Methodological developments in crispness assessment: Effects of cooking method on the crispness of crusted foods

A new method was developed to assess the texture of crispy-crusted foods with a soft, high-moisture core. This method, applied to commercial pre-cooked chicken nuggets, combines characteristics derived from the force/displacement curves of the whole sample with characteristics of the simultaneously emitted sound. The use of a not-sharp blade probe to perform the test proved to be an effective technique for characterizing the texture of chicken nuggets after different final cooking processes. The force curves of the samples differed with the cooking process. Deep-fried samples and those cooked in a conventional oven presented jagged force curves and acoustic signals with many peaks, both characteristics of crispy products. The curve profiles of microwaved samples were drastically different and typical of tough, gummy products. The use of a susceptor package in microwave heating improved the crispness of the samples. The number of sound peaks was the acoustic parameter that best discriminated between the samples. It was found that although the moisture and fat contents of the core and crust are closely related to the texture characteristics, samples with similar water contents can have very dissimilar crispness characteristics. The fat content of the core did not change significantly with the final cooking process in any of the samples.     

Adhesion in fried battered nuggets: Performance of different hydrocolloids as predusts using three cooking procedures

Batter systems have to turn into a crisp crust after frying and they have to adhere to food substrate surfaces which are sometimes very smooth. As a result, treating the substrate with a predust is highly recommended. Predust agents act by absorbing the moisture on the substrate surface, creating a rough outer surface on the substrate and ensuring optimal binding between substrate and batter. Normally, the same wheat flour used in the formulation of the batter is used for dusting. In this study, three different hydrocolloids were used as predusting materials for battered fish nuggets and their performances in three different cooking procedures were evaluated. Oxidised starch, xanthan gum and HPMC were compared with wheat flour (control), using deep frying, conventional oven and microwave oven. Image analysis, an innovative method in this area, was used to quantify adhesion. The performance of the hydrocolloids used as predusting agents depended on the cooking procedure.     

A film of alginate plus salt as an edible susceptor in microwaveable food

An important quality problem when cooking or warming battered and breaded foods in a microwave oven is the resulting lack of crunchiness due the way microwaves heat foods. In this regard products are beginning to be designed specifically for microwave heating, by using active packaging (with susceptors) or/and by changing the batter formulation. In this study, a completely new approach was undertaken to avoid that problem: a film of alginate gel with high salt concentration between substrate and batter was used as an edible susceptor.     

南洺河铁矿中部矿段开采参数优化的数值模拟

借助FLAC3D数值计算,建立了南洺河铁矿矿块回采过程三维数值模型,在不同岩体位置设立了应力应变监测点,分析了8 m和10 m 2种矿块结构参数条件下不同开采时期的岩体三维宏观力学特性,通过对比采区岩体力学特征、充填体力学特征以及岩体移动变形规律及破坏情况对矿块结构参数进行优化,确定是否留设永久矿柱。结果表明,围岩稳定状况在采用8 m宽采场结构参数时要明显优于10 m宽采场的结构参数,矿体回采时不预留3 m宽条形矿柱充填后顶板只是出现小幅度沉降,不会出现大规模冒落现象。     

Improvement of crunchiness of battered fish nuggets

In this study, two strategies to improve the crunchiness of fish nuggets for microwave final cooking were employed: addition of dextrin into batter formulation, and using a package containing a susceptor material, which improves heat transmission and increases the temperatures reached in the microwave. In this work, two dextrins (one of high solubility and other of medium solubility) were used to study their effect in battered, prefried fish nuggets, finally cooked by three different procedures: deep frying, microwaving and microwaving with susceptor packaging. In addition, all tests were performed with and without batters containing methylcellulose in order to assess the effect of oil uptake. The crunchiness of fish nuggets was evaluated by a recently developed method which simultaneously registered texture and sound measurements during the cutting of the nuggets. The profiles of the fried nuggets had numerous force and sound peaks and a typical jagged plateau shape, whereas those of the microwaved samples had force peaks that disappeared and the profiles adopted a smooth ascending curve. However, the use of the susceptor slightly improved the number of sound peaks. In addition, sensory crunchiness and other sensory attributes were measured by a trained panel. When the dextrins-containing nuggets were cooked by microwave and susceptor, they were perceived as crunchier as and oilier than the other samples.     

Reduction behaviour of agglomerated iron ore nuggets by devolatisation of high-ash,high-volatile lignite coal for pig iron production

High-quality coking coals all over the world are gradually approaching extinction. These days, steel industries are trying to focus more on the utilisation of non-coking grades of coal. The present work involving high-ash, high-volatile lignite coal can be used indirectly in iron-making processes. Direct use is not possible due to low amount of carbon and high value of ash. High ash content leads to huge sulphur content, and this leads to high cost involvement in secondary processes. On the other hand, huge amount of iron ore fines are generated during mechanised mining, sizing, screening, transportation, beneficiation and sintering processes. Iron ore nuggets are formed from inferior quality iron ore fines using suitable binders with the applied pressure. Mechanical properties of iron ore nuggets are also assessed through shatter and abrasion test. A furnace was designed, to indirectly utilise high-ash, high-volatile lignite coal, for pre-reduction iron ore nuggets. Iron ore nuggets were partly reduced by CO, H₂ and fine carbon produced from volatilisation of coal. Optimized pre-reduced nuggets, having high mechanical stability was directly charge in the raising hearth furnace for pig iron production.     

Effect of comminution temperature on the quality and shelf life of buffalo meat nuggets

Buffalo meat nuggets were prepared after equilibrating the ingredients to temperatures of 4, 10, 25 and 37 °C. Following comminution for 6 min, the temperatures of the batters were 16.3, 19.3, 27.4 and 34.8 °C and their pH and emulsion stability ranged from 6.18 to 6.29 and 88.76 to 95.33%, respectively. Increasing temperature of comminution led to increased cooking losses and TBARS values. However, even at 37 °C, complete emulsion breakdown did not occur as the cooking losses were still only about 12%. Texture profile analysis revealed an inverse relationship between chopping temperature and shear force. Sensory evaluation indicated that, at least up to comminution temperatures of 27.4 °C, the nuggets were acceptable. The aerobic mesophilic bacterial counts were higher for the nuggets made from batters with higher temperatures but, even at the 21st day of storage, the counts were well below the levels likely to cause spoilage in meat products. Results suggested that comminuted buffalo meat products can be manufactured in conditions where refrigeration is not available, by a preservation system (mostly chemical) to decrease microbial and chemical spoilage and also by devising an efficient marketing system for their early distribution (preferably 14 days).     

Effect of incorporation of dairy products in chevon nuggets

This paper presents the different ways of incorporating various coprecipitates obtained from milk in chevon nuggets. The chevon was obtained from a rare but popular breed called Black Bengal goat. Milk coprecipitates of varying composition were in the formulations. Emulsion stability, yield, moisture and protein contents were not affected significantly, whereas shear force, pH, various organoleptic properties were found to be affected significantly. This method may potentially lead to the development of new emulsion-based nuggets.