香菇醪糟的发酵工艺及品质分析

以香菇和糯米为原料,制作一种集香菇和普通醪糟营养于一体的新型香菇醪糟。在单因素试验的基础上,选取对香菇醪糟酿造工艺有影响的因素作为控制变量,以感官评分为指标通过L_9(3~4)正交试验对酿造工艺条件进行优化。结果表明,香菇醪糟的最佳发酵工艺为:香菇提取液添加量25%,酒曲添加量0.8%,发酵温度32℃,发酵时间48 h。在此条件下,香菇醪糟中还原糖含量12 g/100 g,总酸含量0.6 g/100 g,酒精含量3.0 g/100 g,感官评分90.47。此香菇醪糟发酵工艺丰富传统醪糟的风味口感、营养价值,可为保健型醪糟的开发提供理论参考。     

慢消化淀粉定量测定方法的比较研究

慢消化淀粉是指在人体小肠中能完全被消化吸收,但吸收速度较慢的一类淀粉.慢消化淀粉血糖指数低.具有特殊的生理功能,是近年来的研究热点;但是慢消化淀粉的定量测定仍然没有统一的标准.用了3种常用的慢消化淀粉定量测定方法:Englyst法、Shin法、Miao法,对大米淀粉、小麦淀粉和糯米淀粉3种原料中的慢消化淀粉进行定量测定,并进行比较分析.结果表明:Miao法模拟了人体胃肠道的生理条件,具有重复性好,操作简单等明显优势,适合,于谷物类原料中慢消化淀粉含量的测定;用该法测得的大米淀粉、小麦淀粉、糯米淀粉的慢消化淀粉含量分别为:41.6%、49.4%、54.4%.     

可溶性大豆膳食纤维对糯米淀粉体外消化性的影响及其作用机制

以糯米淀粉为原料,研究可溶性大豆膳食纤维对其体外消化性的影响。结果表明,可溶性大豆膳食纤维的添加显著降低了糯米淀粉的体外消化率,添加量越多,效果越显著。可溶性大豆膳食纤维添加量为25%时,糯米淀粉的快消化淀粉含量从83.17%减少至68.90%,慢消化淀粉、抗性淀粉含量分别从11.57%、5.26%增加至18.12%、12.98%。可溶性大豆膳食纤维的添加可以阻碍水分子进入到淀粉内部,延缓糯米淀粉的糊化过程,降低糯米淀粉对消化酶的敏感性。傅里叶变换红外光谱分析结果显示,糯米淀粉和可溶性大豆膳食纤维间没有通过新的结合键相互作用。采用扫描电子显微镜观察到可溶性大豆膳食纤维对糯米淀粉有黏附包裹的作用,阻碍了消化酶的酶解作用。     

薏米醪糟酒的工艺条件研究

采用半固态发酵工艺酿制薏米醪糟酒。以薏米和糯米为主料,甜酒曲和白糖为辅料,通过单因素实验优选出薏米醪糟酒的最佳发酵工艺条件,即发酵时间48 h,发酵温度33℃,酒曲添加量1%,薏米与糯米比1.4∶1,蒸煮时间60 min(煮25 min,蒸35 min),料水比1∶2.5,加糖量12%。在此条件下酿制的薏米醪糟酒呈白色有光泽,酒香纯正浓郁,具有米酒特有的芳香,酒体醇和、爽适、酸甜、入口醇滑。     

灌浆期糯米淀粉精细结构变化

分别对灌浆期11、13、15、17、22、27和35 d糯稻米取样,研究其淀粉形态、晶体和分子结构,揭示糯稻米成熟过程中淀粉精细结构的变化规律,以期为筛选慢消化性、抗老化性等新型糯米淀粉食品的加工原料提供科学依据。扫描电镜(SEM)和激光粒度仪(LPSA)研究结果表明,灌浆期糯米淀粉中出现球形颗粒,随着淀粉成熟,逐渐转化成为多面体状的颗粒,且颗粒峰值粒径不断增大,由5.92μm增加至6.77μm。X-射线衍射图谱(XRD)研究显示,灌浆期糯米淀粉晶型不变,然而淀粉晶体结晶度从31.0%增加至37.5%。采用阴离子色谱(HPLC-AEC)、高效尺寸排阻色谱联合多角度激光检测器与示差检测器联用系统(HPSEC-RID-MALLS)对样品分子结构进行检测发现,灌浆期淀粉分支密度逐渐增加,由81.91%提高至83.88%;灌浆后期大分子淀粉分子含量增加,相对分子质量6.817×10~7～1.033×10~8;灌浆后期糯米淀粉在水中更容易聚集。     

食林漫步

旧时在成都，人们走在街头就有可能听到“醪糟儿粉子”的叫卖声。《现代汉语词典》里有“醪糟”的释义，却找不到“粉子”的辞条。其实，粉子和醪糟儿都是由相同的原料——糯米和水制成，只不过制法上大相径庭。     

醪糟加工工艺及其包装技术的研究

通过单因素实验研究了醪糟的最佳加工工艺和瓶装、袋装水浴高温杀菌确定最佳包装技术参数。实验以糯米为原料采用糖化发酵,通过对加工醪糟过程中糯米的浸泡时间、添加酒药的种类、发酵温度、发酵时间以及发酵环境等影响因素的研究,从而选取最佳加工工艺。然后再以该工艺为标准生产醪糟,研究确定了保存醪糟的最佳杀菌时间、温度及包装材料。     

猪肉马铃薯饼的开发研究

马铃薯和猪肉分属于植物性和动物性食物资源,两者产量大,且在营养上有一定的互补性。试验选择两者为主要原料,以感官评价为指标,对猪肉马铃薯饼的生产工艺进行了优化。结果表明:糯米淀粉质量分数为20%,白糖质量分数为10%,猪肉质量分数为20%,盐质量分数为1%时(以马铃薯质量分数为100%基料计),成品感官效果最佳。对比了糯米淀粉、玉米淀粉、变性淀粉三种淀粉,对成品感官影响不大,以糯米粉最优,变性淀粉成本最低。     

湿度对糙糯米发芽过程中淀粉结构及糊化性能的影响

目的 研究湿度对糙糯米发芽过程中淀粉结构及糊化性能的影响。方法 通过扫描电镜、X射线衍射仪、拉曼光谱、差示扫描量热仪、快速粘度测定仪等方法测定糙糯米淀粉结构和糊化性能。结果 发芽处理破坏了糙糯米淀粉的颗粒结构、结晶结构和螺旋结构, 使其淀粉颗粒表面出现凹坑和孔洞, 颗粒粒径减小, 淀粉结构无序化程度增加, 且随着发芽过程中湿度条件的改变, 趋势越加明显。此外, 由于发芽处理对淀粉结构的影响, 致使淀粉的糊化温度、热糊稳定性升高, 而降低了淀粉糊的黏度性能。结论 发芽湿度条件能够显著影响糙糯米发芽过程中淀粉结构特性及糊化性能。     

大米淀粉的结构、组成与应用

本文对大米淀粉的结构、组成和应用进行了综述。较全面地概述了大米淀粉颗粒结构、分子结构特点和大米淀粉中的非淀粉组分(蛋白质和脂质)的性质及其对淀粉性能的影响；分析了大米淀粉和大米变性淀粉的性质及其开发应用情况；探讨了大米淀粉的潜在用途，包括大米多孔淀粉、抗消化淀粉、模拟脂肪和明胶替代物等；同时展望了大米淀粉工业的发展前景。     

绿豆抗性淀粉消化前后益生作用与结构变化的比较

制备与纯化得到了绿豆抗性淀粉及消化抗性淀粉,研究了它们的益生作用及结构变化。结果表明：绿豆抗性淀粉及消化抗性淀粉对双歧杆菌和乳酸杆菌的增殖效果达到100倍以上,对大肠杆菌和产气荚膜梭菌的抑制强度更是高达106倍以上,对粪肠球菌的抑制强度也有10倍,而对梭状杆菌无明显影响;它们的发酵液总酸度增大30%以上,说明它们能被肠道益生菌发酵利用;绿豆抗性淀粉经消化处理后比表面积增加,经发酵后比表面积更大。绿豆抗性淀粉的平均聚合度较之原淀粉降低了一半,发酵后绿豆抗性淀粉或消化抗性淀粉的平均聚合度继续降低30%以上;绿豆抗性淀粉经消化前后的晶型均为B型,绿豆抗性淀粉及消化抗性淀粉经发酵后,晶型都转变为A型,微晶度、亚微晶度及总结晶度较之发酵前都明显降低。     

Digestibility and Pasting Properties of Rice Starch Heat‐Moisture Treated at the Melting Temperature (Tm )

Non‐waxy and waxy rice starches adjusted to 20% moisture (wet based, w.b.) were heated in a differential scanning calorimeter to determine the optimum parameters for producing slowly digestible starch (SDS). Starches heated to the temperature of melting (T_m) and held for 60 min in the calorimeter showed a slow digestibility compared to unheated samples. Digestibility decreased by 25 and 10%, respectively, for non‐waxy and waxy rice starches relative to non‐treated starches. Heat‐moisture treatment of waxy corn, non‐waxy corn and wheat starches at the T_m determined for non‐waxy rice starch did not result in significant decreases in digestibility. For waxy rice starches heat‐treated in microwave or conventional ovens at the T_m , there were slight but significant increases in digestibility of the treated starches compared to non‐treated starches at all incubation times. Digestibility was higher for starches heated for 30 min than for 60 min. Non‐waxy rice starches did not show any significant changes in digestibility. Heat‐moisture treatment at the T_m and the holding time of sample at that temperature in a differential scanning calorimeter were found to be significant to the formation of slowly digestible heat‐moisture treated starch.     

Slowly digestible starch from heat-moisture treated waxy potato starch: Preparation,structural characteristics,and glucose response in mice

Heat-moisture treatment (HMT) was optimised to increase the formation of slowly digestible starch (SDS) in waxy potato starch, and the structural and physiological properties of this starch were investigated. A maximum SDS content (41.8%) consistent with the expected value (40.1%) was obtained after 5 h 20 min at 120 °C with a 25.7% moisture level. Differential scanning calorimetry of HMT starches showed a broadened gelatinization temperature range and a shift in endothermal transition toward higher temperatures. After HMT, relative crystallinity decreased with increasing moisture level and X-ray diffraction patterns changed from B-type to a combination of B- and A-types. Hollow regions were found in the centres of HMT waxy potato starches. HMT intensity significantly influenced SDS level. This study showed that HMT-induced structural changes in waxy potato starch significantly affected its digestibility and the blood glucose levels of mice who consumed it.     

马铃薯抗性淀粉消化前后的益生作用与结构变化

制备与纯化得到马铃薯抗性淀粉及消化抗性淀粉,研究其益生作用与结构变化。结果表明：马铃薯抗性淀粉及消化抗性淀粉对双歧杆菌和乳酸杆菌都有显著的增殖作用,对大肠杆菌和产气荚膜梭菌有强抑制作用,对粪肠球菌、梭状杆菌、兼性细菌没有影响;它们的发酵液总酸度增大,说明它们能被肠道益生菌发酵利用;马铃薯抗性淀粉经消化处理后比表面积增加,经发酵后比表面积更大;马铃薯抗性淀粉的平均聚合度较之原淀粉显著变小,马铃薯抗性淀粉或消化抗性淀粉发酵后的平均聚合度降低;马铃薯抗性淀粉经消化前后的晶型均为B型,其抗性淀粉及消化抗性淀粉发酵后的晶型都转变为A型,微晶度、亚微晶度及总结晶度较之发酵前都明显降低。     

螺杆挤压对马铃薯淀粉消化性及血糖指数的影响

目的研究螺杆挤压对马铃薯淀粉消化特性的影响。方法马铃薯淀粉经过螺杆挤压后(过程中淀粉未膨化),采用酶重量法测定挤压后抗性淀粉的含量变化情况,并通过模拟体外消化和动物实验评价挤压后淀粉的消化性能和餐后血糖上升速率。结果螺杆挤压后马铃薯淀粉中抗性淀粉的含量增加了1.08%,酶解时间为0~1.5 h时,马铃薯淀粉快速消化淀粉的含量减少,酶解时间为1.5~6.5 h时,抗性淀粉和慢消化淀粉的含量增加。挤压后的马铃薯淀粉在一定程度上可以降低小鼠的餐后血糖指数。结论螺杆挤压技术可以提高抗性淀粉和慢消化淀粉的含量,减缓餐后血糖上升速率,为马铃薯食品的深度开发提供一定的参考。     

RS4型抗消化淀粉的结晶结构及消化性能研究

利用偏光显微、X射线衍射等现代分析技术，研究了酯化改性后淀粉颗粒形貌和结晶结构的变化。结果表明，与HylonV玉米淀粉相比，酯化改性后得到的RS4型抗消化淀粉的颗粒形貌和结晶结构都受到不同程度的破坏，尤其导致了结晶形态由B型向V型转变。由此引起淀粉的消化性能发生改变，经体外模拟试验表明，RS4型抗消化淀粉在人工胃液和人工小肠液中都有良好的抗消化性能，且随着抗消化淀粉含量的增加，抗消化性能越显著，显示了其良好的结肠靶向性。     

Long- and short-range structural changes of recrystallised cassava starch subjected to in vitro digestion

The conformational and structural order of resistant starch type III made from cassava starch was studied. The gelatinized starch was debranched using pullulanase and then recrystallised by annealing, temperature-cycling or heat-moisture treatment. Subsequently, the recrystallised products were subjected to in vitro digestion using porcine pancreatic α-amylase and amyloglucosidase. The undigested and digested products were analyzed for polymer chain distribution, crystallinity, molecular order, structural conformations and thermal stability using high performance anion exchange chromatography, wide angle X-ray diffraction, Fourier transform infrared spectroscopy, ¹³C CP/MAS nuclear magnetic resonance and differential scanning calorimetry, respectively. Average degree of polymerisation increased from 20 to 22 glucose units upon digestion. Both the undigested and digested starches comprised mixtures of A, B and V crystalline types. Percentage of crystallinities by X-ray diffraction were 40.9%, 50.7% and 56.2% in annealed, temperature-cycled and heat-moisture treated starches, respectively. These values increased to 47.9%, 54.4% and 58.2%, respectively, in the digested products. The ordered fractions in the undigested annealed, temperature-cycled and heat-moisture treated starches were 69.3%, 71.4% and 79.2%, respectively, as determined by ¹³C CP/MAS nuclear magnetic resonance. However, the disordered phase was indistinct in the digested products although the contents of non-crystalline conformations were significantly (p < 0.01) higher. The melting enthalpies of the digested residues increased by factors of 2.50 in annealed, 2.53 in temperature-cycled and 2.06 in heat-moisture treated starches, suggesting molecular rearrangement in a manner related to the enzyme susceptibility of the initial materials.     

Multi‐scale structural and digestion properties of wheat starches with different amylose contents

The physicochemical and digestion properties of three wheat starches with different amylose contents were studied. Scanning electron microscopy (SEM) showed they displayed a spherical disc‐like form, a lenticular shape and an irregular morphology, respectively. Compared with waxy and normal wheat starches, high‐amylose wheat starch (HAWS) was characterised by the presence of lower molecular weight amylose fraction, and its granules demonstrated the highest resistance to the cooking. The changes in the IR ratio 1022/999–1047/1022 cm^?1 following the gel storage suggested the molecules of HAWS are more readily to re‐associate and re‐organise into a more organised status than other two starches. The determination of glucose release showed that HAWS had the lowest digestion kinetics (P < 0.001), and this difference in the digestion properties between HAWS and the other two starches might imply that starch molecular structure, in particular amylose structure is another key factor for manipulating starch digestion property rather than amylose content alone.     

淀粉的慢消化性能与酶水解速率研究

研究了体外模拟条件下不同淀粉中营养片断,同时建立了酶水解动力学方程来探讨慢消化性能与酶水解速率的关系。结果表明,相比马铃薯与绿豆淀粉,玉米、蜡质玉米、小麦、糯米、大米等谷物淀粉属于理想的慢消化淀粉,它们的酶动力学水解速率小于1h-1,而马铃薯与绿豆淀粉的水解速率大于1h-1。淀粉的水解过程的反应动力学速率比Englyst法更能准确反映淀粉的消化性能。     

Starch digestibility of foods: a nutritional perspective

Dietary starch varies greatly in digestibility and its effects on the utilization of other nutrients. The variation appears to be due to differences in starch components and their crystallinity. Processing treatments, storage conditions, chemical modification, and genetic breeding influence the digestibility of starch. Cereal starches are generally more digestible than root/tuber and legume starches. Although cooking often significantly improves the digestibility of poor and intermediately digestible starches, some foods such as bananas with starches of these types are consumed uncooked. The efficient digestion of starch is especially important to specific groups of people such as infants under 6 months of age. Ruminants must also be provided with highly digestible starch to assure maximum production efficiency. Poor digestibility of starch may have negative effects on the utilization of protein and minerals but is likely to have positive effects on the availability of certain vitamins. Decreases in the rate of starch digestion may have therapeutic application. Most clinical studies have reported that starch blockers do not elicit a significant decrease in the digestion of starch in humans. Much remains to be learned, clarified, and understood about starch digestion and its effects on diabetes and weight control.