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Hyperspectral imaging (HSI) combines conventional imaging and spectroscopy to simultaneously acquire both spatial and spectral information from an object. This technology has recently emerged as a powerful process analytical tool for rapid, non-contact and non-destructive food analysis. In this study, the potential application of HSI for damage detection on the caps of white mushrooms (Agaricus bisporus) was investigated. Mushrooms were damaged by controlled vibration to simulate damage caused by transportation. Hyperspectral images were obtained using a pushbroom line-scanning HSI instrument, operating in the wavelength range of 400-1000 nm with spectroscopic resolution of 5 nm. The effective resolution of the CCD detector was 580 T 580 pixels by 12 bits. Two data reduction methods were investigated: in the first, principal component analysis (PCA) was applied to the hypercube of each sample, and the second PC (PC 2) scores image was used for identification of bruise-damaged regions on the mushroom surface; in the second method PCA was applied to a dataset comprising of average spectra from regions normal and bruise-damaged tissue. In this case it was observed that normal and bruised tissue were separable along the resultant first principal component (PC 1) axis. Multiplying the PC 1 eigenvector by the hypercube data allowed reduction of the hypercube to a 2-D image, which showed maximal contrast between normal and bruise-damaged tissue. The second method performed better than the first when applied to a set of independent mushroom samples. The results from this study could be used for the development of a non-destructive monitoring system for rapid detection of damaged mushrooms on the processing line.

Cumin (Cuminum cyminum) is one of the commonly used spices in food preparations. It is also used in traditional medicine as a stimulant, a carminative, and an astringent. In this study, we characterized the antimicrobial, antioxidant, and cytotoxic activities of cumin. E. coli, S. aureus, and S. faecalis were sensitive to various oil dilutions. The total phenol content of the essential oil was estimated to be 33.43 microg GAE/mg of the oil. The oil showed higher antioxidant activity compared with that of BHT and BHA. The cumin essential oil exhibited a dose-dependent scavenging of DPPH radicals and 5.4 microg of the oil was sufficient to scavenge 50% of DPPH radicals/mL. At a concentration of 0.1 microL/mL, oil destructed Hela cells by 79%. The antioxidant activity of cumin essential oil might contribute to its cytotoxic activity. Acute and subchronic toxicity was studied in a 30-d oral toxicity study by administration to Wistar rats of the essential oil. A 17.38% decrease in WBCs count, and 25.77%, 14.24%, and 108.81% increase in hemoglobin concentration, hematocrit, and platelet count, respectively, were noted. LDL/HDL ratio was reduced to half, which adds to the nutritional effects of cumin. Thus, cumin with a high phenolic content and good antioxidant activity can be supplemented for both nutritional purposes and preservation of foods.

In the present study, foam-mat drying technique is used to dry cantaloupe pulp into powder. Foaming conditions, namely amount of egg white powder, xanthan gum and whipping time, optimized using response surface methodology for minimizing foam density and drainage volume. To evaluate drying behavior of the optimized foam, drying was carried out in a batch-type thin-layer dryer at three drying temperatures (40, 55 and 70C) on 3-and 5-mm thicknesses. Ten thin-layer drying models were evaluated in the kinetics research. Based on the statistic tests performed, Weibull distribution model can describe drying behavior of foams for all drying processes. Moreover, Fick's second law was employed to calculate the effective moisture diffusivity that varied from 3.283 × 10 −9 to 9.483 × 10 −9 m 2 /s and from 4.053 × 10 −9 to 1.216 × 10 −8 m 2 /s with activation energy values of 31.714 and 33.043 kJ/mol for foam thicknesses of 3 and 5 mm, respectively. PRACTICAL APPLICATIONSCantaloupe (Cucumis melo) is a popular fruit and widely consumed in the world. Cantaloupe has many potential health benefits, but it is seasonal fruit and its shelf life is limited. Moreover, cantaloupe is sensitive to high-temperature processes. Foam-mat drying is an alternative for preservation of cantaloupe in the form of dried powder using medium temperatures. Cantaloupe pulp powder have a longer shelf life and may be a suitable source of β-carotene and vitamin C. This powder, because of its ability to contribute special characteristics such as flavor, color and water-binding properties to the final product, can be used as instant beverages, ingredients for bakery or extruded cereal products, ice cream, yogurt as well as pharmaceutical tablets.

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The antimicrobial and biofilm formation preventive properties of Mentha piperita and Rosmarinus officinalis essential oils and chlorhexidine were assessed against Streptococcus mutans and Streptococcus pyogenes. 26 and 20 compounds were identified by GC and GC-MS analysis in hydrodistilled oils from M. piperita and R. officinalis, respectively. The minimal bactericidal concentrations (MBC) of the M. piperita and R. officinalis oils and chlorhexidine were (6000, 2000, 8000 ppm) and (1000, 4000, 1000 ppm) for S. mutans and S. pyogenes, respectively. The decimal reduction time (D) of S. mutans exposed to the oils at their MBC levels was 2.8 min while chlorhexidine showed a longer time. The D values of S. pyogenes on exposure to the MBC levels of M. piperita and R. officinalis oils and of chlorhexidine were 2.14, 4.28 and 2.8 min, indicating a higher efficacy of M. piperita oil. Biofilm formation was performed by growing S. mutans culture with and without essential oils in LB medium in polystyrene tubes. In vitro biofilm inhibitory properties were in the order M. piperita > R. officinalis > chlorhexidine. In vivo experiments on the antibiofilm properties revealed that all concentrations of the oils were significantly (p < 0.001) more effective than chlorhexidine. In conclusion, essential oils may be considered as safe agents in the development of novel antibiofilm agents.

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