Diet rich in phenolics would potentially associate with multiple health benefits. Response surface methodology (RSM) was introduced to optimize the process of ultrasound- and microwave-assisted extraction of bound phenolics from the bran of a newly developed black wheat breeding line Jizi439 and then compared with the traditional alkaline method. The optimum conditions were found to be 66 °C, 48 min, and power 240 W for ultrasound-assisted extraction (UAE), and 120 s, power 420 W for microwave-assisted extraction (MAE), respectively. Total bound phenolic contents (TBPCs), determined by Folin-Ciocalteu reagent, were 8466.7 ± 240.9 μg gallic acid equivalents per gram (μg GAE/g) bran for UAE and 8340.7 ± 146.7 μg GAE/g bran for MAE under optimized conditions, which were both significantly higher than that of the traditional method (5688.9 ± 179.6 μg GAE/g) (p < 0.05). Antioxidant activities (AAs) were determined by DPPH and ABTS methods. UAE extracts showed the highest DPPH scavenging activity (77.5 ± 0.9%), while MAE extracts showed the highest ABTS scavenging activity (72.1 ± 0.6%). Both were significantly higher than that of the traditional method (69.6 ± 1.1% for DPPH and 65.9 ± 0.5% for ABTS) (p < 0.05). Total bound phenolics (TBPs) profiles were further analyzed by HPLC, and results indicated that ferulic acid was dominant, followed by vanillic acid and p-coumaric acid. The contents of each identified individual phenolics were significantly increased by ultrasound and microwave. In conclusion, UAE and MAE were comparable with each other in TBP yields and AAs; however, when taking operation time and energy consumption into consideration, MAE was more efficient than UAE. Our study suggested efficiency extraction methods for further use of bound phenolics as a healthy food ingredient.

Jizi439, a newly developed black wheat breeding line, was reported to effectively regulate blood glucose, which may potentially be associated with its intrinsic high level of phenolic compounds (PCs). To maximize the PCs yield and thereby enhance their antioxidant activity, orthogonal experiments were designed in sequence for extrusion of Jizi439 black wheat bran (BWB) powder and followed by the extraction of PCs assisted with ultrasound technique. White wheat bran was used as a control. The optimum condition for extrusion was 110 °C, 25% feed water content, 140 rpm screw speed; meanwhile, 50 °C, 40 min, 35 kHz ultrasonic frequency, 300 W ultrasonic power for ultrasound-assisted extraction (UAE). Total phenolic content (TPC) as determined by Folin–Ciocalteu method was 2856.3 ± 57.7 μg gallic acid equivalents (GAE) per gram of dry weight (DW) of phenolic extract; meanwhile, antioxidant activity (AA) in terms of DPPH radical scavenging ratio was 85.5% ± 1.1% under optimized conditions, which were both significantly higher than the control. Phenolic acids except for gallic acid, as well as flavonoids, including luteolin and apigenin were increased by extrusion and ultrasound, as suggested by HPLC results. In conclusion, our study would provide a valuable reference for processing Jizi439 BWB before making or commercially utilize it into health-related food products.

Frozen staple food, attributed to its favorable taste and convenience, has a promising development potential in the future. Frequent freezing and thawing, however, will affect its quality. This study simulated several freeze–thaw cycles (FTC) that may occur during the cold chain process of frozen oatmeal cooked noodles (FOCN) production to consumption. The quality changes and their mechanisms were elucidated using methods such as differential scanning calorimetry (DSC), low-field nuclear magnetic resonance (LF-NMR), Fourier-transform infrared spectroscopy (FTIR), confocal laser scanning microscopy (CLSM), texture analysis, and sensory evaluation. The freezable water content of the FOCN decreased because of the FTC treatment, and the relative content of total water in FOCN also decreased accordingly. The increase in β-Turn after FTC induced disorder in the secondary structure of proteins, causing the protein microstructure to become loose and discontinuous, which in turn reduced the water-holding capacity of FOCN. Additionally, FTC reduced the chewiness and sensory score of FOCN. This research will contribute a theoretical foundation for optimizing the cold chain process.

Parboiled rice can effectively retain Se during milling. In this study, Se-enriched rice grains were sprayed with three different concentrations of bioSeNPs fertilizer on the leaves at heading stage and then processed into parboiled and milled rice. The aim was to investigate the effects of parboiling on Se speciation, texture, microstructure, taste, and flavor of cooked rice. The results showed that parboiling enhances the total Se content by making the bran more difficult to remove. At milling for 40 s, selenomethionine (72.6 %-80.1 %) is predominant Se speciation. Parboiled rice exhibited higher hardness, reduced stickiness, with only minor differences in chewiness. The results regarding cooking quality and microstructure indicated that parboiling restricts starch dissolution during cooking, while the protein remains distributed within starch cell gaps. The parboiling enhances umami and flavor while maintaining the original taste and flavor profile. This work provides valuable insights for application of Se-enriched rice in parboiled rice.

Watermelon seeds are readily accepted even after selenium enrichment, thereby potentially helping meet daily selenium requirements of adults. However, no existing studies have elucidated the molecular-level metabolic changes in watermelon seeds induced by selenium enrichment. In this study, UPLC-MS/MS was employed to identify and quantify metabolite alterations in watermelon seeds. A total of 1036 metabolites were identified, and 81 differentially expressed metabolites (DEMs) being screened out. Gene identification and expression analysis were conducted using the Illumina NovaSeq 6000 platform. A total of 18,686 genes were identified, and 999 differentially expressed genes (DEGs) were screened out. Joint omics analysis revealed that DEMs and DEGs were enriched in 25 pathways, primarily involving flavonoid biosynthesis and amino acid metabolism. Genes like PAL, 4CL, CYP73A, and CHS were the key genes for the biosynthesis of flavonoids under selenium treatment, resulting in a significant decrease in the expression level of chlorogenic acid in the pathway. In the amino acid metabolism pathway, genes such as AGXT2, glnA, speE, and thrC played crucial roles, causing significant alterations in the expression levels of metabolites such as L-Alanine, Threonine, and Tryptophan in the pathway. This study provides a theoretical basis for developing watermelon seeds with both selenium-enrichment function and balanced nutrition. The selenium enrichment process can be improved by regulating the expression levels of key genes such as PAL and AGXT2, and the amino acid composition can also be regulated.