[3Ap01-12] 食品機能　その他食品機能

3:00 PM - 3:15 PM JST(6:00 AM - 6:15 AM UTC)

[3Ap04] Effects of Different Processing Methods on Mucosal IgA Production Induced by Resistant Starch-Rich Rice

*Sayaka MATSUMOTO¹, Ayaka NOGUCHI¹, Shinichi KITAMURA², Kenji MATSUMOTO¹ (1. Ishikawa Prefectural University, 2. Osaka Metropolitan University)

Keywords:

Resistant starch,IgA,Rice,Processing method

Objective:Resistant starch (RS) is a type of starch that escapes digestion in the small intestine and reaches the large intestine, where it promotes the production of immunoglobulin A (IgA), a key component of mucosal immunity. This study aimed to investigate the effects of steaming and roasting on RS-rich WE rice and their impact on mucosal IgA production in mice.Methods:WE brown rice was processed by steaming and roasting. Each processed rice sample was incorporated into the AIN-93G diet to achieve a final RS content of 2%. As a control, steamed waxy-type brown rice (RS-free) was used. Eight-week-old male BALB/cAJcl mice (n = 7) were fed these diets for 8 weeks. Fecal bacterial counts were measured at week 7, and feces were collected over 2 days in week 8. After fecal collection, mice were euthanized using CO₂. Short-chain fatty acid (SCFA) levels in the cecum and IgA concentrations in feces, plasma, lungs, and submandibular glands were analyzed.Results:Fecal IgA levels were significantly increased in both the Steamed and Roasted groups, with a greater increase observed in the Roasted group. However, no significant differences were found in IgA concentrations in plasma, lung, or submandibular glands among the groups. Cecal acetate and butyrate levels were significantly elevated in both processed groups, whereas propionate increased only in the Roasted group. Fecal bacterial counts were also significantly higher in the Roasted group alone. These findings suggest that processed WE rice enhances intestinal immune responses and that processing methods influence the immunomodulatory functionality of RS.