大豆生理活性肽的研究(Ⅰ)--酶法水解的工艺

研究了高水解度大豆多肽的制备和脱盐工艺,采用两种蛋白酶AS1.398和Alcalase水解大豆分离蛋白制得水解度为10%～24%的大豆多肽.结果显示在等电点沉淀分离多肽时,相同水解度下,Alcalase酶水解产物的水解得率比AS1.398酶水解产物的水解得率高20%.采用DA201-C大孔吸附树脂对水解液进行脱盐,得到了优化的吸附和解吸的条件.该条件下大孔吸附树脂对水解液的吸附率为89.71%,解吸率为72.30%.     

新型大豆食品——大豆酸凝乳粉的研究

以大豆为原料,用嗜热链球菌和保加利亚乳杆菌比例1:1之混合菌种为发酵剂,并添加适量添加剂A和B,经喷雾干燥制得的大豆酸凝乳具有与酸牛乳相似的外观和口感,产品得率达92%。本实验确定了制作大豆酸凝乳粉的最佳工艺条件,并经正交实验确定了由大豆酸凝乳粉制备酸凝乳的最佳发酵条件。     

新型大豆食品——大豆酸凝乳的研制

以大豆为原料,在适当的工艺条件下,用嗜热乳酸链球菌及保加利亚乳杆菌混和发酵,制得的大豆酸凝乳基本无豆腥味。进行了风味改善的初步尝试,产品进行了感观评定,理化分析及微生物试验。     

全脂大豆热处理条件及其营养评价

通过ＤＳＣ分析，研究了不同含水量的大豆，尿酶及美拉德反应情况，发现水分高的大豆易变性，尿酶失活快于美拉德反应的产生，说明了有效赖氨酸在高水分时保持率较高的机理。控制大豆热处理工艺，使得尿酶活力降至０．４ｍｇ／（ｇｍｉｎ）以下，而大豆中有效赖氨酸的保持率为８０％．通过热处理工艺中温度、时间、水分等参数的分析，得出尿酶活力与有效赖氨酸、氮溶指数之间呈正相关（但非线性相关）；有效赖氨酸与尿酶活力与胰蛋白酶活力呈正相关。     

大豆浓缩蛋白的酶法改性及其在西式火腿中的应用

采用酶法对大豆浓缩蛋白进行改性。以水解度（ＤＨ）为３％和６％的酶法改性大豆浓缩蛋白的功能性质相当或超过大豆分离蛋白。将其应用于西式火腿的加工，提高了产品的出品率和质量。     

水酶法从花生中提取蛋白质与油--酶解工艺参数

采用水酶法从花生中同时提取油与水解蛋白质,对酶制剂的筛选,酶解工艺中酶用量、蛋白质的水解度(DH)、降低乳状液稳定性以及部分破乳的方法等进行了研究.确定选用Alcalase作为水解酶,酶与底物比为2.5 g/dL.推断了DH与清油得率及等电可溶水解蛋白质得率的关系,并对花生水解蛋白质的部分功能性质及花生油质量进行了分析.     

大豆异黄酮与肾脏疾病

大豆异黄酮是大豆中的一种非营养成分，近年来研究表明大豆异黄酮有多种生物学功能，能改善心血管功能，抗肿瘤，改善骨质疏松，间接证据表明对肾脏也有良好保护作用。     

大豆木糖葡聚糖的结构研究

利用４ｍｏｌ／ＬＮａＯＨ提取结合层析柱提纯，从大豆细胞壁物质（膳食纤维）中分离出ＰＲＦ６聚合物组分（即木糖葡聚糖），并对该组分的结构特征作了详尽的剖析。     

大豆多糖的制备及其功能性

本研究利用析因分析,探讨了从豆渣中制取大豆多糖的最适工艺条件,比较了大豆多糖在多种加工条件下的持水性变化,并应用于鱼圆加工,改善了鱼圆的保水性和质构。结果表明,在pH=9,温度30～50℃,处理时间20～30min,液固比4.5∶1时,可将豆渣中的蛋白质去除60%以上。食盐和蔗糖的存在,pH的变化和加热对多糖持水性的影响有限,该大豆多糖可用于多种食品。     

不溶性大豆浓缩蛋白物理改性机理的研究

从分子间作用力的角度，研究了醇法浓缩大豆蛋白（ＡＬＳＰＣ）的物理增溶机理。通过蛋白质溶出物分布可知，分子间力均匀作用于各个ＡＬＳＰＣ蛋白分子，而ＭＳＰＣ蛋白分子则通过共价键形成聚集体，聚集体间无任何形式的作用力。荧光光谱证明疏水性基团处于聚集体内部，因而具有可溶性蛋白结构。对可溶性聚集体的形成机理进行了研究。     

Soy protein consumption and bone mass in early postmenopausal Chinese women

Recent interest has been shown in the potential beneficial effects of phytoestrogens on bone health. As the early years of menopause are a period of rapid bone loss, and the risk for osteoporosis increases substantially, the habitual intake of soy protein and isoflavones may play a role in the retardation of bone loss. This paper reports the results of the baseline cross-sectional analysis of the association between dietary soy protein intake and bone mineral density/content in a population-based study of Chinese women. The sample comprised 454 healthy Chinese women (mean age 55.1±3.57) within the first 12 years of postmenopause. We estimated the dietary intake of soy protein and isoflavones, and other key nutrients, including dietary protein and calcium, using the quantitative food frequency method. Bone mineral density (BMD) and content (BMC) at the spine, hip and total body were measured with a dual energy X-ray densitometer (Hologic 4500A). Soy protein consumption was categorized as quartiles of intake, and related to BMD values at the spine and hip, and BMC of total body. Stratified analyses were carried out among women within or at least 4 years postmenopausal. We observed few differences in BMD/BMC values among the intake quartiles in women within the first 4 years of menopause. However, among the later postmenopausal women, we noted a dose-response relationship with increasing higher BMD values at the trochanter, intertrochanter as well as the total hip and total body with increasing soy protein intake quartiles (P<0.05 from tests for trend). The BMD values differed by about 4–8% between the first and fourth soy protein intake quartiles. Though women from the fourth intake quartile had a 2.9% higher BMD value compared with those from the first intake quartile, the difference was not statistically significant. Stepwise multiple linear regression analyses showed the association between soy intake quartiles and hip BMD as well as total body BMC values remained after adjusting for body weight, which was retained in the final model. Analyses based on soy isoflavones content yielded similar results. This study demonstrated that, among women after the initial few years postmenopausal, soy protein/isoflavones intake had a modest but significant association with hip BMD as well as total body BMC. The effects of soy protein and soy isoflavones on bone health should be further explored in populations with habitual dietary soy intake.     

Soy Protein Isolate Diet Does Not Prevent Increased Cortical Bone Turnover in Ovariectomized Macaques

Summary : Forty-one ovariectomized, cynomolgus monkeys were divided into 4 groups and fed a casein and lactalbumin based diet with or without 17β-estradiol, or a soy protein based diet with or without 17β-estradiol for 7 months. Histomorphometry was done on cortical bone from the mid-shaft femur. 17β-estradiol suppressed ovariectomy-induced increases in bone formation rates, regardless of dietary protein source. Soy protein alone did not prevent increased bone turnover and on the endosteal surface, it actually increased bone turnover when compared to casein/lactalbumin fed monkeys. Received: 30 July 1997/Accepted: 2 December 1997     

Soy Isoflavones May Protect Against Orchidectomy-Induced Bone Loss in Aged Male Rats

Evidence from several studies suggests that soy protein and/or its isoflavones may have beneficial effects on bone in postmenopausal women and animal models who have osteoporosis. The present study examined the dose-dependent effects of soy isoflavones in the context of soy protein or casein on the male skeleton. Thirteen-month-old male Fisher 344 rats were orchidectomized (ORX; 5 groups) or sham-operated (Sham; 1 group) and immediately placed on dietary treatments for 180 days. Diets were semi-purified and the protein source was either casein (Sham and ORX; controls), casein with two added doses of isoflavones (Iso1; 600 mg/kg diet and Iso2; 1200 mg/kg diet), soy protein with normal isoflavones content (Soy; 600 mg/kg diet), or soy protein with added isoflavones (Soy+; 1200 mg/kg diet). A 7% loss of whole body bone mineral density (BMD) was observed due to orchidectomy; however, the ORX induced BMD loss was significantly reduced to 4.3 and 4.7 % with the Soy and Soy+, respectively. Both doses of isoflavones in conjunction with casein also reduced the loss of whole body BMD, albeit not significantly different from ORX control animals. Trabecular bone histomorphometric analysis of the proximal tibia further supported the bone-sparing role of soy isoflavones as indicated by higher percent bone volume and trabecular number, and lower trabecular separation. We conclude that isoflavones exert modest beneficial effects on the male skeleton whether provided with casein or a soy protein.     

Effect of Soy Protein on Bone Metabolism in Postmenopausal Japanese Women

We conducted a cross-sectional study of the effects of soybean protein intake on bone mineral density and biochemical markers in 85 postmenopausal Japanese women. Nutrients in the diet of postmenopausal Japanese women visiting the osteoporosis unit, including subjects with normal lumbar spine bone mineral density (L2–4 BMD), were investigated by questionnaire, and the calculated daily energy, protein, soy protein and calcium intake were obtained. L2–4 BMD was measured with dual-energy X-ray absorptiometry, and assays done of serum alkaline phosphatase (ALP) and serum intact osteocalcin (IOC) as bone formation markers and urinary pyridinoline (UPYR) and urinary deoxypyridinoline (UDPYR) as bone resorption markers. Soy protein intake was significantly associated with the Z-score for L2–4 BMD (r= 0.23, p = 0.038) and UDPYR (r =−0.23, p = 0.034). Stepwise multiple regression analyses showed that soy protein intake is significantly associated with the Z-score for L2–4 BMD (β= 0.225, p = 0.04) and UDPYR (β=−0.08, p = 0.03) among four nutritional factors. These results suggest that high soy protein intake is associated with a higher bone mineral density and a lower level of bone resorption, but further studies are needed to confirm the causal dynamic mechanisms. Received: 17 September 1999 / Accepted: 29 February 2000     

不同低蛋白饮食延缓CRF进程的临床研究

目的：观察大豆蛋白为主的低蛋白饮食（LVPD）和动物蛋白为主的低蛋白饮食（LAPD）延缓CKD3～4期患者肾功能减退的疗效和安全性。方法：42例CKD3～4期（eGFR15～59ml/min）患者分成LVPD（22例）和LAPD（20例）两组,其人口学、疾病程度、治疗状况、蛋白质与热量摄入均具可比性,但LAPD组要求动物蛋白摄入占总蛋白的50%,LVPD组要求动、植物蛋白之比30%和70%,且植物蛋白中大豆蛋白占50%以上。研究周期为12个月。主要观察u-pro、eGFR、Scr、BUN、TC、TG、LDL、HDL、Alb、PA、TF、Ca2＋、P3-及人体测量指数等。结果：两组患者均能改善eGFR、减少u-pro,其中LVPD组自身前后对比差异有统计学意义（P〈0.05～P〈0.01）,LAPD组差异无统计学意义（P〉0.05）,两组间对比差异亦无统计学（P〉0.05）;LVPD组治后较治前血PA、TF、HDL、Ca2＋增高,LDL、P3-降低（P〈0.05～P〈0.01）,其中对HDL、Ca2＋、P3-的疗效优于LAPD组（P〈0.01）;两组血Alb、TC、TG以及人体测量指数基本稳定。结论：LVPD和LAPD对CKD3～4期患者均有一定的减少尿蛋白,延缓肾功能减退的作用,但LVPD在调节脂质及钙磷代谢方面更具有优势。     

大豆异黄酮与皮肤美容

众所周知，大豆是一种营养价值极高的植物性食物，除富含蛋白质、不饱和脂肪酸外，还含有其他许多生物活性成分，大豆异黄酮就是其中的一种。大豆异黄酮具有雌激素样作用，抗氧化、抑制酪氨酸蛋白激酶活性等多种重要药理作用。近年来有关大豆异黄酮在皮肤美容中的应用开始受到人们的关注，本文对此领域的研究概况进行简要综述。     

女性内分泌与骨质疏松

骨质疏松症是目前全球发病率、致残率及医疗费用较高的疾患之一,是以骨强度下降、骨折风险性增加为特征的骨骼系统疾病.因其严重影响人们健康及生活质量,受到医学界广泛关注.骨质疏松症与机体内分泌息息相关,甲状腺功能异常、绝经后女性激素水平下降、补充激素医学干预等,均在不同程度上改变了骨分泌代谢.绝经后骨质疏松症是原发性骨质疏松症中最常见类型,雌、孕激素水平降低是其主要因素.补充女性激素对改善骨质疏松症状具有一定作用,但长期服用将导致激素依赖性肿瘤患病率增加.探索安全而有效的针对女性绝经后骨质疏松的个体化方案成为学术界研究的焦点.     

A prospective study of the effects of 1-year calcium-fortified soy milk supplementation on dietary calcium intake and bone health in Chinese adolescent girls aged 14 to 16

The Chinese diet is low in calcium, including among adolescent girls, with an average intake around 500 mg per day. In this study, we compared the percentage change in bone mineral density and content of the spine and hip region in a 1-year follow-up study between 104 adolescent girls aged 14 to 16 years receiving 375 ml calcium-fortified soymilk supplementation and 95 girls in the control group. The mean percentage changes of bone mineral density/content (BMD/BMC) and standard deviation (SD) at 1 year for the supplementation and control groups were as follows: neck of the femur BMD 2.7±2.94%, 1.8±3.49% (P =0.08); trochanter BMD 3.3±3.27%, 1.6±2.94% (P <0.001); intertrochanter BMD 3.6±3.05%, 2.32±2.95% (P =0.002); total hip BMD 3.1±2.39%, 2.05±2.22% (P =0.001); total hip BMC 3.8±3.05%, 2.6±2.96% (P =0.006). The percent difference between the percentage of bone changes in the supplementation and control groups [100× (soymilk-control)/control] ranged from 45 to 113%. We observed no differences in the spine BMD/C and no differences in changes of height and weight between the soymilk supplementation and control groups, which yielded similar results. Stepwise multivariate regression analysis including height, weight, growth stage, dietary energy, protein, calcium from usual diet and physical activity also showed that supplementation was significantly associated with a percentage increase in BMD/C at the hip. We conclude that 375 ml calcium-fortified soymilk supplementation, or an equivalent of about two glasses, is among the effective strategies for bone acquisition and the optimization of peak bone mass in adolescent girls.     

联合补充大豆异黄酮和钙预防去势大鼠骨质疏松的实验研究

目的 研究联合补充大豆异黄酮和钙对去卵巢大鼠骨质疏松的预防作用。方法 将50只3月龄SD雌性大鼠摘除卵巢后按体重随机分成5组：假手术对照组、手术对照组、大豆异黄酮组（40mg／kgBW）、钙组（100mg／kgBW）、钙＋大豆异黄酮组（Ca100mg／kgBW＋SI40mg／kgBW）。连续灌胃饲养3个月后测定大鼠血清骨钙素，左侧股骨测定骨密度和骨钙含量、右侧股骨进行骨组织形态学计量分析。结果 Ca＋SI组血清BGP水平和股骨骨密度均高于其他去卵巢各组（P〈0．05），但低于Sham组（P〈0．05）；Ca＋SI组大鼠股骨的骨钙含量与Ca组、Sham组差异均无统计学意义；在去卵巢各组大鼠中手术对照组、大豆异黄酮组和钙组大鼠的骨小梁数目和骨小梁厚度显著减少，骨小梁间距明显增宽，与钙＋大豆异黄酮组相比有显著差异（P〈0．05）。结论 与单独补充大豆异黄酮或钙相比，大豆异黄酮与钙的联合应用能够更有效地预防去卵巢大鼠骨质疏松的发生。     

大豆异黄酮对妇女更年期综合征及骨密度的作用研究

目的拟通过人群膳食干预试验,从临床角度研究植物雌激素大豆异黄酮对妇女更年期综合征症状及主要并发症骨质疏松的预防治疗作用。方法依据纳入和排除标准,在哈尔滨地区筛选出更年期妇女90人,随机双盲法分为大豆异黄酮剂量组和安慰剂对照组,每人每天服用大豆异黄酮90mg或者安慰剂,试验期限6个月。通过调查问卷形式记录Kupperman评分,评价更年期综合征症状改善情况;生化学方法检测试食对象血清中骨代谢指标血清钙、血清磷和血清碱性磷酸酶;超声测定桡骨远端和胫骨中段的骨密度。结果大豆异黄酮组Kupperman评分中12项指标的评分均显著下降,反应骨转换的指标血清碱性磷酸酶显著下降,胫骨骨密度显著增加,均有统计学意义。讨论大豆异黄酮可有效改善妇女更年期综合征症状,增加骨密度,预防和治疗由于更年期综合征引起的骨质疏松。