杏仁早餐的浸泡与脆性变化

以自制的杏仁早餐为研究对象,应用Peleg模型来描述杏仁早餐的吸水过程;Peleg模型对杏仁早餐浸泡时脆性变化也具有适用性。计算了不同温度下的Peleg方程常数K1、K2,确定了杏仁早餐的吸水动力学方程。     

不同品种糯米浸泡前后的理化特性比较

为了研究浸泡处理对糯米理化特性的影响,本文选用三种糯米样品,观测了其基本理化指标和粘度曲线等特性。测定浸泡(20℃~35℃)过程中糯米米粒水分含量的变化和最终的含水量,采用Peleg方程拟合糯米的吸水动力学特性,并对糯米浸泡前后红外光谱和X-射线衍射图谱的进行分析比较。研究发现越南米和长江米吸水量大,其最终含水量分别达到36.34%(20℃)和34.64%(28℃),温度对其影响较小;黑香米吸水速度和数量较小,最终含水量为31.99%(35℃),且温度对其影响较大;其次,可运用Peleg方程米对浸泡过程中糯米的近似水分含量进行预测。浸泡前后糯米的红外光谱在1047cm-1与1022cm-1峰的强度比值在0.89~0.92之间,无显著差异。X-射线衍射表明水分子主要进入糯米颗粒内的无定型区和亚结晶区,越南米和长江米样品的亚结晶区变小,黑香米则有所增大。本文研究可为米粉的加工提供理论指导。     

马铃薯淀粉、红薯淀粉、木薯淀粉吸水特性的研究

以马铃薯淀粉、红薯淀粉、木薯淀粉为研究对象,测定此3种淀粉在不同浸泡温度和不同浸泡时间下的水分含量,研究淀粉在不同温度、不同时间条件下的吸水特性,探讨了影响马铃薯淀粉、红薯淀粉、木薯淀粉吸水性质的因素,并用Peleg方程计算了浸泡吸水常数K1和K2,确定了马铃薯淀粉、红薯淀粉及木薯淀粉的吸水动力学方程。结果表明,预测数据与试验数据有较好的一致性。因此,淀粉吸水动力学方程可为淀粉浸泡过程中的水分含量进行预测,为淀粉加工提供理论参考。     

稻谷、糙米吸水动力学研究

以Peleg方程为依据,通过线性回归分析,计算式中的斜率K2和常数K1,利用实验测定水分含量与预测数据间的相对误差E进行拟合度的判定。建立了普通稻谷、高水分稻谷及糙米的吸水动力学方程,经检验,实验测定水分含量值与预测数据间的相对误差E均小于10%。可利用建立的浸泡吸水动力学方程对稻谷和糙米浸泡过程中的近似水分含量进行预测。     

Peleg方程在油炸与热风干面条吸水性比较中的应用

本文探讨了油炸与热风干面条在不同温度、时间浸泡条件下的吸水性质与动力学研究,其中浸泡温度为40～100℃,浸泡时间为0.5～20 min。试验结果表明:两种面条在浸泡初始阶段的吸水速率较高,随着时间的延长,增速逐渐降低并趋于平缓。Peleg方程对两种面条吸水曲线具有较高的拟合性,相关系数均在0.99以上;方程中的速率常数K1与容量常数K2均随温度升高而降低,而且试验发现油炸面条的速率常数K1随温度变化幅度小于热风干面的;在60～80℃间,热风干面吸水速率出现突然增大的转折。对K1、K2与温度进行多种回归分析,得出最佳拟合方程为对数方程,相对系数在0.94以上;在90℃条件下,将通过Peleg方程计算的预测值与试验值进行相对误差分析,得出E(%)在2%左右,相对误差远小于10%,具有较高的精确性。将两种面条不同温度的K1值与温度进行Arrhenius方程拟合,相关系数达到0.94,具有较好的拟合性,同时发现在水浸泡过程中油炸面条的活化能E要高于热风干面。     

籼米、粳米及泰国香米吸水性质及其动力学研究

以籼米、粳米及泰国香米为研究对象,探讨了籼米、粳米及泰国香米的吸水性质及其影响因素.并用Peleg方程计算了浸泡吸水常数K1和K2,确定了籼米、粳米及泰国香米的吸水动力学方程,运用方程计算的预测数据与实验数据有较好的一致性.因此,可运用吸水动力学方程对大米浸泡过程中的近似水分含量进行预测.     

糙米和发芽糙米吸水动力学研究

采用Peleg方程,探讨了糙米和发芽糙米在不同温度(25～65℃)和不同时间间隔下(20～140min)的吸水动力学性质。实验结果表明:Peleg方程能较好地描述糙米和发芽糙米在实验条件下的吸水性质,且相对误差(E)小于10%。在糙米和发芽糙米的吸水模型中,Peleg方程参数K1均随温度升高而减小,K2无明显变化趋势。     

豌豆不同品种加工豆奶适应性研究

对不同豌豆品种加工豌豆豆奶的适应性进行了初步研究.选自河北科技师范学院培育的豌豆新品种宝峰东8号、须菜1号、须菜3号,及我省主栽豌豆品种中豌5号、中豌6号五个品种,在相同条件下进行浸泡、灭酶、磨浆、酶解、调配等处理,比较五个豌豆品种在各处理中的品质优劣.结果表明,宝峰东8号豌豆品种加工豌豆豆奶效果最佳.     

富铬(Ⅲ)豌豆制备及其含铬蛋白组分生物活性研究

目的 制备富铬(Ⅲ)豌豆(Pisum sativum L.),并探究富铬豌豆蛋白的体外生物活性,为新型有机铬产品开发提供参考。方法 以豌豆为实验材料,通过电感耦合等离子体质谱法测定不同形态铬的含量,以有机铬含量为指标评价各因素水平对铬(Ⅲ)的生物富集效应影响;对比不同萌发生长周期的富铬豌豆铬含量及蛋白质铬含量。并通过体外降糖、降脂及抗氧化实验评价富铬豌豆蛋白的生物活性。结果 豌豆种子浸泡的最佳条件为:铬离子浓度为1.32 mmol/L的三氯化铬溶液在20℃浸泡12 h,该条件下,富铬豌豆铬含量约为未富铬豌豆铬含量的930倍,富铬豌豆中有机铬的含量为(170.65±2.61)μg/g,有机化程度达87%;萌发过程中富铬豌豆的铬含量呈下降趋势,但其蛋白质铬含量在萌发第4 d最高,为(82.15±0.45)μg/g,随后下降。生物活性研究表明富铬豌豆蛋白具有良好的体外降糖、降脂及抗氧化活性。结论 利用豌豆通过生物富集方法将无机铬转化为有机铬是切实可行的,富铬豌豆蛋白具有优于普通豌豆蛋白的体外降糖、降脂及抗氧化活性。     

湿热处理对红薯淀粉特性的影响

为了研究湿热处理对红薯淀粉理化和结构等特性的影响,以五种红薯淀粉为实验对象,测定并分析湿热处理后淀粉溶解度、膨润力、持水力、透光率、凝沉性等理化特性的变化情况,进而探明湿热处理对不同初始含水量红薯淀粉吸水特性及晶体结构的影响规律。结果表明,经湿热处理后红薯淀粉的溶解度、膨润力、凝沉性与透光率均较原淀粉降低,持水力均增强,且五种红薯淀粉均呈现相同趋势,说明红薯品种与湿热处理对淀粉性质的影响规律无显著相关性。经湿热处理后红薯淀粉未见新的衍射特征峰,晶体类型仍为C型,而衍射强度和结晶度降低。湿热处理淀粉吸水达到平衡所需要时间较原淀粉短,且饱和吸水量较原淀粉有减小的趋势。利用Peleg模型方程模拟湿热处理后红薯淀粉的吸水规律,并计算出浸泡动力学吸水常数K₁和K₂,确定了淀粉的吸水动力学方程,可预测湿热处理后红薯淀粉在浸泡过程中的水分含量。     

山茱萸籽粕亚临界水降解动力学及多糖性质研究

本实验以山茱萸籽粕为原料,进行山茱萸籽粕亚临界水降解研究,测定不同降解温度、降解时间下液态产物的还原糖含量,采用Saeman模型模拟分析,建立降解动力学方程,得到降解动力学参数,并对降解物进行理化性质的分析。结果表明,Saeman模型能较好反映山茱萸籽粕亚临界水降解的过程,初步降解的反应活化能E_a1为29.47 kJ/mol、还原糖降解活化能E_a2为22.21 kJ/mol、指前因子K₁₀为101.49 min-1、K₂₀为20.28 min-1,在降解温度160 ℃、降解时间20 min条件下,能得到产量较高的还原糖。单糖组成分析表明,山茱萸籽多糖主要由葡萄糖、木糖、半乳糖、半乳糖醛酸组成,其总糖含量高达78.82%;扫描电镜和红外光谱结构分析结果表明,多糖结构呈表面光滑,无规则颗粒状,粒径大小不一的球状结构物,为吡喃型糖苷环骨架;抗氧化活性分析结果表明,山茱萸籽多糖具有较好的自由基清除能力,在质量浓度为1.0 mg/mL时,对DPPH自由基、羟自由基和ABTS自由基清除率分别为85.61%、63.40%、76.20%。本试验结果为山茱萸籽多糖的进一步分离纯化和理化特性、形态结构的分析提供了参考。     

Water changes in canned dry peas and beans during heat processing

The amount of water absorbed by dry peas ( Pissum sativum L. cv. 'Marrowfat') and dry beans ( Phaseolus vulgaris L. cv. 'Haricot') during soaking, blanching and canning was studied. The temperature during soaking significantly affected the water absorption rate up to 40 °C, but not beyond this temperature. The final water content of the product was significantly increased by blanching after soaking as opposed to blanching before soaking. Water uptake was also significantly affected by the water used. Total water uptake was about 150% greater in peas when soft water was used (60 °C). High soaking temperatures with correspondingly short soaking time (4 h at 60 °C) would be advantageous to a food manufacturer. Under these conditions, water absorption is increased in the finished product and the amount of product 'in process' is reduced, allowing a greater flexibility and control of the process.     

EVALUATION OF EFFECTS OF SOAKING AND PRECOOKING CONDITIONS ON THE QUALITY OF PRECOOKED DEHYDRATED PEA, LENTIL AND CHICKPEA PRODUCTS

Peas, lentils and chickpeas were blanched and soaked in water, then cooked with four different cooking methods and dehydrated in a convection tray dehydrator. Color, splitting and butterflying rate; firmness; and rehydration rate were evaluated. Dehydrated yellow and green peas produced by soaking at 22C for 9 h and 82C for 4 h in 0.07% NaHCO₃ solution, and followed by precooking at 110C for 10 min had the best quality with respect to firmness, splitting and butterflying rate. Dehydrated chickpeas produced by soaking at 22C for 9 h and 82C for 3 h in 0.07% NaHCO₃ solution, and followed by precooking at 110C for 10 min had the best quality. Dehydrated lentils produced by soaking at 22C for 2 h and 82C for 20 min in 0.07% NaHCO₃ solution, and followed by precooking at 106C for 10 min had the best quality.

PRACTICAL APPLICATIONS

Traditionally, soaking and cooking of peas, lentils and chickpeas (PLCs) takes one a long time. It is desirable to manufacture dehydrated precooked PLCs to provide convenience for the users. The objective of this study was to investigate the quality of precooked dehydrated PLCs as affected by processing. The fundamental cooking characteristics of PLCs obtained in this study are very useful for the food industry.     

Relationship between physicochemical and cooking properties,and effects of cooking on antinutrients,of yellow field peas (Pisum sativum)

The relationship between the physicochemical and cooking properties of yellow peas was examined in this study. A positive correlation was found between seed weight and water hydration capacity. The Peleg model, which was modified, could be used to describe the water absorption characteristics of peas and could be used to predict the rate of water absorption in the initial water absorption period. Cooking time could be measured objectively using the Mattson cooker. Cooking time was found to decrease with an increase in water hydration capacity. Hardness of cooked peas, measured using a texture analyser, was negatively correlated with both seed weight and water hydration capacity. Seed coats had a significant effect on water hydration and cooking quality of peas. Peas with relatively thin seed coats exhibited higher water hydration capacity, shorter cooking times and softer texture after cooking. The effects of soaking and cooking on trypsin inhibitor activity (TIA) and oligosaccharide levels in peas were also studied. Cooking was more effective than soaking in reducing TIA levels and oligosaccharides (raffinose, stachyose and verbascose) in peas. Copyright © 2003 Society of Chemical Industry     

Water Absorption in Chickpea (C. arietinum) and Field Pea (P. sativum) Cultivars using the Peleg Model

Moisture absorption in seven chickpea cultivars and three field pea cultivars was investigated at 5, 15, 25 and/or 42°C using the Peleg model (M (t) = Mo + t/[K₁+ K₂t]). The Peleg constant K₁ varied with temperature. At a given temperature, the lower the K₁, the more water was absorbed. The Peleg constant K₂ was almost unaffected by temperature and could be used to predict the equilibrium water absorption. A constant K₃ expressing the temperature effect on water absorption (K₁= K₃T + K₄) was developed to distinguish two types of chickpea — Desi and Kabuli. All chickpeas had similar composition and initial moisture. The difference in water absorption rate was probably due to thickness and structure of the seed coat. The Peleg model could be used to predict water absorption in chickpea and field pea.     

HYDRATION KINETICS OF LUPIN (LUPINUS ALBUS) SEEDS

The hydration kinetics of lupin (Lupinus albus) seeds was studied by soaking in water at temperatures of 20, 30, 40 and 50C (±1C) in constant‐temperature water bath for 9 to 12 h. The weight gain due to the hydration process was determined in terms of moisture content (% dry basis). Water absorption rate was high at the early stage of hydration (20–60 min depending on temperature) followed by a decreased rate and finally approaching equilibrium condition. Peleg's equation adequately described the hydration characteristics of lupin seeds under the experimental condition (R² = 0.96 to 0.99). The Peleg rate constant k₁ decreased from 2.537 to 0.241 min/%, while Peleg capacity constant k₂ increased from 0.0036 to 0.0070/% significantly (P < 0.05) with an increase in temperature from 20 to 50C, demonstrating that the water absorption rate increased and water absorption capacity decreased with increase in temperature. The temperature dependence of k₁ and k₂ was described by Arrhenius type equation with R² values of 0.98 and 0.97, respectively, and activation energy of 60.44 kJ/mol. The agreement between experimental and estimated values of the hydration data (R² = 0.97 to 0.99) confirmed that Peleg's equation could be used to describe the hydration characteristics of lupin seeds under the experimental conditions considered.     

加水温度和蒸制时间对莜麦面面条水分状态和质构特性的影响

本文探讨加水温度和蒸制时间对莜麦面面条水分状态和质构特性的影响,旨在找到莜麦面面条制作工艺的关键参数。利用低场核磁共振技术和食品物性仪得到面条的水分状态和质构特性参数,研究了加水温度和蒸制时间对莜麦面面条水分状态和质构特性的影响。结果表明:加水温度和蒸制时间不改变面条中水分的主要存在形式,且水分的主要存在形式是弱结合水;提高加水温度使面条中深层结合水减少并向弱结合水和自由水方向迁移。加水温度由70 ℃升高到90 ℃的过程中,自由水含量先增加后减小,A₂₃由5.14%增加到11.2%后减小至10.4%。当蒸制时间从6 min增加到10 min时,A₂₂值和A₂₃值先升高后降低,A₂₂和A₂₃最大值分别为77.85%和10.67%,且对应的蒸制时间均为9 min。当加水温度从70 ℃升高到90 ℃时,硬度、黏着性、回复性逐渐减小,弹性、黏聚性逐渐增大,咀嚼性先减小后增大。当蒸制时间从6 min升高到10 min时,硬度、黏着性、咀嚼性、回复性先增大后减小,弹性、黏聚性先减小后增大。本研究结果为莜麦面面条的规模化生产提供一定的理论依据。     

超声和碳酸氢钠处理对绿豆浸泡特性的影响

为了改善绿豆的质地特性,提高其浸泡效率,本文研究了超声和碳酸氢钠作用下绿豆的吸水动力学、水分分布、水分迁移、硬度、种皮结构以及总酚和植酸含量的变化。超声对绿豆吸水特性、硬度和营养成分含量的影响与绿豆表皮结构变化有关。400 W超声使绿豆表皮形成微孔通道,提高绿豆的吸水速率以及自由水和结合水的含量,降低硬度,总酚和植酸含量也显著降低（P<0.05）。1.5%碳酸氢钠对绿豆浸泡特性的影响可能是通过改变浸泡液的酸碱性发挥作用。碳酸氢钠会提高浸泡液pH,从而减缓吸水速率,降低总酚含量,抑制植酸含量降低,但对绿豆硬度的降低作用不明显,并且碳酸氢钠组的自由水和结合水含量与对照组有一定差异。若以最低硬度为评价指标,则对照组和1.5%碳酸氢钠组的最佳浸泡时间为7 h,而400 W超声组最佳浸泡时间为4 h。本文探明了超声和碳酸氢钠处理对绿豆浸泡特性的影响机制,可为超声波技术以及碳酸氢钠预处理技术在杂粮食品开发中的应用提供理论指导。