低升糖指数水稻研究进展

大米是典型的淀粉丰富的食物,是全世界大多数人口尤其是亚洲人口每日主要的卡路里来源。目前水稻品种大多数属高升糖指数(全称为血糖生成指数,glycemic index, GI)水稻,会诱发由于高热量摄入而致血糖失调的健康问题。已有大量研究者在探索降低大米血糖指数的方法。本文重点对稻米升糖指数的影响因素、筛选方法、遗传基础以及遗传改良等的相关研究进行总结,并对未来的研究方向提出了一些建议。     

低升糖指数杂交水稻粤泰优马来的选育及应用

世界上的糖尿病人数量庞大,升糖指数(GI)低的大米对以大米为主食的糖尿病人来说与运动和药物治疗的功效相当。目前低升糖指数的水稻品种都是常规水稻品种,产量低,价格高,选育高产的低升糖指数杂交水稻品种尤为迫切。用三系不育系粤泰A和高直链淀粉含量恢复系马来稻配组育成低升糖指数的杂交水稻粤泰优马来,该组合糙米GI低,仅为46.0,是第1个选育成功的低升糖指数杂交水稻组合,具有产量高、抗性强、熟期适宜、适应性广等特点。介绍了其选育过程、特征特性及栽培、制种技术要点。     

Estimating Glycemic Index of Rice-Based Mixed Meals by Using Predicted and Adjusted Formulae

The estimation of glycemic index(GI) of rice-based mixed meal either by using predicted GI(GI_(pred)) or adjusted GI(GI_(adj)) formula is unclear.This study aimed to determine the glycemic response of rice in rice alone or mixed meals and to identify the appropriate formula for estimating the GI of rice-based mixed meals.The glycemic responses produced by the rice alone(red rice,fragrant white rice or parboiled rice) and the rice-based mixed meals(fried red rice,fried fragrant white rice or fried parboiled rice) which provided 25 g available carbohydrate were assessed in 11 healthy individuals.To determine the measured GI(GImeasured) of rice alone and rice-based mixed meals,participants underwent three repeated tests of a reference food(Glucolin~?).Tests were performed in random order on nine separate visits after an overnight fasting for at least 8 h.Capillary glucose at baseline(0 min),15,30,45,60,90 and 120 min from starting the meals was assessed and used to determine the incremental area under the curve(iAUC_(120)).The agreement between GImeasured and the estimation formulae(GI_(pred) or GI_(adj)) were determined using Bland-Altman analysis.The iAUC_(120) after consuming rice alone was significantly higher than the rice-based mixed meals except for fried fragrant rice,which was comparable to the rice alone(P 0.05).The GI_(measured) values of rice were categorized as medium(61 for parboiled rice,67 for fragrant white rice,and 68 for red rice).GI_(pred)(r = 0.40,P 0.01) and GI_(adj)(r = 0.41,P 0.01) were significantly correlated with iAUC_(120).The agreement between GI_(measured) and GI_(adj) is apparent suggesting the usefulness of GI_(adj) in estimating meal GI of rice-based mixed meals.     

Estimated Glycemic Index and Dietary Fiber Content of Cookies Elaborated with Extruded Wheat Bran

The increasing demand for high-fiber products has favored the design of numerous bakery products rich in fiber such as bread, cookies, and cakes. The objective of this study was to evaluate the dietary fiber and estimated glycemic index of cookies containing extruded wheat bran. Wheat bran was subjected to extrusion process under three temperature profiles: TP1;(60, 75, 85 and 100 °C), TP2;(60, 80, 100 and 120 °C), and TP3;(60, 80, 110 and 140 °C) and three moisture contents: (15, 23, and 31 %). Cookies were elaborated using extruded wheat bran (30 %), separated into two fractions (coarse and fine). The dietary fiber content of cookies elaborated with extruded wheat bran was higher than the controls; C0 (100 % wheat flour) and C1 (30 % of no extruded bran coarse fraction) and C2 (30 % of no extruded bran fine fraction). The higher values of dietary fiber were observed on cookies from treatments 5 (TP1, 31 % moisture content and coarse fraction) and 11 (TP2, 31 % moisture content and coarse fraction). The estimated glycemic index of cookies ranged from 68.54 to 80.16. The dietary fiber content of cookies was increased and the lowest glycemic index corresponded to the cookies elaborated with extruded wheat bran. Cookie made with the treatment 11 had a better dietary fiber content and lower estimated glycemic index.     

Soaking Induced Changes in Chemical Composition,Glycemic Index and Starch Characteristics of Basmati Rice

An attempt was made to determine the qualitative changes in basmati rice(Pusa Basmati 1121, PB1121) during soaking at 40 ℃ to 80 ℃. Soaking temperature had significant effect(α = 0.01) on chemical composition, glycemic index and starch characteristics of rice. Starch content, apparent amylose content, crude protein content and crude fat content in un-soaked rice were found to be 73.24%, 27.26%, 8.79% and 2.56%, respectively, but differences in these traits were observed after soaking. Amylose to amylopectin ratio(Am/Ap) decreased from 0.59 to 0.52(soaked at 80 ℃). Crude fibre and crude ash contents increased after soaking. The mineral composition(K, P, S, Ca, Mg, Mn, Fe, Cu and Zn) in soaked rice was found to be 16.46% higher than un-soaked rice at the same degree of polishing. Glycemic index of un-soaked rice was found to be 58.41, but decreased to 54.31 after soaking at 80 ℃. Pasting properties, scanning electron microscope images, and X-ray diffractograms suggested partial gelatinization of starch in the temperature range of 60 ℃ to 80 ℃. Based on qualitative changes in rice(apparent amylose content, Am/Ap ratio and crystallinity rate), it was concluded that intermediate soaking temperatures(60 ℃ to 70 ℃) would be useful for soaking of PB1121.     

Cinnamon Shows Antidiabetic Properties that Are Species-Specific: Effects on Enzyme Activity Inhibition and Starch Digestion

Despite considerable research the evidence around the antidiabetic properties of cinnamon remains equivocal, and this may be due to varietal differences which is an aspect that is understudied. This study systematically compared the anti-hyperglycaemic properties of the four major commercial cinnamon types used around the world (Chinese; Cinnamomum cassia [CC], Indonesian; C. burmanii [IC], Vietnamese; C. loureirii [VC], and Ceylon; C. zeylanicum [SC]). LC-MS analysis showed distinct diffrences in the phytochemical profiles of cinnamon with SC showing the lowest coumarin concentration. CC and IC had the highest polyphenol levels and antioxidant potential, and all four types differed significantly in their content (P?<?0.001). All cinnamon types showed potent species-specific effects on starch digestion enzyme activity inhibition (P?<?0.001), CC was most effective against α-amylase and all four strongly inhibited α-glucosidase compared to acarbose. Cinnamon significantly reduced starch breakdown during oral (P?=?0.006) and gastric (P?=?0.029) phases of gastro-intestinal digestion with IC and SC showing consistent effects. No effects of cinnamon were seen in the intestinal phase. IC, VC and SC showed the greatest potential to inhibit formation of advanced glycation endproducts (AGEs) during digestion. In conclusion, cinnamon demonstrates anti-hyperglycaemic properties, however effects are species-specific with best overall properties seen for Ceylon cinnamon.

     

灵芝木质素降解酶研究及其潜在应用进展

灵芝不仅具有很好的药理活性,而且具有高效降解木质素的潜在特性。为进一步了解灵芝木质素降解酶作用机制及其表达调控,促进灵芝木质素降解酶研究和相关产业发展,分别对木质素降解酶组成和生物降解机制、灵芝木质素降解酶表达调控以及灵芝木质素降解酶潜在应用前景进行评述,并针对灵芝降解木质纤维素过程研究中存在的问题提出相关研究建议。     

EGCG抑制波罗的海希瓦氏菌生物被膜和腐败活性的研究

以海产品腐败菌波罗的海希瓦氏菌(Shewanella baltica)为对象,评价了儿茶素单体抑制生物被膜的效果,并分析效果最佳的单体对该菌生物被膜和腐败活性的影响。结果表明,5种儿茶素单体均能抑制S.baltica生物被膜形成,其中表没食子儿茶素没食子酸酯(Epigallocatechin gallate,EGCG)抑制率最高,其最小抑菌质量浓度为40μg·m L-1,亚抑菌质量浓度10~30μg·m L-1的EGCG对细菌生长无显著影响。在30μg·m L-1 EGCG作用下,群体感应(Quorum sensing,QS)信号分子呋喃酮酰硼酸二酯(Autoinducer-2,AI-2)、二酮哌嗪类化合物(Diketopiperazine,DKPs)cyclo-(L-Pro-L-Leu)和cyclo-(L-Pro-L-Phe)活性显著下降(P0.05),其抑制率分别为63.95%、27.43%和21.94%。亚抑菌浓度EGCG能显著抑制S.baltica生物被膜形成、泳动能力和蛋白酶活性(P0.05),呈现浓度依赖性,在30μg·m L-1时抑制率分别为55.18%,66.71%和46.67%。因此,EGCG在亚抑菌浓度下能够干扰S.baltica的QS系统,有效抑制生物被膜形成,减弱致腐能力,研究为EGCG作为新型的QS抑制剂调控食品腐败菌奠定基础。     

Inhibition of Three Diabetes-Related Enzymes by Procyanidins from Lotus (Nelumbo nucifera Gaertn.) Seedpods

Plant Foods for Human Nutrition - The inhibitory effects of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpods on the activities of α-amylase, α-glucosidase and protein tyrosine...     

Antioxidant and Antiglycation Activities of Syzygium paniculatum Gaertn and Inhibition of Digestive Enzymes Relevant to Type 2 Diabetes Mellitus

Plant Foods for Human Nutrition - Advanced glycation end-products (AGEs) may be a contributing factor in the development of diabetes-specific vascular pathologies that affect the retina, glomerulus...     

砂姜黑土区小麦籽粒质量及利用潜力研究

为了解安徽省宿州市砂姜黑土区大田小麦籽粒质量现状,评估该区域小麦加工利用潜力,以2011-2013年安徽省宿州市砂姜黑土区抽取的107份大田小麦样品为试验材料,参照相关标准分析了小麦籽粒质量特性及其加工利用能力。结果表明,宿州砂姜黑土区大田小麦容重平均为792±17 g·L^-1,籽粒蛋白质含量平均为14.2±1.6%,湿面筋含量平均为29.1±3.6%,面团稳定时间平均为11.8±9.7 min;容重、籽粒蛋白质含量、湿面筋含量年际间变异较小,面团稳定时间年际间变异较大。2011-2013年宿州砂姜黑土区大田小麦样品中有20.56%达到《优质小麦-强筋小麦》二等标准。宿州砂姜黑土区生产的小麦籽粒质量为中筋偏强类型;以湿面筋含量、面团稳定时间为依据,宿州砂姜黑土区大田小麦适宜加工面条、馒头、饺子等传统中式面制品。     

桑皮纤维的结构与性能

对桑皮纤维的资源、桑皮纤维的化学组成、物理机械性能、形态结构、制备工艺以及产品开发进行了综述,认为桑皮纤维具有较大的使用潜力和广阔的开发前景.     

茶黑毒蛾防治指标的研究

茶黑毒蛾 Dasychira baibarana Matsumura 是茶树的一种主要害虫。本报告通过对幼虫取食量、取食嫩叶和老、成叶的比例及田间摘除老、成叶后对产量影响的模拟试验结果表明,茶黑毒蛾幼虫的平均取食量为1710.4毫克,越冬代幼虫取食嫩叶占总量的78.33%,第1代幼虫占20.98%。越冬代幼虫的危害嫩叶当量 D=0.00134公斤,第1代幼虫虫量与产量损失的关系式为(?)=0.0001377x~(1.247)。根据防治总费用、茶叶产量、价格及防治效果的调查,每亩年产150公斤干茶的茶园,越     

Potential of Plant Proteins Digested In Silico by Gastrointestinal Enzymes as Nutritional Supplement for COVID-19 Patients

Plant Foods for Human Nutrition - Currently, no specific drug and vaccine are available for the new coronavirus SARS-CoV-2, and nutritional supplementation should be helpful. This study tried to...     

化感植物对受黄曲霉侵染花生植株保护酶活性的影响

盆栽条件下研究具化感作用潜力的植物对受黄曲霉侵染花生植株叶片保护酶POD、CAT和SOD的活性的变化.结果表明,香根草根和香茅能有效降低黄曲霉对花生的毒害,其中,以香根草根的效果最为显著,它显著提高了花生植株的保护酶活性,并降低了黄曲霉对光合作用的影响.     

黑豆叶面积指数及干物质积累与产量的关系

试验以沈农黑豆3号和辽黑1号为试验材料,研究了黑豆在不同施肥水平下的干物质积累动态及叶面积指数与产量的关系。结果表明：各品种在施肥水平下的干物质、叶面积指数及产量均高出对照,叶面积指数与产量的相关性在始花期达显著水平,在结荚期达到极显著水平;干物质与产量的显著相关性出现在结荚期。始花期至结荚期黑豆保持着较高的叶面积指数可以增加相应的干物质积累量、荚数、粒数,选用优良品种辅以高产栽培措施,可以获得较高的产量。     

纸片型1-MCP对杨桃果实采后病害的抑制与抗病相关酶的诱导

研究纸片型1-MCP(1-甲基环丙烯)处理对采后‘香蜜’甜杨桃果实病害指数、抗病相关酶活性和总酚含量的影响。采后杨桃果实用0(对照)和0.6μL/L的纸片型1-MCP处理12 h后,在(15±1)℃下贮藏。贮藏期间定期测定果实病害指数、果实抗病相关酶如几丁质酶(CHI)、β-1,3-葡聚糖酶(GLU)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)和过氧化物酶(POD)活性及总酚含量的变化。结果显示:与对照果实相比,纸片型1-MCP处理能有效降低杨桃果实病害指数,提高CHI、GLU、PAL、PPO和POD的活性,保持较高的总酚含量。表明纸片型1-MCP对抑制杨桃果实采后病害的发生与抗病相关酶活性的升高及酚类物质的合成有关。     

In Vitro Starch Digestibility and Estimated Glycemic Index of Mung Bean (Vigna radiata L.) as Affected by Endogenous Proteins and Lipids,and Exogenous Heat-Processing Methods

Plant Foods for Human Nutrition - The aim of this study was to investigate the in vitro starch digestibility and estimated glycemic index (eGI) of mung bean (Vigna radiata L.) as affected by...