthan (0.075%/0.225%) in which formation of hydrated gel granules of gums intensifies light diffraction due to the decreased particle size. This synergistically formed viscous three-dimensional gel network is responsible for the highest cohesiveness and gumminess of the same sample between the ketchup formulations containing two gums. Organoleptic properties of ketchup samples containing konjac-mannan/xanthan showed no significant difference with the control sample. PRACTICAL APPLICATIONS: Development of modern food technologies along with the lifestyle changes over the past few decades and grown public awareness of the relevance between health and nutrition have considerably increased the consumption of ready meals containing low-fat and fiber-rich functional condiments. Ketchup is a popular sauce thickened with tomato pulp powder, potato or corn starch, modified starch, and severally available hydrocolloids such as carboxymethyl cellulose, xanthan, guar, and locust bean gum. In this research work, mixtures of konjac-mannan and xanthan/tragacanth hydrocolloids are used to produce new ketchups with improved physical and rheological properties and lower prices.