Malted weaning food made from maize,soybean, groundnut and cooking banana

Infant malnutrition and mortality are common in Africa, although Africa is endowed with agricultural produce that could be harnessed through processing to produce adequate infant food. This project was set up to explore the possibility of using local raw materials to develop a nutritious, low‐dietary‐bulk, cheap infant food. The materials used included cereal (maize), pulses (soybean and groundnut) and tuberiferous plants (cooking banana). The grains were first germinated and dried or kilned before milling and formulation. The malted products were compared with fermented ones in terms of nutritional, dietary bulk and acceptability criteria. Malting increased the nutrient content, reduced the dietary bulk and enhanced the taste of the infant food. In terms of protein content, least gelation concentration and overall acceptability, malted samples had values in the range of 138–151 mg g^?1, 150–175 g l^?1 and 7.2–8.82 respectively, while the control (fermented) sample had values of 54 mg g^?1, 100 g l^?1 and 6.29 respectively. Roasting of malted cereals above 55 °C reduced the bulk reduction ability but enhanced the taste of the products. A combination of malted maize and soybean, roasted groundnut and cooking banana in the ratio of 50:15:15:20 gave a very recommendable weaning food for infants between the ages of 6 months and 2 years. © 2002 Society of Chemical Industry     

浅谈酶在非接触印刷废纸脱墨中的应用

简要地介绍了纤维素酶、半纤维素酶和淀粉酶在非接触印刷废纸脱墨中的研究及其应用     

Protein Extraction from Heat-stabilized Defatted Rice Bran: II. The Role of Amylase, Celluclast, and Viscozyme

ABSTRACT: The effectiveness of 3 carbohydrases for protein extraction from heat-stabilized defatted rice bran (HDRB) was evaluated. Amylase, viscozyme and celluclast extracted a maximum of 45.4, 12.1, and 28.5% protein, respectively. Further study showed that extracted protein ranged from 9.5 to 58.4% under conditions of water to bran ratio (5:1 to 20:1), α-amylase (0 to 110000 units/10 g rice bran), temperature (35 to 55 °C), and time (1 to 8 h). The maximum protein extracted was 58.4% with a water to bran ratio of 17:1, 87637 units amylase, and 50.9 °C. These results suggest that impure food-grade amylase containing protease is more effective than celluclast and viscozyme in protein extraction from HDRB.     

淀粉液化液灭酶方法的研究

某些情况下淀粉液化液需要严格控制液化的程度 ,因此需要及时终止残余淀粉酶的活性。实验用降低液化液 pH值、升高温度、以及两者并用等 3种方法结束液化反应过程 ,实验结果可作为工业生产过程参考。     

One‐step production of 2,3‐butanediol from starch by secretory over‐expression of amylase in Klebsiella pneumoniae

BACKGROUND: 2,3‐Butanediol (2,3‐BD) is a valuable chemical that can be biosynthesized from many kinds of substrates. For commercial biological production of 2,3‐BD, it is desirable to use cheap substrate without pretreatment, such as starch. However, there have been few reports on the production of 2,3‐BD directly from starch. RESULTS: In this work, gene malS coding for α‐amylase (EC 3.2.1.1) precursor was inserted into plasmid pUC18K, and secretory over‐expression of α‐amylase was achieved by engineered Klebsiella pneumoniae. The extracellular recombinant amylase accelerated the hydrolyzation of starch, and one‐step production of 2,3‐BD from starch was carried out by engineered K. pneumoniae. A 2,3‐BD concentration of 3.8 g L^?1 and yield of 0.19 g 2,3‐BD g^?1 starch were obtained after 24 h fermentation. CONCLUSION: The one‐step production of 2,3‐BD from starch was achieved by secretory over‐expression of amylase in K. pneumoniae. This would simplify the process and reduce the production cost considerably by enabling use of starch with minimal pretreatment. Copyright © 2008 Society of Chemical Industry     

面粉中的淀粉组分对面条蒸煮品质的影响

从面粉中提取淀粉、直链淀粉和支链淀粉,按不同的梯度添加到原面粉中制作面条.然后测定面条的蒸煮特性,寻找出淀粉、直链淀粉和支链淀粉对面条蒸煮品质影响的规律.实验表明:随着淀粉添加量的增加,面条的干物质吸水率、干物质损失率、蛋白质损失率都出现了上升的趋势;随着直链淀粉添加量的增加,面条的干物质吸水率出现了下降的趋势,而干物质损失率、蛋白质损失率都出现了上升的趋势;随着支链淀粉添加量的增加,面条的干物质吸水率出现了上升的趋势,而干物质损失率、蛋白质损失率都出现了下降的趋势.     

纳米糊精微球对头孢曲松钠的吸附及其释药性能

以糊精为原料,三偏磷酸钠为交联剂,利用反相微乳液法制备糊精纳米微球,并对头孢曲松钠的吸附载药和释药性能进行了研究。为模拟人体血液环境,选取了pH 7.4的磷酸二氢钠-磷酸氢二钠缓冲液为介质考查了糊精微球的吸附载药及降解性能。实验表明,纳米糊精微球对头孢曲松钠的载药率为9.44%,载药能力随着投药量的增加而增加,温度对载药能力的影响不显著,在α-淀粉酶存在的条件下,降解6 h后有23.94%的纳米糊精微球被降解。     

Extraction,optimisation and characterisation of phenolics from Thymus vulgaris L.: phenolic content and profiles in relation to antioxidant,antidiabetic and antihypertensive properties

The objectives of this study were to examine varying extraction conditions of Thymus vulgaris L. as related to phenolic content and profiles of the extracts and their antioxidant, antihypertensive and antidiabetic properties. Phenolics were extracted under various conditions pertaining to free and bound phenolics, solvent type and combination of extraction time and temperature, and these extracts were evaluated in terms of their antioxidant activities and inhibitory activities of angiotensin‐converting enzyme (ACE), α‐glucosidase and α‐amylase. The acetone–water solvent mixture (1:1; v/v) produced the extract with the greatest phenolic content, antioxidant activity and inhibitory activities of ACE and α‐glucosidase. The optimal extraction temperature for maximum phenolic content and antioxidant activity associated with methanol extraction was 60 °C, whereas a lower temperature at 40 °C was required to maximise inhibitory activities for ACE, α‐glucosidase and α‐amylase. An inverse relationship was seen between antioxidant and glucosidase inhibitory activities vs. the ACE and α‐amylase inhibitory activities, which suggests the need for extractions to be directed to specific bioactivities of thyme extracts. Generally, the results indicate major differences in phenolic profiles among the tested extraction conditions with thymol as the predominant phenolic seen in most extractions, while gallic acid, rosmarinic acid or diosmin also predominated in other extracts. Extracts with the same predominant phenolic compound and similar phenolic content showed major disparities in their ACE, glucosidase and α‐amylase inhibitory activities, indicating that the major phenolic profiles of thyme extracts may not be necessarily related to the degree of inhibition of ACE, glucosidase and α‐amylase enzymes.     

Influences of pretreatment and drying methods on composition,micro/molecular structures and some health‐related functional characteristics of dietary fibre powder from orange pulp residues

Influences of pretreatment methods (washing, blanching, soaking in ethanol), drying methods (hot air‐drying, infrared‐drying, microwave‐drying) and drying temperature on selected characteristics of dietary fibre powder from orange pulp residues were investigated. Pretreatments improved the hydration properties, oil‐holding capacity and glucose dialysis retardation index, but led to losses of fibres, decreased α‐amylase inhibitory activity and aflatoxin B₁ adsorption capacity. Hydration properties, oil‐holding capacity and glucose uptake depended on the structure and porosity of the fibre, while the ability to inhibit α‐amylase and AFB₁ adsorption depended more on the content and molecular fingerprinting of the fibre. Drying condition did not significantly affect functional properties of the fibre, except for the ability to uptake glucose, inhibit α‐amylase and adsorb AFB₁ (P ≤ 0.05). Hot air‐drying at 60 °C resulted in fibre with the highest ability to decrease the rate of glucose and AFB₁ adsorption.     

Changes of porcine pancreas α‐amylase in activity and secondary conformations under inhibition of tea polyphenols

To investigate two‐sided functions of tea polyphenols (TP) in antinutrition and energy balance modulation, TP were extracted from Chinese green tea and used to complex porcine pancreas α‐amylase (PPA). Changes of PPA in activity and secondary conformations were analysed. Porcine pancreas α‐amylase was found sensitive to TP treatment. Tea polyphenols exhibited IC₅₀ at 0.41 mg mL^?1 against PPA and maximum inhibitory rate (98.17%) at 3.0 mg mL^?1. Tea polyphenols inhibition was concluded as noncompetitive pattern based on its unchanged Km value (0.98 mg mL^?1) for soluble starch substrate. Tea polyphenols inhibition arose from pH 1.5 to 10.14, covering gastric and intestinal environments inside body. Circular dichroism spectra analysis revealed regular changes of PPA in secondary conformations (increased proportions of α‐helix and β‐sheet) prior to its inactivation at low TP concentrations. Tea polyphenols‐inhibited PPA had distinct double‐negative peaks at 204 nm and 208 nm. Porcine pancreas α‐amylase was inactivated by TP in ways of complexation and modification of secondary conformations.