No abstract

Quantitative analysis of carotenoids has been extensively reported using UV-Vis spectrophotometry and chromatography, instrumental techniques that require complex extraction protocols with organic solvents. Fourier transform infrared spectroscopy (FTIR) is a potential alternative for simplifying the analysis of food constituents. In this work, the application of FTIR with attenuated total reflectance (ATR) was evaluated for the determination of total carotenoid content (TCC) in Cucurbita spp. samples. Sixty-three samples, belonging to different cultivars of butternut squash (C. moschata) and pumpkin (C. maxima), were selected and analyzed with FTIR- ATR (attenuated total reflectance). Three different preparation protocols for samples were followed: homogenization (A), freeze-drying (B), and solvent extraction (C). The recorded spectra were used to develop regression models by Partial Least Squares (PLS), using data from TCC, determined by UV-Vis spectrophotometry. The PLS regression model obtained with the FTIR data from the freeze-dried samples, using the spectral range 920–3000 cm−1, had the best figures of merit (R2CAL of 0.95, R2PRED of 0.93 and RPD of 3.78), being reliable for future application in agriculture. This approach for carotenoid determination in pumpkin and squash avoids the use of organic solvents. Moreover, these results are a rationale for further exploring this technique for the assessment of specific carotenoids in food matrices.

The blackberry (Rubus glaucus Benth) and the bilberry (Vaccinium meridionale Swartz) are natural sources of antioxidants; they are known for their preventive role against degenerative diseases. In this study, the aromatic profile was evaluated using an electronic nose, including the antioxidant properties and the vitamin C, phenolic and anthocyanin contents during three stages of blackberry and bilberry ripening. A completely random statistical design was followed and the results presented differences in the aromatic profile: a higher anthocyanin content (1.59 mg of cyn-3-glu g-1 in the bilberry and 0.26 mg of cyn-3-glu g-1 in the blackberry) and total phenols (5.57 mg of caffeic acid g-1 bilberry and 2.68 mg caffeic acid g-1 blackberry). The behavior of the evaluated properties was independent in each of the fruits.

Bee pollen is a hive product, resulting from floral pollen agglutination by worker bees and it is characterized by its excellent bioactive and nutritional composition. Currently, research is focused on bee pollen applications on food industry, because this product has been considered an excellent source of compounds for human nutrition. It is also important in some industries, where color and particle size are important characteristics for production. Due to the granular nature of bee pollen, conventional colorimetry does not allow describing color correctly; thus, digital image analysis is a better alternative. This technique could also allow classifying bee pollen according to its appearance beyond the color. Consequently, the aim of this work was to develop a novel methodology for image data processing to classify bee pollen as ingredient in food industry. Seven color groups in samples were established regarding harvest month and particle size.It was possible to calculate the percentage of each color group in all samples. This methodology also allowed selecting each fraction for different applications in food industry using colorimetry, granulometry and the 2 relationship between both of them.

The interest about probiotic bacteria supplementation in fruit beverages has been increased recently in order to develop functional beverages without lactose. That is a technological challenge since pH and storage temperature can affect their viability. The aim of this study was to evaluate the viability of three commercial probiotic strains (L. paracasei, L. casei and L. rhamnosus) in mango beverage stored at 4°C. This research was developed in three stages: the assessment of the acid strain tolerance, the selection of a prebiotic as cellular protectant against environmental stress, the evaluation of physiochemical and sensory stability during storage. L. casei was chosen as the most stable strain with FOS at 5% as a prebiotic substance that stimulated its growth. At the final stage, it was found that L. casei produced significant changes in pH and titratable acidity in mango beverages after one week at 4°C, which was also detected by consumers with good sensory acceptance