With an increasing incidence rate, ulcerative colitis (UC) is an idiopathic inflammation of the colon causing diarrhea and blood in the stool. Existing studies have shown that oxidative stress is an important factor leading to UC, while superoxide dismutase (SOD) has a certain effect on relieving UC symptoms. To improve its bioavailability, superoxide dismutase (SOD) was self-assembled into nanoparticles (ΔSOD) by heating it. The activity, transmembrane capacity and radical scavenging capacity of ΔSOD were significantly better than those of native SOD. ΔSOD liposomes (L-ΔSOD) were prepared by reverse-phase evaporation and orally administered to mice with UC. The results showed that compared with the positive control and model groups, L-ΔSOD significantly ameliorated UC, reduced disease activity index (DAI) score, restored the morphology of colon tissue, increased the length of colon, reduced the density of colon and spleen coefficient, and restored the integrity of mucosal epithelium. Besides, L-ΔSOD could reduce the contents of malondialdehyde (MDA) and pro-inflammatory factors in colon tissue and increase the levels of glutathione peroxidase (GSH-Px) and tight junction protein mRNA expression. These results confirmed that oral L-ΔSOD has a good ameliorative effect on UC, which will lay the foundation for the application of SOD in promoting human health.

Instant rice with added coarse grain (IR/CG) is a new type of coarse grain product which is self-heating and convenient to eat and has the nutritional value of coarse grains. However, its health effects are not clear yet. Therefore, in this study, the effect of IR/CG on glucose and lipid metabolism was explored in mice with type 2 diabetes mellitus (T2DM) induced by high fat diet (HFD) combined with intraperitoneal injection of streptozotocin. The mice were fed on HFD alone (model), its mixture with IR/CG in different ratios: 25% (low-dose IR/CG, IR/CG-L), 50% (medium-dose IR/CG, IR/CG-M), and 75% (high-dose IR/CG, IR/CG-H), IR/CG alone, or a basal diet (control). During the dietary intervention, the body mass, fasting blood glucose, food intake and glucose tolerance of the mice were measured. After the IR/CG intervention for four weeks, the organ coefficients were calculated, and the pathological changes in liver and pancreas tissues were examined by hematoxylin and eosin (HE) staining. Fasting insulin levels, blood glucose and lipid levels, and proinflammatory cytokines levels were determined. The experimental results showed that dietary supplementation of IR/CG improved blood glucose and lipid levels in T2DM mice to different extents, and this effect was more prominent in the IR/CG-H and IR/CG groups. In addition, IR/CG-H and IR/CG significantly mitigated insulin resistance, decreased insulin secretion, glucagon and HbA1c levels, and reduced oxidative stress injury and inflammatory cytokine levels in T2DM mice. By analyzing the organ index and pathological sections of liver and pancreas tissues, it was found that IR/CG intervention could effectively alleviate liver steatosis and partially restore the structure of the pancreatic islets in mice. Therefore, the substitution of high-fat diet by IR/CG has a significant effect on regulating blood glucose and lipids in T2DM mice, which can provide a theoretical basis for the development of self-heating rice products and functional foods with coarse-grain.

To explore the formation pattern of 5-hydroxymethylfurfural (5-HMF) and the safety of dried longan during processing and storage, this study monitored the changes in 5-HMF content during drying and storage at different temperatures. The changes in the contents of reducing sugar, total acid and total free amino acid and browning degree during processing were determined and their correlation with 5-HMF content was analyzed. Moreover, the safety of dried longan was analyzed using in vitro simulated digestion experiments and a Caco-2 cell model. The results showed that as the drying temperature increased above 85 ℃, the 5-HMF content significantly increased (P < 0.05). The 5-HMF content was positively correlated with the total acid content and browning degree, but negatively correlated with the contents of total free amino acid and reducing sugar. During storage at different temperatures (4, 25, and 37 ℃), the 5-HMF level first increased and then decreased with storage time, and showed different increasing trends under different storage conditions. At 25 ℃, the 5-HMF content began to decline earliest and was lower overall. The 5-HMF content briefly increased during oral digestion, but significantly decreased during gastric and intestinal digestion. The water extract of dried longan inhibited the absorption of 5-HMF and counteracted the cytotoxicity of 5-HMF at 24 mmol/L to Caco-2 cells. These results indicated that optimizing the drying and storage conditions of dried longan can reduce the content of 5-HMF. In the case of normal consumption, the human digestive tract can reduce 5-HMF in dried longan, improving its safety for consumption.