Evaluation of red bean protein [Vigna angularis] isolate on rheological properties of pork myofibrillar protein gels induced by microbial transglutaminase

The effects of 1% red bean protein isolate (RBPI) on the gel properties of myofibrillar protein (MP) in various levels of microbial transglutaminase (MTG: 0%, 0.1%, 0.5%, & 1%) were evaluated. The cooking yield (CY) of the MP gels decreased with increasing MTG level, while the addition of RBPI improved the CY of the MP gels. Gel strength (GS) was also improved when RBPI was incorporated into the MP gels containing higher than 0.5% of MTG. The addition of MTG and RBPI was slightly changed the endothermic peak temperatures. Scanning electron microscopy (SEM) showed that the three‐dimensional structure of MP with RBPI alone or in combined with MTG was compacted as compared to the control. Based on the results, RBPI could be functioned as a substrate for MTG (0.5–1.0%) and a water binder of meat protein gel mediated by MTG.     

Preventive effect of adding antioxidants on mutagenic compound formation in fumes of cooking oil

The preventive effect of various antioxidants on the formation of mutagenic compounds such as trans,trans‐2,4‐decadienal in degummed peanut oil (DPO) fumes was investigated. The mutagenicity of the DPO fumes was significantly reduced by antioxidants added before heating. The addition of antioxidants increased the smoke point and oxidative stability of DPO and decreased the yield of oil fumes and the amount of mutagens. Butylated hydroxyanisole and butylated hydroxytoluene were more effective than natural antioxidants in reducing the amount of four enal compounds in fumes from DPO. Thus edible cooking oil with a high smoke point, less fume and lower mutagenicity might be developed with an appropriate antioxidant. Copyright © 2004 Society of Chemical Industry     

Inhibitory effects of Hibiscus sabdariffa L extract on low‐density lipoprotein oxidation and anti‐hyperlipidemia in fructose‐fed and cholesterol‐fed rats

Hibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low‐density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid‐reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu²⁺‐mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high‐fructose diet (HFD) fed rats and serum cholesterol in high‐cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL‐cholesterol (LDL‐C) to HDL‐cholesterol (HDL‐C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD‐ or HCD‐fed rats. Copyright © 2004 Society of Chemical Industry     

Effect of high power ultrasonic treatment on whey protein foaming quality

High power ultrasonic energy at 20%, 40% and 60% amplitude was applied on whey protein suspension at concentrations of 100, 150 and 200 g kg^?1 for 5, 15 and 25 min to improve its foaming quality. Ultrasound‐treated whey protein suspension at 200 g kg^?1 showed improvement in terms of increased foaming capacity by 18%, foam stability by 35%, consistency index by 18%, storage modulus by 17%, loss modulus by 26% and viscosity by 21% compared with untreated whey protein. For maximally ultrasound‐treated samples of 60% amplitude treated for 25 min, the improved whey protein foams also had a 46% increase in the number of more evenly distributed fine bubbles which had a size smaller than 0.0025 mm³ as imaged using X‐ray microtomography.     

黑木耳胞外多糖深层发酵培养基组成的优化

研究了营养性因子对黑木耳深层发酵的影响.结果表明,葡萄糖、酵母膏、豆饼粉有利于黑木耳菌体生长和胞外多糖的形成.正交优化实验得到最佳培养基组成:葡萄糖40g/L,豆饼粉9g/L,KH2PO44g/L,无机盐X22g/L.     

大豆纤维/麻交织物一浴法染色工艺

对大豆蛋白纤维与麻类纤维及其交织物的染色性能进行研究。利用两类纤维不同的染色特性，通过对染料的筛选，确定了不同的染色工艺条件，如pH值和温度等控制，达到一浴同色和一浴双色染色的预期效果。     

Optimisation of enzymatic hydrolysis for concentration of squalene in palm fatty acid distillate

BACKGROUND: Squalene was concentrated from palm fatty acid distillate (PFAD) in this study using commercial immobilised Candida antarctica lipase (Novozyme 435^®). The PFAD was neutralised (NPFAD) using an alkali to liberate the free fatty acids and then hydrolysed at 65 ± 1 °C. The enzymatic hydrolysis on NPFAD was optimised using response surface methodology (RSM) before being neutralised again to obtain a concentrated squalene fraction. RESULTS: A five‐level, three‐factor central composite rotatable design was adopted to evaluate the effects of the enzymatic hydrolysis parameters reaction time (4–12 h), water content (50–70% w/w) and enzyme concentration (1.5–3.5% w/w) on the percentage yield of squalene concentration. The optimal reaction parameters for maximum yield of squalene concentration were identified from the respective contour plots. The optimal enzymatic hydrolysis conditions were a reaction time of 7.05 h, a water content of 61.40% w/w and an enzyme concentration of 2.23% w/w. CONCLUSION: RSM was used to determine the optimal conditions for enzymatic hydrolysis of NPFAD with C. antarctica lipase for maximum recovery of squalene which could be implemented on an industrial scale. Copyright © 2008 Society of Chemical Industry     

Comparative physicochemical stability and efficacy study of lipoid S75-biopeptides nanoliposome composite produced by conventional and direct heating methods

Liposomes are used as effective nanodelivery devices to improve the physicochemical stability and biological efficacy of the encapsulated peptides and proteins. In this study, nanoliposome composite of lipoid S75-entrapped angiotensin I-converting enzyme (ACE)-inhibitory biopeptides was prepared by conventional (BLS75-CM) and direct heating (BLS75-DHM) methods. The nanoliposomes (BLS75-CM and BLS75-DHM) were stored at 4^°C for 8 weeks and evaluated for physicochemical stability in terms of particle size, polydispersity index (pdi), zeta potential, and encapsulation efficiency (EE). These were also studied for residual ACE-inhibitory efficacy following their digestion under simulated gastrointestinal tract condition. The BLS75-CM was found to maintain higher physicochemical stability in terms of particle size, pdi, and zeta potential compared to BLS75-DHM. However, the BLS75-DHM indicated higher EE and efficacy with greater residual ACE-inhibitory activity of 47.37% compared to 44.18% and 36.84% that were obtained for the digested BLS75-CM and digested biopeptides without encapsulation, respectively. In vitro release study showed a cumulative biopeptides release of 66.41% and 69.00% from BLS75-CM and BLS75-DHM, respectively. The results of transmission electron microscopy showed spherical appearance of the nanoliposome capsules while Fourier Transform Infrared spectroscopy indicated the presence of ionic complexation and hydrogen bonds between the biopeptides and their phospholipid matrix.     

Effect of polyglycerol esters of fatty acids on physicochemical properties and stability of β‐carotene nanodispersions prepared by emulsification/evaporation method

The effects of six different polyglycerol esters of fatty acids (PGEs) as nonionic emulsifiers on the physicochemical properties and stability of β‐carotene nanoparticles in oil‐in‐water dispersions produced by an emulsification/evaporation technique were examined. The β‐carotene particle size was measured by a laser diffraction technique, and the stability and retention of β‐carotene during various preparation steps and storage were determined by HPLC. In the prepared nanodispersions the β‐carotene particle size decreased with increasing degree of glycerol polymerisation and decreasing carbon number of the fatty acid group in the PGE. The particle size of β‐carotene in nanodispersions containing polyglycerol monooleate was generally larger than that in the presence of polyglycerol monolaurate. During storage at 4 °C, although the β‐carotene content in the nanodispersions showed a significant ( P < 0.05) decrease with increasing storage period, the size distribution of β‐carotene was almost unchanged in all prepared nanodispersions. In general, the mean diameter of β‐carotene nanoparticles ranged from 85 to 132 nm. In the light of their ability to physically stabilise β‐carotene particle formation, it is suggested that PGEs with a high degree of glycerol polymerisation may be useful in the preparation of β‐carotene nanodispersions. The best stabilisation was obtained using 10 g kg^?1 decaglycerol monolaurate. Copyright © 2004 Society of Chemical Industry