Rice protein and other proteins in extruded rice starch
What it found
Adding rice protein, soy isolate protein or whey concentrate protein to extruded rice starch lowered how quickly the starch was broken down in lab tests.
The proteins also blocked an enzyme that digests starch.
What they found
Animal and lab studies
Starch digestibility
All three proteins reduced the starch digestibility of the extruded samples in lab tests.
Enzyme inhibition
Native soy isolate protein and whey concentrate protein suppressed amyloglucosidase activity. All three proteins blocked the enzyme more strongly after being broken down.
Protein-starch interaction
The proteins and starch interacted through non-covalent bonds and formed more ordered structures in the extruded samples.
V-type structure
The extrusion process helped form a V-type structure in the samples.
Slowly digestible starch
The combined amount of slowly digestible starch and resistant starch went up when less amylose leached out and when the 1047/1022 cm-1 ratio was higher.
What the authors conclude
- They say that adding protein during extrusion can affect starch digestibility by interacting with starch molecules and by blocking amylase activity.
- They note that adding protein during extrusion increased the nutritional value of the extrudate and decreased starch digestibility.
- They suggest this could provide new healthy staple food options for groups such as diabetic and overweight people.
How it was done
Protein is the second major component in starchy foods, but how different protein sources affect starch digestibility was still unclear.
They made extruded rice starch with rice protein, soy isolate protein or whey concentrate protein and measured its structure, digestibility and enzyme activity in the lab.
What it can’t tell you
- We summarised it from the abstract only.
- These are lab tests on extruded rice starch, not studies in people.
- They cannot show how these protein and starch mixtures affect blood sugar or health in a person eating them.
Who paid
- Funding
- Funded by Special Support for Post-doc Creative Funding in Shandong Province; Jiangsu Agricultural Science and Technology Innovation Fund; Science & Technology Pillar Program of Jiangsu Province; Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment & Technology (from the PubMed record).
- Authors work at
- Jiangnan University, China; The Affiliated Wuxi Children's Hospital of Nanjing Medical University, China
The paper
- Title
- Effects of rice protein, soy isolate protein, and whey concentrate protein on the digestibility and physicochemical properties of extruded rice starch
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Bao H, Liu Q, Yang Y, et al (2023). Effects of rice protein, soy isolate protein, and whey concentrate protein on the digestibility and physicochemical properties of extruded rice starch. Journal of food science. doi:10.1111/1750-3841.16458PubMed 36704898DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error