CABRAL, L. M. C.

CRUZ, A. P. G.

FREITAS, S. P.

LEAL JUNIOR, W.

TONON, R. V.

TORRES, A. G.

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400Effects of Food Processing on Food ConstituentsEXTRACTION OF ANTHOCYANINS FROM GRAPE POMACE GENERATED DURING THE PRODUCTION OF WHITE WINEAna Paula G. Cruz1, William L. Junior2, Renata V. Tonon2, Alexandre G. Torres1, Suely P. Freitas1, Lourdes M. C. Cabral21Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil2Embrapa Food Technology, Rio de Janeiro, RJ, Brazil.E-mail: renata.tonon@embrapa.brGrape is one of the most cultivated fruit in the world being primarily destined for industrial processing. In 2010, the main wine region of Brazil processed about 530 tons of grapes. The high generated volume, around 20% of the total processed fruit, the short harvest period and some polluting characteristics make the grape pomace a serious environmental problem. However, this residue can be considered as an interesting source for the recovery of bioactive compounds, mainly phenolic ones, with qualitative and quantitative variation due to many different factors such as the grape cultivar, the fruit processing, among others. The objective of this research was to determine the best condition for the hydro alcoholic extraction of the grape pomace generated during the production of white wine regarding the anthocyanin recovery. For this purpose, it was planned a 23 factorial design with triplicate at the central point, having as independent variables the ethanol content (30-70%), pH (2-4) and the ratio substrate: solvent (1:3 to 1: 9). The contents of total and monomer anthocyanins were the dependent variables. The grape pomace was previously hydrated and the extraction was carried out for two hours at 50 °C. The ratio substrate: solvent has positively influenced the anthocyanin extraction. But it was observed that the increase in pH and the increase in pH associated with the decreased of the ethanol content resulted in a decrease of the anthocyanin extraction. By using pH 2.0, 30% ethanol and the ratio substrate: solvent equal to 9:1 an overall yield of 99% was verified. Under these conditions, it was estimated a recovery of 173 mg of anthocyanin for 100g of grape pomace.Keywords: waste recovery, bioactive compounds, grape pomace.401Effects of Food Processing on Food ConstituentsPHYSICOCHEMICAL PROPERTIES OF MICRO PARTICULATED ZEIN PROTEINSBehic Mert1 and Aziz Tekin21Middle East Technical University Food Engineering Department Ankara Turkey2Ankara University Food Engineering Department Ankara TurkeyProteins provide many functional properties such as structure forming (gluten), texture improvement (soy protein), and formation of stable emulsions. Certain proteins (zein-corn protein and kafirin-sorghum protein) are storage prolamins and they have limited functional properties.. Due to its hydrophobic nature, zein does not aggregate or form gel. When mixed with water zein settles down very quickly, on the other hand if the concentration in water is increased, zein forms a plastic structure. It is well known that viscoelastic dough is essential for the leavened bread products. Thus, rising of corn breads is inferior compared to the wheat flour breads.Improving functional properties of zein protein was the main goal of this study. Producing zein with better functional properties can provide wider range of applications. More specifically, high shear (~15000000 1/s) microparticulation of zein using microfluidization was conducted in this study. Measurement of the thermal properties of the microparticulated zein using differential scanning colorimetry showed that especially tertiary structure of the protein molecules were modified during the process. DSC thermograms also indicated that increased microfluidization pressure lead to greater particulation of the protein and destruction of the globular structure. Experiments with the FTIR spectroscopy showed that microparticulation of zein proteins with high-pressure microfluidization resulted in damaging the tertiary structure of the protein molecules which may caused more hydrophilic structure and thereby better functionality. This presentation will outline the methodology and procedures that were used to produce microparticulated zein proteins. It will also present the physiochemical changes occurred in the structure of the proteins as a result of high pressure microfluidization process. 

Extraction of anthocyanins from grape pomace generated during the production of white wine.

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