Journal Articles

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Author: search.filters.author.Singh HSubject: search.filters.subject.Casein

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    Heat-induced interactions between microfluidized hemp protein particles and caseins or whey proteins
    (Elsevier Ltd, 2025-01) Ma S; Ye A; Singh H; Acevedo-Fani A
    The rising demand for sustainable proteins leads to increased interest in plant proteins like hemp protein (HP). However, commercial HP's poor functionality, including heat aggregation, limit its use. This study explored the heat-induced interactions of hemp protein particles (HPPs) with milk proteins, specifically whey proteins and caseins. Using various analysis techniques-static light scattering, TEM, SDS electrophoresis, surface hydrophobicity, and free sulfhydryl content-results showed that co-heating HPPs with whey protein isolate (WPI) or sodium caseinate (NaCN) at 95 °C for 20 min reduced HPPs aggregation. HPPs/WPI particles had a d4,3 of ∼3.8 μm, while HPPs/NaCN were ∼1.9 μm, compared to ∼27.5 μm for HPPs alone. SDS-PAGE indicated that whey proteins irreversibly bound to HPPs, through disulfide bonds, whereas casein bound reversibly, possibly involving the chaperone-like property of casein. This study proposes possible mechanisms by which HPPs interact with milk proteins and impact protein aggregation. This may provide opportunities for developing hybrid protein microparticles
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    Heat-induced colloidal interactions of whey proteins, sodium caseinate and gum arabic in binary and ternary mixtures
    (Elsevier Ltd, 2013-11) Loveday SM; Ye A; Anema SG; Singh H
    Many food-grade proteins and polysaccharides will aggregate together when acidified or heated, due to electrostatic and hydrophobic interactions. At low concentrations, aggregates are soluble and colloidally stable, and they have potential applications as Pickering emulsifiers and nutrient carriers. Sodium caseinate (SC) and gum arabic (GA) at pH. 7 will form colloidal aggregates when heated, but aggregation is largely reversed on cooling. Whey proteins (in the form of whey protein isolate, WPI) will aggregate irreversibly with GA when they are heated together, but aggregation is often so rapid and extensive that aggregates precipitate. Here we sought to overcome those limitations, and to develop an in situ method for quantifying heat-induced aggregation. Aggregation was measured using temperature-controlled dynamic light scattering equipment and transmission electron microscopy. Combinations of SC, WPI and GA were heated at either pH. 7 or 3.5, and the weight ratio of protein to polysaccharide was held at 1:5 for simplicity. Heat-induced colloidally stable aggregates of SC. +. WPI. +. GA did not dissociate on cooling. Aggregation was measured in situ, both in temperature ramps and with isothermal experiments. In situ measurement allowed us to avoid potential artefacts stemming from the temperature changes and measurement delays associated with ex situ measurements. This work demonstrated how the size and heat-stability of colloidal protein-polysaccharide aggregates can be tailored by judicious selection of proteins, pH and heat treatment.