The increasing global population and consumer demand for protein will render the provision of protein a serious future challenge. The lower environmental impact of insect farming makes the consumption of insects an appealing solution, although consumers in developed countries often respond to the idea of eating insects with disgust. One approach to accustom consumers to insects as part of their diet is through the application of functional insect extracts as food ingredients. Here, the interfacial and emulsion properties of protein extracted from Tenebrio molitor (MP) was investigated in comparison to commercial whey protein (WP). The MP showed higher interfacial activity and faster adsorption kinetics at the oil/water interface. The mean droplet size of high shear processed oil-in-water (o/w) emulsions (20% w/w oil) stabilised with MP assumed a process limited value at the lowest protein concentration, included in this study, of 0.44% w/w based on aqueous phase. Stepwise increase in protein concentration to 0.88%, 1.75% and 2.63% revealed, in the case of WP stabilised emulsions, that the same process limited droplet diameter was reached at 1.75% protein addition. With a view to potential future application of MP as a food emulsifier MP stabilised emulsions were exposed to common formulation and process conditions such as varied pH, salt, heat, chilling and freezing. Except for flocculation after heating to 90 °C and at pH close to the isoelectric point (IEP) of the MP, the microstructure of the emulsions remained unchanged. MP shows promise as a food emulsifier and represents a vehicle for the introduction of insect protein into the diet of societies not accustomed to eating insects

Emulsifying properties of cocoa particles have been investigated in systems containing purified sunflower oil (PSO) and water at varying pH, concentration and source of cocoa particles including cocoa powders (CP), cocoa fibre (CF) and cocoa mass (CM). The effect of cocoa particle source, pH and cocoa particle concentration on emulsion stability was evaluated by following changes in characteristic droplet diameter. Size distributions acquired on the emulsions and aqueous cocoa particle suspensions overlapped. Based on cryo-SEM imaging of the emulsions, isolation of cocoa particle fines and a process of washing the cocoa particles to remove any water soluble molecules, it was concluded that the cocoa particle fines not captured by the small angle laser diffraction method employed for sizing, act as Pickering particles. This research has demonstrated a universal nature of a natural food particle to stabilise oil-in-water emulsions not requiring particle modification or adjusting of the solution properties of the emulsion phases.

In this paper, we demonstrate the functionality and functionalisation of waste particles as an emulsifier for oil-in-water (o/w) and water-in-oil (w/o) emulsions. Ground coffee waste was chosen as a candidate waste material due to its naturally high content of lignin, a chemical component imparting emulsifying ability. The waste coffee particles readily stabilised o/w emulsions and following hydrothermal treatment adapted from the bioenergy field they also stabilised w/o emulsions. The hydrothermal treatment relocated the lignin component of the cell walls within the coffee particles onto the particle surface thereby increasing the surface hydrophobicity of the particles as demonstrated by an emulsion assay. Emulsion droplet sizes were comparable to those found in processed foods in the case of hydrophilic waste coffee particles stabilizing o/w emulsions. These emulsions were stable against coalescence for at least 12 weeks, flocculated but stable against coalescence in shear and stable to pasteurisation conditions (10 min at 80 °C). Emulsion droplet size was also insensitive to pH of the aqueous phase during preparation (pH 3–pH 9). Stable against coalescence, the water droplets in w/o emulsions prepared with hydrothermally treated waste coffee particles were considerably larger and microscopic examination showed evidence of arrested coalescence indicative of particle jamming at the surface of the emulsion droplets. Refinement of the hydrothermal treatment and broadening out to other lignin-rich plant or plant based food waste material are promising routes to bring closer the development of commercially relevant lignin based food Pickering particles applicable to emulsion based processed foods ranging from fat continuous spreads and fillings to salad dressings.

Summary: This study was conducted to determine the effect that a popping head (like a rice cake machine), a low‐shear and low‐water processing technology, has on the concentration of antinutritional factors in chickpeas and red kidney beans. Seeds were popped under several parameters (popping time, sample format and equipment type) and analysed against soaking (1:5 w/v in reverse osmosis water for 24 h), roasting (100 g at 180 °C for 20 min) and boiling (1:5 w/v in reverse osmosis water at 100 ± 1 °C for 1 h) processes. Popping and roasting significantly reduced phytic acid content in chickpeas (6%–22%) and red kidney beans (16%–39%). In contrast, phytic acid content after soaking and boiling was not significantly different to raw seeds. Condensed tannins were significantly reduced in red kidney beans after soaking (74%), boiling (100%) and 4 s popping (28%–42%) treatments and increased in both pulses after roasting (137%) and 8 s popping (21%–47%). Further analysis showed that the soluble phenolic content increased with popping, but total and bound phenolic content was reduced. These results demonstrate that the high temperatures and pressures applied during the popping process effectively reduce antinutritional factors in pulses, compared to conventional processing methods.

Summary: Low‐density expanded starchy products are often desirable, particularly in the snack food industry. Levels of shear and amylose are often deemed crucial factors for expansion. In this study, maize starches containing low (waxy), normal and high levels of amylose were compared after processing. Low shear processing used a popping head (similar to a rice‐cake machine), while high shear (~450 kJ kg⁻¹) samples (pellets and directly expanded) were created using twin‐screw thermomechanical extrusion. Native starches and ground extruded materials (<106 µm) were popped using the same conditions (230 °C, 4 s, water content 12% wwb). All samples tested created fused aerated cakes, which had little or no remaining crystallinity, except for the directly popped waxy sample, which retained ~17% of its original crystallinity. Water absorbances and solubilities were influenced greatly by the starch source and marginally by the amount of processing. On processing, waxy samples showed increased solubility while those with normal amylose content had greater absorption. The densities of all the popped samples were similar despite marked differences in shear regime history and the major variations in the amylose and amylopectin ratios. These results challenge the expected relationships between shear and different starches’ potential to expand.

Sensory lexicons provide an important tool for describing the sensory properties of emerging, unfamiliar foods such as edible insects. This study sought to establish and validate a sensory lexicon for the description and differentiation of edible insects commercially available in Australia and prepared using common preservation and cooking methods (freeze-drying, hot-air drying, roasting, sautéing and deep-frying). Five species were evaluated, including house crickets (Acheta domesticus), yellow mealworm larvae (Tenebrio molitor), king mealworm larvae (Zophobas morio), tyrant ants (Iridomyrmex spp.) and green tree ants (Oecophylla smaragdina). Following generic descriptive sensory analysis methods, a trained panel (n=8) developed a sensory lexicon of 29 aroma and flavour descriptors, and 16 texture descriptors. Vocabulary were then categorised and ordered to generate a sensory wheel. Due to a lack of cross-over in sensory attributes between species, sub-categories of species-specific vocabulary were also generated for each insect. The lexicon enabled sensory profiling of commercially available edible insect samples which revealed large variation in aroma, flavour, and texture attributes due to both species and preparation method. This work provides a platform for development of a globally relevant edible insect sensory lexicon. International collaboration will enable expansion of the lexicon for use with other insect species and preparation methods, insect-derived ingredients (such as insect powder, defatted insect powder and textured insect protein) and in different cultural settings. As the industry grows, the applicability of vocabulary for differentiating within species and between competitive products should also be assessed.