不同发芽条件对蚕豆植酸酶活性变化和性质的影响

以蚕豆为试材,研究了发芽过程中植酸酶在蚕豆不同部位的变化和性质。发芽蚕豆不同部位植酸酶活性呈现先高后低的变化趋势,子叶植酸酶在发芽第6天达到最高值。超声波处理对发芽蚕豆胚根和子叶植酸酶活性有一定促进作用,其中以15min超声波处理对胚根植酸酶活性影响最大,5min处理、10min处理和15min处理均对子叶植酸酶活性有显著影响。在发芽过程中不同光照对蚕豆进行处理,不论胚根、子叶还是胚芽,黑暗处理植酸酶活性高于光照处理。核酸抑制剂放线菌素(Act-D)和蛋白质抑制剂环已酰胺(CHM)对发芽蚕豆胚根、子叶和胚芽中的植酸酶活性有一定影响,其中以CHM的抑制效果最为明显。     

不同发芽条件对大麦中植酸含量及植酸酶活力的影响

大麦发芽过程中,发芽温度、浸麦水pH值及浸麦水中金属离子的种类和含量是影响大麦中植酸含量及植酸酶活力的重要因素。实验发现,当发芽温度为16℃时,植酸酶较高温和低温发芽更早的被激活,其活力达到4.032 8U/g(绝干),更加有利于植酸的分解;在浸麦水为中性条件下浸麦,植酸酶活力上升较快,植酸含量迅速下降;在浸麦期间添加Ca2+、Mg2和Fe3+等金属离子对植酸酶的活力有较大抑制作用。     

热激处理和柠檬酸提高发芽糙米中植酸酶活性

研究了热激处理和柠檬酸发芽介质对糙米的内源植酸酶活性的影响,并采用响应面设计优化了热激处理条件。结果表明,随着热激时间的延长,糙米中植酸酶的活性逐渐升高,达到峰值后下降。利用中心组合响应面设计实验,预测并验证的优化的热激和浸泡条件为,热激温度50℃,热激时间30min,浸泡时间6h。以2mmol/L柠檬酸缓冲液(pH5.2)作为发芽介质,植酸酶活性随着发芽时间的延长,先升高后下降;发芽3d,植酸酶活性达到最高值(241.27U/kg),高于原料糙米(115.57U/kg)。本工艺提高了发芽糙米的内源植酸酶活性,为开发糙米食品中降低植酸和保持营养价值的提供了基础数据。     

热激处理和柠檬酸提高发芽糙米中植酸酶活性

研究了热激处理和柠檬酸发芽介质对糙米的内源植酸酶活性的影响,并采用响应面设计优化了热激处理条件。结果表明,随着热激时间的延长,糙米中植酸酶的活性逐渐升高,达到峰值后下降。利用中心组合响应面设计实验,预测并验证的优化的热激和浸泡条件为,热激温度50℃,热激时间30min,浸泡时间6h。以2mmol/L柠檬酸缓冲液(pH5.2)作为发芽介质,植酸酶活性随着发芽时间的延长,先升高后下降;发芽3d,植酸酶活性达到最高值(241.27U/kg),高于原料糙米(115.57U/kg)。本工艺提高了发芽糙米的内源植酸酶活性,为开发糙米食品中降低植酸和保持营养价值的提供了基础数据。      

不同储藏条件下小麦粉植酸酶活性变化规律研究

在不同储藏条件下,对小麦粉中植酸酶活性变化规律进行研究。采用储藏条件为:相对湿度分别是55%和70%,温度分别为10℃、15℃、20℃、25℃、30℃、35℃,以此进行小麦粉模拟储藏试验。结果表明,小麦粉植酸酶活性为先快速上升,而后趋于平稳,继而下降;温度、时间对酶活性影响极其显著;小麦粉中植酸酶作用有限,大多数磷都以有机磷形式存在。     

发芽处理对蚕豆主要成分和γ-氨基丁酸的影响

研究了酸性低氧胁迫和非胁迫条件下,蚕豆发芽过程中主要营养成分的变化,以及γ-氨基丁酸(GABA)的富集情况。结果表明:随着发芽时间的延长,胁迫和非胁迫条件下发芽5.5 d后,蚕豆蛋白含量分别提高了18%和3%,淀粉含量降低了19%和22%,还原糖分别比发芽前提高了157%和63%。胁迫条件下蚕豆GABA含量是原料的49.26倍,非胁迫条件下没有显著差异。因此,可以将酸性低氧胁迫下发芽的蚕豆用于生产富含GABA保健食品,可以显著蚕豆的经济价值。     

工艺参数对发芽糙米中植酸含量的影响

研究发芽糙米生产过程中糙米所含抗营养因子植酸的变化规律,以发芽温度、发芽时间、浸泡时间、赤霉素浓度等工艺参数对产品植酸含量的影响进行了正交试验,试验结果表明:发芽温度和发芽时间对植酸含量的影响显著,发芽温度的提高和发芽时间的持续使糙米中植酸的含量逐步下降;通过发芽降低糙米植酸含量的最佳工艺参数组合为:发芽温度36℃、发芽时间34 h、浸泡时间12 h、赤霉素(GA3)浓度0.30 mg/L,此条件下发芽糙米产品中的植酸含量为3.22 mg/g.     

发芽蚕豆富集γ-氨基丁酸的培养液组分优化

以蚕豆为试材,研究谷氨酸钠(MSG)、CaCl2、和VB6对发芽蚕豆谷氨酸脱羧酶(GAD)及γ-氨基丁酸(GABA)的影响,采用Box-behnken设计对发芽蚕豆富集GABA的培养液组分进行了优化,并对发芽蚕豆富集GABA的二次回归模型进行分析。结果表明,低氧联合盐胁迫下,MSG、CaCl2和VB6对发芽蚕豆GAD及GABA的影响均达到显著水平(P<0.005)。经过回归分析建立了GABA含量对培养液组分的二次回归模型,回归方程的决定系数达到0.976,说明方程能很好的预测GABA富集含量的变化。蚕豆富集GABA的最适培养液组分为MSG 1.1 mg/mL、CaCl2 6.1 mmol/L、VB6 72μmol/L,此时,GABA富集量达到(1.98±0.09)mg/g DW,为对照[(1.08±0.01)mg/g DW]的1.83倍。     

浸泡条件对燕麦发芽过程中酶活性的影响

为探究浸泡条件对燕麦发芽过程中淀粉酶、蛋白酶以及纤维素酶活力的影响,通过在不同的浸泡温度、时间和含有不同金属离子的浸泡水溶液中浸泡燕麦籽粒,测定燕麦中各酶活力随发芽时间的变化情况。研究结果表明,燕麦浸泡最优条件为浸泡温度15℃,时间8 h,浸泡水溶液添加2 mmol/L MgSO₄。在此浸泡条件下,16℃发芽10 d,发芽燕麦中的总淀粉酶、α-淀粉酶、蛋白酶和纤维素酶活力较高,分别达到54.39、25.3、0.55和1.35 U/g。      

低氧联合NaCl胁迫下蚕豆发芽富集γ-氨基丁酸培养条件优化

以蚕豆(启豆2号)为原料,研究了低氧联合NaCl胁迫下培养条件对γ-氨基丁酸(GABA)富集的影响。结果显示:非胁迫培养时间、培养pH和胁迫培养时间显著影响发芽蚕豆GABA积累。蚕豆发芽富集GABA最佳培养条件是非胁迫培养1.5 d、培养液pH 3.5和低氧联合NaCl胁迫4 d,在此条件下其GABA含量可达1.06mg/g DW,为原料蚕豆的7.57倍。     

发芽处理对蚕豆主要营养成分与抗营养因子的影响

研究发芽处理对启豆2号蚕豆主要营养成分与抗营养因子含量的影响。对蚕豆发芽前后蛋白质、脂肪、淀粉、VC、氨基酸、植酸和单宁含量测定。结果表明：蚕豆在发芽1d时可溶性蛋白质含量显著增加,随后逐渐下降;粗脂肪和淀粉含量均呈下降趋势;发芽2d时VC含量显著增加,达到最大58.65mg/100g,随后逐渐下降,5d后VC含量仍高于未发芽的;发芽后1～2d蚕豆的氨基酸含量略有增加;发芽1d抗营养因子植酸含量下降了33.55%,随后平缓;发芽1d蚕豆的单宁含量增加到462.70mg/100g,2～3d增加比较平稳,5d急剧增加至1306.10mg/100g。可推知,将启豆2号蚕豆发芽1～2d的作为食用及加工的较佳时期。     

Effect of Several Germination Treatments on Phosphatases Activities and Degradation of Phytate in Faba Bean (Vicia faba L.) and Azuki Bean (Vigna angularis L.)

Abstract: Two assays were conducted to investigate the changes of faba bean (Vicia faba L.) and azuki bean (Vigna angularis L.) phosphatases (phytase [Phy] and acid phosphatase [AcPh]) and the degradation of its substrates (inositol phosphate esters) during seed germination. The 1st assay was to establish the optimal germination conditions of faba bean and azuki bean to improve the endogenous phosphatases and increase the hydrolysis of phytate and, in the second assay, to determine the different lower phosphate esters of myo‐inositol produced during the germination process. In the 1st assay, seeds were soaked for 12 and 24 h and germinated for 3 and 5 d with and without the addition of gibberellic acid (GA₃). In the second assay, seeds were soaked for 12 h and germinated for 1, 3, and 5 d with GA₃. Phy (up to 3625 and 1340 U/kg) and AcPh (up to 9456 and 2740 U/g) activities, and inositol hexaphosphate (IP6) (8.23 and 7.46 mg/g), inositol pentaphosphate (IP5) (0.55 and 0.82 mg/g), and inositol tetraphosphate (IP4) (0.26 and 0.01 mg/g) were detected in ungerminated faba bean and azuki bean, respectively. The germination process caused a significant increase of Phy and AcPh activities in faba bean (up to 147% and 210%) and azuki bean (up to 211% and 596%) and a reduction in the phytate phosphorus content (up to 81% and 63%, respectively). Phytate phosphorus content was affected only by soaking time in the case of faba bean. Finally, during the course of germination, IP6 and IP5 were rapidly degraded in faba bean (88% and 39%) and azuki bean (55% and 56%), and IP4 was only a short‐living intermediate, which was increased during hydrolysis and degraded to inositol triphosphate. In this manner we could obtain a low‐phytate, endogenous phosphatase‐rich ingredient for enhancing human nutrition.     

Effects of Phytases and Dehulling Treatments on In Vitro Iron and Zinc Bioavailability in Faba Bean (Vicia faba L.) Flour and Legume Fractions

ABSTRACT: In vitro digestions were performed on faba bean flours with decreased phytate contents and on 2 dephytinized or nondephytinized faba bean fractions, a dehulled faba bean fraction, and a hull fraction with low and high fiber and tannin contents, respectively. In vitro bioavailability iron and zinc was defined as the relative amount of iron and zinc that became soluble after enzymatic treatment. Faba bean samples were sequentially digested with enzymes, including amylase, pepsin, pancreatin, and bile, under certain conditions following the enzymatic degradation procedure. Iron and zinc in vitro bioavailability of whole faba bean flours were significantly improved by phytate degradation, even if the phytate were not all degraded. Total dephytinization of dehulled faba bean led to an obvious increase in iron and zinc in vitro bioavailability, but that of hulls had no effect on either iron or zinc in vitro bioavailability. Fibers and tannins other than phytate are more important in chelating a high proportion of iron and zinc in faba bean hulls.     

A Characterization of Faba Bean Starch (Vicia faba L.)

In Far East faba bean starch is always present in several food applications. But often the starch quality is low and knowledge of characteristic attributes do not exist. Therefore, we tried to isolate a faba bean starch with few impurities, and to analyse the starch quality with different types of techniques. Furthermore, a comparison between three cultivars (two Chinese and one German) should point to possible differences. The crude protein content of all isolated starches was lower than 0.3% dry matter. Particle size distribution of the starch granules was mainly between 20 and 40 μm diameter. Gelatinization range was between 56 and 81°C. Brabender viscograms showed very stable hot gels with no viscosity reduction during the hot phase. A gel filtration analysis of the starch molecules gave relevance to molecular weights of amylose between 100 and 200 × 10³ MW. In spite of quite different genetic backgrounds and agricultural conditions the quality of the starches was not very different between the two Chinese and one German cultivars.     

The impact of processing on phytic acid,in vitro soluble iron and Phy/Fe molar ratio of faba bean (Vicia faba L.)

BACKGROUND: Faba bean is one of the important legumes in Asian countries. It is also a major source of micronutrients in many rural areas. Unfortunately, the bioavailability of iron from faba bean is low because it is present as an insoluble complex with food components such as phytic acid. The influence of soaking, germination and fermentation with the expectation of increasing the bioavailability of iron was investigated. RESULTS: Fermentation treatments were most effective in decreasing phytic acid (48–84%), followed by soaking at 10 °C after preheating (36–51%). Steeping faba beans for 24 h at 25 °C had the least effect on the removal of phytic acid (9–24%). With increased germination time at 30 °C, phytic acid progressively decreased from 9 to 69%. Most wet processing procedures, except soaking after wet preheating, caused losses of dry matter and iron (8–15%). In vitro iron solubility, as a percentage of total iron in soaked faba bean after dry preheating, was significantly higher than in raw faba bean (P < 0.05). Fermentation and germination did not have significant effects on the solubility of iron. CONCLUSION: The expected improvement of iron bioavailability levels due to lower phytic acid was not confirmed by increasing levels of in vitro soluble iron. Soaking, germination and fermentation can decrease phytic acid in faba bean. However, results from in vitro solubility measurement of iron showed little improvement of iron bioavailability in fermented and germinated faba beans over untreated raw faba beans (P < 0.05). It seems that componets of dietary fibre other than phytic acid are more important in binding iron. Probably, a complex association between dietary fibre and iron is the reason for the poor bioavailability of iron in faba bean. Copyright © 2009 Society of Chemical Industry     

In vitro starch digestibility of fresh and sun‐dried faba beans (Vicia faba L.)

Fresh and sun‐dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre‐associated resistant starch (FARS) contents as well as α‐amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The α‐amylolysis rate decreased with increasing storage time, i.e. long‐stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry     

黑豆发芽条件及其异黄酮提取物特性研究

对黑豆发芽条件及其中异黄酮提取物特性进行了探讨。结果表明：黑豆最佳发芽条件为浸泡温度38℃、浸泡时间15h、发芽温度32℃、发芽时间50h;发芽黑豆中的异黄酮具有较高的清除羟自由基能力、清除超氧阴离子自由基能力和很好的抗油脂氧化能力;通过对异黄酮组分的测定可知,发芽后以葡糖苷（IFG）形式存在的异黄酮含量降低,以甙元（IFA）形式存在的异黄酮含量增加。     

Extraction of favism‐inducing agents from whole seeds of faba bean (Vicia faba L var major)

The objective of the present study was to establish a suitable procedure by which favism‐inducing glycosides vicine and convicine could be completely removed from whole seeds of faba beans without distorting their shape or reducing their nutritive value. Detoxification procedures carried out were extraction by water or, 10 g l^?1 acid solutions (acetic, citric and phosphoric acid) using stepwise or continuous soaking procedures. Three cultivars of the beans were used in the study. In the stepwise soaking procedures, the seeds were soaked in either water or acid solution at 40 °C for different periods while in the continuous flow techniques, the solutions were constantly passed through a seed reservoir under different time–temperature–flow rate conditions. Extraction of vicine and convicine increased with increasing temperature and period of soaking and/or continuous flow of soaking solutions. Neither stepwise soaking nor autoclaving could effectively remove the favism factors from the whole seeds. The best results were obtained with continuous flow soaking in tap water, giving vicine‐ and convicine‐free seeds. The protein contents of treated seeds were only slightly affected and their physical structure remained intact. Thus, it was concluded that the latter procedure was the method of choice for detoxification of dry whole seeds. Copyright © 2005 Society of Chemical Industry