Ailey Aparecida Coelho Tanamati

Mid-infrared spectroscopy and support vector machines applied to control the hydrogenation process of soybean oil

The industrial hydrogenation of soybean oil is well established. However, its control is carried out through time-consuming methods. The objective of this study was to evaluate the mid-infrared spectroscopy (FTIR-ATR) in tandem with support vector machines (SVM) in controlling the hydrogenation process. Models were constructed to predict the content of saturated fatty acids (SFA), unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), trans fatty acids (TFA), polyunsaturated fatty acids (PUFA) and the iodine value (IV). The values predicted by the SVM models were compared to values obtained through gas chromatography. Feasible multivariate models were obtained with r2 minimum of 0.96 and RMSEP in the range of 0.65–2.65. Feature selection using correlation spectra was also efficient, maintaining the performance of the models and reducing the number of variables used by up to 94%. Therefore, it was demonstrated that FTIR-ATR methodology with SVM could be applied to monitor industrial hydrogenation.

Formulation of mayonnaises containing PUFAs by the addition of microencapsulated chia seeds, pumpkin seeds and baru oils

There is an increasing demand for healthier foodstuff containing specific compounds such as Polyunsaturated Fatty Acids (PUFAs). In the case of PUFAs, protection against oxidative degradation is challengeable and microencapsulation emerges as an alternative. Mayonnaises containing microencapsulated oils could be a source of PUFAs. The objective was to formulate mayonnaises containing microencapsulated chia seeds oil, pumpkin seeds oil or baru oil. Micrometric particles with high encapsulation efficiency were produced and thermal analyses indicated an increased thermal stability of all oils after encapsulation. Rheology studies highlighted an increase in the mayonnaise viscosity when microparticles containing chia and pumpkin seeds oil were added. Mechanical texture was not affected by the presence of microparticles in the mayonnaise in all formulations tested. Nevertheless, samples containing microcapsules up to 5%wt were not distinguished from the base-mayonnaise in the sensorial test. Overall, enriched mayonnaises were successfully produced and encapsulation was efficient in protecting oils from oxidation.

Partial Substitution of Margarine by Microencapsulated Chia Seeds Oil in the Formulation of Cookies

Partial substitution of margarine by microencapsulated chia oil (rich in n-3 and n-6 fatty acids) in carnauba wax solid lipid microparticles was investigated, to obtain cookies containing omega-3 and omega-6. The microparticles were prepared by the hot homogenisation in which the lipid phase is molten and dispersed as small droplets in an aqueous phase followed by a cooling/solidification step. Cookies were produced using only margarine (control) and also with partial substitution of margarine by microencapsulated chia oil (15% and 30%wt). Texture profile analysis results of the cookie dough (pre-baking) were affected (p < 0.05) by partial substitution; however, the puncture force of the baked cookies was not impacted. The α-linolenic acid concentration increased 48.5 and 110.4%, respectively, when compared with the control sample, and the atherogenicity and·thrombogenicity indexes were significantly reduced. The thermal behaviour of the microparticles was similar before and after incorporation into the cookies (differential scanning calorimetry), despite melting during baking of the cookies. Cookies with 30%wt substitution exhibited the highest storage colour stability. Changes in the cookie moisture sorption were detected due to the presence of the microcapsules, which is probably an indication of water immobilisation by sodium caseinate used in the particle formulation. Sensory analysis demonstrated good acceptability for the sample with 15%wt margarine substitution.

Industrial Hydrogenation Process Monitoring Using Ultra-compact Near-Infrared Spectrometer and Chemometrics

The hydrogenation process of soybean oil is monitored through time-consuming methodologies that demand sample preparation and produce chemical residues. Thus, it is necessary to develop faster low-cost waste-free instrumentation methodologies. The aim of this work was to evaluate an ultra-compact near-infrared spectrometer in tandem with the partial least squares regression (PLSR) or support vector regression (SVR) in the control of the hydrogenation process. Models were used to predict the saturated fatty acids (SFA), unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), trans fatty acids (TFA), polyunsaturated fatty acids (PUFA), and the iodine value (IV). The values predicted by the PLSR and SVR models were compared to the experimental values obtained by gas chromatography. A methodology for feature selection was also assessed, which was able to reduce by up to 85% the variables used in the models without loss of performance. The values obtained for root mean square error of cross validation, root mean square error of calibration, root mean square error of prediction, and r2 remained very close for both PLSR and SVR. Regarding RSD, all values were above 5% for the PLSR models, whereas for the SVR, the RSD presented values lower than 5% for IV and UFA. It is worth noting that the spectrometer used has low cost, effortless assembly, and easy handling, which allows its use in any environment. Through the results obtained, it was demonstrated that the ultra-compact NIRS spectrometer in tandem with PLSR or SVR represent an alternative to monitor the industrial hydrogenation process of soybean oil.

Chemical, sensory and microbiological stability of freeze-dried Nile tilapia croquette mixtures

The stability of tilapia croquette mixtures was evaluated for 240 days, through analyses of water activity (aw), lipid oxidation (TBARS) and sensory and microbiological assays. The control mixture was composed of tilapia mince, wheat and rye flours and seasonings while the enriched mixture also contained flaxseed flour. Aw increased significantly over time, from 0.1666 to 0.5392 for the control mixture and from 0.0554 to 0.5415 for the enriched mixture. TBARS values increased from 0.08 to 0.38 mg kg−1 for the control mixture and from 0.11 to 0.40 mg kg−1 malondialdehyde (MDA) for the enriched mixture. Appearance, texture and overall acceptance of the control mixture remained constant and the flavour improved during storage, while sensory attributes of the enriched mixture did not change. Overall acceptance was nearly 8 for the control mixture and 6 for the enriched mixture using a 9-point hedonic scale, where 9 = ‘like a lot’ and 1 = ‘dislike intensely’. Microbiological parameters did not exceed the legal limits allowed for consumption. Both mixtures remained suitable for consumption after 240 days.

Evaluation of enzymatic detergent efficiency in removing lipids from meat package

Food industry is increasingly concerned about their role in environmental responsibility. Recycling of meat package is a challenge since the presence of residual lipids limit the amount of recycled material that could be added to the pure material. In this work the efficiency of an enzymatic detergent in removing total lipids residues from discharged meat polyethylene package was evaluated. The experimental parameters were the enzymatic detergent concentration, temperature and the mass of package used during the detergent application. Soxhlet extraction (3 hours, 40 oC,) was used to determine the amount of total lipids present in the package both before and after the use of the detergent. The solvent used was petroleum ether and the amount of total lipids was determined gravimetrically. The polyethylene meat package presented an initial amount of total lipids of (15.7± 0.7) %. Results demonstrated that the efficiency increased with the increase in temperature and detergent concentration as well as with the decrease in the mass of the polyethylene sample. Any decrease in the enzymatic activity was observed for the evaluated temperatures. Also there was a limit in the amount of polyethylene package that could be used probably because greater amounts of sample hindered stirring and homogenization. According to the experimental design the maximum efficiency is expected to be 81.72% when the following conditions are used: 54°C, enzymatic detergent concentration of 19g/L and a package sample amount of 4 grams. DOI: 10.14685/rebrapa.v5i3.178