家用豆浆机制作胚芽豆浆

以发芽大豆为原料,利用豆浆机工装平台,优化胚芽豆浆的制浆工艺。通过对粉碎温度、煮浆时间的单因素试验,发现较佳的粉碎温度为70℃、煮浆时间为4min。采用优化后的胚芽豆浆程序制得的胚芽豆浆含γ-氨基丁酸1.36mg/100g,游离氨基酸0.455g/100g,游离氨基酸中必需氨基酸0.219g/100g,分别是原程序干豆豆浆的3.68,1.34,8.87倍。尽管胚芽豆浆中胰蛋白抑制剂活力为干豆豆浆的1.27倍,但总体营养价值仍得到显著提升。     

烘烤大豆制备发酵豆乳流变学特性的研究

以烘烤大豆为原料,经瑞士乳杆菌(Lactobacillus helveticus,LH-B02)和干酪乳杆菌(Lactobacillus casei,L.casei-01)组合发酵制备发酵豆乳,研究了发酵豆乳的流变特性和物理性质。结果表明,大豆经过烘烤处理后,发酵豆乳表现出较弱的粘弹性和剪切稀化特性,酸乳的凝胶体系更加疏松,感官上表现为口感更加柔软;与未经烘烤的大豆发酵豆乳相比,烘烤处理后大豆发酵豆乳的持水力和亮度都显著下降,颜色趋于绿色和黄色;烘烤赋予发酵豆乳淡淡的烘烤香气,豆腥味降低,风味得到明显的改善。     

发芽糙米粉理化性质研究

对发芽粳糙米粉和发芽籼糙米粉基本成分、微观结构、热焓特性及糊化性质(RVA)等进行了研究。结果表明:与糙米粉相比,发芽糙米粉中粗脂肪含量降低,蛋白质含量增加,总淀粉含量降低,粗纤维、灰分等含量变化不明显;随着发芽时间的增长,糙米粉峰值粘度、最低粘度、崩解值、最终粘度和回升值都降低;发芽糙米粉峰值温度、起始温度、终止温度及焓值均比糙米粉低,且籼糙米高于粳糙米。扫描电镜结果显示:发芽后糙米粉颗粒结构变得较疏松,棱角不太明显,发芽籼糙米粉颗粒结构较发芽粳糙米粉颗粒结构更加疏松,淀粉颗粒体积更小。      

Effect of components extracted from okara on the physicochemical properties of soymilk and tofu texture

ABSTRACT:  The physicochemical properties of soymilk and the texture of tofu were compared with regard to 2 kinds of soymilk, one of which was prepared by squeezing homogenates before heating and the other was prepared by squeezing after heating raw soymilk with okara, residue of soymilk production. Relative particulate protein content and viscosity were higher and pH was lower in the soymilk prepared by the latter method, in which liberated lipid bodies were decreased and more lipids were precipitated with protein after centrifugation, suggesting a change in the interaction between proteins and lipids. A difference in the distribution of proteins and lipids was also implied by analysis with a laser particle size analyzer. The breaking stress of tofu made with 0.30% glucono-delta-lactone increased in accordance with an increase in particulate protein. The calcium and magnesium contents increased in soymilk prepared by squeezing after heating with okara. Viscosity was slightly increased and pH decreased by adding calcium to the soymilk, but the particulate protein content and breaking stress of tofu did not increase significantly. To examine the effect of macromolecules, okara was extracted by boiling and dialyzed. Viscosity and particulate protein content in soymilk increased as the dialyzed extracts of the okara were added. The breaking stress of tofu was increased by adding the dialyzed extracts but excessive amounts of the extracts resulted in softer tofu. Spectra of Fourier-transform infrared spectroscopy and electrophoresis-separated patterns of proteins indicated that the dialyzed extracts contained mainly polysaccharides and the Basic 7S globulin protein.     

Biological activities of fermented soybean paste (Doenjang) prepared using germinated soybeans and germinated black soybeans during fermentation

To produce doenjang with enhanced biological activities, doenjang was prepared by fermenting regular soybeans (RS), germinated soybeans (GS), and germinated black soybeans (GBS) for 90 days. The isoflavone contents in GS and GBS-doenjang were slightly higher than in RS-doenjang in the early stage of fermentation. The DPPH radical scavenging activity of GBS-doenjang was highest at 70.00% after 30 days of fermentation. The angiotensin-converting enzyme (ACE) inhibiting effects increased as the fermentation period progressed, and were significantly (p<0.05) higher in GBS-doenjang (58.69%) than in other preparations after 75 days of fermentation. The greatest fibrinolytic activities were 127.59 and 100.00% in nontreated GBS-doenjang and GBS-doenjang treated for 30 min at 55°C, respectively. There were significant (p<0.05) correlations between the total isoflavone content and the antioxidant activity (0.779) and between the isoflavone content and the ACE activity-inhibiting effects (0.669). GBS-doenjang exhibited greater antioxidant activities, ACE-inhibition, and fibrinolytic activities than RS and GS-doenjang.     

Germination improves the functional properties of soybean and enhances soymilk quality

The effects of soybean variety and germination time on structural changes, antinutritional factor content, antioxidant activity of germinated soybean, and on the functional properties of soymilk were comprehensively investigated. The results showed that the antioxidant activity increased with increasing germination time. The content of antinutritional factors decreased with increasing germination time. Soybean varieties with the lowest tannin and trypsin inhibitor content were DN690 and HJ1. Lipoxygenase activity and phytic acid content showed no significant differences among soybean varieties. The content of α-helices and β-turns in soybean protein decreased with increasing germination time, while the content of β-sheets was increased. Soybean protein was progressively broken down into smaller molecular peptides during the germination process. The digestion and content of soluble protein in soymilk increased with germination. In summary, we show that germination is an effective, cheap, and green method that improves the functional properties of soybean and soymilk.     

Antioxidant and antiinflammatory properties of germinated and hydrolysed Brazilian soybean flours

The effect of germination in combination with Alcalase hydrolysis of Brazilian soybean cultivar BRS 133 on the production of soybean flours with bioactive peptides as modulators of oxidative stress and markers of inflammation was monitored. The electrophoretic profile showed a weak protein breakdown during germination. However, a strong breakdown of the proteins can be observed after the first hour of hydrolysis with Alcalase. MALDI-TOF-MS analysis of the protein extracts showed differences in the intensity and profile of peptide mass fingerprint due to germination and hydrolysis. Germinated flour showed higher soluble protein concentration and antioxidant capacity. All soybean protein extracts and protein hydrolysates produced (G0, G18 and G72) showed a significant (p < 0.05) inhibition on inflammatory markers such as nitric oxide (20.5–69.3%), iNOS (22.8–93.6%), PGE₂ (64.0–88.3%), COX-2 (36.2–76.7%), and TNF-α (93.9–99.5%) in LPS-induced RAW 264.7 macrophages. However, protein extracts of flours with 18 h of germination were more potent in inhibiting pro-inflammatory responses when compared to 72 h. It can be concluded that a combination of 72 h of soybean BRS 133 germination and 1 h Alcalase hydrolysis resulted in the formation of bioactive compounds with more potent antioxidant activity, and improvement in the reduction of some of the markers of inflammation.     

甘薯抗性淀粉理化性质研究

采用酶法结合超声波处理制备抗性淀粉,并分析其颗粒分布、晶体结构类型、淀粉分子结构、热特性等理化特性 结果表明,甘薯抗性淀粉颗粒分布、粒径大小、晶体结构、熔融温度明显不同于甘薯淀粉.甘薯抗性淀粉平均粒径、糊化峰值温度、终止温度大于甘薯淀粉;甘薯淀粉结晶结构表现为C型,甘薯抗性淀粉结晶结构表现为B型,酶解辅以超声波处理的方法可以制备高含量的抗性淀粉.     

Protein quality and antioxidant properties of soymilk derived from black soybean after in vitro simulated gastrointestinal digestion

Protein quality and antioxidant properties of soymilk derived from black soybean (eight varieties) in China were analysed following in vitro simulated gastrointestinal digestion (including dialysis). Soymilk from black soybean possessed high okara weight but low yield, protein content and sensory scores. The in vitro digestibility of protein in all black soymilk samples was higher than 60%, and the Shenmu black soybean exhibited the highest digestibility. Non-digested milk from the black soybean exhibited significantly high total phenolic content (TPC) (127.15–173.04 mg/100 mL), ferric-reducing antioxidant power (FRAP) (272.18–366.27 μmol L⁻¹) and DPPH free radical-scavenging activity (61.20–83.81%). These parameters were significantly lower in the non-digested soymilk than those in soymilk after gastric digestion but higher than those of soymilk in the dialysed fraction. Gastric digestion significantly increased bioactive compound levels released from black soymilk, and the bioaccessibility of phenolic compounds was 24.37–36.05%. Hence, black soymilk was sufficiently available for human absorption.     

Hydration properties,soymilk and okara yield of soybean affected by agronomic factors

The effects of row space and irrigation on 100‐seed weight water uptake, leaching loss, soymilk, and okara yield of soybean were investigated. Row space affected leaching loss, whereas irrigation significantly altered 100‐seed weight, water uptake, volume change, leaching loss, and the soymilk yield of soybeans. Irrigation on the third day resulted in desirable hydration properties. The soymilk yield significantly correlated (p < 0.01 or 0.05) to the hydration properties, e.g., 100‐seed weight, water uptake, volume change, and leaching loss. A predictive regression model (R = 0.860) has been proposed for the soymilk yield.     

Hydration properties,soymilk and okara yield of soybean affected by agronomic factors

The effects of row space and irrigation on 100-seed weight water uptake, leaching loss, soymilk, and okara yield of soybean were investigated. Row space affected leaching loss, whereas irrigation significantly altered 100-seed weight, water uptake, volume change, leaching loss, and the soymilk yield of soybeans. Irrigation on the third day resulted in desirable hydration properties. The soymilk yield significantly correlated (p < 0.01 or 0.05) to the hydration properties, e.g., 100-seed weight, water uptake, volume change, and leaching loss. A predictive regression model (R = 0.860) has been proposed for the soymilk yield.     

脱皮大豆等温吸水模型与复水磨浆工艺参数优化

研究大豆浸泡时间（6、8、10、12、14、16 h）对豆浆理化特性和感官品质的影响,为大豆浸泡时间的选择提供理论支撑。实验以大豆水分含量及分布、可溶性蛋白质含量、固形物含量、粒径、黏度、稳定性及感官评分作为考察指标,分析浸泡时间对豆浆品质的影响并确定大豆适宜的浸泡时长;采用Pearson相关系数对浸泡时间、大豆水分组成与豆浆品质的关系进行分析。低场核磁共振结果表明,T₂₁、T₂₂、T₂₃信号值随着浸泡时间延长而升高,大豆吸附水的占比增加,大豆浸泡12 h后水分达到饱和状态。豆浆的品质研究结果表明,随着浸泡时间的延长,豆浆的蛋白质转移率、体积平均粒径、黏度均呈现先升高后降低的趋势,总固形物含量显著降低（P<0.05）,豆浆稳定性先降低后升高;豆浆的感官评分值随着大豆浸泡时间的增加先增加后降低,8 h豆浆的感官综合评价值最高为1.0466,其次是10 h的豆浆。基于以上结果,优选大豆浸泡时间为8 h,虽然该时间的豆浆黏度低,口感浓度评分低,亮度值低;但是其可溶性蛋白质含量最高,为0.905 g/100 g,蛋白转移率可达到16.61%;总固形物含量仅次于6 h的豆浆,含量为3.185 g/100 g;而且色差b值最低,感官综合评价值最高。相关性分析结果表明：浸泡时间与大豆结合水占比、自由水占比呈显著负相关,与吸附水占比呈显著正相关（r=−0.9638、−0.8241、0.9391）;豆浆的品质指标受到浸泡时间影响,其中浸泡时间与豆浆可溶性蛋白质、总固形物含量、L值呈显著负相关,与a值呈显著正相关关系（r=−0.9122、−0.9726、−0.8238、0.9385）。

     

Wet grinding characteristics of soybean for soymilk extraction

Wet grinding of hydrated soybean was carried out with mixer grinder, stone grinder and colloid mill which revealed that particle size had a profound effect on the protein recovery in the extracted milk with a maximum recovery of 89.3%. Greater reduction in particle size was achieved with mixer grinder (180 μm) with 5 min of grinding while reduction was not significant beyond 18 min (233 μm) in stone grinder. Specific energy consumption in colloid mill was only one-fourth of the mixer grinder while stone grinder required twice the energy. Although Kick’s, Rittinger’s and Bond’s laws could not be applied for total grinding duration, all the three classical laws were found suitable after the initial grain break-up period (2 min). Temperature and duration of thermal treatment given during hot extraction influenced protein recovery and viscosity of soymilk. The results suggest that colloid mill is a potential device for industrial scale operation.     

Structure,trypsin inhibitor activity and functional properties of germinated soybean protein isolate

The objective of this research was to investigate the effects of germination on functional and conformational properties as well as the in vitro trypsin digestibility of soy protein isolate (SPI). The influences of germination on the molecular properties of SPI were also evaluated. The germination degraded lipoxygenase, α, α' subunits of β‐conglycinin (7S) and acidic chains of glycinin (11S) of soybean. Concomitantly, the loss of tertiary structures of SPI occurred due to the germination. The trypsin inhibitor activity of germinated SPI presented a decreasing trend, followed by an increase in the growth of hypocotyls. The in vitro trypsin digestibility of germinated SPI followed a consistent trend with the trypsin inhibitor activity. The protein solubility (PS) and emulsifying properties of SPI were improved by the germination, in a hypocotyl length‐dependent manner. The data suggest that some selected functional properties and the in vitro digestibility of soy proteins can be improved by means of the germination.     

加工方式对发芽糙米理化性质影响研究进展

介绍了发芽糙米的营养价值及生理功效,综述了加工方式对发芽糙米理化性质的影响,提出发芽糙米在食品加工中有待解决的问题,并展望未来发展前景,以期为发芽糙米的功能性食品开发提供参考。     

Effects of parboiling and fluidized bed drying on the physicochemical properties of germinated brown rice

Changes in physicochemical properties of germinated brown rice (GBR) and parboiled germinated brown rice (PGBR) dried in a fluidized bed dryer at 110–150 °C were investigated. Results indicated that parboiling altered the properties of GBR owing to starch gelatinisation. The moisture content, yellowness, peak viscosity and hardness of PGBR increased, but internal fissured kernel, cooking time, water absorption and total solids loss decreased when compared to GBR. γ‐aminobutyric acid (GABA) content in GBR was 23.31 mg per 100 g and was reduced to 17.91 mg per 100 g in PGBR. The drying times required to reduce the moisture content of GBR and PGBR to 16% d.b. were 4.01–7.65 min and 5.11–9.50 min, respectively. Final moisture content, which is optimum to prevent internal fissures of dried GBR and PGBR, was 27–29% and 25–28% d.b., respectively. The same trend was observed in the physicochemical properties of GBR and PGBR when increasing drying temperature and time.     

富含多肽的发芽豆乳饮料的研制

研究发芽大豆富集多肽的培养条件,并以富含多肽的发芽大豆为原料,进行发芽豆乳饮料研制;采用正交试验设计对豆乳饮料配方和稳定剂添加量进行研究。结果表明,采用pH 5.0的柠檬酸缓冲液(CBS)培养大豆发芽5d多肽含量达到最高值,为88.71mg/g;以饮料的感官评定值为指标,优化出的多肽豆乳饮料配方为蔗糖添加量8%、柠檬酸添加量0.025%、牛奶添加量20%。稳定剂添加试验表明:PGA添加量为0.15%、黄原胶为0.05%、CMC为0.05%时饮料的稳定性最佳。大豆发芽改善了豆乳口感,豆乳中多肽含量是未发芽豆乳的2倍,产品色泽乳白,具有豆香味。     

Composite wheat–germinated brown rice flours: selected physicochemical properties and bread application

Selected physicochemical properties of composite [wheat/germinated brown rice (GBRF)/germinated glutinous brown rice (GGNBRF)] flours at 100:0:0 (control), 70:30:0, 60:30:10, 60:40:0 and 50:40:10 (%) were evaluated. Germination (steeping at pH 3 for 24 h at 35 °C) increased free gamma‐aminobutyric acid from 2.11 to 32.7 and 2.41 to 30.69 mg per 100 g flour for GBRF and GGNBRF, respectively. The 60:30:10 and 50:40:10 composite flours exhibited the lower peak viscosity (70.42 and 68.54 RVU, respectively). The setback viscosity of composite flours containing GGNBR was significantly lower than other flours. The presence of GBRF and GGNBRF significantly lowered specific volume and expansion ratio of breads. However, all sensory liking scores, except for appearance, were not significantly different among composite flour breads. Overall liking scores of all breads ranged from 6.8 to 7.2 (like moderately). This study demonstrated feasibility of incorporating GBRF and GGNBRF up to 50% by weight in bread formulations without compromising sensory liking.