Kevin Sutton

Knowledge of how protein incorporation affects the rheological behavior of plant‐based, high‐protein food inks and their 3D printing fidelity remains limited, especially in the absence of flow enhancers and stabilizers that typically mask the individual contributions of core components. This study establishes quantitative relationships between ink composition, rheological properties, and printing performance in wheat–pea protein ink systems. Pea protein isolate (PPI) was incorporated into wheat flour (WF)‐based inks across a range of water contents (45%–65%), with PPI replacing WF on a dry‐mass basis (PPI:WF ratios ranging from 0:100–35:65). Increasing the PPI:WF ratio increased the viscoelastic modulus and post‐shear viscosity, enhancing self‐supporting capacity but reducing viscosity recovery post‐shear. At elevated temperatures (from 20°C to 50°C), a significant increase in the loss factor (tan δ ) reduced the fidelity of 3D printing, indicating the temperature dependency of WF‐PPI inks. The highest 3D printing fidelity was achieved at 20°C with a 25% PPI incorporation and a water content of 50% of the total mass. These findings demonstrate that the 3D printing fidelity of high‐protein inks is governed by a combination of viscoelastic, shear‐recovery, and thermal response properties. The absence of flow enhancers and stabilizers further provides a well‐defined model system for discovering the contributions of individual protein and carbohydrate components to ink rheology and printability.

Pulsed electric field (PEF) and probiotic fermentation affected the nutritional and functional qualities of an oat-pea based yoghurt alternative.

Apples and pears are among the most popular and frequently consumed fruits worldwide. The polyphenol and dietary fibre components of these fruits are known to influence the gut microbiota and the subsequent human health outcomes. This study investigated the effects of New Zealand grown apples and pears with differing polyphenol contents on the structure and function of the human gut microbiota. Five apple and two pear cultivars underwent in vitro human digestion and microbial fermentation. Samples taken at 0 and 18 h were analysed for changes in pH, microbial composition, and organic acid production. The change in pH after faecal fermentation was influenced by the type of fruit (apple or pear), with lower pH being observed in the apples. Significant apple or pear cultivar effects were observed for the gut microbiome and organic acid production. The apple cultivar ‘Golden Hornet’ produced the least butyrate and the greatest microbial alpha diversity, while the pear ‘PremP009’ showed greater butyrate production with increases in a butyrogenic species (Acidaminococcus intestini). Further studies are needed to investigate the effect of cultivar and type of fruit on nutrient absorption and microbial fermentation and the impact of these on human health.

Plant proteins are increasingly incorporated into food products to enhance their nutritional value. However, little is known about how this alters the textural perceptions of such products. This study investigated the substitution of up to 35% wheat flour with pea protein isolate (PPI) into pasta sheets to determine how this influenced texture. Furthermore, an in vivo human mastication test (n = 116 participants) was conducted to evaluate oral tactile perceptions (perceived firmness, stickiness, and brittleness) and chewing time associated with PPI-containing pasta. Cooked pasta hardness decreased from 145 to 96 N at 5% PPI substitution due to the disruption of gluten network but increased to 144 N at 15–25% PPI substitution, indicating a stronger protein network at higher PPI substitution levels. In vivo, pasta substituted with 25% PPI required a shorter chewing time and was perceived as less firm, less sticky, and more brittle than wheat flour-only pasta. Regardless of pasta samples, fast chewers (average chewing time ≤13 s) were better at recognizing differences in pasta firmness, while slow chewers (>13 s) were more sensitive to changes in stickiness and brittleness. The results obtained in this study could contribute to the design of protein-rich pasta tailored to populations with specific texture requirements (e.g., softer texture for the elderly).

Plant-based foods are being increasingly favored to feed the ever-growing population, but these need to exhibit improved nutritional value in terms of protein quality and digestibility to be considered a useful alternative to animal-based foods. Germination is essential for plant growth and represents a viable method through which the protein quality of plants can be further improved. However, it will be a challenge to maintain efficient rates of germination in a changing climate when seeds are sown. In the context of the indoor germination of seeds for food, consumption, or processing purposes, a more efficient and sustainable process is desired. Therefore, novel techniques to facilitate seed germination are required. Pulsed electric fields (PEF) treatment of seeds results in the permeabilization of the cell membrane, allowing water to be taken up more quickly and triggering biochemical changes to the macromolecules in the seed during germination. Therefore, PEF could be a chemical-free approach to induce a stress response in seeds, leading to the production of secondary metabolites known to exert beneficial effects on human health. However, this application of PEF, though promising, requires further research to optimize its impact on the protein and bioactive compounds in germinating seeds.

The objective of this study was to evaluate the effect of pulsed electric fields (PEF) on the in vitro starch digestibility properties of oat flour. A wide range of PEF process intensity was investigated (electric field strength between 2.1 and 4.5 kV/cm and specific energy inputs between 52 and 438 kJ/kg using 20 μs square wave bipolar pulse at 100 Hz). The results revealed that PEF applied at a high electric field strength and energy 421 kJ/kg at any field strength intensities raised the RDS (from 15% to 19–20%), but the rate of starch digestion was not affected (maintained at 3.3–3.7 × 10⁻² min⁻¹ vs. untreated at 3.8 × 10⁻² min⁻¹). Further analysis of the structure, particle size, and thermal stability of PEF-treated oat flour through fractionation into three distinct flour segments revealed that PEF could cause major modifications in the particle size, damage and aggregation of starch granules, and destruction of the long- and short-range ordered structures of starch. Data gathered in this study indicate that PEF treatment can be a reliable strategy to modulate the in vitro starch digestibility of oat flour, either by reasonably slowing down the digestion rate or enabling a slightly higher amount of starch to be readily accessible by digestive enzymes without affecting the digestion rate.