全谷物发芽糙米韧性饼干制作工艺优化

为了拓展发芽糙米的利用途径,丰富全谷物食品种类,本文以发芽糙米粉替代部分小麦粉应用于饼干,开展了配方及焙烤工艺参数对韧性饼干品质特性的影响研究,优化了饼干的制作工艺.结果表明,随着发芽糙米粉的增加,饼干色泽降低,硬度呈上升趋势,延展度、感官评分均呈先增加后降低的趋势;增大黄油的添加量,延展度、膨松度变化较小;增大糖粉的...     

Grain storage systems and effects of moisture,temperature and time on grain quality - A review

Global grain production has been increasing every year, which highlights the need for investment, maintenance, and effective management in warehouses. Warehousing is a major bottleneck as it influences the possibility of negotiating for better market prices. In order for profitability to be increased, assurance of product quality for the consumer is necessary. Hence, there is a need for standardization of scientific research and the production chain in this field. The purpose of this bibliographic review is to describe the existing storage systems for grains, steps to be taken for care, and the main studies carried out in this field, to guarantee grains of good quality. The maintenance of the characteristics of the grains after harvest, is essential to guarantee grains of good quality to consumers. However, there are still deficiencies in the field of grain storage, and features of the different systems and conditions to be adopted for each of them are provided in this review.     

糙米原料对挤压速食粥品质特性的影响

为选择适用于挤压速食粥的原料糙米,本文采用挤压膨化的加工工艺对8种糙米原料进行处理,并对8种挤压速食粥进行了品质分析,结果表明:挤压后糙米结构更加紧实均一,其中,黑龙江圆粒粳糙米和长粒粳糙米、2013和2014年的早籼米较其他试样品质更优。在品质指标、质构特性和感官评价对比中,粳糙米挤压速食粥总体品质好于籼糙米挤压速食粥。在风味分析中,共鉴定出27种风味物质,其中醛类物质为主要化合物,而风味物质总含量差别不大。相关性分析表明,复水率与感官评价总分呈极显著(P<0.01)正相关,复水时间与感官评价总分呈显著(P<0.05)负相关。本研究表明,黑龙江圆粒粳糙米和长粒粳糙米的综合品质最佳,适合作为挤压速食粥的原料米。     

“双重冲击”下世界油菜籽及其加工品生产、贸易格局变动分析

近年爆发的贸易争端与新冠肺炎疫情,对世界油菜籽及其加工品的生产、贸易格局产生了一定影响,研究这一问题对保障中国油菜籽及其加工品进口供应链安全具有重要意义。总结分析了世界油菜籽及其加工品生产、贸易格局变动特征,实证分析了主要进出口国(地区)的显示性比较优势与贸易互补性,探讨了贸易争端与新冠肺炎疫情对世界油菜籽及其加工品生产、贸易格局的“双重冲击”。主要结论为：中长期看,“双重冲击”不会大幅改变基于比较优势的世界油菜籽及其加工品的生产、贸易格局;短期内,进出口大国之间的贸易争端将加剧国别替代,中国与加拿大、俄罗斯、澳大利亚的贸易规模将逐渐此消彼长;新冠肺炎疫情增加了贸易成本和供应链风险,对提升跨国物流与供应链绩效提出了更高要求。     

免疫磁珠高通量自动净化-超高效液相色谱法测定粮食中玉米赤霉烯酮

基于免疫磁珠高通量自动净化的前处理方法,使用超高效液相色谱仪对粮食中玉米赤霉烯酮的含量进行测定。首先将免疫磁珠与玉米赤霉烯酮的反应时间、样品提取液和不同粮食基质的净化效果进行优化。经方法验证,超高效液相色谱的检出限和定量限分别为3.5 μg/kg和12.0 μg/kg。在优化条件下,全麦粉和玉米全粉阴性样品的3 个添加水平的加标回收率在99.04%～109.26%之间,变异系数不大于6.88%。玉米全粉、全麦粉、糙米粉、小麦粉等粮食基质中玉米赤霉烯酮成分的国家有证标准物质或质控样品的测定结果在标准值及其扩展不确定度范围内,变异系数不大于3.54%,测定结果较为满意。采用Bland-Altman法对免疫磁珠净化法和免疫亲和柱净化法之间的差异进行分析,结果显示这2 种净化方法的差异在可接受范围内,因此,这2 种方法在净化和富集粮食中玉米赤霉烯酮时可互相代替使用。免疫磁珠净化方法配套使用的真菌毒素全自动净化仪可同时净化10～24 个样品,平均每个样品的净化时间约为2～3 min,实现粮食中玉米赤霉烯酮的高通量自动净化。超高效液相色谱分析速度快、灵敏度高、准确性高,可用于检测粮食中玉米赤霉烯酮的含量。     

Mono-Sized Anion-Exchange Magnetic Microspheres for Protein Adsorption

In this study, mono-sized anion-exchange microspheres with polyglycidylmethacrylate were engineered and processed to introduce magnetic granules by penetration–deposition approaches. The obtained magnetic microspheres showed a uniform particle diameter of 1.235 μm in average and a good spherical shape with a saturation magnetic intensity of 12.48 emu/g by VSM and 12% magnetite content by TGA. The magnetic microspheres showed no cytotoxicity when the concentration was below 10 μg/mg. The magnetic microspheres possess respective adsorption capacity for three proteins including Bovine albumin, Hemoglobin from bovine blood, and Cytochrome C. These magnetic microspheres are also potential biomaterials as targeting medicine carriers or protein separation carriers at low concentration.     

建立一种增强酶抑制法快速检测谷物中有机磷农药残留

本研究的目的是建立一种增强的酶抑制法,实现对谷物中有机磷农药残留的快速检测。通过对酶抑制法中所使用的提取剂、酶、增强剂的选择和优化,并比对抑制率的差异,最终确定使用丁酰胆碱酯酶作为催化酶、乙醇作为提取剂、溴代琥珀酰亚胺作为增强剂。在此条件下,建立了硫代磷酸脂类有机磷农药对硫磷、辛硫磷、毒死蜱和三唑磷的标准曲线(决定系数R2 > 0.98),抑制中浓度(IC₅₀)分别为0.01、0.11、0.16和0.03 μg/L,满足了硫代磷酸酯类农药在不同谷物中的安全残留限量的检测需求。采用本研究改良的酶抑制法对200个不同来源的谷物样本(稻谷、小麦、玉米、糙米、杂粮)进行分析,检测出13个阳性样本,同时,因酶抑制法特异性的限制,产生了1个假阳性和1个假阴性样本。检测结果与气相色谱法符合率达到98%,表明该方法可有效用于谷物中有机磷农药残留检测。本研究可为我国粮食质量安全监管提供有力的技术支撑。     

固态发酵对藜麦营养成分、酚类物质含量及抗氧化活性的影响

为筛选可改善藜麦营养成分,提高酚类物质含量及抗氧化活性的固态发酵适宜菌种,为藜麦产品的开发提供理论依据,本文利用植物乳杆菌、酿酒酵母、米根霉、米曲霉和好食脉胞菌对藜麦进行了30和48 h的单菌和混菌固态发酵,分析测定了不同菌种固态发酵对藜麦基本营养成分、酚类物质组成及抗氧化活性的影响。结果表明,固态发酵后,藜麦中淀粉含量由54.61%降至最低为39.32%,不可溶性膳食纤维含量由2.32%降至最低为0.26%,可溶性膳食纤维含量由2.58%升至最高为4.38%。随发酵时间由30 h延长至48 h,藜麦中游离态多酚和黄酮含量分别是未发酵的1.72和1.72倍,结合态多酚和黄酮含量分别是未发酵的2.88和1.84倍。固态发酵后,虽然游离酚粗提液的抗氧化能力和DPPH自由基清除能力有所下降,而藜麦结合酚粗提液的抗氧化能力、DPPH和ABTS+自由基清除能力明显升高（P<0.05）。综上,采用多个菌种混合固态发酵48 h时,藜麦酚类物质的抗氧化活性提高更加明显,其中,植酸乳杆菌、酵母菌、好食脉孢菌混合发酵48 h后,藜麦抗氧化活性较高,是最佳的固态发酵菌种组合。     

Rice cultivars affect fitness-related characteristics and digestive physiology of the rice weevil,Sitophilus oryzae (L.) (coleoptera: Curculionidae)

The rice weevil, Sitophilus oryzae (L.), is one of the main pests of rice and other stored grains. Due to the negative effects of synthetic pesticides on the environment and non-target organisms, more environmentally benign alternative control techniques are needed for controlling pests. In the present study, the development, reproduction, and digestive enzyme activity of Sitophilus oryzae (L.) were evaluated on 12 rice cultivars under laboratory conditions [28 ± 1 °C, 60 ± 5% RH, and a photoperiod of 16:8 (L: D) h]. Among tested rice cultivars, the developmental time of S. oryzae immature stages was the shortest on DomSiah (33.0 days), Hashemi var. Guilan (34.0 days) and Hashemi var. Mazandaran (34.0 days) and the longest on Neda (44.5 days). The highest fecundity was recorded for beetles reared on cultivars DomSiah (316.8 eggs), Hashemi var. Mazandaran (301.1 eggs), and Hashemi var. Guilan (293.3 eggs); and the lowest for beetles reared on cultivar Neda (147.0 eggs). The highest survival of immature stages was recorded on cultivars Hashemi var. Mazandaran (80.0%), AliKazemi (75.2%), DomSiah (73.6%), and Hashemi var. Guilan (71.0%) whereas those on cultivar Neda (25.3%) had the lowest survival. The female adults that developed from larvae reared on cultivars Neda, Govhar, and Fajr had the lowest body mass (67.7, 68.6, and 69.4 mg). Also, the males’ mass was the lowest on cultivars Neda, Fajr, Shiroudi, and Govhar (60.7, 62.2, 62.9 63.3 mg, respectively). The adults developed from larvae reared on cultivars Fajr and Neda had the lowest levels of α-amylase activity (1.77 and 1.64 mU/min/individual, respectively). Also, those reared on cultivar Neda had the lowest levels of protease activity (0.067 OD/min/individual). Results suggest cultivar Neda, as an unsuitable food for S. oryzae development that negatively affects the amylolytic and proteolytic activity of this pest, could be considered in the integrated management programs of this pest.