永川豆豉传统发酵过程中的大豆异黄酮变化

为了探明永川豆豉在传统发酵过程中大豆异黄酮总含量和构成变化,采用高效液相色谱技术对永川豆豉传统发酵过程中大豆异黄酮总量和构成进行测定。结果表明：永川豆豉在发酵加工过程中大豆异黄酮总含量由发酵起始的3117mg/kg下降到豆豉成熟时的1754mg/kg;大豆异黄酮构成变化显著,游离苷元型大豆异黄酮含量迅速增加由发酵起始的3.2%上升到豆豉成熟时的95.7%,同时结合糖苷型大豆异黄酮含量迅速降低。     

Physico‐functional and antioxidant properties of purple‐flesh sweet potato flours as affected by extrusion and drum‐drying treatments

Effects of extrusion and drum‐drying treatments on physico‐functional and antioxidant properties of flours prepared from purple‐flesh sweet potato were evaluated. Extrusion variables were feed moisture contents (MC; 10%, 13%, 16%) and screw speeds (SS; 250, 325, 400 r.p.m.), whereas drum‐drying was done at 120, 130 or 140 °C. Effects of MC were generally greater than SS on flour properties. Extruded flours showed higher water absorption and water solubility indices compared with control nonextruded flours. Regardless of SS, total phenolic content and antioxidant activities (DPPH and ABTS) of flours processed at 10% MC were significantly higher than those at 13% and 16%. Both extruded and drum‐dried flours exhibited no peak viscosity, indicating complete gelatinisation of starch. Maximum phenolic content and antioxidant activities of drum‐dried flours were obtained at 140 °C. Although drum‐dried flours had higher antioxidant capacity than extruded flours, both flours could potentially be used as food ingredients.     

干燥工艺对紫薯全粉理化性质及花色苷的影响

为了提高紫薯全粉的品质,保留其营养价值,本文以紫薯\     

Isoflavone content and apoptotic effect in HT-29 cancer cells of a soy germ extract

Colon cancer is one of the leading causes of death and a major public health problem in western countries. We examined the isoflavone content of 70% ethanol extract of soy germ (SG) and its apoptotic effect in HT-29 colon cancer cells. Our results showed that the major isoflavones of the SG extract were daidzein and genistein, and it effectively induced apoptosis in HT-29 cancer cells. In addition, nuclear factor-kappa B (NF-κB) expression was reduced in cells treated with the SG extract, which reduced cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) expression. These combined effects ultimately resulted in apoptosis via caspase-3 activation. In addition, daidzein and genistein, the major isoflavones of SG extract, also exerted the apoptotic effect against HT-29 cancer cells. These results suggest that the inhibition of NF-κB expression is the most important factor in the induction of apoptosis in HT-29 cells treated with the SG extract.     

干燥方式对SPC功能性和结构的影响

通过研究不同干燥方法(冷冻干燥和喷雾干燥)对SPC(大豆浓缩蛋白)的NSI(氮溶指数)、起泡性和乳化性的影响,并利用凝胶电泳和傅立叶红外光谱方法研究不同干燥方法对SPC结构的影响;探讨SPC功能性质改善的机理。     

Urinary isoflavone excretion in Korean adults: comparisons of fermented soybean paste and unfermented soy flour

BACKGROUND: This study compared the 24 h urinary excretion of isoflavone algycones after the consumption of fermented soybean paste or unfermented soy flour in a population of healthy Koreans (four males and five females). An equivalent amount (20 mg) of total isoflavone was consumed as either 52 g of soybean paste or 12.2 g of soy flour in a randomised, crossover trial consisting of two single‐time‐point feedings and having 3 day run‐in and washout periods between feedings. RESULTS: Analysis of starting materials indicated that daidzein (1.4%) and genistein (1.4%) constituted a smaller proportion of the total isoflavones in soy flour as compared with soybean paste (55.3% daidzein and 45.7% genistein). Free and glycosidic forms of isoflavones differed significantly between the two soy products. Levels of β‐glycosides as well as total glycosides (β‐glycosides, malonyl and acetyl forms) were two‐fold higher in soy flour as compared with soybean paste. Malonyl forms predominated in soy flour. CONCLUSIONS: The consumption of soybean paste resulted in significantly higher urinary excretion of both daidzein and genistein as compared with soy flour (P < 0.05 and P < 0.01 respectively). Copyright © 2007 Society of Chemical Industry     

大豆胚芽中提纯皂甙和异黄酮的研究

探讨了以水为介质,对大豆胚芽中的皂甙和异黄酮进行微波和超声波前处理,提取效果和纯溶剂萃取法相比,经正交实验,结果表明：经450W功率微波处理30min,400w功率超声波在40℃处理45min,固液比为1：20,温度为60℃,时间为1h,再经40％的乙醇,浸提2次。异黄酮提取率从1．2％提高到1．74％,皂甙从4．4％提高到5．8％,比溶剂法的提取率分别提高了43％和32％,经聚酰胺柱层析分离纯化,大豆异黄酮和大豆皂甙产品纯度达到38％和94％。     

Characterisation of soy extract processed under different drying methods and extraction conditions

Soybean extract (SE), enriched in soy soluble polysaccharide (SSPS), was evaluated in three different conditions varying in extraction temperature and drying process: SE‐A ?80 °C, freeze‐dried, SE‐B ?80 °C, spray‐dried, SE‐C ?95 °C, spray‐dried. Spray‐dried SE presented lower moisture content, smaller and more uniform particles. In addition, zeta potential showed the same negative surface charge for all extracts showing the prevailing behaviour of SSPS. Moreover, all biopolymers were composed of three main molecular weight (Mw) fractions, but the Mw distribution was different between the three ingredients, reflecting their rheological behaviour in aqueous solution. Higher mean Mw led to enhanced apparent viscosity observed in neutral and acid pH for SE‐A, followed by ‐B and ‐C, respectively. The inverse behaviour was observed for intrinsic viscosity at neutral pH. However, SE‐C showed lower intrinsic viscosity at acid pH, which was attributed to protein–polysaccharide interaction presents in the solution.     

干燥方式对不同接枝度的大豆分离蛋白-麦芽糊精聚合物性质影响

以大豆分离蛋白（SPI）和麦芽糊精（MD）为原料制备不同接枝度的SPI-MD聚合物,研究比较喷雾干燥和冷冻干燥两种处理方式对不同接枝度下的SPI-MD聚合物性质的影响,如溶解度、疏水性、持水性、乳化性、乳化稳定性及起泡性、泡沫稳定性等的影响。实验表明,喷雾干燥样品的溶解性,表面疏水性和乳化性高于冷冻干燥样品;冷冻干燥样品则具有较好的持水性。另外,两种干燥样品的乳化稳定性非常接近。不同接枝度的两种干燥样品起泡性差异较大,且泡沫稳定性都相对较差。      

预处理及干燥方法对果蔬干制品VC含量影响的研究进展

文章从干燥预处理和干燥技术2个果蔬干制的重要环节出发,对国内外关于预处理和干燥方法对果蔬干制品V_C含量影响的研究现状进行了较全面的综述。     

植物乳杆菌58发酵豆乳产大豆异黄酮苷元条件的优化

本研究通过测定植物乳杆菌58在不同碳源中的生长和产β-葡萄糖苷酶情况,筛选菌株的最适碳源,并确定接种至豆乳的最佳时间.在接种量、糖含量、发酵时间和发酵温度等单因素实验基础上,根据Box-Behnken中心组合原理进行响应面实验设计,以大豆异黄酮苷元含量为指标,进一步优化菌株58发酵豆乳产大豆异黄酮苷元条件.结果显示,植...     

Changes in characteristics of sweet potato flour prepared by different drying techniques

The changes occurring in the characteristics of sweet potato flour as a result of processing were investigated. Pasting behaviour of drum dried and hot air-dried sweet potato flour was determined using Rapid Visco-Analyser. The pasting characteristics decreased due to gelatinization of starch during processing. The degradation of starch by amylases during hot air drying further lowered the water binding capacity/viscosity and total amylose and increased the digestibility compared to those of drum dried and native flour. Swelling power and solubility of the flours increased as a result of processing which subsequently increased with increase in temperature. Scanning electron micrographs of starch granules showed tendency of clustering, especially in drum dried samples. X-ray diffraction patterns showed alteration from Ca-type to V-type with a marked reduction in crystallinity index as a result of processing. The ¹³C NMR spectra of processed starches showed reduced peak intensities and line widths due to depolymerizing effects, and also pointing to their change in crystallinity.     

不同干燥方式对陈皮中7种黄酮含量及抗氧化性的影响

目的 考察不同干燥方式对广陈皮和普通陈皮中7种黄酮含量及其抗氧化性的影响。方法 对广东新会茶枝柑和福建芦柑果皮采用3种干燥方式(自然晾晒、热风烘干、冷冻干燥)制备陈皮, 利用高效液相色谱法测试样品中7种黄酮(橙皮苷、香蜂草苷、甜橙黄酮、去甲基川陈皮素、3,5,6,7,8,3’,4’-七甲氧基黄酮、川陈皮素、橘皮素)的含量, 采用二苯苦味酰肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)、2,2’-联氮-二-(3-乙基-苯并噻唑啉-6-磺酸)[2,2’-azinobis(3-ethylbenzothiazoline-6-sulphonic acid), ABTS]、OH自由基清除活性和还原能力测试样品的抗氧化性。结果 对于本研究的两种陈皮, 热风烘干和自然晾晒陈皮的黄酮含量较高; 热风烘干陈皮的抗氧化性最高, 其次是自然晾晒, 且OH自由基清除活性较其他方法更能真实地反映陈皮黄酮的抗氧化性。结论 热风烘干制备陈皮具有较高的黄酮含量和抗氧化性。研究结果可为区分了解不同干燥方式制备陈皮的品质提供依据, 同时为陈皮干燥方式的选择提供参考。     

The influence of additives and drying methods on quality attributes of fish protein powder made from saithe (Pollachius virens)

BACKGROUND: Fish protein powder (FPP) is used in the food industry for developing formulated food products. This study investigates the feasibility of increasing the value of saithe (Pollachius virens) by producing a functional FPP. Quality attributes of spray and freeze‐dried saithe surimi containing lyoprotectants were studied. A freeze‐dried saithe surimi without lyoprotectants was also prepared as a control sample. RESULTS: The amount of protein, moisture, fat and carbohydrate in the FPPs were 745–928, 39–58, 21–32 and 10–151 g kg^?1. Quality attributes of FPPs were influenced by the two drying methods and lyoprotectants. The highest level of lipid oxidation was found in the control and the second highest in the spray‐dried FPP. The spray‐dried fish protein had the lowest viscosity among all FPPs. Gel‐forming ability of samples with lyoprotectants was higher than that of the control. Water‐binding capacity, emulsion properties and solubility of the freeze‐dried fish protein containing lyoprotectants were significantly higher than spray‐dried and control samples. However, functional properties of spray‐dried FPP were higher than the control sample. CONCLUSION: It is feasible to develop value‐added FPP from saithe surimi using spray‐ and freeze‐drying processes, but freeze‐dried FPP containing lyoprotectant had superior functional properties and stability compared with spray‐dried sample. Both products might be used as functional protein ingredients in various food systems. Copyright © 2010 Society of Chemical Industry     

Isoflavone content of soybean cultivars grown in eastern Canada

Soybean (Glycine max (L) Merr) seeds contain isoflavones that have positive impacts on human health. The objective of this study was to determine isoflavone concentrations of early maturing soybean cultivars grown in different environments and to determine their relation to other important seed characteristics. Twenty soybean cultivars were grown in replicated trials at two sites in Montreal, Canada in 2002/2003 and their total and individual isoflavone concentrations were determined by high‐performance liquid chromatography. Seed yield, 100‐seed weight and oil, crude protein and crude fiber concentrations were concurrently determined. Total and individual isoflavone concentrations were significantly affected by cultivar, site and year. Total isoflavone concentration ranged from 360 to 2241 µg g^?1 and averaged 851 µg g^?1 across environments and cultivars. Variation across environments ranged from 20 to 100% for specific cultivars. Total isoflavone concentration was, on average, 40% greater in 2003 than 2002, which was characterized by above average temperatures and severe drought. Despite significant cultivar × year × site interactions, cultivars with consistently high and low isoflavone concentrations across environments were identified. Weak but significant positive correlations were observed between total isoflavone concentration and seed yield, 100‐seed weight and crude fiber, indicating that isoflavone concentration is positively associated with other desirable seed characteristics. Copyright © 2004 Society of Chemical Industry     

Okara flours from chickpea and soy are thickeners: increased dough viscosity and moisture content in gluten-free bread

The by-product of plant-based beverages, okara, can be dried in a nutritious flour, but it generates dense bakery products due to high water absorption. Gluten-free bread often tastes dry, so the objective of this work was evaluating okara flour as thickener for mouthfeel enhancement. Proximate analysis revealed that chickpea okara contained more starch than soy (35.3 vs. 3.41 g/100 g), less insoluble fibre (43.3 vs. 57.0 g/100 g) and protein (9.51 vs. 18.1 g/100 g). Water absorption capacity was higher in okara than flour and for soy (8.29 vs. 6.01 g g⁻¹, respectively). When added to a gluten-free batter, both okara flours significantly increased viscosity. Upon addition of either okara to gluten-free bread (2% w/w) moisture content increased from 31.6 to 33.5 and 36.5 g/100 g, while crumb hardness increased by up to 45% and specific loaf volume decreased by up to 42%. Soy okara flour enhanced moistness of gluten-free bread.     

Effect of temperature and water availability during late maturation of the soybean seed on germ and cotyledon isoflavone content and composition

BACKGROUND: Isoflavone content in soybean seeds is strongly influenced by both environment and genotype. However, little is known about the effect of environment and genotype on isoflavones in germ versus cotyledons. To determine the effect of temperature and soil moisture status during soybean seed development on seed isoflavone concentration and composition, a set of two French and three US cultivars of similar maturity were grown in the greenhouse. At the R6 growth stage, plants were subjected to one of three night/day temperature regimes (13/23°, 18/28° or 23/33 °C) in either optimal or sub‐optimal soil water conditions. RESULTS: In cotyledons, a three‐ to six‐fold variation in total isoflavone content was observed between the high and low temperature treatments, whereas the germ contents had less than a two‐fold variation. Soil water supply had less effect than temperature on the isoflavone contents and compositions. In both seed parts, the isoflavone concentrations were highly dependent on the cultivar. CONCLUSION: These results show that isoflavone content and composition in cotyledon and germ are unrelated and it should be possible to independently manipulate these seed traits through plant breeding and crop management systems. Copyright © 2007 Society of Chemical Industry     

Fruit snacks from raspberries: influence of drying parameters on colour degradation and bioactive potential

Raspberries were dehydrated using air and freeze‐drying with wet and dry sugar infusion pretreatments. Product quality factors such as colour, bioactive compounds, antioxidant capacity and sensorial characteristics were analysed. Special emphasis was placed on the analysis of anthocyanin degradation and its relationship with colour deterioration and with polymeric compounds development and browning. Freeze‐dried raspberries presented a higher retention of bioactive compounds and a lower content of polymeric compounds than air‐dried ones. Dried samples without pretreatment (control) showed the highest retention of total phenolic content (freeze‐dried ≈82% and air‐dried ≈37% retention), but the lowest sensory acceptability. Although sugar infusion pretreatments caused an important loss of bioactive compounds (9–18% of TPC retention), a higher sensorial acceptability was obtained. Pretreatments with bisulphite and acid allowed obtaining the best quality attributes in terms of anthocyanin and polyphenol content, antiradical activity and colour retention. Polyphenol intake through pretreated dried raspberries (115–299 mg gallic ac./100 g intake) would be higher in some cases than that of usually consumed foods as vegetables, cereals and several fresh fruits.