Heat treatments of defatted soy flour: impact on protein structure, aggregation, and cold-set gelation properties

INGRASSIA, ROMINA; PALAZOLO, GONZALO G.; WAGNER, JORGE R.; RISSO, PATRICIA

Food Structure

Elsevier Q1 a la fecha de publicación

Año: 2019 vol. 22

2213-3291

Q1 según Scimago a la fecha de publicaciónThis study reveals thatmildheat treatments of defatted soy flour promote Maillard reaction and modifyits protein techno-functional propertiessuch assolubility, aggregation,and cold-set gelation.Glycation was promoted by treatments of defatted soy flour (DSF) at 60ºC for12, 24 and 48 h with and without relative humidity control (RHC and WRHC, respectively) at 79%. All samples presented a significant increase of glycation extent (GE), reaching the higher value after 48h at RHC.Despite all samples presented a similar protein denaturation degree, theGE increment was accompanied bya decrease of antitrypticactivity.Protein solubility (PS) of DSF remained constant for treated samples WRHC. However, PS decreased progressively with thetreatment time at RHC. SDS-PAGE of soluble proteins revealed a positive relation between band intensities and PS. Despite sample dispersions showed a protein particle size increment with treatment time, further aggregation after heat-treatments at 100ºC produced a similar protein size distribution among samples.Rheological and microstructural studies of cold-set gels of samples obtained WRHC revealed no changes in the maximum elastic modulus (G?max) and a slight increase of its pore sizes. However, samples obtained with RHC showed cold-set gels with a progressive G?max decrease with the treatment time, which could be related to a coarser gel microstructure. In the more extreme condition, the sample obtained after 48 h at RHC showed a total loss of gelation capability. These results can be used to address the developmentof new tofu-like food products with different rheological properties.