不同方法处理的芝麻粕营养价值评定

选用5头健康、体重35 kg左右,在回肠末端安装简单“T”型瘘管的杂交阉公猪(杜×长×大),采用有重复5×5拉丁方设计,测定经不同方法处理的4种芝麻粕(发酵芝麻粕+赖氨酸(FSML),酶解芝麻粕(ESM),发酵芝麻粕(FSM)和普通芝麻粕(SM))饲喂生长猪的消化能、代谢能,粗蛋白表观消化率及真消化率、磷消化率和氨基酸回肠末端表观消化率及真消化率.结果表明:不同处理方法显著影响芝麻粕能量、磷和粗蛋白的利用率,并且改善了部分氨基酸回肠末端表观消化率及真消化率.FSM和FSML的粗蛋白表观消化率、粗蛋白真消化率和磷消化率均显著高于SM和ESM (P ＜0.05).相对于ESM,FSM和FSML的消化能均提高了6.29％,代谢能均提高了7.85％ (P ＜0.05).FSML的苏氨酸、苯丙氨酸、赖氨酸和丝氨酸的回肠末端表观消化率相对于SM分别提高了4.42个百分点、9.30个百分点、7.28个百分点和4.12个百分点(P＜0.05);FSM和FSML的苯丙氨酸回肠末端表观消化率与真消化率均显著高于SM和ESM (P ＜0.05);但SM的丙氨酸回肠末端表观消化率较FSM提高了3.74个百分点(P＜0.05).FSM的脯氨酸回肠末端真消化率相对于ESM和SM分别提高了9.06个百分点和9.86个百分点(P＜0.05).结果显示,芝麻粕发酵后可以提高芝麻粕能量、粗蛋白、磷和部分氨基酸的利用率.     

紫山药淀粉与其抗性淀粉理化性质的比较

以紫山药淀粉为研究原料,采用不同方法分别制备压热、酶解-压热及双酶纯化抗性淀粉,分析比较了紫山药淀粉与其抗性淀粉的理化性质。试验结果表明:紫山药淀粉颗粒呈圆形或椭圆形且表面光滑;抗性淀粉颗粒破碎且呈不规则型。4种淀粉的化学结构相似,与原淀粉相比,抗性淀粉没有生成新的基团。抗性淀粉样品的凝沉速度随直链淀粉含量的增加而加快,冻融稳定性则降低;碘吸收曲线向支链淀粉吸收波长方向偏移。流变学分析表明与原淀粉相比抗性淀粉表观黏度均增大,剪切结构恢复力与抗性淀粉含量成反比。     

低GI淀粉原料的筛选及理化特性和体外消化特性的研究

以豌豆、马铃薯、玉米、木薯、大米、小麦、鹰嘴豆中的淀粉为研究对象,对其淀粉颗粒形貌、粒径分布、糊化特性、直链淀粉含量及淀粉组分进行探究,并采用体外消化试验分析7种淀粉的体外消化特性,计算其预测血糖生成指数(expected glycemic index,eGI)。结果表明:豌豆淀粉和鹰嘴豆淀粉粒度分布比较集中,大小较均匀;豌豆淀粉和鹰嘴豆淀粉的回生值较高,易于老化;豌豆淀粉和鹰嘴豆淀粉的直链淀粉含量较高,玉米淀粉中快消化淀粉含量最高,马铃薯淀粉慢消化淀粉含量最高,而鹰嘴豆淀粉的抗性淀粉含量最高。体外消化试验结果表明:鹰嘴豆淀粉体外消化率曲线增速最慢,7种淀粉的eGI值从低到高依次为:鹰嘴豆淀粉(48.9)小麦淀粉(57.7)豌豆淀粉(59.9)玉米淀粉(67.3)木薯淀粉(70.2)马铃薯淀粉(70.3)大米淀粉(76.3)。     

主要粮食饲料资源氨基酸消化利用率的研究

采用8头初始体重为(27．2±2．3)kg、在回肠末端装有简单T型瘘管的杜长大三元杂交公猪, 手术康复后随机分成2组,每组4头,每组采用同一豆粕-玉米淀粉基础日粮,按拉丁方设计,用于测定豆粕、棉粕、菜粕、稻谷、油糠、统糠和玉米7种饲料原料的回肠和粪氨基酸消化率。结果表明:所测氨基酸平均表观消化率回肠比粪低5—8个百分点(P<0．05);稻谷氨基酸表观消化率比玉米低5％;所测原料氨基酸表观消化率与中国饲料数据库等报道结果基本吻合。     

日粮添加木聚糖酶对肉仔鸡表观消化率及肠道组织形态的影响

通过在小麦基础日粮中添加木聚糖酶,研究了木聚糖酶对肉仔鸡回肠及总消化道养分和非淀粉多糖(NSP)表观消化率及小肠形态的影响.试验将7日龄肉仔鸡随机分为3组,即为小麦基础日粮中添加0%、0.03%和0.1%的加酶组,饲喂至21日龄.结果表明:与对照组相比,0.1%的加酶组显著提高了淀粉在回肠和总消化道中的表观消化率(P<0.05),极显著提高了可溶性非淀粉多糖(SNSP)、不溶性非淀粉多糖(INSP)在回肠的表观消化率(P<0.01),显著提高了SNSP的总消化道表观消化率(P<0.05).此外,0.1%的加酶组还极显著降低了十二指肠的肠壁厚(P<0.01),并极显著增加了肉仔鸡回肠隐窝深度和绒毛高度(P相似文献   

芋头淀粉与其他淀粉物理特性比较研究

对不同产地的芋头淀粉糊的物理性质与玉米、木薯、马铃薯、小麦淀粉进行了比较研究.结果表明:芋头淀粉糊的性质劣于马铃薯和木薯,与玉米和小麦淀粉性质相似,而奉化芋头、芋子淀粉明显优于其它芋头淀粉.     

焙烤打粉杂粮的淀粉消化组分及餐后血糖反应

以红小豆、黑米、燕麦、山药干、芡实5种杂粮食材为样品,采用体外模拟小肠消化方法,测定焙烤后打粉,并用不同温度冲糊的处理对其中快消化淀粉、慢消化淀粉和抗性淀粉含量的影响;测定进食各样品后3 h的餐后血糖反应。研究发现,焙烤打粉冲糊处理显著降低了除山药干之外其它食材的抗性淀粉含量,提升红小豆餐后血糖反应的幅度最大;冲糊温度可以调控抗性淀粉含量,其中对山药干的影响最大。提示:通过改变食材物理状态和冲糊温度,可以有效调控餐后消化速度,以适应消化能力和血糖控制需求不同的人群。     

不同品种山药蒸制过程中淀粉消化率及抗氧化活性

本实验以不同品种山药的淀粉相关特性、生物活性成分、抗氧化能力和微观结构为评价指标,研究蒸制时间对铁棍山药、淮山药、糯山药3 种山药的营养品质和抗氧化活性的影响,并探究山药微观结构和品质变化的内在联系。结果表明,蒸制处理后,3 种山药样品中的总淀粉质量分数和抗性淀粉质量分数均显著减少（P＜0.05）,但可消化淀粉（快消化淀粉和慢消化淀粉）及表观直链淀粉质量分数显著增加（P＜0.05）,同时山药淀粉的持水力增强,溶解度下降。3 种山药中,蒸制15 min的淮山药总可溶性多酚和总黄酮含量最高,分别为1.04 mg/g和0.83 mg/g,同时,其抗氧化能力也最强,铁离子还原力、1,1-二苯基-2-苦基肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率和羟自由基清除率分别为165.56 μmol/g、58.15%和82.26%。扫描电子显微镜观察发现,蒸制后山药样品颗粒呈特征性的块状和不规则的结构,表面粗糙并有裂缝。综合比较,蒸制时间对3 种山药样品的品质特征及活性成分的影响差异较大,蒸制15 min后山药样品的总可溶性多酚和总黄酮含量最高,抗氧化活性也最强,蒸制20 min后山药样品中的可消化淀粉含量较高,而生山药的微观结构特征较好,说明适度蒸制可以提高山药淀粉的消化率和山药的抗氧化能力。     

生长猪对菜籽饼中氨基酸表观消化率的研究（上）

选择健康、体重约45公斤长白×成华阉公猪4头,安装“T”型回肠痿管。以 Cr_2O_3作指示剂,用直接法测定了生长猪对浓缩菜籽蛋白、脱毒菜籽饼的氨基酸表观消化率;用套算法测定了200型机榨浸提菜籽饼(甘兰型)的氨基酸表观消化率;并进行了比较。结果表明:1)用粪分析法测得的氨基酸表观消化率高于回肠法的结果;用粪指示剂法测得的结果与全粪法的接近。2)用粪分析法测得的浓缩菜籽蛋白的氨基酸表观消化率,比脱毒菜籽饼的高,但多数差异不显著(P>0.05);而用回肠法测得的结果,则浓缩菜籽蛋白比脱毒菜籽饼的低,且多数达显著(P<0.05)或极显著水准(P<0.01)。但赖氨酸、蛋氨酸差异不显著。故从应用角度看,可认为两种菜籽饼的氨基酸表观消化率接近。3)200型机榨浸提菜籽饼必需氨基酸中,赖氨酸表观消化率最低(回肠法、全粪法、粪指示剂法测得的结果分别为48.84%、68.41%和63.25%)。     

几种薯类与豆类抗性淀粉的抗消化性及其益生效应

采用压热法制备了木薯、红薯、马铃薯、豌豆和绿豆5种抗性淀粉,研究了它们对人工胃液和人工肠液的抗消化性,以及它们对肠道益生菌生长的影响。结果表明:人工胃液对木薯、红薯、马铃薯、豌豆和绿豆抗性淀粉的消化作用很小,人工肠液对它们有明显的消化作用;经人工胃液和人工肠液先后作用,它们的消化率都比单独人工肠液处理后的要高;各种抗性淀粉对双歧杆菌、嗜酸乳杆菌、保加利亚乳杆菌、乳链球菌都有不同程度的增殖作用。综合分析可知,对肠道益生菌增殖作用最强的是豌豆抗性淀粉,其次是红薯和绿豆抗性淀粉,再次是马铃薯抗性淀粉,最差的是木薯抗性淀粉。     

Physicochemical, pasting and thermal properties of tuber starches as modified by guar gum and locust bean gum

This study was carried out in order to compare the functional characteristics of isolated starch from five tuber crops, yam, taro, sweet potato, yam bean and potato, as well as effect of guar gum (GG) and locust bean gum (LBG) on pasting and thermal properties of tuber starches. The results showed that total amylose content of five tested starches ranged from 17.85% to 30.36%. The results of pasting behaviour showed that potato starches exhibited the highest peak viscosity and yam starch presented a stable curve with little breakdown viscosity. Addition of GG and LBG resulted in a significant increase in peak, final viscosity, breakdown and setback viscosity for all tuber starches ( P  < 0.05), but a slight decrease in pasting temperature. The gelatinisation enthalpy (Δ H ) for starches with GG and LBG was slightly lower than those of the starches alone in yam and sweet potato, but not in taro and yam bean.     

Effects of mucilage on the thermal and pasting properties of yam, taro, and sweet potato starches

This study investigates the effects of water-soluble mucilages (0, 2.5, and 5 g/100 g; w/w, dry basis) on the thermal and pasting properties of isolated starches from three root and tuber crops. The results show that yam tuber presents the greatest level of mucilage and also possess the largest amylose content of the three isolated starches. The addition of mucilage caused a remarkable increase in the temperature of gelatinization for the three tested starches due to the competition for water during starch gelatinization. Furthermore, adding mucilage increased the phase transition temperature range (Tc-To) of starches but decreased enthalpy (ΔH). However, although the pasting temperature increased with the addition of mucilage into tuber starches, it did not change that of taro starch. The peak viscosity of taro and sweet potato starches decreased significantly as their mucilages were added into each starch suspension system (p < 0.05). However, the addition of mucilage slightly increased the viscosity of yam starch. Furthermore, the addition of mucilage slightly increased the swelling power of yam and taro starches, but did not change that of sweet potato starch.     

Comparative analysis of starch properties of different root and tuber crops of Sri Lanka

The physicochemical properties of starches of six different root and tuber crop species grown mainly in Sri Lanka showed significant differences among the tested crop species and varieties. The median granule size of starch of tested root and tuber crop species varied from 33.5 to 10.2 μm. The largest granule size and the highest blue value were given by the canna, Buthsarana, and yam species, in that order. The amylose content of cassava was higher than those of sweet potato and many yams. High peak viscosities, high breakdown, and high final viscosities were observed in yams, and, generally, such starch showed a high swelling power. According to the correlation analysis, these pasting properties would mainly be due to their larger starch granule size. Based on the thermal properties, cassava starch showed less energy requirement for gelatinization and thus gelatinized at lower temperatures. Furthermore, a higher susceptibility of raw cassava starch toward fungal glucoamylase was observed. The low enzyme digestibility of raw yam starch would be due to its large granules. Correlation analysis showed that the blue value and starch granule size were important in determining the pasting, thermal, and other properties of starch.     

Relationship between the physicochemical properties of starches and the glycemic indices of some Jamaican yams (Dioscorea spp.)

Starch granules from round leaf yellow yam (RY), Lucea yam (LY), white yam (WY), and Chinese yam (CY) grown in Jamaica were isolated and the relationship between starch amylose content, crystallinity, microscopic properties, in vitro digestibility, and the glycemic index (GI) of the tubers was investigated. The results indicate that RY had the highest amylose content (265.30 +/- 0.09 g/kg starch) while CY the lowest (111.44 +/- 0.03 g/kg starch). A corresponding variation in starch digestibility and GI was also observed, as CY which had the highest in vitro digestibility had the highest GI (21.27 +/- 0.01 and 97.42 +/- 0.62%, respectively), while RY, LY, and WY starches with low digestibility had lowest GI. Differences in the crystalline pattern of the different starches were observed, where RY, LY, and WY displayed the type B crystalline pattern while CY had the intermediate crystallite (type C).     

Effect of debranching and storage condition on crystallinity and functional properties of cassava and potato starches

Debranching starch by pullulanase is considered to improve the RS content of starch which is widely used to produce the starch‐based foods with high‐health benefit impacts. In this study, the cassava and potato starches were debranched by pullulanase, followed by an autoclave treatment and storage at −18°C, 4°C, or 25°C to investigate their crystallinity and functional properties. After debranching, the potato starch contained significantly higher CL (35.4 glucose units) than did the cassava starch (32.4 glucose units). The debranched cassava and potato starches after retrogradation at the storage temperatures had a typical B‐type crystalline structure although the native cassava and potato starches exhibited the different crystalline forms (A‐ and B‐type, respectively). The RS contents of the debranched cassava and potato starches significantly improved with higher RS content of the debranched potato starch than that of the debranched cassava starch at the same storage condition. The storage temperature significantly affected the RS formation of the debranched starches with the highest RS content at storage temperature of −18°C (35 and 48% for the debranched cassava and potato starches, respectively). The debranched starches had significantly lower viscosities and paste clarities but higher solubilities than did the native starches. As a result, the debranched cassava and potato starches can be considered for use not only in functional foods with enhanced health benefits but also in pharmaceutical and cosmetic industries.     

Enzymatic hydrolysis of potato starches containing different amounts of phosphorus

The rapid hydrolysis of potato starches differing in phosphorus content, as well as sweet potato, cassava and yam starches, was accomplished by treatment of gelatinised starches with bacterial liquefying α-amylase at 50 °C for 1 h, followed by Bacillus licheniformis α-amylase at 55 °C up to 24 h, and then by glucoamylase at 40 °C for a further 24 h. Among the potato starches, the high-phosphorus starches showed higher starch resistant capacity than the medium-phosphorus starches, as well as other tuber and root starches. The hydrolysis rate of tuber and root starches was not greatly influenced by their amylose content and median granule size. Only glucose was detected in the almost completely hydrolysed tuber and root starch samples, indicating that the concomitant enzymes treatment could hydrolyse both the α-1,4 and α-1,6 linkages of the starches examined.     

凉粉草胶与不同淀粉混合体系糊化和质构性质的研究

凉粉草胶(MBG)与淀粉作用可以形成凝胶。为比较不同淀粉与MBG混合体系糊化和凝胶性质的差异,选取玉米等八种常见淀粉,利用Brabender糊化仪、质构仪、对MBG与不同淀粉混合体系的糊化和质构性质进行了研究。结果发现,MBG对谷类淀粉(大米、小麦、玉米)和豆类淀粉(绿豆、豌豆)的糊化性质的影响都比较显著,对薯类淀粉(木薯、马铃薯、甘薯)的不显著,但MBG与薯类淀粉混合体系的黏度远高于MBG与豆类和谷类淀粉的;MBG与大米淀粉形成的凝胶硬度最大,与马铃薯淀粉形成的凝胶硬度次之,与豌豆淀粉形成的凝胶硬度最小。淀粉与MBG之间相互作用的强弱可以从Brabender糊化曲线上的特征点值E-D来比较。     

Characterisation and preliminary lipid-lowering evaluation of starch from Chinese yam

The physicochemical properties and preliminary lipid-lowering activities of starch separated from the tuber of Chinese yam (Rhizoma dioscoreae cv. Anguo) were investigated and compared with potato starch, to determine the possibility of using it for human consumption. The two starches showed differences in physicochemical properties, such as swelling power, turbidity, gelatinisation and crystalline properties. Chinese yam starch significantly decreased the serum total cholesterol, triglyceride and LDL-cholesterol levels in hyperlipidaemic rats. The serum total cholesterol, triglyceride and LDL-cholesterol decreased by approximately 33.8%, 46.2% and 27.5%, respectively. The HDL-cholesterol level was not modified significantly, potato starch also reduced total cholesterol, triglyceride and LDL-cholesterol but the results were not significant. The results showed that starch from Chinese yam will lower blood lipid levels.     

Physicochemical Characterization and Application of Yam (Dioscorea cayenensis‐rotundata) Starch as a Pharmaceutical Excipient

Yam starch from Dioscorea cayenensis‐rotundata complex was isolated and characterized by scanning electron microscopy (SEM), particle size analysis, X‐ray diffraction, differential scanning calorimetry (DSC), compaction and rheology, and compared to maize (Zea mays) and potato (Solanum tuberosum) starches. Yam starch exhibited a log‐normal distribution of flattened ovoid shaped granules with a mean particle size of 25 µm. X‐ray diffraction showed a C‐type crystalline pattern with the degree of relative crystallinity estimated to be 34%. DSC analysis suggests that the crystalline regions in yam starch are thermally and structurally more stable as in maize and potato. Irrespective of the relative humidity (39, 67, 78% R.H.) yam starch exhibited higher moisture uptakes than maize starch and lower than potato. Intermediate values of swelling power and amylose leaching were obtained for yam as compared to maize and potato. Compaction properties of yam and potato starches were similar. However, compacts from yam presented a relatively lower tensile strength. Aqueous starch systems (4%) of yam and maize starches showed analogous shear‐thinning (pseudo‐plastic) behavior suitably described by the power‐law model. These results support the potential use of yam starch as excipient comparable to potato starch in pharmaceutical solid forms and as thickening agent similar to maize in pharmaceutical applications.     

Physicochemical properties and in vitro digestibility of flours and starches from taro cultivated in different regions of Thailand

This research aimed to study physicochemical properties and in vitro digestibility of flours and starches from taro cultivated in different regions of Thailand, that is, Kanchanaburi (KB), Chiang Mai (CM), Phetchaburi (PB) and Saraburi (SB). Taro starches were extracted from taro flours using either water or alkaline extraction. The taro flours had significantly (P ≤ 0.05) larger particle size, higher pasting and gelatinisation temperatures, and resistant starch content but lower total starch content, whiteness (L* value), paste viscosities and clarity than their corresponding extracted starches. All the taro starches exhibited polygonal and irregular granules and gave A-type X-ray diffraction pattern. The alkaline-extracted taro starches had significantly (P ≤ 0.05) higher extraction yield, total starch content, L* value, pasting and gelatinisation temperatures, and paste clarity but lower granular size, amylose content, resistant starch content, paste viscosities and relative crystallinity than their water-extracted counterparts.