Characterisation of gluten-free pasta through conventional and innovative methods: Evaluation of the cooking behaviour

The rapid stiffening of a well-developed gluten network able to entrap swollen starch granules is a key factor for the high quality of durum wheat pasta during cooking. Good resistance and firmness, low stickiness and limited release of organic materials into the cooking water are quality traits of primary importance for traditional pasta. In gluten-free (GF) pasta, the formation of a scaffold of retrograded starch can be an alternative to gluten networking: it confers rigidity to the cooked product and reduces pasta stickiness and loss of soluble materials into the cooking water. In a previous paper, 14 commercial GF spaghetti samples were studied as uncooked products from a chemical, biochemical and physical point of view. The aim of this study was to determine the cooking behaviour of these samples. A durum wheat pasta was also included as reference. Suitable cooking conditions were adopted and different conventional and innovative evaluations (i.e. compression test, creep test) were performed as a function of cooking time. Different behaviours were evidenced, often related to the ultrastructural organization of the uncooked products. In particular, the creep test revealed to be very effective in discriminating among the properties of the different GF spaghetti.     

Automatic segmentation of relevant textures in agricultural images

One important issue emerging strongly in agriculture is related with the automatization of tasks, where the optical sensors play an important role. They provide images that must be conveniently processed. The most relevant image processing procedures require the identification of green plants, in our experiments they come from barley and corn crops including weeds, so that some types of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations. Also the identification of textures belonging to the soil could be useful to know some variables, such as humidity, smoothness or any others. Finally, from the point of view of the autonomous robot navigation, where the robot is equipped with the imaging system, some times it is convenient to know not only the soil information and the plants growing in the soil but also additional information supplied by global references based on specific areas. This implies that the images to be processed contain textures of three main types to be identified: green plants, soil and sky if any. This paper proposes a new automatic approach for segmenting these main textures and also to refine the identification of sub-textures inside the main ones. Concerning the green identification, we propose a new approach that exploits the performance of existing strategies by combining them. The combination takes into account the relevance of the information provided by each strategy based on the intensity variability. This makes an important contribution. The combination of thresholding approaches, for segmenting the soil and the sky, makes the second contribution; finally the adjusting of the supervised fuzzy clustering approach for identifying sub-textures automatically, makes the third finding. The performance of the method allows to verify its viability for automatic tasks in agriculture based on image processing.     

园林植物的设计特性探析

从园林植物的生长类型、形态、色彩、质地4个方面,对植物的设计特性及其应用进行综合论述,提出了比较全面的关于园林植物种植设计的方法与思路,以期对今后景观设计中植物的配置与造景提供借鉴。     

Sensory texture of cooked rice is rather linked to chemical than to physical characteristics of raw grain

This paper describes the multidimensional features of the texture of cooked rice (in particular the visual aspect and mechanical attributes) determined by sensorial analysis and links these attributes with a wide range of physicochemical characteristics of raw grain (in particular certain cell wall components). Textural classes of cooked rice did not fit classical grain ranking, which is primarily based on shape. For the classification of cultivars, it would be preferable to use chemical characteristics of raw kernels such as amylose content and Tgel (for prediction of firmness), but also protein (adhesiveness and stickiness) and arabinoxylan contents (deformation), which determine the textural properties of cooked rice. Leached amylose has been measured, and the particular role of soluble amylose on the surface behaviour (stickiness and adhesiveness) of the cooked grain is discussed.     

牛肉饼中不同油脂复配比例的优化

[目的]将富含不饱和脂肪酸的植物油脂（葵花油、橄榄油和牛油）替代部分牛油添加到牛肉饼中,探寻最佳的比例组合。[方法]采用正交试验设计确定牛肉饼中葵花油、橄榄油和牛油的添加量对牛肉饼质构的影响以及最优比例的优化。应用感官评分法对牛肉饼的口感、组织状态、滋气味、色泽进行评分,并对牛肉饼的质构进行测定。[结果]感官评定与质构测定结果较一致,最佳组合均为5%葵花油、4%橄榄油和3%牛油。[结论]通过正交试验得出其最佳工艺配方,可按照此比例添加到瘦牛肉馅中加工成品质优良的牛肉饼。     

预混合方式及肉馅冻藏对乳化肠贮藏品质的影响

[目的]研究僵直前预混合加水比例和肉馅冻藏对乳化肠贮藏期间保水及质构性质的影响。[方法]僵直前猪肉用总用水的25％或50％以及不加水进行预混合。预混合肉馅在～18℃冻藏35d,对照组肉馅不冻藏。利用冻藏及非冻藏肉馅制作乳化肠,使用质构仪、压力仪和天平测定乳化肠刚产出时的产率、硬度、总压出汁液和贮藏至10、20及30d的硬度和贮藏损失。[结果]冻藏降低肉馅的盐溶性蛋白质溶解度;肉馅预混合加水比例及冻藏对肉馅茵落总数无显著影响。肉馅的冻藏及不加水预混合使得贮藏0d的乳化肠硬度偏低,并在贮藏期内硬度快速增加,、25％预混合加水比例的非冻藏肉馅有最高的产率,最低的贮藏损失和总压出汁液,最少的贮藏期硬度增加。[结论]僵直前预混合加水比例及肉馅冻藏影响肉馅理化、微生物性质和乳化肠保水质构性质。     

凝固型发酵酸豆乳制备工艺

为了提高凝固型发酵酸豆乳的质量,消除豆腥味,改善口感,以感官评分为参考指标,研究了乳酸菌和豆水比对酸豆乳质量的影响,并进行了质构分析。结果表明:豆水比200∶1 000,添加RSJ2菌种得到的凝固型发酵酸豆乳感官评价最好,质构分析得出当凝胶强度较低、破裂强度和黏度适中、破裂距离较长时,凝固型发酵酸豆乳的口感较好。      

The impact of redox agents on sugar-snap cookie making

The impact of the oxidants potassium bromate and potassium iodate and the reducing agents L-cysteine, glutathione and sodium metabisulfite on sugar-snap cookie making was investigated. Spread behavior of cookie dough during baking (spread rate, set time and collapse) was monitored and texture properties of the baked cookies were determined. Low levels of redox agents impacted neither dough nor cookie properties. High levels of reducing agents (10,000 ppm on a flour base) significantly decreased set time, and, hence, cookie diameter. They also decreased the degree of collapse, which then, evidently, also increased cookie height. Earlier setting and higher resistance to structural collapse, but also the higher intrinsic break strength of the cookie material when adding high levels of reducing agents could be explained on a molecular level as resulting from earlier and more pronounced gliadin–glutenin cross-linking. In contrast, when high levels of oxidizing agents were added, a postponed setting, a more pronounced collapse and decreased intrinsic cookie break strength were observed. The present work demonstrates the importance of heat-induced gluten polymerization during cookie baking and confirms that free sulfhydryl groups are necessary for the polymerization reactions. A model illustrating the role of gluten cross-linking during cookie making is put forward.     

Development of wheat kernels with contrasting endosperm texture characteristics as determined by magnetic resonance imaging and time domain-nuclear magnetic resonance

Spikes and seeds from diploid ‘einkorn’ wheat Triticum monococcum and two near-isogenic hard and soft common wheat (Triticum aestivum) lines were harvested at regular intervals from 7 days post-anthesis (dpa) and analysed by non-destructive magnetic resonance imaging (MRI) and time domain-nuclear magnetic resonance (TD-NMR). A large amount of free water occurred in rachises, glumes and awns of spikes collected at 7 dpa, and accumulated in the physiologically active cells of the endosperm at 21 dpa. In the final stages of kernel development, awns and seed embryos exhibited a high MR signal due to the presence of free water likely associated with biological activities. TD-NMR relaxation time distributions obtained by discrete exponential fitting, distributed exponential fitting and SLICING multivariate analysis offered detailed information on mobility behaviour of water molecules in developing seeds and were able to differentiate two soft and hard isolines from common wheat cv. Enesco at early stages of seed development.