A rheological characterisation of mashed potatoes enriched with soy protein isolate

High Protein Yangyu jiaotuan (): In Vitro Oral-Gastro-Small Intestinal Starch Digestion and Some Physico-Chemical, Textural, Microstructural, and Rheological Properties

Biomimetic foods are expected to have potential health benefits for the management and prevention of chronic diseases, such as diabetes and cardiovascular disease. In the current research, two commercially available and affordable plant proteins (soy protein isolate-SPI and pea protein isolate-PPI) at two levels (5%, 10%) were added to the Yangyu jiaotuan with the objective of developing a product with reduced glycaemic properties and high protein content while maintaining its original taste and texture. The results showed that several important textural properties such as hardness and chewiness did not change significantly during the refrigerated storage. The storage modulus G' increased with refrigerated storage time for different samples, but there were significant differences among the five samples (with and without protein addition) with respect to frequency dependence during rheological measurements. The in vitro starch digestion experiments showed that the starch hydrolysis of Yangyu jiaotuan decreased considerably (by up to 42.08%) with the increase in PPI content and during refrigerated storage due to starch retrogradation. Protein has protected the microstructure and there was less damage when compared to samples without protein. The bimodal peaks of the particle size distribution curves showed that the newly developed Yangyu jiaotuan contains two different sizes of particles; the smaller particles (~30 μm) corresponded to PPI and starch granules, while the larger particles corresponded to the fragments of the gel network of the starch matrix. Based on the above results, Yangyu jiaotuan mixed with pea protein is a convenient potato staple food product, which complies with the biomimetic potato food very well.

Effects of starch type and concentration on the physicochemical properties of bilayer-stabilized oil-in-water emulsion gels enriched with β-1,3/1,6-D-glucans

BACKGROUND

In recent years, consumer interest in low-fat foodstuffs having a clean label and potential benefits over physiological functions has shown a growing trend. β-1,3/1,6-d-Glucans (BGs) from Saccharomyces cerevisiae have been recognized as excellent immune-modulating compounds. Bilayer-stabilized oil-in-water emulsion gels (BEGs) containing oil droplets covered by myofibrillar proteins-gum arabic membranes were used for entrapping BGs in the inner phase. This study investigated the effects of starch type (waxy maize starch, WMS; potato starch, PS) and concentration (0.0-50 g kg^-1 ) on the physicochemical properties of BEGs composed of: 200 g kg^-1 rapeseed oil, 40 g kg^-1 myofibrillar proteins, 14 g kg^-1 gum arabic, 15 g kg^-1 BGs, 1 g kg^-1 citric acid.

RESULTS

The results showed that BGs were successfully incorporated into the inner phase of BEGs and stability testing showed no separated oil and sediment layer. BEGs were characterized by droplet diameter of d_3,2 = 3.62 ± 0.209 μm and electrical charge of the outer membrane of -27.4 ± 0.257 mV. Increasing starch concentration significantly (P < 0.05) affected values of the studied rheological parameters, but to a greater extent in relation to PS than WMS. Sensory analysis showed that BEGs were most desirable at WMS and PS concentrations of 40-50 and 30-40 g kg^-1 , respectively.

CONCLUSIONS

BEGs containing oil droplets covered by myofibrillar proteins-gum arabic membranes can be used as carriers for insoluble β-glucans and manufactured with a wide range of rheological properties and sensory features desired by consumers. © 2020 Society of Chemical Industry.