Effects of varying degree of milling (DOM) (0–22%) on the bran layer structure, physicochemical properties, and cooking quality of brown rice were explored. As the DOM increased, bran degree, protein, lipid, dietary fiber, amylose, mineral elements, and color parameters (a* and b* values) of milled rice decreased while starch and L* value increased. Microscopic fluorescence images showed that the pericarp, combined seed coat-nucellus layer, and aleurone layer were removed in rice processed at DOM of 6.6%, 9.2%, and 15.4%, respectively. The pasting properties, thermal properties, and palatability of rice increased as the DOM increased. Principal component and correlation analysis indicated that excessive milling lead to a decline in nutritional value of rice with limited impact on enhancing palatability. Notably, when parts of aleurone cell wall were retained, rice samples exhibited high cooking and sensory properties. It serves as a potential guide to the production of moderately milled rice.

For a better understanding of the difference in functional components and functions among different parts of highland barley bran,the contents of protein,β-glucan and polyphenol,antioxidant activity,and alkyl radical intensity in highland barley bran with various milling rates were compared.The results showed that the contents of total protein,albumin,globulin,glutenin,free polyphenol,bound polyphenol,free flavone,bound flavone and condensed tannin first increased and then decreased with increasing milling rate.Protein mainly existed in bran flour with a milling rate of 17.74％and 19.22％.Bran flour with 9.7％milling rate had the highest phenol content,and the trend in antioxidant activity was consistent with that in the content of phenols.The contents of β-glucan and gliadin increased from outside to inside,and reached the highest value at a milling rate of 25.99％.Alkyl radical intensity was significantly higher at 1.54％-5.84％milling rates than at 7.67％-25.99％milling rates,indicating a higher susceptibility to oxidation.The findings of this study provide a theoretical basis for the deep processing of different layers of highland barley bran.

This study aimed to investigate the phase behavior of chitosan (Cs) - highland barley gliadin (HBG) complex and application in stabilizing Pickering emulsion. The turbidity results indicated that the insoluble complex was more likely to form between Cs and HBG at the higher concentration of HBG and NaCl (the optimal concentration ratio (1:40). The results of scanning electron microscope (SEM) and surface tension showed that the insoluble complex formed between Cs and HBG at pH 4.0 had better solubility and surface wettability. The results of isothermal titration calorimetry (ITC) indicated that each molecule of Cs could interact with 1, 2, and 7 HBG molecules under pH 2.5, 3.2, and 4.0, respectively. In addition, the Pickering emulsion stabilized by Cs-HBG complex showed great rheological properties, thermal stability and storage stability under the conditions of pH 4.0, concentration ratio (Cs:HBG) of 1:40, and oil fraction of 50%. These researches would contribute to the better utilization of polysaccharide-hydrophobic protein complex in the food and pharmaceutical fields.

In this work, the effect of incorporating highland barley prolamin (HBP) on the properties of highland barley β-glucan (HBBG) films was investigated. Besides, the improvement of black rice bran anthocyanins (BRA) on intelligence effect of HBBG/HBP film was studies. The addition of HBP enhanced the barrier properties of HBBG film, indicating that the water vapor permeability and oxygen permeability of HBBG film decreased. In addition, the mechanical, thermal, optical properties and water contact angle of HBBG film were also found to be improved by the addition of HBP. The colors of HBBG/HBP/BRA films changed quickly and could be distinguished by eye in different pH solution and ammonia environment due to the abundant anthocyanins in BRA. Furthermore, the stability of anthocyanins in BRA was enhanced through hydrogen bond among BRA, HBBG and HBP. Therefore, HBBG/HBP/BRA films have broad prospects in intelligent packaging.

The impacts of interaction between proanthocyanidin (PC) and decolorized highland barley protein (DHBP) at pH 7 and 9 on the functional and conformational changes in DHBP were investigated. It was shown that PC strongly quenched the intrinsic fluorescence of DHBP primarily through static quenching. PC and DHBP were mainly bound by hydrophobic interactions. Additionally, free sulfhydryl groups and surface hydrophobicity obviously decreased in DHBP after combining with PC. The zeta potential of DHBP–PC complexes at pH 7 increased significantly. A change in the structure of DHBP was caused by interactions with PC, resulting in an increase in the number of β-sheets, a decrease in the number of α-helixes, and a spectral shift in the amide Ⅱ band. Furthermore, the presence of PC enhanced the foaming properties and antioxidant activity of DHBP. Overall, this study suggests that DHBP–PC complexes at pH 7 could be designed as a stable additive, and illustrates the potential applications of DHBP–PC complexes in the food industry.

作者以发芽前后青稞中β-葡聚糖、γ-氨基丁酸、游离氨基酸、总多酚等营养成分的质量分数以及β-葡聚糖酶、蛋白酶等酶活性为指标,并结合高血压大鼠收缩压、心率等指标的变化情况,研究萌发对青稞营养品质和其降血压效果的影响.结果发现,青稞β-葡聚糖、淀粉和蛋白质质量分数随萌发时间延长而降低,γ-氨基丁酸质量分数在萌发 48h达到最高,总多酚、总黄酮质量分数以及β-葡聚糖酶、淀粉酶和蛋白酶的活力随萌发时间延长而增加.总游离氨基酸质量分数尤其是必需氨基酸质量分数经萌发处理后显著升高(P<0.05),表明发芽能提高青稞营养价值.此外,与青稞相比,发芽青稞更利于降低高血压大鼠的收缩压、心率、血管紧张素Ⅱ和血管生成素(P<0.05),表明发芽青稞有更好的缓解高血压作用.

This study investigates the functional and conformational changes in highland barley proteins (HBPs)-salidroside complexes formed by non-covalent bond interactions. The free sulfhydryl contents of HBPs are decreased from 37.65 +/- 1.90 mu mol/g protein to 18.86 +/- 0.14 mu mol/g protein after binding with salidroside. The fluorescence spectroscopy show that two fluorescence peaks are observed and salidroside enhance the fluorescence intensity of HBPs at the high addition level of salidroside (0.5-1 mmol/g protein). Secondary structure, surface hydrophobicity, and Zeta potential of HBPs are also changed by salidroside with different addition level (0-1 mmol/g protein). HBPs-salidroside complexes exhibit better functional properties (emulsifying and foaming properties) than HBPs, which is probably due to conformational changes in the HBPs. The combination of HBPs and salidroside increase the antioxidant ability of HBPs. Overall, salidroside has the potential to improve the structural characteristics and functional properties of HBPs, especially their antioxidant ability.

To explore effects of decoloration on highland barley proteins (HBPs) aggregation, physicochemical properties, structural characteristics, and functional characteristics of decolorized highland barley proteins (DHBPs) were investigated. In order to compare the aggregation of HBPs, wheat proteins (WPs) were selected as a control group. The solubility, turbidity, particle size and surface hydrophobicity of HBPs increased obviously (P < 0.05) after decoloration, but still lower than WPs. Electrophoretic analysis showed that the bands amount of HBPs and DHBPs were lower than WPs, while decolorization had no effect on the bands amount of HBPs. Moreover, chemical bonds contents of DHBPs were higher than HBPs, but significant lower (P < 0.05) than WPs. The Fourier-transform infrared spectroscope showed that secondary structures of HBPs were more flexible after decoloration. Besides, foaming property, emulsifying property and water holding capacity of DHBPs increased significantly (P < 0.05). To conclude, the aggregation behavior and functional properties of HBPs were improved by the decolorization.

以自发性Ⅱ型糖尿病小鼠(T2DM)为受试对象,给予分别添加了10％青稞和5％,10％,20％发芽青稞的高热能饲料,研究青稞和发芽青稞在降血糖、降血脂方面的活性.结果表明:5％,10％,20％发芽青稞均能降低T2DM的空腹血糖、胰岛素水平、胰岛素敏感指数、血清总胆固醇、低密度脂蛋白和载脂蛋白B含量,提高卵磷脂胆固醇酰基转移酶活性,提高载脂蛋白A含量,从而缓解小鼠体内糖脂代谢紊乱.

The aim of this study was to explore the impact of hypoxia stress germination on qualities of highland barley (HB). The main functional components, physicochemical properties, and cooking qualities of HB were investigated after hypoxia stress germination. Results showed that gamma-aminobutyric acid, total phenols, total flavonoids, essential amino acids, and fragrance components of HB were significantly increased (P < 0.05) after germination. The relative crystallinity, pasting viscosity, breakdown, setback and enthalpy of hypoxia stress germinated highland barley was decreased as compared to ungerminated HB. However, gelatinization temperature, onset temperature, peak temperature and conclusion temperature of HB increased after germination. The micro-cracks presented on the surface of kernel might be the main reason for improvement of cooking characteristics of HB. To conclude, hypoxia stress germination improved the functional nutrients, physicochemical properties, texture, flavor and taste of HB, which might be an effective method to improve the cooking and edible quality of whole grains.

以昆仑15号、黑老鸦青稞、瓦蓝青稞为研究对象,利用分层碾磨技术,将青稞籽粒由外至内分离出七部位粉.对七部位粉的理化指标进行分析,并采用隶属函数法与主成分分析相结合的方法对各部位粉的营养价值进行了综合评价.结果表明,青稞中的灰分、蛋白质、脂肪、多酚和原花青素含量随籽粒由外至内逐层递减,β-葡聚糖含量在第二、第三部位达到最大值.因此,根据营养成分含量分布情况推测第一部位为青稞粉皮层,第二、三部位为糊粉层,第四至第七部位为胚乳层.隶属函数和主成分分析结果表明,在本实验中获得的七部位青稞粉中,第二部位的青稞粉营养价值最高,尤其是蛋白质含量最高.

以青稞种子为原料,采用金属离子、亚硒酸钠和低温胁迫等处理方式,研究不同胁迫方式对青稞籽粒中主要功能性成分β-葡聚糖和γ-氨基丁酸(GABA)含量的影响.实验结果表明:随着发芽时间的延长,青稞籽粒发芽后β-葡聚糖含量呈下降趋势,GABA含量呈现先增加后减少的趋势.5种金属离子(Fe2+、Fe3+、Cu2+、Mg2+、Zn.2+)胁迫萌发青稞籽粒,有利于β-葡聚糖的降解,且抑制了GABA积累.亚硒酸钠胁迫萌发青稞籽粒中β-葡聚糖、GABA含量低于对照组,表明亚硒酸钠促进了β-葡聚糖的降解,且不利于GABA的积累.低温-20℃胁迫青稞籽粒发芽后,其β-葡聚糖和GABA含量均比15℃和低温5℃组高.因此,低温-20℃胁迫有利于抑制青稞籽粒中β-葡聚糖降解,同时促进了GABA的富集.

通过人体试验检测和评价了青稞全粉含量≥51％挂面的血糖生成指数(Glycemic index,GI).结果表明,以葡萄糖为参考(GI值以100计),受试者食用青稞挂面后,血糖值在餐后15 min和30 min 2个时间点具有统计学差异;青稞挂面的GI值为53.63,血糖负荷(Glycemic load, GL)值为5.37.根据GI值等级划分标准,青稞挂面GI＜55,属低GI食物,表明青稞全粉挂面可以有效控制血糖平衡.