Distribution and in vitro availability of selenium in selenium-containing storage protein from selenium-enriched rice...

Area of Science:

• Agricultural Chemistry
• Food Science
• Biochemistry

Background:

• Selenium (Se) enrichment in rice is crucial for human nutrition.
• Understanding Se distribution and optimizing extraction are key for bioavailability.
• Organic Se forms are generally more bioavailable than inorganic Se.

Purpose of the Study:

• To determine Selenium distribution in Se-enriched rice.
• To optimize extraction methods for Se-containing proteins.
• To assess the in vitroSe availability of the extracted Se-protein product.

Main Methods:

• Orthogonal analysis was used to optimize Se-protein extraction conditions.
• In vitro gastrointestinal digestion simulated Se bioavailability.
• High-performance liquid chromatography (HPLC) or similar techniques likely used for Se speciation.

Main Results:

• Selenium was predominantly found as organic Se (97.15%), with glutelin containing the highest amount (31.3%).
• Optimal extraction conditions were identified: 20:1 volume-to-weight ratio, 0.08 M NaOH, 3 hours at 35°C.
• The optimized method produced a Se-rice protein product (83.5% protein, 9.09 µg/g Se).
• This product digested into low molecular weight peptides, including selenomethionine (52.3% of total Se).

Conclusions:

• Se-enriched rice primarily contains organic Se, mainly in the glutelin fraction.
• Optimized extraction efficiently yields a high-protein Se product.
• The Se-protein product demonstrates good in vitro digestibility, releasing bioavailable selenomethionine.