浸泡和微波处理对三种高粱熟化的影响

为研究浸泡和微波处理对三种高粱熟化工艺参数的影响,采用单因素实验的方法,探讨浸泡时间和浸泡温度对高粱吸水率,以及微波时间和微波功率对高粱蒸煮熟化程度和熟化时间等工艺参数的影响。结果表明,随着浸泡时间的增加,三种高粱的吸水率均呈现先上升后平稳的趋势,龙米粮1号、龙杂13号和红糯高粱的最佳浸泡时间分别为2、2和3 h;随着浸泡温度的增加,三种高粱的吸水率呈上升的趋势,最佳浸泡温度分别为45、35和35 ℃。在最佳浸泡时间和浸泡温度条件下,当微波功率600 W和微波处理8 min时,龙米粮1号高粱熟化程度达到100%,蒸煮熟化时间缩短20 min;微波功率800 W和微波处理时间11 min时,龙杂13号高粱熟化程度达到100%,蒸煮熟化时间缩短20 min;微波功率800 W和微波处理时间11 min时,红糯高粱熟化程度达到100%,其蒸煮熟化时间缩短15 min。研究确定了三种高粱最佳浸泡和微波处理工艺参数,为高粱熟化工艺提供了技术参数。     

浸泡参数与米饭品质关系的研究

根据南方米饭快餐的产业化需求和目前煮饭设备的现状,通过实验和研究,分析了大米吸水率与浸泡温度和时间的关系和浸泡参数对米饭品质的影响,并因此确定了大米浸泡吸水率与浸泡温度和时间的关系曲线和浸泡参数与米饭品质曲线。得出吸水率与温度、浸泡时间呈正比,米饭的品质与吸水率呈抛物线关系。     

蒸谷米快速浸泡工艺研究

研究不同浸泡工艺包括温度-时间、微波、酸碱溶液、低浓度乙醇、酶对稻谷吸水率的影响,结合蒸谷米外观品质及米饭质构分析,筛选有效的快速浸泡工艺。结果表明,在稻谷∶水为1∶1(g/mL)、温度60~70℃、浸泡4~5 h时,便达到浸泡工艺要求,吸水率达到30%;能显著提高稻谷吸水率的方法是质量比5%的纤维素酶浸泡4 h,吸水率达30.07%;能显著缩短浸泡时间方法是5 min、700 W微波浸泡,吸水率为31.69%。且2种浸泡工艺对蒸谷米的外观品质和米饭质构无不良影响,有望作为蒸谷米快速浸泡工艺进行应用。     

不同浸泡条件下糙米吸水特性的研究

针对发芽糙米生产工艺中浸泡处理这一关键步骤,对糙米的吸水特性进行了初步研究。选取3种稻谷为原料,通过改变浸泡温度、浸泡时间、浸泡溶液浓度,考察在不同浸泡条件下糙米粒的吸水效果。结果表明:在相同条件下提高浸泡温度,可提高前2~4 h吸水率,缩短吸水达饱和的时间;浸泡溶液的浓度越高,在前2~4 h吸水率越低,但对达到饱和时的吸水率没多大影响。     

豆芽生产中大豆浸泡条件与吸水率和发芽率的关系研究

以大豆新品种“南农86—4”为材料，研究豆芽生产中大豆浸泡条件与大豆吸水率和发芽率的关系。发现采用不同浸泡用水量和不同浸泡温度时，吸水率与浸泡时间之间的关系为二次方程。根据吸水率与浸泡时间的二次方程及不同浸泡条件对发芽率的影响，认为在豆芽生产中最佳用水量为大豆重量的2倍，最佳浸泡温度为25℃。     

预熟化全籽粒芸豆加工工艺优化

为了实现芸豆与大米共煮同熟的目的,采用恒温浸泡、低压蒸煮和热风干燥技术对芸豆进行预熟化研究。以浸泡温度、低压蒸煮压力和低压蒸煮时间为自变量,以糊化度为响应值,进行试验设计,得到芸豆预熟化的最佳工艺参数为:浸泡温度50℃,低压蒸煮压力50kPa,低压蒸煮时间5min,该条件下芸豆糊化度为70.50%。经预熟化处理后的芸豆颗粒外观保持完整,水分含量为7%,在与大米共煮时能实现同熟。     

温度和时间对发芽糙米中γ-氨基丁酸含量的影响

以福建省农科院水稻所提供的籼稻"繁71-49"为原料,对发芽糙米的生产工艺进行研究.研究了浸泡温度、浸泡时间、发芽温度和发芽时间等因素对吸水率、发芽率和γ-氨基丁酸含量的影响.结果表明,吸水率和发芽率与浸泡温度和时间有关,吸水率影响发芽率,发芽时间对发芽糙米的γ-氨基丁酸含量产生影响;制备高含量γ-氨基丁酸的最适宜条件是:浸泡温度30℃、浸泡时间24 h、发芽温度30℃、发芽时间28 h;采用该工艺,发芽后糙米中γ-氨基丁酸含量是未发芽糙米的2.3倍,是精白米的7.6倍.     

高温流化对黑米蒸煮品质的改良效果

针对黑米蒸煮难、口感差、需提前浸泡的问题,采用高温流化技术处理黑米,以改善黑米蒸煮品质。研究了流化温度、流化时间和进料速度对黑米蒸煮品质的影响,通过单因素和正交试验得到最优工艺参数为流化温度155℃,进料速度60 kg/h和流化时间60 s,并且影响黑米蒸煮品质的主要因素是温度。经高温流化处理后,黑米出现裂缝并伴随糊化的产生,从而吸水通道被打开,黑米粉的糊化特性也得到改善,结果与原料相比,处理过的黑米在40℃水温下浸泡200 min的吸水率为41.09%,增加了24%(P0.05);最佳蒸煮时间为22.83 min,缩短了4 min(P0.05);抗氧化活性没有显著变化(P0.05);黑米煮前不用浸泡,黑米饭的柔软度、黏性和综合评分显著提高(P0.05)。高温流化显著改善了黑米的蒸煮品质。     

红米粉对小麦面团特性及馒头品质的影响

利用快速黏度测定仪、核磁共振成像分析仪、拉伸仪等设备,研究红米粉对小麦面团加工特性及馒头品质的影响。结果表明,随着混合粉中红米粉比例的增大,衰减值、回生值和糊化温度增大,低谷黏度、最终黏度和糊化时间呈下降趋势,峰值黏度先增大,但在红米粉添加量达到15%后减小;面团中深层结合水相对含量下降,弱结合水的流动性增强,自由水的含量增加;吸水率、形成时间、粉质指数随呈下降趋势,稳定时间先降低再升高。在发酵时间一定时,面团的各拉伸指标数值随红米粉添加量的增大均呈下降趋势。通过0.1～10 Hz范围内的频率扫描可知,弹性、黏性模量均增加,tanδ值降低。所制馒头的硬度、胶着性和咀嚼性显著上升,而弹性、内聚性、回复性和比容明显下降。综上所述,红米粉的添加改变了混合面团加工特性和馒头品质。为了提高红米粉的利用率和馒头的营养价值,红米粉的添加量不宜超过15%。     

不同预加工方式对马铃薯片中丙烯酰胺的影响

研究不同预加工方式对油炸马铃薯片中丙烯酰胺生成的影响,进而探讨一种可有效抑制马铃薯片中丙烯酰胺含量的方法。将马铃薯片在不同温度（120℃ ～200℃）及不同时间（0 ～30 min）下进行油炸处理,通过品质指标及丙烯酰胺含量的变化趋势确定最佳油炸时间及温度,利用高效液相色谱法测定经热烫和添加剂浸泡后马铃薯片中丙烯酰胺的含量,并计算丙烯酰胺抑制率。在未进行预处理条件下,随着油炸时间及油炸温度的增大,质量损失率、色差呈整体上升趋势,水分活度、水分含量及还原糖含量呈整体下降的趋势,丙烯酰胺含量呈先上升后下降的趋势;在油炸前进行不同预处理对马铃薯片中的丙烯酰胺具有显著抑制作用,90℃热烫处理协同5 g/L半胱氨酸溶液浸泡处理10 min对马铃薯片中丙烯酰胺的抑制率达到了100%。因此,热烫协同半胱氨酸溶液浸泡处理是一种可有效抑制马铃薯片中丙烯酰胺含量的方法。     

Effects of hardshell character on cooking time of common beans grown in the semiarid highlands of Mexico

The present study was undertaken to develop a protocol to screen bean germplasm for the hardshell character, evaluate the effect of hardshell on cooking time and study the relationship between hardshell and other seed characteristics in bean genotypes grown in the semiarid highlands of Mexico. Between 50 and 75% of the variation in cooking time of recently harvested beans was explained by differences in the degree of water absorption after soaking for 18 h. Seed coat brightness was negatively correlated with water absorption and increased cooking time in two of the three populations evaluated. The difference in cooking time and water absorption between scarified (hilum perforated) and unscarified seed of different genotypes would indicate that the hardshell characteristic plays a major role in extending the cooking time of beans. This study indicates that when seeds have an initial moisture content of 90 g kg^?1 seed or less, the hardshell problem is easily detected after soaking for 18 h, while the problem is rarely detected when initial seed moisture levels are 120 g kg^?1 or higher. Selection against the hardshell characteristic could be practised in bean germplasm using this information as part of a protocol to shorten the cooking time of beans grown in the Mexican highlands.     

Hydration Kinetics of Red Kidney Beans (Phaseolus vulgaris L.)

Soaking of dry red kidney beans was studied at 20, 30 40 and 60°C by the method of weight gain until equilibrium conditions were attained. Water absorbed during soaking was a function of both soaking time and temperature. Soaking at high temperatures increased the hydration rate constant and decreased soaking time to achieve equilibrium. Compared to unblanched beans, the application of a pre-blanching step considerably reduced hydration times of blanched beans. Due to the plasticity effect acquired upon blanching, blanched beans showed a significantly high hydration rate constant and exhibited a more constant equilibrium moisture content regardless of soaking temperature. Activation energy values (E_a) of the hydration process were 6.48 Kcal/mole for blanched and 14.25 for unblanched beans.     

红豆预熟化工艺及理化性质的研究

针对红豆种皮厚、难以煮熟等特点，通过“微波预处理–浸泡–蒸煮”的预熟化技术开发出一款能与大米同煮同熟的红豆产品。在利用响应面法优化预熟化工艺的基础上，对不同糊化度预熟化红豆的外观、色泽、糊化特性、质构和复煮特性进行测试。结果表明：微波时间、微波功率、浸泡时间、蒸煮时间的增加均会显著提升红豆的糊化度。与原料红豆相比，预熟化红豆的色泽变暗、体积膨大数倍、硬度降低、糊化粘度降低、复水性增加7.5～8.8倍，且模拟白米蒸煮条件复煮后无白芯。但随着糊化度的增加，红豆颗粒吸水膨胀、表皮破裂严重、感官分数下降、复水性先增加后降低。综上，优化预熟化最佳工艺为：微波功率640 W，微波时间30 s，浸泡时间6.5 h，蒸煮时间20 min，所得预熟化红豆的糊化度约为57.52%。     

Hard-to-Cook Phenomenon in Beans: Effects of Accelerated Storage on Water Absorption and Cooking Time

Black beans stored for 7–14 days at 41°C, 100% RH, required more cooking time than fresh beans and thus paralleled cooking time for beans stored forr more than 1 yr at room temperature. With corrections for solids lost during soaking, water absorption did not differ between fresh and stored beans. The rate of electrolyte leakage was greater from stored beans than from fresh samples, indicating that the cotyledon deteriorated during aging. Bean moisture content was found to be related to cooking time. In general, the higher the moisture content after soaking, the shorter the cooking time. However differences in cooking times between fresh and aged samples persisted regardless of bean moisture content.     

THE EFFECT OF PHYTATE AND FIBER CONTENT ON COOKING QUALITY IN FABA BEANS

Seventy-six faba bean lines were analyzed for their phytic acid content in the whole seeds and in the cotyledons. The fiber content was also determined in 17 Faba bean lines. The seed weights; % testa weight-of the seeds; and % moisture uptake (water imbibition) after overnight soaking in distilled water or increasing concentrations of EDTA solutions were measured and recorded. The relation between the above mentioned dependent variables and the cooking time for seed softening (min.) in 76 faba bean lines was studied and simple and multiple correlation coefficients were computed with a total of 70 operations. Significant correlation coefficients were found between phytic acid content in the cotyledons, % testae weight of the seeds; moisture uptake after soaking the seeds in distilled water overnight and cooking time for 50% softening (min). The faba bean lines 606/ 303; 606/ 308, 608/ 334, 609/ 350, proved to be of excellent cooking quality, since their cooking time for 50% seed softening did not exceed 10 min.     

The multi-step process optimisation of candied kidney beans with high nutrients and γ-aminobutyric acid retention

The candied kidney bean contains a vital bioactive compound called γ-aminobutyric acid (GABA), which could be easily lost in the traditional producing processes like soaking, cooking and candying. The traditional procedure distinctly decreased the GABA content to the GABA retention rate of 34.01% in the candied kidney bean. In this study, the optimum technological methods of soaking, cooking and candying were determined by single factor experiment according to the GABA content. The optimised producing condition was that the kidney bean was soaked at 55°C for 5 h, followed by atmospheric steaming for 35 min and then subjected to microwaving candying at 150 W for 25 min. By the optimal procedure, the GABA content retention reached 75.33%. Meanwhile, the texture, nutrient contents and antioxidant capacity were obviously improved in the candied kidney beans produced by the optimal methods.     

Nutritional quality of legume seeds as affected by some physical treatments, Part 1: Protein quality evaluation

The effect of water soaking, boiling, roasting, microwave cooking, autoclaving, fermentation and micronization on the nutritional quality of cowpea, pea and kidney bean was investigated. Pea seeds showed the highest crude fat, crude fiber and the lowest moisture contents while kidney bean had the lowest crude fat and the highest crude protein and ash contents. Glu and Asp were the main amino acids in all legumes while Cys and Met contents were the lowest. The protein efficiency ratio (PER), protein chemical score (CS) and the essential amino acid index (EAAI) of raw seeds ranged from 2.15 to 2.95, 39.07 to 68.30, and 55.49 to 62.84, respectively. Soaking, boiling, microwave cooking and autoclaving increased the total essential amino acids in all samples. Furthermore, raw and treated samples showed higher Lys content than the reference protein. Autoclaving was the most effective in improving protein quality followed by micronization, microwave cooking and fermentation. In addition, in vitro protein digestibility was improved after soaking, boiling, microwave cooking, autoclaving and fermentation but was reduced after roasting and micronization.     

Effects of Vacuum Hydration on the Incidence of Splits in Canned Kidney Beans (Phaseolus vulgaris)

Dry red kidney beans were canned using two different pretreatments: soaking for 12 hr at 20°C, and vacuum hydration for 5 min followed by soaking for 2 hr at temperatures from 45-59.1°C. Samples were then packed, processed to commercial sterility, and tested for percentage of split beans after processing. Vacuum hydration pretreatments greatly decreased the incidence and severity of splitting in the canned product and accelerated water uptake while retaining the same moisture content after soaking as the conventional soak treatment. Vacuum-hydrated beans gained less moisture during retorting than conventionally treated samples.     

Effect of processing on available carbohydrate content and starch digestibility of kidney beans (Phaseolus vulgaris L.)

The effects of different soaking and cooking methods were investigated on available carbohydrate content and starch digestibility of red and white kidney beans. Total soluble sugars, reducing sugars, non-reducing sugars and starch contents of red and white kidney beans were 9.95 and 11.3%, 0.82 and 0.96%, 9.13 and 10.3%, and 44.4 and 47.8%, respectively. All these available carbohydrate components decreased to various extents as a result of soaking and cooking. From 2.51 to 13.6% and 7.03 to 28.0% of total soluble sugars were lost on soaking kidney beans in tap water and sodium bicarbonate solution, respectively. However, losses in total soluble sugars were maximum (19.9–60.9%) on cooking pre-soaked kidney beans. Losses in starch contents were 4.27 to 24.7% and 30.4 to 70.7% as a result of the soaking and cooking processes, respectively. Besides these losses, starch digestibility of kidney beans was also markedly improved as a result of cooking. However, no appreciable improvement in starch digestibility was observed after soaking kidney beans in water or alkaline solution.     

Impact of pre-treatment (soaking or germination) on nutrient and anti-nutrient contents,cooking time and acceptability of cooked red dry bean (Phaseolus vulgaris L.) and chickpea (Cicer arietinum L.) grown in Ethiopia

Pulses are processed in diverse ways prior to consumption. Soaking and germination are among the most common traditional, household-level food processing strategies. This study was carried out to determine the effects of soaking, germination, cooking and their combinations on the contents of selected nutrients and anti-nutrients of red dry bean and chickpea. In addition, the effects of pre-treatment on cooking time and the acceptability of dishes prepared from red dry bean and chickpea were determined. The nutrient compositions (zinc, iron and calcium) of most soaked-cooked and germinated-cooked red dry bean and chickpea samples were not significantly different than those of respective controls. However, soaking and germination pre-treatments significantly lowered the phytate and tannin contents of the red dry bean and chickpea samples, with a few exceptions, and overall, polyphenol contents were lower after soaking-cooking than after germination-cooking. Most scores for sensory attributes of bean-based and chickpea-based dishes prepared from soaked or germinated samples were not significantly different than those of the controls. For most red dry bean and chickpea samples, longer germination times yielded superior results in terms of reductions in cooking time, tannin content, and phytate:zinc and phytate:iron molar ratio.