DHA bioaccessibility in infant formulas and preschool children milks.

Docosahexaenoic acid (DHA, 22:6n-3) is an essential long chain polyunsaturated fatty acid associated with the development of the nervous system that has to be consumed by infants through breast milk or complementary food sources and which consumption is also usually inadequate in preschoolers. In this work, the in vitro bioaccessibility of DHA from two commercial infant formulas (8.9 and 9.1%) and two preschool children milks (6.9 and 7.2%), with similar DHA contents but formulated with different ingredients, was not improved by the presence of egg phospholipids in the product formulation. In addition, the importance of the choice of an age-appropriate in vitro digestion method was demonstrated by comparing the DHA bioaccessibility from the infant formulas by the Infogest 2.0 standardized method and a simulated digestion method specific for infants.

Identification of volatiles and odor-active compounds of aromatic rice by OSME analysis and SPME/GC-MS.

During cooking, aromatic rice has a pleasant and characteristic aroma, a relevant factor to add sale value and attract consumer interest. This work studied the volatile compounds of aromatic rice (IAC 500) aiming at identifying those responsible for the aroma and flavor of the cooked rice. The description of the aromatic notes of the IAC 500 rice was carried out by a trained and selected sensory panel, followed by olfactometry (OSME) and identification by GC-MS of the rice volatile compounds extracted by SPME. A total of 80 volatiles was sensorially perceived and/or detected in the chromatographic effluent, of which 65 were identified, 44 presented some odor, and 36 were odorless. Among the odorous compounds, 15 were not detected by GC-FID or GC-MS. This study confirmed the compound 2-acetyl-1-pyrroline as the impacting volatile compound to the aroma of aromatic rice since it presented a very low percentage of area in the chromatogram and a high odor intensity. Other 43 compounds presented odor in lower intensities, but also contributed to the overall aroma of IAC 500 rice. From the 11 aromatic notes mentioned by the trained panel (cooked vegetable/seed, corn, hominy, green, porridge, popcorn, fresh baked cake/bread, milk, caramel, tapioca flour and flower), eight were related to the volatile compounds responsible for their aroma.

Aroma profile of rice varieties by a novel SPME method able to maximize 2-acetyl-1-pyrroline and minimize hexanal extraction.

The solid phase microextraction (SPME) has been the most used technique for the extraction of volatile compounds from rice because of its easy operation and solvent-free. The extraction parameters, sample mass and incubation temperature, were optimized through a central composite rotational design (CCRD), aiming at maximizing the extraction of 2-acetyl-1-pyrroline (2AP), the main compound responsible for the aroma in aromatic rice, and minimizing the generation of hexanal, a marker of lipid oxidation. Besides, the time of sample incubation and fiber exposure for the extraction of the volatile compounds from rice were determined. The optimized conditions for SPME were: 2.5 g of ground rice in a 20 mL vial, sample incubation at 80 °C for 60 min and exposure of the divinylbenzene/carboxene/polydimethylsiloxane (DVB/CAR/PDMS) fiber in the headspace for 10 min. The optimized method was sucessfuly applied to 12 varieties of rice and principal component analysis (PCA) was performed to observe similarities in their volatile profile. A total of 152 volatile compounds were identified among the different rice varieties. From these, 42 were identified in arborio rice, 47 in basmati brand A, 43 in basmati brand B, 55 in black rice, 63 in brown rice, 39 in jamine rice, 50 in parboiled brown rice, 43 in parboiled rice, 54 in red rice, 63 in sasanishiki rice, 46 in white rice and 70 in wild rice.