Effects of Cellulose Gums on Rheological Interactions in Binary Mixtures of Xanthan Gum and Locust Bean Gum

Optimizing the Rheological and Textural Properties of Chapatti Enriched with House Crickets (Acheta domesticus) Flour Using Hydrocolloids by an I-Optimal Design

The fortification of food with edible insect flour can improve its nutrition profile, but also affect its techno-functional characteristics. In this study, an I-optimal design was applied to improve the rheological and textural properties of wheat flour chapatti containing 10% cricket (Acheta domesticus) flour. More specifically, the impact and optimal addition of hydrocolloids (carboxymethyl cellulose, hydroxypropyl methylcellulose, guar gum and xanthan gum) and water content were studied. For all the responses, the model and model terms were highly significant and showed the different impact of the hydrocolloids on the rheological properties. To evaluate the predictive power of the models, two sets of optimal process settings were chosen: one based on dough properties, and another on baked chapatti. For both sets, the actual responses were in the range of predicted responses for almost all properties. In addition, it was shown that using the settings based on dough properties, the actual responses were not significantly different from the control chapatti, whereas for the settings based on baked chapatti, there were differences in terms of the extensibility of both dough and chapatti. Thus, the I-optimal design is suitable to optimize the dough properties and the baked chapatti when enriching chapatti with cricket flour.

Spray drying of non-chemically prepared nanofibrillated cellulose: Improving water redispersibility of the dried product

Despite increasing interest in using nanofibrillated cellulose (NFC) as food thickener and emulsifier, poor water redispersibility of dried NFC, which is form suitable for practical utilization, significantly limits such applications. Studies are lacking on preparation of dried NFC with superior redispersibility. The present study therefore proposed and examined strategies to improve water redispersibility of spray dried NFC via the use of selected co-carriers, i.e., gum Arabic with/without xanthan gum, carboxymethyl cellulose or pectin. Synergistic interactions between NFC and co-carriers, as confirmed by X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra, helped prevent NFC agglomeration during spray drying. All reconstituted spray-dried NFC/co-carriers suspensions exhibited shear-thinning and gel-like behaviors, thus supporting the use of such suspensions as thickener and emulsifier. Spray-dried NFC with 80% gum Arabic and 20% xanthan gum (SD-NFC/GA20XG) resulted in suspension with highest viscosity; the suspension also performed best at recovering viscous characteristics of NFC. Water thickened by SD-NFC/GA20XG had strongest shear-thinning behavior, indicating that SD-NFC/GA20XG suspension resulted in smoothest mouth feel and easiest swallowing. Such observations were supported by XRD patterns of SD-NFC/GA20XG, which suggested that its relative crystallinity was the lowest. Its FTIR spectra also showed the highest intensity of -OH bending and carbonyl bands, which are directly related to water adsorption capability of NFC. Use of reconstituted SD-NFC/GA20XG as emulsifier also resulted in highest stability for oil-in-water (O/W) Pickering emulsion during storage for up to 30 days.

Hydrophobized cellulose nanocrystals enhance xanthan and locust bean gum network properties in gels and emulsions

Locust bean/xanthan gum (LBG/XG) synergistic networks have previously been well studied, with evidence that junction zones between the two polymers result in hydrophobic domains. Here we report on the effect of both hydrophilic and hydrophobic cellulose nanocrystals (CNCs) on the rheological properties of the individual gums, the gum networks, and emulsion gels consisting of the gum network and corn oil. We also take advantage of differences in the autofluorescent spectra for each of the components to map their distribution within the gel and emulsion gel systems. Whilst both types of CNC confer thermal stability to the systems, hydrophilic CNCs induce minor changes in rheological properties of synergistic gels and prove to be detrimental to the stability of the emulsion gels. In contrast, hydrophobic CNCs associate with the LBG/XG network, affecting the rheological response. Their inclusion in the emulsion gel system results in smaller, more homogeneously distributed oil droplets with a resultant increase in the storage modulus by an order of magnitude compared to the CNC-free and hydrophilic CNC systems. We conclude that hydrophobic CNCs play a critical role in stabilising LBG/XG network gels and emulsions.