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The use of non-destructive techniques, such as photothermal techniques, can be used for characterization of non-homogeneous materials with different components and thermophysical properties. Among the photothermal techniques, the photoacoustic microscopy (PAM) has been used to obtain thermal images of different samples, ranging from semiconductors to biological materials. In the present study, the thermal imaging of six different creole corn varieties was obtained by using PAM. According to the color, these varieties were nominated as M1 (orange–yellow), M2 (blue), M3 (blue), M4 (light yellow), M5 (yellow), and M6 (red). Thermal images allowed us visualize corn characteristic features and structures, with higher values of photoacoustic signal amplitude in floury regions and pedicel. The highest values of photoacoustic signal amplitude corresponded to M1 (0.39), M6 (0.35), and M5 (0.34) corn samples, followed by M4 sample. Also, colorimetric parameters L*a* and b* of the creole corn samples were evaluated, and they showed significant statistical differences (p < 0.5). The colorimetric results were analyzed by the statistical method of Kernel density estimation, showing a higher density of data in the B component, followed by R and G. The non-destructive techniques allow characterizing non-homogeneous materials with different components. Thermal images, obtained by using PAM, can be analyzed by several statistical methods. [ABSTRACT FROM AUTHOR]

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Vegetable oils have been widely studied as biofuel candidates. Among these oils, jojoba ( Simmondsia chinensis) oil has attracted interest because it is composed almost entirely of wax esters that are liquid at room temperature. Consequently, it is widely used in the cosmetic and pharmaceutical industries. To date, research on S. chinensis oil has focused on to its use as a fuel and its thermal stability, and information about its thermal properties is scarce. In the present study, the thermal effusivity and conductivity of jojoba oil between $$20\,{^{\circ }}\hbox {C}$$ and $$45\,{^{\circ }}\hbox {C}$$ were obtained using the inverse photopyroelectric and hot-ball techniques. The feasibility of an inverse photopyroelectric method and a hot-ball technique to monitor the thermal conductivity, and the thermal effusivity of the S. chinensis is demonstrated. The thermal effusivity decreased from 538 $$\hbox {W}\cdot \,\hbox {s}^{1/2}\cdot \,\hbox {m}^{-2}\cdot \,\hbox {K}^{-1}$$ to 378 $$\hbox {W}\cdot \,\hbox {s}^{1/2}\cdot \,\hbox {m}^{-2}\cdot \,\hbox {K}^{-1}$$ as the temperature increased, whereas the thermal conductivity remained the same over the temperature range investigated in this study. The obtained results provide insight into the thermal properties of S. chinensis oil between $$20\,{^{\circ }}\hbox {C}$$ and $$45\,{^{\circ }}\hbox {C}$$ . [ABSTRACT FROM AUTHOR]

The pro-health action of germinated lentils could be useful to be added with wheat flour in the production of box bread. In this work, we spectroscopically evaluate the germinated and non-germinated lentils, and use them at the concentrations of 5 and 10% for the production of box bread. The chemical and physical tests of the bread and its determination of phenolic acids and flavonoids (by HPLC) were also performed. As well as the evaluation of the quality of flour and dough used to produce the bread and the acceptance of the germinated lentil bread with a population of 20 people with diabetes or with diabetic relatives It is shown that: (1) The amplitude of photoacoustic signal obtained by photoacoustic spectroscopy is modified as a function of the percentage of germinated lentil (GL) flour (0, 5 or 10%) add to the bread; being higher the photoacoustic amplitude to higher concentration of GL in the absorption band of 300-425 nm, which is related to higher content of phenols and flavonoids. (2) The contents of phenolic acids (Sinapinic, β- resorcylic, Chlorogenic and Ferulic) and flavonoids (Quercetin and Isorhamnetin) tended to increase in the germinated lentil bread with 10% concentration of germinated lentil flour with respect to the control bread (0% GL). (3) The addition of germinated lentils flour to 5 and 10% into wheat flour to produce bread with higher hardness and less cohesiveness than bread based on wheat flour only. The Falling number indicate that there is no significant difference between the control sample and the 5% GL flour, while in the 10% GL flour there was a reduction of 21 s, with respect to the control. The effect of the germinated lentil flour percentage on the pasting properties of the flours was significant between the control and 10% GL flour. In general, the quality of the dough and flour are modified due to the addition of germinates lentils, and this affectation increases with the increase in the concentration of GL. (4) The bread added with germinated lentil has sensory acceptance with a group of people with diabetes and/or diabetic relatives in their attributes in general. The obtained results thus support the production of wheat bread with mixed germinated lentils flour, as a nutraceutical option for human consumption., (© Association of Food Scientists & Technologists (India) 2019.)