Binding of aromatic compounds with soy protein isolate in an aqueous model: Effect of pH

Abstract

Interactions of the flavoring compounds hexyl acetate (HxAc), heptyl acetate (HpAc), linalyl formate (LiFo), linalyl acetate (LiAc), geraniol, linalool, limonene, and myrcene with soy protein isolate (SPI) were estimated in pH 3.0, 6.0, and 9.0 aqueous solutions using headspace solid‐phase microextraction gas chromatography–mass spectrometry (SPME–GC–MS). The binding capacity of HxAc, HpAc, LiFo, LiAc, geraniol, and linalool increased in the pH of the medium from 3 to 9. For limonene and myrcene, an unexpected increase in headspace concentration or a “salting‐out” effect was observed. Between pH 3 and 9, better accessibility to the primary hydrophobic sites as a result of a modification to the protein's flexibility was observed. Practical applications SPME method is a technology of dynamic adsorption for flavors. The lowest level of lead be practicably detected in food as low as the practiced concentration of flavors (0.01–0.1 mM) in our study. At low concentrations of flavors, it is close to the actual flavor's concentration of food. In the previous studies, the technology, such as equilibrium dialysis, headspace‐gas phase which need higher concentration of flavors (>0.2 mM). The interaction between flavors and protein has a different binding law at high and low concentrations. As we produced the acid fruit soy protein milk beverage, the off‐flavors present in the beverage were due to the change in the interaction between denature SPI and flavors. The present work is aimed at paving the way for further research to elucidate flavor imbalances in acid fruit soy protein milk beverage.

The science of plant‐based foods: Constructing next‐generation meat, fish, milk, and egg analogs

“…Knowledge of these types of interactions is often useful when designing plant‐based food products. For instance, plant‐based proteins may bind to aromatic flavor molecules in beverages, thereby altering the overall flavor profile (Guo, He, Wu, Zeng, & Chen, 2019; Wang & Arntfield, 2015). In some cases, this would be desirable because it reduces the level of off‐flavors, but in other cases it may be undesirable because it alters the anticipated flavor profile.…”

Binding of dual‐flavour compounds by soy protein isolate in aqueous model systems

“…1e–h). SPI also shows the presence of a hydrophobic surface (Viry et al ., 2018), which may serve as the second binding site for ethyl caprylate and undecanal at high concentrations (Guo et al ., 2019a, 2019b). Feyzi and others had been reported that safranal binding to whey possesses the similar results (Feyzi et al ., 2019).…”

“…(2017) have reported that the ‘salting‐out’ effect of limonene is observed in the case of mixed esters and limonene in aqueous SPI. Using SPME‐GC/MS, the ‘salting‐out’ effects of limonene were also found to be exhibited in aqueous SPI (Guo et al ., 2019a, 2019b). However, based on dynamic coupled column liquid chromatography method, which provides a direct measure of interactions in the liquid through the intermediary phases of total solubility, some studies have reported that limonene has a strong interaction with β‐lactoglobulin (Jouenne & Crouzet, 2000).…”

Study on the Interaction Mechanism Between Soybean Protein Isolates and Lemon Flavor: Isomerization and Degradation of Citral

“…By an 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescent probe method, in the aqueous solution, SPI hydrophobicity was determined with modifications (21). SPI was centrifuged at 12,000 × g, times is 15 min, temperature is 37 • C, the supernatants were diluted in 20 mmol/L citric acid phosphate buffer (pH 5.0-pH9.0), obtain SPI concentrations ranging from 0.1 to 0.002 mg/mL.…”